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Minerals 2018, 8(4), 147; https://doi.org/10.3390/min8040147

Review
Integrated Mineral Carbonation of Ultramafic Mine Deposits—A Review
1
Ministry of Education Key Laboratory of High Efficiency Mining and Safety for Metal Mines, School of Civil and Resource Engineering, University of Science and Technology Beijing, No. 30 Xueyuan Road, Haidian District, Beijing 100083, China
2
Australian Centre for Sustainable Mining Practices, School of Mining Engineering, University of New South Wales, Sydney, NSW 2052, Australia
3
Trent School of the Environment, Trent University, Peterborough, ON K9L 0G2, Canada
*
Authors to whom correspondence should be addressed.
Received: 15 March 2018 / Accepted: 4 April 2018 / Published: 9 April 2018

Abstract

:
Recently, integrated mineral carbonation for CO2 sequestration has received significant attention due to the high potential for commercialization towards mitigating climate change. This review compiles the work conducted by various researchers over the last few years on integrated mineral carbonation processes in the mining industry, which use ultramafic mine wastes as feedstock for mineral carbonation. Here, we introduce the basic concepts of mineral carbonation including a brief description of the process routes and pre-treatment techniques. We discuss the scope of integrated mineral carbonation process application, and critically review the integrated mineral carbonation process in the mining industry including modified passive carbonation techniques in tailing storage facilities, and ex-situ carbonation routes using fresh tailings. The focus of the discussions is the role of reaction condition on the carbonation efficiency of mine waste with various mineralogical compositions, and the benefits and drawbacks of each integrated mineral carbonation process. All discussions lead to suggestions for the technological improvement of integrated mineral carbonation. Finally, we review the techno-economic assessments on existing integrated mineral carbonation technologies. Research to date indicates that value-added by-products will play an important role in the commercialization of an integrated mineral carbonation process.
Keywords:
CO2 sequestration; mineral carbonation; ultramafic tailings; mine waste

1. Introduction

The global climate has been warming at a faster pace than in any other period since 1850 [1]. The main cause of climate change is burning fossil fuels to meet global energy demands, which disturbs the balance of the carbon cycle and increases the concentration of greenhouse gases (especially CO2) in the atmosphere [2]. The atmospheric CO2 concentration reached 404 ppm in October 2017—44.3% above pre-industrial levels (280 ppm) [3]. At the same time, the average global temperature shows a warming of 0.8 °C [4]. If no additional efforts are made to constrain or manage anthropogenic greenhouse gas emissions, the CO2 equivalent concentration is expected to exceed 1000 ppm by 2100, which would result in a global mean surface temperature increase of 2.6 to 4.8 °C [1].
International efforts to mitigate climate change began in earnest in 1992 when the United Nations Framework Convention on Climate Change (UNFCCC) was introduced and adopted. UNFCCC aimed at “stabilized greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” [5]. The CO2 emission targets of UNFCCC-involved countries were outlined for the period of 2020 to 2030 in the Paris Agreement [6], which was negotiated with the awareness that global warming is a serious threat, and its ultimate goal was to limit global warming to less than 2 °C while pursuing efforts to limit the temperature rise to 1.5 °C relative to pre-industrial levels [6]. However, to reach these goals, the global community must find affordable and practical solutions for managing carbon.
Currently, various strategies and solutions have been adopted by countries for the purpose of reducing anthropogenic CO2 emissions. These approaches include: improving energy efficiency; using energy sources that are less carbon-intensive (e.g., natural gas, hydrogen, and nuclear power) or renewable (e.g., solar, wind, hydropower, geothermal and bio-energy); enhancing biological sinks (i.e., afforestation and reforestation); and CO2 capture and storage (CCS) [7]. Of these approaches, CCS is the only option that can meet the enormous demand for CO2 reduction. It is estimated that CCS could reduce 85–90% of CO2 from large-emission sources and energy-intensive emitters [7]. In the CCS process, CO2 is concentrated from diluted sources and transported to storage locations. Research on and demonstration of CCS technology has grown significantly in recent years with the hope that it can one day become economically feasible [8].
Since burning of fossil fuels causes a carbon flux from the lithosphere to the atmosphere, strategies and solutions that reverse this process by creating a carbon flux from the atmosphere back to the lithosphere can permanently solve the current anthropogenic CO2 problem and mitigate global warming. CO2 sequestration by mineral carbonation is such a process that could permanently store CO2 and establish a “circular economy” [9]. The mining industry could potentially apply mineral carbonation using ultramafic mine wastes and offset their greenhouse gas emissions. This paper reviews the current research on integrating mineral carbonation in the mining industry. First, the development of mineral carbonation is briefly introduced. Then, the integrated mineral carbonation in mining industry is reviewed, with special focus on modified passive carbonation method and ex-situ mineral carbonation. Finally, a techno-economic assessment is provided.

2. Mineral Carbonation

Mineral carbonation has been developed by harnessing the natural weathering process of magnesium, calcium and iron oxide-based silicate minerals, which transforms atmospheric CO2 into carbonate minerals [10]. Equation (1) shows the simplified reaction process of mineral carbonation.
( Mg , Ca , Fe ) SiO 4 ( s ) + CO 2 ( g ) MgCO 3 ( s ) + SiO 2 ( s )
Comparing with other approaches of CCS (e.g., geological storage), mineral carbonation has several advantages and merits. First, mineral carbonation is the only option that can permanently store CO2 without monitoring [11]. The carbonate products are naturally abundant minerals, which are environmentally friendly and leakage-free for geologic timescales. In addition, the abundance of Mg/Ca-silicates on Earth offers enormous capacity for sequestering CO2 [12]. There is a wide range of materials that can be used for mineral carbonation, not only naturally occurring formations, such as olivine, serpentine and wollastonite, but also highly reactive wastes comprised of Mg/Ca-rich materials, such as fly ash, iron and steel slags, cement kiln dust, and ultramafic mine wastes [13]. In addition, the carbonation process generates heat, namely exothermic reaction (Equation (1)), and the reactions can be self-perpetuated without additional energy input [14]. Theoretically, the heat of exothermic carbonation can be utilized in the endothermic mineral dissolution, but this has not yet been demonstrated in practice. The only drawback of mineral carbonation is that the reaction kinetics are often too slow and thus research has focused on accelerating carbonation rates.

2.1. Process Routes

Mineral carbonation was proposed by Seifritz [15] in 1990. Since this date, numerous researchers have attempted to accelerate the reaction between CO2 and alkaline minerals in two broad environmental conditions, in-situ and ex-situ [14,16]. In-situ mineral carbonation injects CO2 into mantle peridotite and basalts deposits, and the reaction occurs in an underground, possibly hydrothermal, environment. Conversely, ex-situ mineral carbonation is achieved in a separate reactor or an industrial process where the operational conditions are easy to control [17]. Ex-situ mineral carbonation can also apply CO2 as a carbon source for chemical production (e.g., carbonates), which can be used as building materials, aggregates, and cementitious phases [18,19]. Figure 1 shows a conceptual diagram depicting CCS strategies via mineral carbonation. Developments in process routes have been reviewed in numerous papers related to mineral carbonation [20,21].
Ex-situ mineral carbonation has focused on two broad methods: direct and indirect mineral carbonation. Direct mineral carbonation is completed in one single reaction step [23], whereas indirect carbonation introduces an additional step by extracting the reactive compound [20]. Both direct and indirect methods have two different possible routines, namely a dry process and an aqueous process, which have different CO2 sorption characteristics. In a dry process, CO2 molecules are chemisorbed to the solid by strong chemical bonds or physisorbed by weaker inter-molecular bonds due to the interactions between CO2 molecules and a sorbent [24]. In aqueous sorption, CO2 is dissolved into the solvent first, and then is reacted with olivine or serpentine [25].
At present, mineral carbonation has only reached the demonstration and pilot scales [21]. Although no economically viable mineral carbonation process has been developed so far, some attractive concepts and experimental results suggest the possibility for scaling up and commercializing the carbonation process over the next decade [26]. For example, the Carbfix pilot project in Iceland can carbonate 95% of injected CO2 in less than two years [27]. The direct aqueous carbonation route proposed at National Energy Technology Laboratory, formerly Albany Research Council in the U.S., has been evaluating the most promising ex-situ process for industrial application to date [23], which is commonly used as a baseline for comparison of other carbonation technologies. The indirect two-step pH-swing carbonation method developed at Finland’s Åbo Akademi University has produced results that are able to compete with the direct aqueous carbonation process developed at National Energy Technology Laboratory when using serpentine to trap CO2 [28]. In cases where geological storage is not applicable, mineral carbonation processes could be an alternative option for the storage of small to medium CO2 emissions (<2.5 Mt CO2 per site) [21].

