Search Results (9)

In this study, calcium hexaboride (CaB₆) was successfully synthesized from anhydrous colemanite (Ca₂B₆O₁₁) via a mechanochemical approach. The synthesis process was optimized in two stages: by adjusting the reaction time and varying the carbon-to-colemanite ratio. Structural and compositional analyses were performed using FT-IR, XRD, SEM, and EDX techniques. The optimal synthesis condition was found to be a carbon-to-colemanite ratio of 10:1 and a reaction time of 1020 min, yielding the highest Ca–B vibrational intensities in FT-IR spectra. The mechanochemical method enabled CaB₆ formation at ambient conditions without the need for high temperature or pressure, offering a significant advantage over traditional methods. The results suggest that this method can serve as a low-energy route for the synthesis of metal borides, which are promising candidates for applications in refractory materials, electronics, and hydrogen storage systems. Full article

The global construction industry heavily relies on cementitious systems, which are a major contributor to carbon dioxide emissions due to the energy-intensive nature of cement production. These emissions account for approximately 8% of global CO₂ output, exacerbating climate change and environmental degradation. The global reliance on cementitious systems has led to substantial carbon dioxide emissions during cement production, intensifying the need for environmentally sustainable alternatives. Turkey, which holds 73% of the world’s boron reserves, offers a unique opportunity to explore boron-based minerals like colemanite as potential replacements for cement. In this study, the effects of colemanite (a boron mineral) and four fiber types—steel, basalt, carbon, and polypropylene—on the compressive strength, flexural strength, and water absorption of mortar mixtures incorporating air-entraining admixtures were investigated. All mixtures contained 0.1% air-entraining admixture (by cement weight), with fixed parameters: a water/binder ratio of 0.485, a sand/binder ratio of 2.75, and slump-flow values of 190 ± 20 mm. Cement was partially replaced with colemanite at 3% and 5%, while fibers were added at 0.5% by volume. Fresh-state properties (slump-flow and admixture requirements) and hardened-state properties (28-day compressive/flexural strength and water absorption) were evaluated. Selected samples underwent SEM analysis for microstructural assessment. Key findings revealed that both colemanite and fibers increased admixture demand to achieve target slump flow. While colemanite and fibers collectively enhanced compressive strength, their interactions varied: basalt and carbon fibers exhibited superior performance in mixtures without colemanite, whereas steel fibers showed greater efficacy in colemanite-containing mixtures. The strength increase was less pronounced when colemanite was introduced to mixtures containing carbon, polypropylene fibers, and basalt. The trend of flexural strengths was comparable to that of compressive strengths. SEM images revealed that the void distribution in the samples, influenced by the effects of colemanite and fibers, had a more dominant effect on compressive and flexural strengths. Water absorption inversely correlated with mechanical performance. This study not only contributes to reducing the carbon footprint of cementitious systems by partially replacing cement with colemanite but also provides practical insights to optimize the use of fibers to increase strength performance and reduce water absorption properties from durability parameters. These findings support the development of more sustainable and durable materials. Full article

Pharmaceutical residues in water and wastewater have become a worldwide problem with environmental and public health consequences. Antibiotics are of special importance because of the emergence of antibiotic-resistant genes. This study evaluates the adsorptive removal of four common fluoroquinolone antibiotics by using natural colemanite as an alternative adsorbent for the first time. Batch adsorption experiments were conducted for the mixture of fluoroquinolones as well as for individual compounds during the isotherm studies. Adsorption kinetic results indicated that the process followed the pseudo-second-order (PSO) model, while the Langmuir model described the sorption isotherms. The effects of pH and temperature on adsorption performance were determined, and the results indicated that the adsorption was endothermic and spontaneous, with increasing randomness at the solid–liquid interface. The effects of real water and wastewater matrices were tested by using tap water, surface water, and wastewater samples. Reusability experiments based on five adsorption–desorption cycles indicated that the adsorption performance was mostly retained after five cycles. The adsorption mechanism was elucidated based the material characterization before and after adsorption. The results indicate that colemanite can be used as an effective and reusable adsorbent for fluoroquinolone antibiotics as well as for other pollutants with similar physicochemical properties. Full article

