Search Results (5)

The complexities of high PV penetration in the electricity grid in Slovenia based on targets proposed in national energy and climate plan were explored. Scenarios modeled an increase in installation power from 1800 MW in 2030 to 8000 MW in 2050. They were analyzed using energy modeling and life cycle assessment to assess the technical and environmental aspects of high PV grid penetration. The results showed that the increase in PV production from 2200 GWh (2030) to 11,090 GWh (2050) showed an unfavorable course of excess electricity in the system, resulting in the need for short-term and long-term storage strategies and exports of electricity. LCA analysis showed that penetration of a high share of PV results in a decrease in the impact category of global warming, which is higher in 2050 green scenarios that phase out coal and lignite electricity sources (80.5% decrease) compared to the 2020 baseline scenario. The increase in mineral resource scarcity can be observed with an increase in PV share when comparing the 2030 (50%) and 2050 (150%) BAU scenarios with the baseline scenario (2020). Factors such as environmental impacts, technical challenges, and the impact on the grid must be considered when implementing a decarbonization strategy. Full article

Coal gangue is a solid waste with low carbon content discharged during the course of the coal mining process. The resource utilization of coal gangue could solve environmental problems caused by its excessive production, such as soil contamination and land occupation. This study proposed to produce high-strength thermal insulation bricks using coal gangue as the primary material and three other mineral powders as auxiliary materials, including K-feldspar, CaCO₃ and fly ash. A systematic analysis was conducted to explore the optimum raw material addition ratio and optimum sintering temperature; then, the intrinsic structure of thermal insulation bricks and their sintering formation mechanisms were revealed. The results showed that the optimal ratios of coal gangue, K-feldspar, CaCO₃ and fly ash were 65 wt%, 15 wt%, 10 wt% and 10 wt%, respectively; the compressive strength of the thermal insulation brick produced under this ratio was 22.5 MPa; thermal conductivity was 0.39 W m⁻¹ k⁻¹. During sintering processes, mineral powders sufficiently fused to form a skeleton, and the CO₂ derived from CaCO₃ formed pores. The optimum sintering temperature was 1150 °C, because at this temperature, K-feldspar had the best effect in promoting the conversion of CaCO₃ to Ca-feldspar. The high level of the relative crystallinity of Ca-feldspar (about 76.0%) helped raise the Si–O network’s polymerization degree (NBO/T = 1.24), finally raising the compressive strength of thermal insulation bricks. The innovative method of using coal gangue to make thermal insulation bricks not only solved the environmental pollution caused by coal gangue but also provided excellent construction materials with high practical application value. Full article

The reuse in high-value materials is one of the important resource utilization approaches of phosphorus tailings. At present, a mature technical system has been formed on the reuse of phosphorus slag in building materials, and silicon fertilizers in the extraction of yellow phosphorus. But there is a lack of research on the high-value reuse of phosphorus tailings. In order to make safe and effective utilization of phosphorus tailing resources, this research concentrated on how to solve easy agglomeration and difficult dispersion of phosphorus tailing micro-powder, when it was recycled in road asphalt. In the experimental procedure, phosphorus tailing micro-powder is treated in two methods. One method is to directly add it with different contents in asphalt to form a mortar. Dynamic shear tests were used to explore the effect of phosphorus tailing micro-powder on the high-temperature rheological properties of asphalt influence mechanism of material service behavior. The other method is to replace the mineral powder in asphalt mixture. The effect of phosphate tailing micro-powder on the water damage resistance in open-graded friction course (OGFC) asphalt mixtures was illustrated, based on the Marshall stability test and the freeze–thaw split test. The research results show that the performance indicators of the modified phosphorus tailing micro-powder meet the requirements for mineral powder in road engineering. Compared with standard OGFC asphalt mixtures, the residual stability of immersion and freeze–thaw splitting strength were improved when replace the mineral powder. The residual stability of immersion increased from 84.70% to 88.31%, and freeze–thaw splitting strength increased from 79.07% to 82.61%. The results indicate that phosphate tailing micro-powder has a certain positive effect on the water damage resistance. These performance improvements can be attributed to the larger specific surface area for phosphate tailing micro-powder than ordinary mineral powder, which can effectively adsorb asphalt and form structural asphalt. The research results are expected to support the large-scale reuse of phosphorus tailing powder in road engineering. Full article

On 22 September 2020, General Secretary Xi made a solemn commitment to the international community at the general debate of the seventy-fifth session of the United Nations General Assembly to achieve carbon peak and carbon neutrality, and he announced specific goals at the Climate Ambition Summit. China is striving to achieve carbon peak by 2030 and carbon neutrality by 2060. At the same time, during the Fifth Plenary Session of the Nineteenth Central Committee of the CPC and the Central Economic Work Conference, specific arrangements for related goals have been made. During these two sessions in 2021, carbon peak and carbon neutralization were also mentioned in the government work report for the first time, which became the “hot words” discussed by the delegates and one of the key subjects of the 14th Five-Year Plan. Against the current backdrop of “double carbon”, reforms must urgently be made in the education and teaching of the resource major in colleges and universities to achieve the goal of carbon neutralization with high quality, promote discipline construction, and explore and implement the development model of “new engineering”. With regard to the resource exploration industry, mining, dressing and smelting will produce a large amount of carbon dioxide, solid waste and tailings, which can be neutralized by injecting solid waste or tailings reservoirs through green mine construction and carbon capture. On the one hand, the comprehensive utilization efficiency of mines can be improved in this way. On the other hand, a large amount of carbon can be stored underground, which is an important method of achieving the goal of carbon neutrality. In this study, we took the core course “Mineral Resources Exploration” from the resource exploration major as an example to think about and study the ways the education and teaching of resource majors could be reformed, such as exploration engineering under the guidance of the carbon neutrality target, which has certain guiding significance regarding the improvement of the training quality of resource major students. Full article

The discovery of new mineral deposits contributes to the sustainable mineral industrial development, which is essential to satisfy global resource demands. The exploration for new mineral resources is challenging in Canada since its vast lands are mostly covered by a thick layer of Quaternary sediments that obscure bedrock geology. In the course of the recent decades, indicator minerals recovered from till heavy mineral concentrates have been effectively used to prospect for a broad range of mineral deposits including diamond, gold, and base metals. However, these methods traditionally focus on (visual) investigation of the 0.25–2.0 mm grain-size fraction of unconsolidated sediments, whilst our observations emphasize on higher abundance, or sometimes unique occurrence of precious metal (Au, Ag, and platinum-group elements) minerals in the finer-grained fractions (<0.25 mm). This study aims to present the advantages of applying a mineral detection routine initially developed for gold grains counting and characterization, to platinum-group minerals in <50 µm till heavy mineral concentrates. This technique, which uses an automated scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer, can provide quantitative mineralogical and semi-quantitative chemical data of heavy minerals of interest, simultaneously. This work presents the mineralogical and chemical characteristics, the grain size distribution, and the surface textures of 2664 discrete platinum-group mineral grains recovered from the processing of 5194 glacial sediment samples collected from different zones in the Canadian Shield (mostly Quebec and Ontario provinces). Fifty-eight different platinum-group mineral species have been identified to date, among which sperrylite (PtAs₂) is by far the most abundant (n = 1488; 55.86%). Textural and mineral-chemical data suggest that detrital platinum-group minerals in the studied samples have been derived, at least in part, from Au-rich ore systems. Full article