2.2. Pre-Treatment

In some cases, the reactivity of Ca/Mg-silicates, particularly serpentine, cannot be enhanced sufficiently by the careful selection of a process route and conditions alone. Pre-treatment options can improve reaction kinetics for some potentially attractive Ca/Mg-silicates by activating the mineral for carbonation [29]. All pre-treatment options either aim to destroy the mineral lattice or create disorder in crystal structure, thus increasing the specific surface area, freeing some of the required cations (e.g., Ca and Mg), and creating an amorphous phase [23]. Pre-treatment can be conducted by thermal [30,31], chemical [32,33], or mechanical means [34,35,36].
Thermal activation removes chemically-bound water, which can increase the porosity and the resulting surface area. Thermal treatment is suitable only for serpentine group minerals, which contain up to 13 wt % chemically bound water. By heating these to 600–700 °C, the hydroxyl groups of serpentine are removed [37], thereby significantly increasing the carbonation rate. The optimum temperature for thermal activation depends on the serpentine composition. Extremely high temperature will lead to re-crystallization and needs to be avoided for the purpose of activation. There are some thermal activation process other than heat treatment including steam [38] and microwave treatment [11].
Chemical activation aims at polarize and weaken the calcium or magnesium bonds within the silicate structure. As a result, the solubility of magnesium silicate minerals increases, thus overcoming its slow dissolution kinetics. An array of chemicals has been proposed to enhance mineral carbonation. Chemicals that have been used for extracting magnesium or calcium from silicate minerals include inorganic acids (HCl, H2SO4, and H3PO3), organic acids (HCOOH, CH3COOH, and CH3COOH), bases (NaOH and KOH), and salts (NH4Cl, (NH4)2SO4, and NH4NO3) [20,33]. It is commonly recognized that sulfuric acid is the best extraction agent, and that it can extract more than 70% of the magnesium from serpentine and produce a silica by-product with a high surface area (an increase in surface area from 8 to 330 m2/g). For selective leaching, ammonium salts have performed better than sulfuric acid [39]. However, chemical activation tends to form a silica gel, which may trap the required cations needed for mineral carbonation.
Mechanical activation via high-energy attrition grinding not only decreases particles size and increases the surface area of minerals, but also introduces imperfections into the crystal lattice [40,41]. The mechanical activation of serpentine often focuses on the structural changes caused by losing –OH molecules [36,42]. Studies on the use of mechanical activation on ultramafic rocks are constantly expanding. They have focused on comparing individual mineral (e.g., olivine or serpentine) [36,43] responses to the grinding energy input [44,45] and milling instruments (e.g., planetary mills, vibration mills, attrition mills, or tumbling mills) [34,40], as well as milling atmosphere (e.g., N2, CO2 or air) [46], solutions (e.g., water, alcohol or acid) [43,47], and temperatures [48].
The combination of two pre-treatment methods, such thermal-chemical activation [49], chemical-mechanical activation [50], thermal-mechanical activation [51] can achieve unexpected activation effects. Except for the above mentioned pre-treatment methods, some novel processes for enhancing the rate of mineral carbonation have been proposed for waste materials [52]. For example, co-utilization with wastewater (or brine solution) [53]; biological enhancement using enzymes and microorganisms [54]; reactor integration, such as rotating packed bed [55]; ultrasonic vibration [56]; and electrolysis treatment [57]. Although these novel treatment methods could not activate materials up to the level that the former three techniques could reach, they are promising for the industrialization application as Ca/Mg containing waste materials (e.g., steel slag, fly ash, ultramafic tailings, etc.) are already related to industrial operations (e.g., mines), which could dramatically reduce the cost of mineral carbonation.

3. Integrated Mineral Carbonation in Mining

As a carbon-intensive industry, mining is facing ever-increasing pressure to reduce CO2 emissions as a result of emerging carbon management policies [58]. Integrated mineral carbonation processes in the mining industry that use mine wastes (e.g., waste rock, tailings, and slag) to trap CO2 [59] are advantageous for their ability to manage CO2 emissions and remediate potentially hazardous materials (e.g., chrysotile) [60]. By using mine wastes, especially tailings, many of the costs associated with the comminution required for mineral carbonation are absorbed as part of conventional ore processing. This has a large impact on the costs associated with altering tailings to a carbonate form. There is also the possibility that carbonation of mine wastes could create profit through carbon credits, which opens the opportunity to turn marginal projects, such as low-grade nickel deposits, into economically viable operations [61,62].

3.1. Suitable Mine for Mineral Carbonation

The ultramafic rock-hosted ore deposits that are favored for integrated mineral carbonation technologies include chrysotile [63], nickel [64,65,66], chromium [67,68], diamond [69] and platinum group element (PGE) mines [70,71]. These mine types are abundant worldwide and their CO2 storage potential is large [61]. Figure 2 shows the potential of large and super-large ultramafic mine sites that are suitable for the integrated mineral carbonation process [72]. Notably, the annual amount of mining tailings produced globally could potentially offset approximately 1.5% of annual global CO2 emissions [73]. The principle minerals being targeted for CO2 sequestration in the ultramafic mine wastes are olivine and serpentine group minerals.

3.2. Modified Passive Carbonation Method

Weathering and carbonation of ultramafic mine wastes may occur passively, within tailings storage facilities at both closed and active mines without human mediation [75]. Passive carbonation relies on the exposure of tailings to the Earth’s atmosphere, hydrosphere, and biosphere, thereby allowing natural weathering and gradual carbonation (Figure 3). Field studies have demonstrated that certain mines can offset approximately one-tenth of their annual CO2 emissions through passive carbonation of tailings [76]. These offsets are achieved through the precipitation of hydrated Mg-carbonate minerals including lansfordite [MgCO3·5H2O], nesquehonite [MgCO3·3H2O], dypingite [Mg5(CO3)4(OH)2·5H2O], and hydromagnesite [Mg5(CO3)4(OH)2·4H2O]. These minerals are commonly seen as efflorescent crusts associated with the tailings and are stable for long periods [77,78,79].
Passive carbonation rates in ultramafic tailings storage facilities are highly variable and are controlled by a variety of factors including: (1) tailings mineralogy and physical properties; (2) mineral processing and mine design; (3) tailings handling and storage (e.g., subaerial versus subaqueous); and (4) local climate. Passive carbonation similar to other forms of carbonation may be limited by: (1) CO2 supply; (2) mineral dissolution; or. in rare cases, (3) carbonate precipitation [80]. For example, passive carbonation at the Mount Keith Nickel Mine in Western Australia is limited by CO2 supply as evidenced by experiments mimicking pore water chemistry and stable carbon and isotopes of carbonates from the site [76]. Rate-limiting processes may also work somewhat in concert to limit carbonation. For instance, tailings at the Diavik mine are mainly stored sub-aqueously, which limits CO2 ingress that in turn limits carbonic acid generation that would aid mineral dissolution [69]. Thus, rate limitations are typically a function of tailings mineralogy and storage conditions. It is necessary to determine the rate limitation to devise an appropriate acceleration strategy to optimize carbonation [80].
Carbonation of mine tailings that only contain relatively less reactive silicate minerals (e.g., olivine and serpentine group minerals) compared to oxide and hydroxide minerals will tend to be limited by mineral dissolution. Mg-silicate minerals such as forsterite (Mg2SiO4) and serpentine group minerals [Mg3Si2O5(OH)4] have pH-dependent dissolution rates that are much faster than other silicate minerals, yet their dissolution at Earth’s surface conditions is still sluggish [22,81]. There are few economically viable options for accelerating mineral dissolution of silicate minerals. One possibility is the application of acid-generating materials that are colonized by Acidithiobacillus spp., which can dramatically enhance magnesium leaching from silicate minerals [82,83] (Figure 3). Grinding to a finer grain size to increase metal recovery would also accelerate mineral dissolution by creating greater surface area [84,85,86]. Enhancing mineral dissolution rates to increase the flux of available cations remains the greatest challenge in implementing mineral carbonation technologies at mine sites.
One alternative strategy is referred to as “enhanced weathering”, which is a geoengineering approach that relies on mining, pulverization, and distribution of ultramafic and mafic rock to remove CO2 from the atmosphere as dissolved inorganic carbon (e.g., HCO3) by accelerating natural weathering [87,88]. This strategy “accepts” that silicate dissolution is inherently slow, but relies on extended “reaction times” in the environment, e.g., dissolution continues until a mineral grain is fully dissolved. This strategy could be implemented with the use of preexisting ultramafic mine tailings, which would eliminate the need for superfluous mining.
Certain mine tailings contain highly reactive phases such as oxide and hydroxide minerals. For instance, the Mount Keith tailings contain a minor abundance of brucite [Mg(OH)2], which has a pH-dependent dissolution rate that is orders of magnitude faster than olivine or serpentine group minerals [22]. In laboratory experiments, brucite carbonation remains CO2-limited even when exposing it to CO2-rich fluids [89,90]. Thus, acceleration can be achieved by increasing the rate CO2 supply. Firstly, a CO2 source must be identified, whether only atmospheric CO2 is available or a point source of CO2-rich gas (e.g., flue gas from diesel-burning generators on site). In the former case, passive carbonation can be accelerated through simple tailings modification, such as increasing the surface area of tailings, optimizing tailings distribution, and enhanced aeration of the tailings (e.g., tilling) [75]. These tailings management practices increase the diffusion of atmospheric CO2 into tailings pore waters, which allows for greater carbonation. These practices contradict conventional tailings management that generally aims to limit tailings exposure to the atmosphere. However, ultramafic mine tailings are usually benign (e.g., very low acid-generating potential/high neutralization potential) and pose no substantial risk to the environment with the possible exception of asbestos and chromite mine wastes. Alternatively, point sources with CO2-rich gasses could be utilized (Figure 3) [89]. Some mines that are off-the-grid will generate electricity using fossil fuel-fired generators or will be within a reasonable distance to other point sources of CO2 (Figure 2). These CO2-rich gasses could be injected into tailings, incorporated into ore processing, or used in specially designed reactors following ore processing [91]. CO2 supply could be further enhanced by accelerating the hydration of dissolved CO2 gas to form a hydrated phase (e.g., HCO3). For instance, using carbonic anhydrase catalyzes the hydration of aqueous CO2 [54,90].
In general, carbonation in ultramafic mine wastes is not limited by carbonate precipitation. The kinetic reactions are sufficiently fast that there generally is no need for acceleration. For example, nesquehonite has little kinetic inhibition and will begin precipitating soon after a solution becomes saturated [92]. However, precipitation of magnesite (MgCO3), the stable form of magnesium carbonate, is kinetically inhibited at Earth’s surface conditions [92]. Thus, magnesite formation in ultramafic tailings does not occur even if tailings pore waters are supersaturated with respect to magnesite, which is often the case at ultramafic mines. Overcoming this kinetic inhibition would allow for greater carbonate formation. For example, utilizing surfaces with high carboxyl site densities has been shown to accelerate magnesite formation in the laboratory at room temperature within 10 s of days [93]. Other biological approaches could be harnessed to increase carbonate deposition in mining environments. For example, cyanobacteria can mediate Mg-carbonate precipitation in the natural environment (Figure 3) [60,94]. Moreover, the by-products of carbonation, such as photoautotrophic biomass, can be harvested as biofuel [94]. Alternatively, seeding with carbonate promotes mineral nucleation [95]; and periodically adding small amounts of water keeps partial pore saturation at optimum levels [96,97], which promotes the conversion of CO2 gas to a hydrated form.
The main advantage to these modifications that accelerate passive carbonation is that they operate at ambient temperature and pressure conditions, and therefore the energy consumption should be low. While these strategies do not aim to achieve complete carbonation of the tailings, there is the potential for substantial offsets at a cost that aligns with current carbon prices and are thus likely to be economically feasible. Importantly, not all tailings will be suitable for these strategies; for example, tailings that are highly carbonated [82] or those that contain abundant sulfides [98]. Careful selection of the mine site and carbonation process are necessary first steps.

