A Study on the Occurrence of Vanadium in the Qingshan Lead-Zinc Deposit,Guizhou Province
Vanadium(V)is a strategic critical metal.Its mineralization research has attracted much attention.The Qingshan lead-zinc deposit in Guizhou Province is located in the Weining-Shuicheng Pb-Zn-Ag metallogenic belt within the Sichuan-Yunnan-Guizhou metallogenic domain.There are the Qingshan and Hengtang ore districts in the deposit which is a medium-sized lead-zinc deposit.Previous preliminary studies showed that V is abnormally enriched in the ore of the oxidized ore zone in the Hengtang oreblock,but its occurrence state is unknown yet.In order to find out the occurrence state of V in lead-zinc oxide ores,altered dolomite and diabase,inductively coupled plasma mass spectrometry(ICP-MS),powder X-ray diffraction(XRD),and scanning electron microscopy(SEM)were used to systematically analyze their mineral assemblages and chemical compositions.The results show that V contents of the oxidized lead-zinc ore,altered dolomite,and altered diabase range from 11.9×10-6 to 5 963×10-6,168×10-6 and from 448×106 to 701× 10-6,respectively,with respective enrichment coefficients of 20,1.2 and 4.1 relative to average V content of the bulk crust.The V occurred as independent mineral of descloizite([PbZn(VO4)(OH)])in the lead-zinc oxide ore and altered dolomite.Descloizite contains relatively high As content due to the subsititution of V by As in form of isomorphism.No independent V mineral was found in altered diabase.V could mainly occur in the form of isomorphic substitution of Ti in anatase or rutile(TiO2)in altered diabase.In addition,the good correlations between V and Cu,Ni,Mo,Bi in ores indicate that these elements could be co-precipitated simultaneously to have formed the ore,with similar enrichment regularities.The distribution patterns of rare earth elements and trace elements of ores are respectively similar to those of the altered dolomite,indicating that they had been experienced similar hydrothermal process.Whether V was mainly sourced from the metasomatic leaching of dolomite or the magmatic-hydrothermal fluid related to diabase needs to be further studied.This study shows that V occurred in forms of independent mineral and isomorphism in oxidized ore/altered dolomite and diabase in the Qingshan deposit.It is of certain indicative significance for the comprehensive utilization of V in lead-zinc ores.