Genetic, neuropathological and biochemical investigations have revealed meaningful relationships between aluminum (Al) exposure and neurotoxic and hematotoxic damage. Hence, intensive efforts are being made to minimize the harmful effects of Al. Moreover, boron compounds are used in a broad mix of industries, from cosmetics and pharmaceuticals to agriculture. They affect critical biological functions in cellular events and enzymatic reactions, as well as endocrinal and mineral metabolisms. There are limited dose-related data about boric acid (BA) and other boron compounds, including colemanite (Col), ulexite (UX) and borax (BX), which have commercial prominence. In this study, we evaluate boron compounds’ genetic, cytological, biochemical and pathological effects against aluminum chloride (AlCl₃)-induced hematotoxicity and neurotoxicity on different cell and animal model systems. First, we perform genotoxicity studies on in vivo rat bone marrow cells and peripheric human blood cultures. To analyze DNA and chromosome damage, we use single cell gel electrophoresis (SCGE or comet assay) and micronucleus (MN) and chromosome aberration (CA) assays. The nuclear division index (NDI) is used to monitor cytostasis. Second, we examine the biochemical parameters (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), total antioxidant capacity (TAC) and total oxidative status (TOS)) to determine oxidative changes in blood and brain. Next, we assess the histopathological alterations by using light and electron microscopes. Our results show that Al increases oxidative stress and genetic damage in blood and brain in vivo and in vitro studies. Al also led to severe histopathological and ultrastructural alterations in the brain. However, the boron compounds alone did not cause adverse changes based on the above-studied parameters. Moreover, these compounds exhibit different levels of beneficial effects by removing the harmful impact of Al. The antioxidant, antigenotoxic and cytoprotective effects of boron compounds against Al-induced damage indicate that boron may have a high potential for use in medical purposes in humans. In conclusion, our analysis suggests that boron compounds (especially BA, BX and UX) can be administered to subjects to prevent neurodegenerative and hematological disorders at determined doses. Full article

The risk of resource depletion for future generations of humanity is often cited as an important issue. The choice of impact categories and characterization models for resource extraction in LCA is no more precise than other impact categories and models. This means that more discussion is needed on the use of resources. In this article, the potential depletion of Boron and Boron minerals (Colemanite, Ulexite, Tincal) are studied. These minerals have a big role for the world and for Turkey; however, this resource is limited. Using the life cycle assessment methodology, one can estimate the resource depletion through the indicator “abiotic resource depletion”. Several models can evaluate this indicator, but the most used models are ReCiPe and CML (that is the previous attempt of ReCiPe) methods. Here, we estimated the damage that is done to natural resource scarcity. The values that are calculated by these two methods were compared to identify the potential evolution of the model and to observe the gap between these two models. The ReCiPe method refers to the average amount of extra ore that is produced in the future to extract 1 kg of boron ore or boron minerals resource. On the other hand, The CML method depends on the final reserve amount in terms of depletion. The results show no depletion shortly for boron ore and boron minerals. Correlation coefficients were calculated in the ReCiPe method, and ‘high uncertainty’ was estimated since R² < 0.8. This research highlights the fact that there is the necessity to propose different impact factors for the various minerals and not only for boron (that is done today). Full article