3.3. Ex-Situ Mineral Carbonation

In an active mining operation, it is possible to apply the ex-situ carbonation to fresh tailings, which are more active for carbonation than weathered ones due to minimal authigenic carbonate content [82]. Accelerated mineral carbonation includes feedstock pre-treatment (e.g., thermal, chemical and/or mechanical activation), followed by a direct or indirect carbonation process in gas–solid phases or aqueous phases at high temperature and high pressure. These advanced technologies have been adopted to estimate the suitability of mine waste materials as feedstock for CO2 sequestration (Table 1).
Current investigations into integrated mineral carbonation processes mostly focus on mine waste that contains serpentine and brucite [11,91]. Currently, mine waste materials consisting of partially-serpentinized olivine draws the most attention [108]. Styles et al. studied the behavior of various ultramafic rock compositions in acid leaching in the presence of ammonium bisulfate. The Mg leaching extent after 1 h was: lizardite (78%) > serpentinized peridotites (65%) > forsterite (55%) > antigorite (40%) > pyroxene- and amphibole-rich rocks (25%) [109]. Bodénan et al. have examined the reactivity of variably serpentinized olivine in a direct aqueous carbonation process. They found that the degree of serpentization made no difference on the performance of carbonation when an attrition stirrer was applied during carbonation (Figure 4) [74]. Li and Hitch found that the reactivity of partially-serpentinized olivine is higher than that of pure olivine in a direct aqueous carbonation process, due to large surface area and poorly ordered structures induced by serpentinization [84,85,86]. As partially-serpentinized olivine is the most abundant form of ultramafic rock in nature [109], it is of great significance and provides the potential for ex-situ mineral carbonation to become widely employed in the mining industry. Thus, accurate mineralogical characterization of mine waste materials is necessary for process development.
The integrated mineral carbonation process proposed for carbonation of ultramafic mine wastes takes advantage of the technologies developed for ex-situ mineral carbonation of natural occurring ultramafic rock and innovates according to its own properties. The most common methods for mine waste pre-treatment are thermal activation using calcination [67], microwave heating [11], steam mediation [110], and chemical activation using organic or inorganic acids [11]. These pre-treatment methods greatly accelerate serpentine carbonation. However, pre-treatment methods, such as thermal activation and chemical activation by organic ligands, may not appreciably accelerate the reaction rate of olivine [111]. Li studied the mechanical activation on mine waste materials consisting of partially-serpentinized olivine. Regardless of milling conditions, forsterite, the olivine mineral variety in the mine waste, was found to be the main mineral being mechanically-activated and carbonated. It was determined that lizardite, a hydrated magnesium silicate also common in ultramafic-hosted mineral deposits, acted as catalyst by assisting forsterite reaching high levels of activation. This condition generated a greater CO2 conversion to carbonate than that of pure olivine with the equal specific milling energy input [112].
Amongst various ex-situ mineral carbonation routes, the direct carbonation method is commonly applied in the current study of the integrated mineral carbonation process (Table 1). The direct carbonation route is simple and easy to operate in industry. It provides the potential to store CO2 directly from a flue gas [102]. This will save the CO2 capture and concentration cost, which take up to 9–30% of the total cost of the integrated mineral carbonation process [62,113]. Li and Hitch [104,114] studied the direct gas–solid carbonation of mine waste using carbon dioxide adsorption isotherm at 25 °C. They systematically analyzed the effect of surface area, micropore volume, and weight ratio for Mg to Si, and forsterite crystal structure disorder on the CO2 adsorption capacity (or CO2 sequestration efficiency). However, they only used pure CO2 for the study and the process is not optimized. Veetil et al. [102] studied the direct gas–solid carbonation of activated serpentine mining residue using a simulated cement flue gas. They optimized the operation temperature (T), CO2 partial pressure (PCO2) [102], and the carbon dioxide-water vapor ratio (PCO2:PH2O) [99]. However, the CO2 sequestration efficiency only reached 0.07 g CO2/g residue after carbonation for 1 h at the optimum condition (T = 200 °C, PCO2 = 0.47 MPa, PCO2:PH2O = 1.8), due to the poor gas–solid interaction. Pasquier et al. [67] pursued the direct aqueous carbonation of thermal-activated serpentine mining residue in a stirred reactor using a simulated cement flue gas at low temperature and pressure. The CO2 sequestration efficiency was enhanced to 0.28 g CO2/g residue after carbonation for 15 min at the optimum condition (T = 22 °C, PCO2 = 0.19 MPa, PCO2:PH2O = 1.8) [101]. Kemache et al. [115,116] tested the direct aqueous carbonation process at pilot scale. Although they obtained a low process efficiency compared to that in the laboratory, it was a meaningful step for mineral carbonation research under real conditions. They suggest optimizing the heat-treatment and the carbonate precipitation to enhance the pilot scale process efficiency [115]. Adding a liquid recirculation process in the pilot scale plant seems to be a promising strategy and reaches a CO2 sequestration efficiency of 0.47 g CO2/g residue [117], which doubled the value obtained from the optimal conditions in the laboratory scale (0.28 g CO2/g residue) [101].
Some integrated mineral carbonation processes adopt the indirect aqueous carbonation process to add value to the process through recovering valuable metals and producing pure carbonate, a potential value-added product. Teir et al. [107] studied the indirect aqueous carbonation of serpentine rock from a nickel stockpile through a pH-swing process using HCl (or HNO3) and NaOH to adjust the pH. They successfully separated the iron oxide (88 wt %) and amorphous silica (82 wt %), and produced a high purity carbonate product (99 wt % hydromagnesite). However, this process did not recover the nickel content, which remains in the carbonated products. Recovery of nickel before carbonation is recommended [107]. Uddin et al. [50] used a combination of chemical (H2SO4) and mechanical (grinding) treatment to disintegrate the chrysotile fibers in low grade nickel ore, which reduced the pulp viscosity and enhanced the nickel recovery in downstream flotation. At the same time, the generated MgO-rich tails are potential candidate for CO2 capture and sequestration. Figure 5 shows the relationship between nickel recovery and MgO rejection before and after pretreatment [50]. For the same purpose, Bobicki et al. [118,119] destroyed the serpentine content in low grade nickel ore using microwave treatment. They found that this treatment converted serpentine in ultramafic nickel ores to olivine, which improved the grindability of ores and reduced the viscosity of the ore slurries. Thus, both ore processing and mineral carbonation were improved from the microwave treatment [11]. Similarly, Mayer et al. [70] studied the indirect aqueous carbonation of platinum group metal (PGM) tailings by pH-swing process, which used both organic and inorganic acid for cation extraction. They suggested that the process would be coupled with PGM recovery in the tailings to increase the economic viability of mineral carbonation [70]. The experience in mineral carbonation of nickel ore would provide guidance to the PGM mines.

