An in-process technology approach is proposed to identify the source of acid mine drainage(AMD)generation and prevent its formation in a porphyry copper waste rock(WR).Adopting actions before stockpiling the WR enable...An in-process technology approach is proposed to identify the source of acid mine drainage(AMD)generation and prevent its formation in a porphyry copper waste rock(WR).Adopting actions before stockpiling the WR enables the establishment of potential contaminants and predicts the more convenient method for AMD prevention.A WR sample was separated into size fractions,and the WR’s net acidgenerating potential was quantified using chemical and mineralogical characterization.The diameter of physical locking of sulfides(DPLS)was determined,and the fractions below the DPLS were desulfurized using flotation.Finally,the WR fractions and tailing from the flotation test were submitted to acid-base accounting and weathering tests to evaluate their acid-generating potential.Results show that the WR’s main sulfide mineral is pyrite,and the DPLS was defined as 850μm.A sulfide recovery of 91%was achieved using a combination of HydroFloat^(®)and Denver cells for a size fraction lower than DPLS.No grinding was conducted.The results show that size fractions greater than DPLS and the desulfurized WR are unlikely to produce AMD.The outcomes show that in-processing technology can be a more proactive approach and an effective tool for avoiding AMD in a porphyry copper WR.展开更多
Quartz is a vital raw material for advanced industries,with high-purity quartz(HPQ,greater than or equal to 99.99%SiO_(2))being indispensable in semiconductor manufacturing,photovoltaic cells,optical fibers,and medica...Quartz is a vital raw material for advanced industries,with high-purity quartz(HPQ,greater than or equal to 99.99%SiO_(2))being indispensable in semiconductor manufacturing,photovoltaic cells,optical fibers,and medical technologies.This review critically examines the evolution of HPQ purification technologies,highlighting their mechanisms,efficiencies,and sustainability challenges.Traditional chemical methods such as hydrofluoric acid leaching and chlorination remove impurities but pose significant environmental and safety risks.Thermal treatments,including high-temperature annealing(higher than 1000℃),deliver improved crystallinity but require substantial energy input.Physical approaches,including flotation,grinding,and magnetic separation,are more environmentally friendly but insufficient for achieving semiconductor-grade purity.Recent innovations,particularly hybrid processes such as microwave-assisted leaching and bioleaching,have demonstrated notable improvements in impurity removal and resource optimization.However,challenges remain in managing complex mineralogy,high reagent consumption,and operational costs.Beyond purification,this review also evaluates the scalability,environmental impact,and potential of sustainable strategies to meet the growing global demand for HPQ.By consolidating applications,purification pathways,and associated challenges into a unified framework,this review provides a comprehensive foundation for advancing both technological innovation and sustainable practices in HPQ production.展开更多
基金supported by Agencia Nacional de Investigación y Desarrollo de Chile(ANID)Anillo-Grant ANID/ACT210027,Fondecyt 1211498,and ANID/AFB230001+1 种基金the ANID scholarship Grant 21210801partially performed by Luis Cisternas during the visit to the Universitédu Québec,supported by MINEDUC-UA project,code ANT1999.
文摘An in-process technology approach is proposed to identify the source of acid mine drainage(AMD)generation and prevent its formation in a porphyry copper waste rock(WR).Adopting actions before stockpiling the WR enables the establishment of potential contaminants and predicts the more convenient method for AMD prevention.A WR sample was separated into size fractions,and the WR’s net acidgenerating potential was quantified using chemical and mineralogical characterization.The diameter of physical locking of sulfides(DPLS)was determined,and the fractions below the DPLS were desulfurized using flotation.Finally,the WR fractions and tailing from the flotation test were submitted to acid-base accounting and weathering tests to evaluate their acid-generating potential.Results show that the WR’s main sulfide mineral is pyrite,and the DPLS was defined as 850μm.A sulfide recovery of 91%was achieved using a combination of HydroFloat^(®)and Denver cells for a size fraction lower than DPLS.No grinding was conducted.The results show that size fractions greater than DPLS and the desulfurized WR are unlikely to produce AMD.The outcomes show that in-processing technology can be a more proactive approach and an effective tool for avoiding AMD in a porphyry copper WR.
基金financial support from the Shandong Provincial Natural Science Foundation(No.ZR2021QE122)the Shandong Provincial Department of Science and Technology Key Project(No.2023TZXD021)the Shandong Provincial Department of Science and Technology(No.ZTYJY–KY–2033–11)。
文摘Quartz is a vital raw material for advanced industries,with high-purity quartz(HPQ,greater than or equal to 99.99%SiO_(2))being indispensable in semiconductor manufacturing,photovoltaic cells,optical fibers,and medical technologies.This review critically examines the evolution of HPQ purification technologies,highlighting their mechanisms,efficiencies,and sustainability challenges.Traditional chemical methods such as hydrofluoric acid leaching and chlorination remove impurities but pose significant environmental and safety risks.Thermal treatments,including high-temperature annealing(higher than 1000℃),deliver improved crystallinity but require substantial energy input.Physical approaches,including flotation,grinding,and magnetic separation,are more environmentally friendly but insufficient for achieving semiconductor-grade purity.Recent innovations,particularly hybrid processes such as microwave-assisted leaching and bioleaching,have demonstrated notable improvements in impurity removal and resource optimization.However,challenges remain in managing complex mineralogy,high reagent consumption,and operational costs.Beyond purification,this review also evaluates the scalability,environmental impact,and potential of sustainable strategies to meet the growing global demand for HPQ.By consolidating applications,purification pathways,and associated challenges into a unified framework,this review provides a comprehensive foundation for advancing both technological innovation and sustainable practices in HPQ production.
