Study On The Comprehensive Recovery Of A Bismuth-containing Scheelite In Shaanxi Province

Bismuth-containing scheelite is a multi metal ore with complex ore properties,so it is difficult to realize comprehensive recovery of tungsten and bismuth.The comprehensive recovery of bismuth and tungsten is studied,the mechanism of the electrochemical adjuster is discussed too.All above these,the main points of the thesis are indicated as following:The process mineralogy results show that the value minerals mainly include scheelite and bismuthinite and scheelite is shaped granular structure distribution in feldspar-quartz vein.Moreover,scheelite is closely related to quartz and Bi bearing minerals.In addition,bismuth-containing minerals mainly exist in form of bismuthinite with fine size,which is disseminated in the ores.The technological categorie of ore is potash feldspar-quartz vein refractory tungsten?bismuth?ore.The single floatation test shows that the bismuth concentrate with Bi grade of28.22%,recovery rate of 52.07%and the tungsten concentrate with WO₃ grade of63.94%,recovery of 89.09%can be obtained under the process of“selective floatation of bismuth-normal temperature roughing-heating cleaning”,with the condition of sodium carbonate as pH modifiers,sodium silicate as inhibitor and oxidized paraffinum sodium as collector for scheelite.The test of gravity-floatation joint process shows that adapt the process of jigging tail-shaker roughing-floatation of tungsten-bismuth separation can obtain the tungsten concentrate with WO₃ grade of 66.95%and recovery rate of 90.07%,as well as the bismuth concentrate with Bi grade of 24.38%and recovery rate of 63.24%,the mineral processing index is better than the single flotation,so this process is the recommended process.The orthogonal test results of bismuth and scheelite separation show that the factors affecting the recovery of bismuth are in the descending order as the dosage of pine oil,the dosage of electrochemical adjuster,the dosage of copper sulfate,the dosage of xanthate and grinding fineness.The factors affecting pulp potential and the pH value are in the descending order as the dosage of electrochemical adjuster,the dosage of xanthate,the dosage of pine oil,the dosage of copper sulfate and grinding fineness.In addition,electrochemical adjuster can produce a better floatable sulfur monomer on the natural bismuth surface,thus improve the floatability of the natural bismuth.Finally,effective separation of bismuth and scheelite is realized.The test of comprehensive recovery of quartz from tailings shows that the high quality quartz concentrate with silicon dioxide grade of 99.45%and 97.22%is obtained by color separation-coarse size grinding classification-fine size floatation flowsheet,which meet the requirements of quartz sheet.In this paper,tungsten,bismuth and quartz are effectively recovered from bismuth-containing scheelite,the study has some significance for the comprehensive recovery of similar ores.In addition,the successful application of electrochemical floatation in separation of bismuth and scheelite expands the application fields.