4. Techno-Economic Analysis

One of the major challenges for CCS is to reduce its cost for large scale application. The life cycle of CCS includes CO2 capture, CO2 transportation, CO2 storage and utilization. Life cycle assessment on the cost of the full chain of CCS process is commonly adopted to evaluate the feasibility of a CCS project [28,74,120,121]. Table 2 lists the cost of the CCS technology as of 2014; however, it should be noted that the cost is expected to decrease as technology improves. The most cost efficient form of ex-situ mineral carbonation is still approximately six times higher compared to geological storage.
The economic analysis on the integrated mineral carbonation process in mining industry was first studied by Hitch and Dipple [122], whose model shows the tradeoff of carbonation cost versus carbonation efficiency (Figure 6). In a case study of Turnagain Nickel Deposit located in northern British Columbia, Canada, the theoretical carbonation potential was estimated to be 81.9 Mt CO2 over a 29-year mine life [61]. The integrating mineral carbonation process yielded a net present value of $131.5 million at a discount rate of 8%, with an operating cost of $82.5/t CO2 [122]. A carbonation efficiency of 60% could be achieved using mechanical activation as a pre-treatment method and the mine can potentially sequester 14.6 Mt CO2/year using their mineral wastes during the life of mine at an operating cost in the range of $104–107/t CO2 [113]. Pasquier et al. [123] investigated an integrated mineral carbonation process using southern Québec mining wastes to trap CO2, applied heat treatment to activate the waste materials, adsorbed CO2 directly from flue gas, and recovered the by-products (pure carbonate). The mine could sequester 0.39 Mt CO2/year. The global process cost is estimated at $144/t CO2, and the generated revenues is $644/t CO2. The payback period is 1.4 years [123]. From an economic point of view, this process is highly beneficial. However, these estimations were based on electricity generated by inexpensive hydroelectric, which is not applicable for other projects that use coal or natural gas as power supplies.
Table 3 lists the costs of some projects using updated CCS technology. From an economic perspective, integrated mineral carbonation within the mining industry [122] has the potential to compete with geological storage methods [124]. Although the cost of mineral carbonation is reduced via integrating into the mining industry, its cost is still too high for application given current carbon prices. For example, the California cap and trade price is only approximately $15/t CO2. Revenue that is generated from value-added products (e.g., pure carbonate) and through enhanced metal recovery during carbonation (e.g., Ni) may allow for carbonation processes to be economically viable. The pure carbonates produced through indirect mineral carbonation method are of high value and easy to use. However, the carbonate products generated from direct mineral carbonation process, which are mixtures of carbonates, amorphous silica, and unaltered silicates are hard to use. Further study on the potential application of carbonation products would add value to integrated mineral carbonation process and may lead towards economically viable technologies.

5. Conclusions

Integrated mineral carbonation in the mining industry has been widely studied in recent years. Research has demonstrated that there is great potential for commercial applications. The modified passive carbonation method in tailings storage facilities are relatively inexpensive and may benefit tailings reclamation. However, conversion rates are relatively slow and not all tailings are suitable for this method. The ex-situ carbonation of mine waste mostly focuses on serpentine group minerals given their abundance. The carbonation of partially weathered olivine needs to be investigated further to develop more effective carbonation routes for various ultramafic mines. The techno-economic analysis of integrated mineral carbonation shows great potential for commercialization, especially when the carbonate products can be utilized. A cost model for adopting integrated mineral carbonation process in an area using power generated from coal or natural gas is required to advance carbonation technologies worldwide.

Acknowledgments

The work was supported by the Fundamental Research Funds for the Central Universities (FRF-TP-17-077A1) and Beijing Municipal Science and Technology Project (Z161100002716023) to Jiajie Li, the Carbon Management Canada National Centre of Excellence (C390) to Michael Hitch, a Tier 2 Canada Research Chair in Environmental Geoscience to Ian M. Power, and China Scholarship Council (201706430037) to Yueyi Pan.

