The high calcium type stone coal from Hubei province was leached by water and dilute acid separately after being roasted with different dosage of Na Cl. The water leaching rate of vanadium（WLRV） was low and only 26....The high calcium type stone coal from Hubei province was leached by water and dilute acid separately after being roasted with different dosage of Na Cl. The water leaching rate of vanadium（WLRV） was low and only 26.8% of vanadium can be leached by water when 4% Na Cl was added, but the acid leaching rate of vanadium（ALRV） was relatively high. Calcium in the high calcium type stone coal is greatly superfl uous relative to vanadium, hence, the calcium reacts with vanadium to form Ca（VO3）2, Ca2V2O7 and Ca3（VO4）2orderly during the stone coal roasting process and high temperature is beneficial to the reactions between calcium and vanadium, which was validated by simulated reactions between pure calcium carbonate and vanadium pentoxide. These calcium vanadates are all water insoluble but acid soluble and this causes the low WLRV and relatively high ALRV. After calcium removal by HCl, the WLRV is highly enhanced and reaches about 50% when only 2% Na Cl was added. If the HCl content is too high, the stone coal is easily sintered and the formed glass structure can enwrap vanadium, which leads the WLRV to decline. Single water leaching process is not appropriate to extract vanadium from high calcium type stone coal.展开更多
基金Funded by the Fundamental Research Funds for Central Universities(WUT:2013-IV-001)the Ministry of Education of the People's Republic of China(No.20120143120007)
文摘The high calcium type stone coal from Hubei province was leached by water and dilute acid separately after being roasted with different dosage of Na Cl. The water leaching rate of vanadium（WLRV） was low and only 26.8% of vanadium can be leached by water when 4% Na Cl was added, but the acid leaching rate of vanadium（ALRV） was relatively high. Calcium in the high calcium type stone coal is greatly superfl uous relative to vanadium, hence, the calcium reacts with vanadium to form Ca（VO3）2, Ca2V2O7 and Ca3（VO4）2orderly during the stone coal roasting process and high temperature is beneficial to the reactions between calcium and vanadium, which was validated by simulated reactions between pure calcium carbonate and vanadium pentoxide. These calcium vanadates are all water insoluble but acid soluble and this causes the low WLRV and relatively high ALRV. After calcium removal by HCl, the WLRV is highly enhanced and reaches about 50% when only 2% Na Cl was added. If the HCl content is too high, the stone coal is easily sintered and the formed glass structure can enwrap vanadium, which leads the WLRV to decline. Single water leaching process is not appropriate to extract vanadium from high calcium type stone coal.
