Research On Beneficiation Technology Of Antimony-bearing Carlin-type Primary Gold Deposits In Guizhou

Antimony-containing Carlin-type raw gold ore is the important mineral resource of gold and antimony in China,in which the main metallic minerals are stibnite,pyrite,arsenopyrite,etc.Gold is always wrapped in the carrier of sulphide ore in the form of micro-fine particle and the close adhesion of minerals causes the inefficient beneficiation recovery of this ore.The paper chooses the antimony-containing Carlin-type raw gold in Guizhou as research object.The low content of beneficial elements largely wrapped by sulphide ore like pyrite and arsenopyrite brings big challenge for beneficiation.Researches of process mineralogy indicate that the gold grade in raw ore is 2.04g/t.The gold mostly exists in pyrite and arsenopyrite as micro-fine particle and its proportion is 85.34%.The antimony grade in raw ore is 0.81%,mainly in the form of stibnite,accounting for 73.29%.The main metal minerals are arsenopyrite,pyrite and stibnite,and the gangue minerals are hydromica,dolomite,quartz,carbon,etc.The texture and structure of raw ore is complicated for the paragenesis of stibnite and arsenopyrite,which also brings difficulties to beneficiation.Aiming at this raw ore,three principle technological processes,“preferential floatation of sulfur by depressing antimony”,“bulk floatation of gold and antimony and separation”,“preferential floatation of antimony”are applied.The results show that,by comparison,the effect index of“bulk floatation of gold and antimony and separation”is bad.While“preferential floatation of sulfur by depressing antimony”costs lime added and“bulk floatation of gold and antimony and separation”needs the secondary separation of gold and antimony,“preferential floatation of antimony”obtains better index in natural PH.Therefore,the process of“preferential floatation of antimony”is chosen.The condition of“preferential floatation of antimony”was optimized by small test.The final roughing condition of optimal antimony floatation is 1000g/t sodium silicate,1000g/t lead nitrate,20+10g/t ammonium dibutyl dithiophosphate+ethyl thio carbamate and 45g/t 2~#oil.The final roughing condition of optimal gold floatation is1000g/t sodium carbonate,500g/t copper sulfate,120g/t sodium n-butylxanthate and75g/t 2~#oil.Through small open-circuit and closed-circuit test,the test flow of“one-roughing,two-cleaning,two-scavenging”for antimony floatation and the successive return in preceding tailings for gold floatation.Applying this flow,we obtain the antimony concentrate of 46.45%antimony grade and 75.83%antimony recovery,and the gold concentrate of 25.56g/t gold grade and 91.09%gold recovery.The 15-day extended continuous separation test proves the rationality and reliability of technological process assured by laboratory test,in which the test index is45.12%antimony grade and 72.97%antimony recovery in antimony concentrate and25.45%gold grade and 91.57%gold recovery in gold concentrate.The cost estimation indicates that higher economic benefits shall be achieved by applying this experiment method.This paper provides theoretical and technological guidance for the floatation of antimony-containing Carlin-type raw gold ore.