Author Contributions

Jiajie Li designed the outline and wrote most of the paper; Michael Hitch gave suggestions for the paper and provided proofreading; Ian M. Power wrote Section 3.2 and provided proofreading; and Yueyi Pan contributed part of Section 2.1.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. IPCC (Intergovernmental Panel on Climate Change). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change; Pachauri, R.K., Meyer, L.A., Eds.; IPCC: Geneva, Switzerland, 2014. [Google Scholar]
  2. Hänchen, M. CO2 Storage by Aqueous Mineral Carbonation: Olivine Dissolution and Precipitation of Mg-Carbonates; ETH Zurich: Zurich, Switzerland, 2007. [Google Scholar]
  3. GMD. Trends in Atomospheric Carbon Dioxide. Available online: http://www.esrl.noaa.gov/gmd/ccgg/trends/data.html (accessed on 10 February 2018).
  4. Ray, P.K. Hi-Tech Horticulture and Climate Change: Principle and Applications. In Climate Dynamics in Horticultural Science; Choudhary, M.L., Patel, V.B., Siddiqui, M.W., Mahdi, S.S., Eds.; Apple Academic Press: Waretown, NJ, USA, 2015; pp. 1–22. [Google Scholar]
  5. UNFCCC (United Nations Framework Convention on Climate Change). United Nations Framework Convention on Climate Change. 1992. Available online: http://unfccc.int/files/essential_background/background_publications_htmlpdf/application/pdf/conveng.pdf (accessed on 8 April 2018).
  6. UNFCCC (United Nations Framework Convention on Climate Change). Paris Agreement. 2015. Available online: http://unfccc.int/files/essential_background/convention/application/pdf/english_paris_agreement.pdf (accessed on 8 April 2018).
  7. Leung, D.Y.C.; Caramanna, G.; Maroto-Valer, M.M. An overview of current status of carbon dioxide capture and storage technologies. Renew. Sustain. Energy Rev. 2014, 39, 426–443. [Google Scholar] [CrossRef][Green Version]
  8. Boot-Handford, M.E.; Abanades, J.C.; Anthony, E.J.; Blunt, M.J.; Brandani, S.; Mac Dowell, N.; Fernandez, J.R.; Ferrari, M.-C.; Gross, R.; Hallett, J.P.; et al. Carbon capture and storage update. Energy Environ. Sci. 2014, 7, 130–189. [Google Scholar] [CrossRef]
  9. Pan, S.; Chung, T.; Ho, C.; Hou, C.; Chen, Y.; Chiang, P.-C. CO2 Mineralization and Utilization using Steel Slag for Establishing a Waste-to-Resource Supply Chain. Sci. Rep. 2017, 7, 1–11. [Google Scholar] [CrossRef] [PubMed]
  10. Lackner, K.S. A Guide to CO2 Sequestration. Science 2003, 300, 1677–1678. [Google Scholar] [CrossRef] [PubMed]
  11. Bobicki, E.R. Pre-Treatment of Ultramafic Nickel Ores for Improved Mineral Carbon Sequestration. Ph.D. Thesis, University of Alberta, Edmonton, AB, Canada, 2014. [Google Scholar]
  12. Lackner, K.; Wendt, C.; Butt, D.; Joycejr, E.; Sharp, D. Carbon dioxide disposal in carbonate minerals. Energy 1995, 20, 1153–1170. [Google Scholar] [CrossRef]
  13. Bobicki, E.R.; Liu, Q.; Xu, Z.; Zeng, H. Carbon capture and storage using alkaline industrial wastes. Prog. Energy Combust. Sci. 2012, 38, 302–320. [Google Scholar] [CrossRef]
  14. Romanov, V.; Soong, Y.; Carney, C.; Rush, G.E.; Nielsen, B.; O’Connor, W. Mineralization of carbon dioxide: A literature review. ChemBioEng Rev. 2015, 2, 231–256. [Google Scholar] [CrossRef]
  15. Seifritz, W. CO2 disposal by means of silicates. Nature 1990, 345, 486. [Google Scholar] [CrossRef]
  16. Yuen, Y.T.; Sharratt, P.N.; Jie, B. Carbon dioxide mineralization process design and evaluation: Concepts, case studies, and considerations. Environ. Sci. Pollut. Res. 2016, 23, 22309–22330. [Google Scholar] [CrossRef] [PubMed]
  17. Geerlings, H.; Zevenhoven, R. CO2 mineralization-bridge between storage and utilization of CO2. Annu. Rev. Chem. Biomol. Eng. 2013, 4, 103–117. [Google Scholar] [CrossRef] [PubMed]
  18. Gadikota, G.; Fricker, K.; Jang, S.-H.; Park, A.-H.A. Carbonation of silicate minerals and industrial wastes and their potential use as sustainable construction materials. In Advances in CO2 Capture, Sequestration, and Conversion; American Chemical Society: Washington, DC, USA, 2015; pp. 295–322. [Google Scholar]
  19. Markewitz, P.; Kuckshinrichs, W.; Leitner, W.; Linssen, J.; Zapp, P.; Bongartz, R.; Schreiber, A.; Müller, T.E. Worldwide innovations in the development of carbon capture technologies and the utilization of CO2. Energy Environ. Sci. 2012, 5, 7281–7305. [Google Scholar] [CrossRef][Green Version]
  20. Azdarpour, A.; Asadullah, M.; Mohammadian, E.; Hamidi, H.; Junin, R.; Karaei, M.A. A review on carbon dioxide mineral carbonation through pH-swing process. Chem. Eng. J. 2015, 279, 615–630. [Google Scholar] [CrossRef]
  21. Sanna, A.; Uibu, M.; Caramanna, G.; Kuusik, R.; Maroto-Valer, M.M. A review of mineral carbonation technologies to sequester CO2. Chem. Soc. Rev. 2014, 43, 8049–8080. [Google Scholar] [CrossRef] [PubMed][Green Version]
  22. Power, I.M.; Wilson, S.A.; Dipple, G.M. Serpentinite Carbonation for CO2 Sequestration. Elements 2013, 9, 115–121. [Google Scholar] [CrossRef]
  23. O’Connor, W.K.; Dahlin, D.C.; Rush, G.E.; Gerdemann, S.J.; Penner, L.R.; Nilsen, D.N. Aqueous Mineral Carbonation: Mineral Availability, Pretreatment, Reaction Parametrics, and Process Studies; Report No. DOE/ARC-TR-04-002; National Energy Technology Laboratory US DOE: Albany, OR, USA, 2005.
  24. Kwon, S.; Fan, M.; Dacosta, H.F.M.; Russell, A.G.; Berchtold, K.A.; Dubey, M.K. CO2 sorption. In Coal Gasification and Its Applications; Bell, D.A., Towler, B.F., Fan, M., Eds.; William Andrew Publishing, Elsevier Inc.: New York, NY, USA, 2011; pp. 293–339. [Google Scholar]
  25. Guthrie, G.D.; Carey, J.W.; Bergfeld, D.; Byler, D.; Chipera, S.; Ziock, H.; Lackner, K.S. Geochemical Aspects of the Carbonation of Magnesium Silicates in an Aqueious Medium; Los Alamos National Laboratory: Los Alamos, NM, USA, 1999.
  26. Doucet, F.J. Scoping Study on CO2 Mineralization Technologies; CGS: Pretoria, South Africa, 2011. [Google Scholar]
  27. Matter, J.M.; Stute, M.; Snæbjörnsdottir, S.Ó.; Oelkers, E.H.; Gislason, S.R.; Aradottir, E.S.; Sigfusson, B.; Gunnarsson, I.; Sigurdardottir, H.; Gunnlaugsson, E.; Axelsson, G.; et al. Rapid carbon mineralization for permanent diposal of anthropogenic carbon dioxide emissions. Science 2016, 352, 1312–1314. [Google Scholar] [CrossRef] [PubMed]
  28. Nduagu, E.; Bergerson, J.; Zevenhoven, R. Life cycle assessment of CO2 sequestration in magnesium silicate rock—A comparative study. Energy Convers. Manag. 2012, 55, 116–126. [Google Scholar] [CrossRef]
  29. Huijgen, W.J.J.; Comans, R.N.J. Carbon Dioxide Sequestration by Mineral Carbonation, Literature Review Update 2003–2004; Report No. 2005/11 ECN-C-05-022; Energy Research Centre of the Netherlands: Petten, The Netherlands, 2005. [Google Scholar]
  30. Hrsak, D.; Malina, J.; Hadzipasic, A.B. The decompostion of serpentine by thermal treatment. Mater. Technol. 2005, 39, 225–227. [Google Scholar]
  31. Balucan, R.D.; Dlugogorski, B.Z. Thermal activation of antigorite for mineralization of CO2. Environ. Sci. Technol. 2013, 47, 182–190. [Google Scholar] [CrossRef] [PubMed]
  32. Vega, F.; Sanna, A.; Navarrete, B.; Maroto-Valer, M.M.; Cortés, V.J. Degradation of amine-based solvents in CO2 capture process by chemical absorption. Greenh. Gases Sci. Technol. 2014, 4, 707–733. [Google Scholar] [CrossRef]
  33. Sanna, A.; Gaubert, J.; Maroto-Valer, M.M. Alternative regeneration of chemicals employed in mineral carbonation towards technology cost reduction. Chem. Eng. J. 2016, 306, 1049–1057. [Google Scholar] [CrossRef]
  34. Haug, T.A. Dissolution and Carbonation of Mechanically Activated Olivine. Ph.D. Thesis, Norwegian University of Science and Technology, Trondheim, Norway, 2010. [Google Scholar]
  35. Fabian, M.; Shopska, M.; Paneva, D.; Kadinov, G.; Kostova, N.; Turianicová, E.; Briančin, J.; Mitov, I.; Kleiv, R.A.; Baláž, P. The influence of attrition milling on carbon dioxide sequestration on magnesium-iron silicate. Miner. Eng. 2010, 23, 616–620. [Google Scholar] [CrossRef]
  36. Kim, D.-J.; Sohn, J.-S.; Ahn, J.-G.; Chung, H.-S. Extraction of metals from mechanically milled serpentine. Geosyst. Eng. 2008, 11, 25–28. [Google Scholar] [CrossRef]
  37. Gualtieri, A.F.; Giacobbe, C.; Viti, C. The dehydroxylation of serpentine group minerals. Am. Miner. 2012, 97, 666–680. [Google Scholar] [CrossRef]
  38. O’Connor, W.K.; Dahlin, D.C.; Dahlin, C.L.; Collins, W.K. Carbon dioxide sequestration by direct carbonation: Process minerology of feed and products. In Proceedings of the SME Annual Meeting & Exhibit, Denver, CO, USA, 23–25 February 2001; pp. 1–8. [Google Scholar]
  39. Wang, X.; Maroto-Valer, M.M. Integration of CO2 capture and mineral carbonation by using recyclable ammonium salts. ChemSusChem 2011, 4, 1291–1300. [Google Scholar] [CrossRef] [PubMed]