Borate is an essential material to numerous industries and even to individual countries’ economies, defense, and politics. Almost all industries need borates for production, and almost everybody needs their products. Borate is a compound that contains or supplies boric oxide (B₂O₃). Among the minerals that contain boric oxide, there are only four minerals significant from an economic standpoint, namely borax (tincal), colemanite, ulexite, and kernite. Turkey has almost 70% of all known reserves in the world. Therefore, borates and their products could be one of the main topics for sustainable development in the whole world. The recent development and pursuit of new boron-consuming technologies and alternative products to existing borate-consuming products introduce additional uncertainty to the sustainability of boron minerals. Therefore, the European Union (EU) Commission also declared borate one of the 30 critical raw materials. Turkey is a prosperous country in terms of boron reserves, and it exports almost 96% of borates’ production. In order to better understand the relation between borate minerals and borate products, a material flow analysis (MFA) study has been carried out within the content of this work in order to update the data about the current status of boron. For this purpose, a system has been established that shows the flow of boron material. The extraction, enrichment, and refining processes of boron products are drawn. The results indicate that about 41% of extracted colemanite ore is converted into refined borate, about 31% of tincal ore is converted to refined borate, and 4% of tincal ore is converted to end-usage products, such as detergent. The correctness of the data and the sensitivity of the processes are all estimated values. The results can help in the development of boron sustainability and boron production strategies. The MFA study on tincal and colemanite ore may be an example of boron studies in different countries. Full article

Although there are a lot of studies in literature related to the life cycle assessment (LCA) of mining, there are only a few studies done on the boron mining industry. This paper presents an LCA of the boron mining industry including the extraction, beneficiation, and refinement processes. The main purpose is to identify and compare the environmental impacts associated with the production of 1 ton of refined products (boric acid, borax pentahydrate, borax decahydrate, and sodium perborate) starting from an open pit mine located in Turkey. The life cycle inventory (LCI) was obtained from the data collected from the related literature sources and the company’s reports. This cradle-to-gate analysis has been carried out using the commercial software called SimaPro employing the International Reference Life Cycle Data System (ILCD) 2011 Midpoint+ Life Cycle Impact Assessment (LCIA) method. The results showed that the environmental impact of the refinement process is critical compared to the mining and beneficiations processes. Sulphuric acid, steam, hydrogen peroxide, and sodium perborate which are used in refined boron production cause most of the impact and emission into the environment. Among the refined boron products investigated, the impact of sodium perborate is quite high. Full article

The modern boron applications have adsorbed the mineral processors’ attention to improve typical boron mineral’s (BM) beneficiation methods. In this regard, dry treatment and pretreatment processes—such as magnetic separation and calcination as environmentally friendly methods, due to their minimal or zero adverse effect on the environment—need more consideration. Over the years, anionic flotation has become the main technique for beneficiation of friable BMs; however, there is a gap in the investigation of cationic flotation separation since BMs’ surface negatively charges in a wide pH range. At present, enriching BMs’ flotation via surface modification is taking center stage, which can also be considered for reprocessing long-forgotten BM tailings. As a comprehensive review, this work is going to provide a synopsis of the processes, techniques, optimum parameters, and conditions—such as size reduction, zeta potential, pH, and reagents—which have been employed in the processing of BMs. Gaps in our understanding of BM’s flotation are presented in the context of addressing the existing processes, considering possibilities and rooms for efficiency improvement. Considering these gaps may improve the performance of existing methods for processing fine and ultrafine BMs, and help in the development of new technologies to improve flotation recoveries. Full article

Advances in plant nutrition can be achieved by improving the delivery of micronutrients to the plants. The objective of this research was to compare the efficiency of uptake of different sources of zinc, copper and manganese (sulfates, Ethylenediaminetetraacetic acid (EDTA) and oxides) and boron (boric anhydride and colemanite). We conducted all experiments in maize, repeated the experiment twice, using five replicates per treatment, and used two different media. Results showed that for cations, the soluble sources of micronutrients (sulfate and EDTA) in both media were more efficiently taken up. One-way ANOVA with post hoc Tukey for multiple comparisons of means (95% confidence level) was used for all statistical analyses. Sulfate sources were significantly different when compared to the negative control and to the oxide sources. EDTA sources were significantly different when compared to the negative control and to the oxide sources. Oxide sources were not significantly different from the negative control. For boron, we found a similar trend, with boric anhydride being significantly different when compared to the negative control and to colemanite. Colemanite was significantly different when compared to the negative control. This study generated important information about uptake of soluble and insoluble sources of four micronutrients that can be used for the development of new formulations. Full article