Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-indus...Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-industrial trials were conducted.Vanadium in raw ore mainly exists in sericite,roscoelite,and limonite,predominantly in the forms of V(Ⅲ)and V(Ⅳ).Under the conditions of a feed rate of 30 kg/h,an air flow rate of 28.0 m^(3)/h,an O_(2) flow rate of 4.0 m^(3)/h,and a temperature of 900℃ in both the suspension furnace and fluidized reactor,the vanadium-bearing mica underwent dehydroxylation and transformed into illite-montmorillonite.These changes disrupted the crystal structure of mica,facilitating vanadium extraction.Compared to direct acid leaching,curing-leaching demonstrates better performance in vanadium extraction.Under the conditions of curing temperature of 130℃,acid dosage of 40 wt.%,curing time of 6 h,and leaching time of 3 h,a V_(2)O_(5) leaching efficiency of 83.92% was achieved.展开更多
The purpose of this study is to apply process mineralogy as a practical tool to further understand and analyze the reasons for low leaching rates in the curing-leaching process of vanadium-bearing stone coal and to fi...The purpose of this study is to apply process mineralogy as a practical tool to further understand and analyze the reasons for low leaching rates in the curing-leaching process of vanadium-bearing stone coal and to find a solution or improvement to optimize the leaching index.Using vanadium-bearing stone coal with the V2O5 mass fraction of 0.88%as the research object,the effects of particle size,mineral composition,and sulfuric acid curing on the feed,intermediate,and final products of curing-leaching were analyzed.The main vanadium-bearing minerals in the feed samples included sericite/illite,montmorillonite,kaolinite,limonite,and schreyerite.Through the penetration depth analysis of sulfuric acid,the reason for the high vanadium content in the coarse leaching residue(0.205%V2O5)was found,mainly due to the poor curing effect and incomplete washing after screening.Therefore,thorough washing after sieving and further optimizing the curing process are necessary.The vanadium content of the fine leaching residue(0.078%)was low and the curing-leaching effect was good.However,the vanadium content in the thickened residue(0.296%)exceeded that in the fine leaching residue,which was attributed to the neutralization reaction in the#1 thickener.To solve this problem,the neutralization and thickening processes should be performed in separate equipment.The analysis and detection of key products is helpful for identifying problems and improving the curing-leaching circuit process.展开更多
基金funded by the National Key Research and Development Program of China(No.2020YFC1909704)the Fundamental Research Funds for the Central Universities,China(Nos.N2301026,N2301017).
文摘Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-industrial trials were conducted.Vanadium in raw ore mainly exists in sericite,roscoelite,and limonite,predominantly in the forms of V(Ⅲ)and V(Ⅳ).Under the conditions of a feed rate of 30 kg/h,an air flow rate of 28.0 m^(3)/h,an O_(2) flow rate of 4.0 m^(3)/h,and a temperature of 900℃ in both the suspension furnace and fluidized reactor,the vanadium-bearing mica underwent dehydroxylation and transformed into illite-montmorillonite.These changes disrupted the crystal structure of mica,facilitating vanadium extraction.Compared to direct acid leaching,curing-leaching demonstrates better performance in vanadium extraction.Under the conditions of curing temperature of 130℃,acid dosage of 40 wt.%,curing time of 6 h,and leaching time of 3 h,a V_(2)O_(5) leaching efficiency of 83.92% was achieved.
基金supported by the National Key Research and Development Program of China(No.2020YFC1909704)the National Natural Science Foundation of China(Nos.51904222 and 52074068)+1 种基金the Shaanxi Innovation Capacity Support Plan(2020KJXX-053)the Shaanxi Natural Science Basic Research Program(No.2019JQ-468).
文摘The purpose of this study is to apply process mineralogy as a practical tool to further understand and analyze the reasons for low leaching rates in the curing-leaching process of vanadium-bearing stone coal and to find a solution or improvement to optimize the leaching index.Using vanadium-bearing stone coal with the V2O5 mass fraction of 0.88%as the research object,the effects of particle size,mineral composition,and sulfuric acid curing on the feed,intermediate,and final products of curing-leaching were analyzed.The main vanadium-bearing minerals in the feed samples included sericite/illite,montmorillonite,kaolinite,limonite,and schreyerite.Through the penetration depth analysis of sulfuric acid,the reason for the high vanadium content in the coarse leaching residue(0.205%V2O5)was found,mainly due to the poor curing effect and incomplete washing after screening.Therefore,thorough washing after sieving and further optimizing the curing process are necessary.The vanadium content of the fine leaching residue(0.078%)was low and the curing-leaching effect was good.However,the vanadium content in the thickened residue(0.296%)exceeded that in the fine leaching residue,which was attributed to the neutralization reaction in the#1 thickener.To solve this problem,the neutralization and thickening processes should be performed in separate equipment.The analysis and detection of key products is helpful for identifying problems and improving the curing-leaching circuit process.