  40. Baláž, P.; Turianicová, E.; Fabián, M.; Kleiv, R.A.; Briancin, J.; Obut, A. Structural changes in olivine (Mg, Fe)2SiO4 mechanically activated in high-energy mills. Int. J. Miner. Process. 2008, 88, 1–6. [Google Scholar] [CrossRef]
  41. Kleiv, R.A.; Thornhill, M. Mechanical activation of olivine. Miner. Eng. 2006, 19, 340–347. [Google Scholar] [CrossRef]
  42. Zhang, Q.; Sugiyama, K.; Saito, F. Enhancement of acid extraction of magnesium and silicon from serpentine by mechanochemical treatment. Hydrometallurgy 1997, 45, 323–331. [Google Scholar] [CrossRef]
  43. Rigopoulos, I.; Petallidou, K.C.; Vasiliades, M.A.; Delimitis, A.; Ioannou, I.; Efstathiou, A.M.; Kyratsi, T. Carbon dioxide storage in olivine basalts: Effect of ball milling process. Powder Technol. 2015, 273, 220–229. [Google Scholar] [CrossRef]
  44. Atashin, S.; Wen, J.Z.; Varin, R.A. Investigation of milling energy input on structural variations of processed olivine powders for CO2 sequestration. J. Alloys Compd. 2015, 618, 555–561. [Google Scholar] [CrossRef]
  45. Atashin, S.; Wen, J.Z.; Varin, R.A. Optimizing milling energy for enhancement of solid-state magnesium sulfate (MgSO4) thermal extraction for permanent CO2 storage. RSC Adv. 2016, 6, 68860–68869. [Google Scholar] [CrossRef]
  46. Turianicová, E.; Baláž, P.; Tuček, Ľ.; Zorkovská, A.; Zeleňák, V.; Németh, Z.; Šatka, A.; Kováč, J. A comparison of the reactivity of activated and non-activated olivine with CO2. Int. J. Miner. Process. 2013, 123, 73–77. [Google Scholar] [CrossRef]
  47. Sandvik, K.L.; Kleiv, R.A.; Haug, T.A. Mechanically activated minerals as a sink for CO2. Adv. Powder Technol. 2011, 22, 416–421. [Google Scholar] [CrossRef]
  48. Trapasso, F.; Croci, D.; Plescia, P.; Tempesta, E. Asbestos waste carbonation: A new asbestos treatment with CO2 recovery. In Proceedings of the 3rd International Conference on Industrial and Hazardous Waste Management, Chania, Greece, 12–14 September 2012; pp. 1–8. [Google Scholar]
  49. O’Connor, W.K.; Dahlin, D.C.; Nilsen, D.N. Research status on the sequestration of carbon dioxide by direct aqueous mineral carbonation. In Proceedings of the 18th Annual International Pittsburgh Coal Conference, Newcastle, Austrilia, 3–7 December 2001; pp. 1–12. [Google Scholar]
  50. Uddin, S.; Rao, S.R.; Mirnezami, M.; Finch, J.A. Processing an ultramafic ore using fiber disintegration by acid attack. Int. J. Miner. Process. 2012, 102–103, 38–44. [Google Scholar] [CrossRef]
  51. McKelvy, M.J.; Chizmeshya, A.V.G.; Squires, K.; Carpenter, R.W.; Béarat, H. A Novel Approach to Mienral Carbonation: Enhanceing Carbonation while Avoiding Mineral Pretreatment Process Cost; Report Number: DE-FG26-04NT42124; Arizona State University: Tempe, AZ, USA, 2005. [Google Scholar]
  52. Pan, S.-Y.; Chiang, A.; Chang, E.-E.; Lin, Y.-P.; Kim, H.; Chiang, P.-C. An innovative approach to integrated carbon mineralization and waste utilization: A review. Aerosol Air Qual. Res. 2015, 15, 1072–1091. [Google Scholar] [CrossRef]
  53. Chang, E.E.; Chiu, A.C.; Pan, S.Y.; Chen, Y.H.; Tan, C.S.; Chiang, P.C. Carbonation of basic oxygen furnace slag with metalworking wastewater in a slurry reactor. Int. J. Greenh. Gas Control 2013, 12, 382–389. [Google Scholar] [CrossRef]
  54. Power, I.M.; Harrison, A.L.; Dipple, G.M.; Southam, G. Carbon sequestration via carbonic anhydrase facilitated magnesium carbonate precipitation. Int. J. Greenh. Gas Control 2013, 16, 145–155. [Google Scholar] [CrossRef]
  55. Pan, S.Y.; Chiang, P.C.; Chen, Y.H.; Tan, C.S.; Chang, E.E. Kinetics of carbonation reaction of basic oxygen furnace slags in a rotating packed bed using the surface coverage model: Maximization of carbonation conversion. Appl. Energy 2014, 113, 267–276. [Google Scholar] [CrossRef]
  56. Santos, R.M.; François, D.; Mertens, G.; Elsen, J.; Van Gerven, T. Ultrasound-intensified mineral carbonation. Appl. Therm. Eng. 2013, 57, 154–163. [Google Scholar] [CrossRef]
  57. Li, W.; Li, W.; Li, B.; Bai, Z. Electrolysis and heat pretreatment methods to promote CO2 sequestration by mineral carbonation. Chem. Eng. Res. Des. 2009, 87, 210–215. [Google Scholar] [CrossRef]
  58. Ballantyne, S.M. Greenhouse Gas Emissions in Mining Operations: Challenges and Opportunities in British Columbia, Canada. Ph.D. Thesis, Univerisity of British Columbia, Vancouver, BC, Canada, 2010. [Google Scholar]
  59. Kruse, N.A.; Strosnider, W.H.J. Carbon dioxide dynamics and sequestration in mine water and waste. Mine Water Environ. 2015, 34, 3–9. [Google Scholar] [CrossRef]
  60. McCutcheon, J.; Power, I.M.; Harrison, A.L.; Dipple, G.M.; Southam, G. A Greenhouse-Scale photosynthetic microbial bioreactor for carbon sequestration in magnesium carbonate minerals. Environ. Sci. Technol. 2014, 48, 9142–9151. [Google Scholar] [CrossRef] [PubMed]
  61. Hitch, M.; Ballantyne, S.M.; Hindle, S.R. Revaluing mine waste rock for carbon capture and storage. Int. J. Min. Reclam. Environ. 2010, 24, 64–79. [Google Scholar] [CrossRef]
  62. Hindle, S.R. Feasibility and Sensitivity Analysis of Integrating Mining and Mineral Carbonation: A Case Study of the Turnagain Nickel Project. Ph.D. Thesis, University of British Columbia, Vancouver, BC, Canada, 2011. [Google Scholar]
  63. Larachi, F.; Daldoul, I.; Beaudoin, G. Fixation of CO2 by chrysotile in low-pressure dry and moist carbonation: Ex-situ and in-situ characterizations. Geochim. Cosmochim. Acta 2010, 74, 3051–3075. [Google Scholar] [CrossRef]
  64. Bobicki, E.R.; Liu, Q.; Xu, Z. Mineral carbon storage in pre-treated ultramafic ores. Miner. Eng. 2015, 70, 43–54. [Google Scholar] [CrossRef]
  65. Jacobs, A.D.; Hitch, M. Experimental mineral carbonation: Approaches to accelerate CO2 sequestration in mine waste materials. Int. J. Min. Reclam. Environ. 2011, 25, 321–331. [Google Scholar] [CrossRef]
  66. Sarvaramini, A.; Assima, G.P.; Beaudoin, G.; Larachi, F. Biomass torrefaction and CO2 capture using mining wastes – A new approach for reducing greenhouse gas emissions of co-firing plants. Fuel 2014, 115, 749–757. [Google Scholar] [CrossRef]
  67. Pasquier, L.-C.; Mercier, G.; Blais, J.-F.F.; Cecchi, E.; Kentish, S. Reaction mechanism for the aqueous-phase mineral carbonation of heat-activated serpentine at low temperatures and pressures in flue gas conditions. Environ. Sci. Technol. 2014, 48, 5163–5170. [Google Scholar] [CrossRef] [PubMed]
  68. Veetil, S.P.; Mercier, G.; Blais, J.-F.; Cecchi, E.; Kentish, S. Magnetic separation of serpentinite mining residue as a precursor to mineral carbonation. Int. J. Miner. Process. 2015, 140, 19–25. [Google Scholar] [CrossRef]
  69. Wilson, S.A.; Dipple, G.M.; Power, I.M.; Barker, S.L.L.; Fallon, S.J.; Southam, G. Subarctic weathering of mineral wastes provides a sink for atmospheric CO2. Environ. Sci. Technol. 2011, 45, 7727–7736. [Google Scholar] [CrossRef] [PubMed]
  70. Meyer, N.A.; Vögeli, J.U.; Becker, M.; Broadhurst, J.L.; Reid, D.L.; Franzidis, J.P. Mineral carbonation of PGM mine tailings for CO2 storage in South Africa: A case study. Miner. Eng. 2014, 59, 45–51. [Google Scholar] [CrossRef]
  71. Vogeli, J.; Reid, D.L.; Becker, M.; Broadhurst, J.; Franzidis, J.P. Investigation of the potential for mineral carbonation of PGM tailings in South Africa. Miner. Eng. 2011, 24, 1348–1356. [Google Scholar] [CrossRef]
  72. Picot, J.C.; Cassard, D.; Maldan, F.; Greffié, C.; Bodénan, F. Worldwide potential for ex-situ mineral carbonation. Energy Procedia 2011, 4, 2971–2977. [Google Scholar] [CrossRef]
  73. Power, I.M.; Harrison, A.L.; Dipple, G.M.; Wilson, S.A.; Kelemen, P.B.; Hitch, M.; Southam, G. Carbon mineralization: From natural analogues to engineered systems. Rev. Mineral. Geochem. 2013, 77, 305–360. [Google Scholar] [CrossRef]
  74. Bodénan, F.; Bourgeois, F.; Petiot, C.; Augé, T.; Bonfils, B.; Julcour-Lebigue, C.; Guyot, F.; Boukary, A.; Tremosa, J.; Lassin, A.; et al. Ex situ mineral carbonation for CO2 mitigation: Evaluation of mining waste resources, aqueous carbonation processability and life cycle assessment (Carmex project). Miner. Eng. 2014, 59, 52–63. [Google Scholar] [CrossRef][Green Version]
  75. Wilson, S.A. Carbon Sequestration in Chrysotile Mine Tailings. Ph.D. Thesis, University of British Columbia, Vancouver, BC, Canada, 2005. [Google Scholar]
  76. Wilson, S.A.; Harrison, A.L.; Dipple, G.M.; Power, I.M.; Barker, S.L.L.; Ulrich Mayer, K.; Fallon, S.J.; Raudsepp, M.; Southam, G. Offsetting of CO2 emissions by air capture in mine tailings at the Mount Keith Nickel Mine, Western Australia: Rates, controls and prospects for carbon neutral mining. Int. J. Greenh. Gas Control 2014, 25, 121–140. [Google Scholar] [CrossRef][Green Version]
  77. Power, I.M.; Wilson, S.A.; Harrison, A.L.; Dipple, G.M.; McCutcheon, J.; Southam, G.; Kenward, P.A. A depositional model for hydromagnesite-magnesite playas near Atlin, British Columbia, Canada. Sedimentology 2014, 61, 1701–1733. [Google Scholar] [CrossRef]
  78. Wilson, S.A.; Dipple, G.M.; Power, I.M.; Thom, J.M.; Anderson, R.G.; Raupsepp, M.; Gabites, J.E.; Southam, G. Carbon dioxide fixation within mine wastes of ultramafic-hosted ore deposits: Examples from the Clinton Creek and Cassiar Chrysotile Deposits, Canada. Econ. Geol. 2009, 104, 95–112. [Google Scholar] [CrossRef]
  79. Beinlich, A.; Austrheim, H. In situ sequestration of atmospheric CO2 at low temperature and surface cracking of serpentinized peridotite in mine shafts. Chem. Geol. 2012, 332–333, 32–44. [Google Scholar] [CrossRef]
  80. Power, I.M.; McCutcheon, J.; Harrison, A.; Wilson, S.; Dipple, G.; Kelly, S.; Southam, C.; Southam, G. Strategizing carbon-neutral mines: A case for pilot projects. Minerals 2014, 4, 399–436. [Google Scholar] [CrossRef]
  81. Thom, J.G.M.; Dipple, G.M.; Power, I.M.; Harrison, A.L. Chrysotile dissolution rates: Implications for carbon sequestration. Appl. Geochem. 2013, 35, 244–254. [Google Scholar] [CrossRef]
  82. Power, I.M.; Dipple, G.M.; Southam, G. Bioleaching of ultramafic tailings by acidithiobacillus spp. for CO2 sequestration. Environ. Sci. Technol. 2010, 44, 456–462. [Google Scholar] [CrossRef] [PubMed]
  83. McCutcheon, J.; Dipple, G.M.; Wilson, S.A.; Southam, G. Production of magnesium-rich solutions by acid leaching of chrysotile: A precursor to field-scale deployment of microbially enabled carbonate mineral precipitation. Chem. Geol. 2015, 413, 119–131. [Google Scholar] [CrossRef]
  84. Li, J.; Hitch, M. Ultra-fine grinding and mechanical activation of mine waste rock using a high-speed stirred mill for mineral carbonation. Int. J. Miner. Metall. Mater. 2015, 22, 1005–1016. [Google Scholar] [CrossRef]
  85. Li, J.; Hitch, M. Mechanical activation of ultramafic mine waste rock in dry condition for enhanced mineral carbonation. Miner. Eng. 2016, 95, 1–4. [Google Scholar] [CrossRef]
  86. Li, J.; Hitch, M. Ultra-fine grinding and mechanical activation of mine waste rock using a planetary mill for mineral carbonation. Int. J. Miner. Process. 2017, 158, 18–26. [Google Scholar] [CrossRef]
  87. Renforth, P. The potential of enhanced weathering in the UK. Int. J. Greenh. Gas Control 2012, 10, 229–243. [Google Scholar] [CrossRef]
  88. Schuiling, R.D.; Wilson, S.A.; Power, I.M. Enhanced silicate weathering is not limited by silicic acid saturation. Proc. Natl. Acad. Sci. USA 2011, 108, E41. [Google Scholar] [CrossRef] [PubMed]
  89. Harrison, A.L.; Power, I.M.; Dipple, G.M. Accelerated carbonation of brucite in mine tailings for carbon sequestration. Environ. Sci. Technol. 2013, 47, 126–134. [Google Scholar] [CrossRef] [PubMed]
  90. Power, I.M.; Harrison, A.L.; Dipple, G.M. Accelerating mineral carbonation using carbonic anhydrase. Environ. Sci. Technol. 2016, 50, 2610–2618. [Google Scholar] [CrossRef] [PubMed]
  91. Harrison, A.L. Mechanisms of Carbon Mineralization form the Pore to Field Scale: Implications for CO2 Sequestration. Ph.D. Thesis, University of British Columbia, Vancouver, BC, Canada, 2014. [Google Scholar]
  92. Hänchen, M.; Prigiobbe, V.; Baciocchi, R.; Mazzotti, M. Precipitation in the Mg-carbonate system—Effects of temperature and CO2 pressure. Chem. Eng. Sci. 2008, 63, 1012–1028. [Google Scholar] [CrossRef]
  93. Power, I.M.; Kenward, P.A.; Dipple, G.M.; Raudsepp, M. Room Temperature Magnesite Precipitation. Cryst. Growth Des. 2017, 17, 5652–5659. [Google Scholar] [CrossRef]
  94. Power, I.M.; Wilson, S.A.; Small, D.P.; Dipple, G.M.; Wan, W.; Southam, G. Microbially mediated mineral carbonation: Roles of phototrophy and heterotrophy. Environ. Sci. Technol. 2011, 45, 9061–9068. [Google Scholar] [CrossRef] [PubMed]
  95. Zarandi, A.E.; Larachi, F.; Beaudoin, G.; Plante, B.; Sciortino, M. Multivariate study of the dynamics of CO2 reaction with brucite-rich ultramafic mine tailings. Int. J. Greenh. Gas Control 2016, 52, 110–119. [Google Scholar] [CrossRef]
  96. Assima, G.P.; Larachi, F.; Beaudoin, G.; Molson, J. Dynamics of carbon dioxide uptake in chrysotile mining residues – Effect of mineralogy and liquid saturation. Int. J. Greenh. Gas Control 2013, 12, 124–135. [Google Scholar] [CrossRef]
  97. Harrison, A.L.; Dipple, G.M.; Power, I.M.; Mayer, U.K. The impact of evolving mineral–water–gas interfacial areas on mineral–fluid reaction rates in unsaturated porous media. Chem. Geol. 2016, 421, 65–80. [Google Scholar] [CrossRef]
  98. Assima, G.P.; Larachi, F.; Molson, J.; Beaudoin, G. Comparative study of five Québec ultramafic mining residues for use in direct ambient carbon dioxide mineral sequestration. Chem. Eng. J. 2014, 245, 56–64. [Google Scholar] [CrossRef]
  99. Veetil, S.P.; Pasquier, L.-C.; Blais, J.-F.; Cecchi, E.; Kentish, S.; Mercier, G. Direct gas-solid carbonation of serpentinite residues in the absence and presence of water vapor: A feasibility study for carbon dioxide sequestration. Environ. Sci. Pollut. Res. 2015, 22, 13486–13495. [Google Scholar] [CrossRef] [PubMed]
  100. Ben Ghacham, A.; Cecchi, E.; Pasquier, L.-C.; Blais, J.-F.; Mercier, G. CO2 sequestration using waste concrete and anorthosite tailings by direct mineral carbonation in gas-solid-liquid and gas-solid routes. J. Environ. Manag. 2015, 163, 70–77. [Google Scholar] [CrossRef] [PubMed]
  101. Pasquier, L.-C.; Mercier, G.; Blais, J.-F.; Cecchi, E.; Kentish, S. Parameters optimization for direct flue gas CO2 capture and sequestration by aqueous mineral carbonation using activated serpentinite based mining residue. Appl. Geochem. 2014, 50, 66–73. [Google Scholar] [CrossRef]
  102. Veetil, S.P.; Mercier, G.; Blais, J.-F.; Cecchi, E.; Kentish, S. CO2 sequestration by direct dry gas-solid contact of serpentinite mining residues: A solution for industrial CO2 emission. Int. J. Environ. Pollut. Remediat. 2014, 2, 52–59. [Google Scholar] [CrossRef]
  103. Jacobs, A.D. Quantifying the Mineral Carbonation Potential of Mine Waste Mineral: A New Parameter for Geospatial Estimation. Ph.D. Thesis, University of British Columbia, Vancouver, BC, Canada, 2014. [Google Scholar]
  104. Li, J.; Hitch, M. Carbon dioxide adsorption isotherm study on mine waste for integrated CO2 capture and sequestration processes. Powder Technol. 2016, 291, 408–413. [Google Scholar] [CrossRef]
  105. Li, J.; Hitch, M. Characterization of the microstructure of mechanically-activated olivine using X-ray diffraction pattern analysis. Miner. Eng. 2016, 86, 24–33. [Google Scholar] [CrossRef]
  106. Rigopoulos, I.; Petallidou, K.C.; Vasiliades, M.A.; Delimitis, A.; Ioannou, I.; Efstathiou, A.M.; Kyratsi, T. On the potential use of quarry waste material for CO2 sequestration. J. CO2 Util. 2016, 16, 361–370. [Google Scholar] [CrossRef]
  107. Teir, S.; Kuusik, R.; Fogelholm, C.; Zevenhoven, R. Production of magnesium carbonates from serpentinite for long-term storage of CO2. Int. J. Miner. Process. 2007, 85, 1–15. [Google Scholar] [CrossRef]
  108. Li, J.; Hitch, M. Structural and chemical changes in mine waste mechanically-activated invarious milling environments. Powder Technol. 2017, 308, 13–19. [Google Scholar] [CrossRef]
  109. Styles, M.T.; Sanna, A.; Lacinska, A.M.; Naden, J.; Maroto-Valer, M. The variation in composition of ultramfic rocks and the effect on their suitability for carbon dioxide sequestration by mineralization following acid leaching. Greenh. Gases Sci. Technol. 2012, 2, 408–418. [Google Scholar]
  110. Larachi, F.; Gravel, J.-P.; Grandjean, B.P.A.; Beaudoin, G. Role of steam, hydrogen and pretreatment in chrysotile gas–solid carbonation: Opportunities for pre-combustion CO2 capture. Int. J. Greenh. Gas Control 2012, 6, 69–76. [Google Scholar] [CrossRef]
  111. Declercq, J.; Bosc, O.; Oelkers, E.H. Do organic ligands affect forsterite dissolution rates? Appl. Geochem. 2013, 39, 69–77. [Google Scholar] [CrossRef]
  112. Li, J. Mechanical Activation of Ultramafic Mine Waste Materials for Enhanced Mineral Carbonation. Ph.D. Thesis, University of British Columbia, Vancouver, BC, Canada, 2017. [Google Scholar]
  113. Li, J.; Hitch, M. Economic analysis on the application of mechanical activation in an integrated mineral carbonation process. Int. Biodeterior. Biodegrad. 2016, 128, 63–71. [Google Scholar] [CrossRef]
  114. Li, J.; Hitch, M. Carbon dioxide sorption isotherm study on pristine and acid-treated olivine and its application in the vacuum swing adsorption process. Minerals 2015, 5, 259–275. [Google Scholar] [CrossRef]
  115. Kemache, N.; Pasquier, L.-C.; Cecchi, E.; Mouedhen, I.; Blais, J.-F.; Mercier, G. Aqueous mineral carbonation for CO2 sequestration: From laboratory to pilot scale. Fuel Process. Technol. 2017, 166, 209–216. [Google Scholar] [CrossRef]
  116. Mouedhen, I.; Kemache, N.; Pasquier, L.C.; Cecchi, E.; Blais, J.F.; Mercier, G. Effect of pCO2 on direct flue gas mineral carbonation at pilot scale. J. Environ. Manag. 2017, 198, 1–8. [Google Scholar] [CrossRef] [PubMed]
  117. Kemache, N.; Pasquier, L.-C.; Mouedhen, I.; Cecchi, E.; Blais, J.F.; Mercier, G. Aqueous mineral carbonation of serpentinite on a pilot scale: The effect of liquid recirculation on CO2 sequestration and carbonate precipitation. Appl. Geochem. 2016, 67, 21–29. [Google Scholar] [CrossRef]
  118. Bobicki, E.R.; Liu, Q.; Xu, Z. Microwave heating of ultramafic nickel ores and mineralogical effects. Miner. Eng. 2014, 58, 22–25. [Google Scholar] [CrossRef]
  119. Bobicki, E.R.; Liu, Q.; Xu, Z. Effect of microwave pre-treatment on ultramafic nickel ore slurry rheology. Miner. Eng. 2014, 61, 97–104. [Google Scholar] [CrossRef]
  120. Giannoulakis, S.; Volkart, K.; Bauer, C. Life cycle and cost assessment of mineral carbonation for carbon capture and storage in European power generation. Int. J. Greenh. Gas Control 2014, 21, 140–157. [Google Scholar] [CrossRef]
  121. Azapagic, A.; Cue, R.M. Carbon capture, storage and utilisation technologies: A critical analysis and comparison of their life cycle environmental impacts. J. CO2 Util. 2015, 9, 82–102. [Google Scholar]
  122. Hitch, M.; Dipple, G.M. Economic feasibility and sensitivity analysis of integrating industrial-scale mineral carbonation into mining operations. Miner. Eng. 2012, 39, 268–275. [Google Scholar] [CrossRef]
  123. Pasquier, L.-C.; Mercier, G.; Cecchi, E.; Kentish, S. Technical & economic evaluation of a mineral carbonation process using southern Québec mining wastes for CO2 sequestration of raw flue gas with by-product recovery. Int. J. Greenh. Gas Control 2016, 50, 147–157. [Google Scholar]
  124. Rubin, E.S.; Davison, J.E.; Herzog, H.J. The cost of CO2 capture and storage. Int. J. Greenh. Gas Control 2015, 40, 378–400. [Google Scholar] [CrossRef]
  125. Khoo, H.H.; Sharratt, P.N.; Bu, J.; Yeo, T.Y.; Borgna, A.; Highfield, J.G.; Björklöf, T.G.; Zevenhoven, R. Carbon capture and mineralization in singapore: Preliminary environmental impacts and costs via LCA. Ind. Eng. Chem. Res. 2011, 50, 11350–11357. [Google Scholar] [CrossRef]
Figure 1. Conceptual diagram depicting geoengineering system designed for CCS process via mineral carbonation. Modified from Power et al. [22].
Figure 1. Conceptual diagram depicting geoengineering system designed for CCS process via mineral carbonation. Modified from Power et al. [22].
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Figure 2. Large ultramafic rock-hosted ore deposits lying less than 300 km from a CO2-emission site. Reprinted with permission from Bodénan et al. [74]. Copyright 2014 Elsevier Ltd.
Figure 2. Large ultramafic rock-hosted ore deposits lying less than 300 km from a CO2-emission site. Reprinted with permission from Bodénan et al. [74]. Copyright 2014 Elsevier Ltd.
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Figure 3. A schematic of three mine tailings facilities depicting: (A) passive carbonation under conventional tailings management; (B) CO2 injection; and (C) biological approaches incorporating bioleaching and microbial carbonate precipitation. Modified from Power et al. [22].
Figure 3. A schematic of three mine tailings facilities depicting: (A) passive carbonation under conventional tailings management; (B) CO2 injection; and (C) biological approaches incorporating bioleaching and microbial carbonate precipitation. Modified from Power et al. [22].
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Figure 4. Kinetics of carbonation of various partially-serpentinized olivine as a function of time (T = 180 °C, PCO2 = 2 MPa, 90 g/L) with a continuous passivation layer exfoliation scheme. Hz is Harzburgite, We is Wehrlite, and Lz is Lherzolite. The ratio of serpentine to olivine from high to low is: Hz2 > Hz1 > We1 > Lz1 > Olivine. Reprinted with permission from Bodénan et al. [74]. Copyright 2014 Elsevier Ltd.
Figure 4. Kinetics of carbonation of various partially-serpentinized olivine as a function of time (T = 180 °C, PCO2 = 2 MPa, 90 g/L) with a continuous passivation layer exfoliation scheme. Hz is Harzburgite, We is Wehrlite, and Lz is Lherzolite. The ratio of serpentine to olivine from high to low is: Hz2 > Hz1 > We1 > Lz1 > Olivine. Reprinted with permission from Bodénan et al. [74]. Copyright 2014 Elsevier Ltd.
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Figure 5. Nickel recovery vs. MgO rejection: treated (approaches 1 and 2) vs. untreated ore. Approach 1: 2-h aging and frother (DF250) addition; Approach 2: 5-min aeration, no frother for cons 1 and 2. Reprinted with permission from Uddin et al. [50]. Copyright 2012 Elsevier Ltd.
Figure 5. Nickel recovery vs. MgO rejection: treated (approaches 1 and 2) vs. untreated ore. Approach 1: 2-h aging and frother (DF250) addition; Approach 2: 5-min aeration, no frother for cons 1 and 2. Reprinted with permission from Uddin et al. [50]. Copyright 2012 Elsevier Ltd.
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Figure 6. Conceptual model of mineral carbonation cost versus efficiency for various methods of mineral carbonation. Corroborating data points: (a) natural alteration; (b) heap leaching; and (c) autoclave reaction. Reprinted with permission from Hitch and Dipple [122]. Copyright 2012 Elsevier Ltd.
Figure 6. Conceptual model of mineral carbonation cost versus efficiency for various methods of mineral carbonation. Corroborating data points: (a) natural alteration; (b) heap leaching; and (c) autoclave reaction. Reprinted with permission from Hitch and Dipple [122]. Copyright 2012 Elsevier Ltd.
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Table 1. Summary of current studies on ex-situ mineral carbonation of mine waste materials.
Table 1. Summary of current studies on ex-situ mineral carbonation of mine waste materials.
Mining DepositsMajority MineralsCO2 SourceRock PretreatCarbonation MethodRef.
American Chrome, QCSerpentineFlue gasTADC gas–solid[99]
Old ilmenite mine, QCAnorthiteFlue gasNADC gas–solid
DC aqueous
[100]
Okanogan nickel deposit, WA; Thompson nickel bell, MBSerpentinePure CO2TA, CADC aqueous[64]
American Chrome, QCSerpentineFlue gasTADC aqueous[67,101]
Black Lake mine, QCSerpentineFlue gasTA, MSDC gas–solid[102]
Lonmin Platnum mine, South AfricaEnstatite, plagioclase feldsparPure CO2CAIDC aqueous[70]
Nickel Slag, New CaledoniaOlivine, serpentinePure CO2TA, CA, MADC aqueous[74]
Turnagain deposit, BCOlivine, serpentinePure CO2NADC aqueous[103]
Turnagain deposit, BCOlivine, serpentinePure CO2MADC aqueous,
DC gas–solid
[104,105]
Troodos ophiolite complex, Cyprusclinopyroxene, anorthitePure CO2MADC gas–solid[106]
Black Lake mine, QC; Dumont Nickel project QCChrysotile, lizarditeFlue gasNADC gas–solid[66]
Thetford Mines, QCChrysotileCO2 mixTADC gas–solid[63]
Hitura nickel mine, FinlandSerpentinePure CO2CAIDC aqueous[107]
Note: TA is thermal activation, CA is chemical activation, MA is mechanical activation; MS is magnetic separation, NA is not applied, DC is direct carbonation, IDC is indirect carbonation.
Table 2. The current cost of each CCS component.
Table 2. The current cost of each CCS component.
CCS ComponentTechnologyCost ($/t CO2)Ref.
CO2 capture aPost-combustion (coal-fired)34[7]
Pre-combustion (coal-fired)23[7]
Oxy-fuel (coal-fired)36[7]
Post-combustion (gas-fired)58[7]
Pre-combustion (gas-fired)112[7]
Oxy-fuel (gas-fired)102[7]
CO2 transportationRailway12.64[7]
Ship7.48[7]
Pipeline7.05[7]
CO2 storage & utilizationGeological storage b,c8[21]
In-situ mineral carbonation c17[21]
Ex-situ mineral carbonation50–300[21]
Note: a includes CO2 compression to 10 MPa, b does not include monitoring costs, c includes CO2 transportation cost.
Table 3. The cost of selected CCS projects.
Table 3. The cost of selected CCS projects.
CO2 SourceCO2 CaptureCO2 TransportationCO2 StorageCost ($/t CO2 Avoided)Ref.
NGCC aPost-combustionPipelineGeological storage59–143[124]
SCPC bPost-combustionPipelineGeological storage46–99[124]
IGCC cPre-combustionPipelineGeological storage38–84[124]
NGCCPost-combustionPipelineEOR d10–112[124]
SCPCPost-combustionPipelineEOR(5)–58[124]
IGCCPre-combustionPipelineEOR(16)–46[124]
Oil & gasNot givenPipelineMineral carbonation28–238[122]
NGCCNot appliedPipelineMineral carbonation120–159[125]
Note: a NGCC is the natural gas combined cycle plant; b SCPC is the supercritical pulverized coal burning plant; c IGCC is the coal-based integrated gasification combined cycle system; d EOR is the geological storage with enhanced oil recovery credits.

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