【摘要】 高As,Sb难处理金精矿进行造锍铺金熔炼时，过高的含Sb量会严重影响炉衬寿命，且对后续从阳极泥中回收有价金属产生不良影响，故需对其进行湿法预处理。采用Na₂S+Na OH预脱除高Sb金精矿中的Sb，探讨碱性硫化浸出工艺的适宜控制条件，并揭示金属Mn抑制因多硫化物和硫代硫酸盐而导致的Au伴随浸出的控制机制。通过对高As,Sb金精矿的X射线衍射（XRD）、扫描电镜-能谱（SEM-EDS）及矿相分析可知，Sb主要以Sb₂S₃和Sb₂O₃形式存在，而Au包裹在硫化物和硅酸盐中。电化学测试及产物X射线光电子能谱（XPS）分析表明，金属Mn粉抑制剂优先氧化为Mn²⁺，并逐渐转化为Mn OOH和Mn O（OH）₂，可有效降低溶液中的氧化还原电位，防止S^2-氧化为S₂O₃^2-和S_n^2-并实现抑制Au伴随浸出的效果。在Na₂S 100 g·L^-1+Na OH 100 g·L^-1，液固比（L/S）为3∶1,Mn抑制剂添加量为5%（添加剂与原矿质量比）的较优浸出控制条件下，75℃浸出30 min可使含量20.85%的锑预脱除率达到93.3%；与不加抑制剂相比，Au的伴随浸出率最高可降低65.33%；浸出渣中Sb降为1.75%,Au含量为34.6 g·t^-1，其富集率达到96%，完全满足精矿中Sb预脱除和浸出渣中Au富集的预期目标。更多还原

【Abstract】 With the gradual exhaustion of easy-to-treat gold mineral resources,gold production enterprises are pressured to utilize the refractory gold concentrate with high impurity contains arsenic and antimony as alternate.Since golds in these refractory ores are usually deposited with other metal sulphides and silicates,and mostly embedded in stibnites,pyrites and arsenopyrites,it is hard to achieve effective gold extraction by conventional wet process.Therefore,efficiently matte smelting capturing-Au technology have been adopted for treating refractory gold mixed copper concentrates.However,high-content of antimony seriously affect the lining life during matte smelting,and also have a negative impact on the subsequent recovery of valuable metals from anode slime.In consequence,it is of great significance to seek suitable technological strategies to pre-removed antimony from this high-Sb gold concentrates before being charged in bottom blowing melting furnace.In this work,Na₂S+Na OH alkaline leaching was adopted to pre-remove Sb from high-antimony containing gold concentrates.Based on the chemical composition and mineralogical phases analysis,the process parameters of alkaline leaching were determined according to thermodynamic analysis and electrochemical potential （E_h）-p H diagram.Then,single-factor experiment was carried out to detect the effect of Na₂S and Na OH concentration,temperature and liquid-solid ratio （L/S） on the leaching rate of Au and Sb,simultaneously,the inhibition mechanism of Mn to minimize co-leaching of gold caused by polysulfides and thiosulfates was also studied by means of electrochemistry analysis and X-ray photoelectron spectroscopy （XPS）.Furthermore,the gold contents in concentrates and leaching residues were analyzed by fire assay method,the chemical composition of others was analyzed by chemical titration and inductively coupled plasma mass spectrometry （ICP-MS）.Besides,the morphologies and phase structure were analyzed by scanning electron microscope-energy dispersive spectrometer （SEM-EDS）,X-ray diffraction （XRD） and mineral phases analysis,especially the mineralogical phases of gold and antimony.The results showed that the major minerals in antimony bearing gold concentrates had been detected as stibnite （Sb₂S₃）,arsenopyrite （Fe As S）,pyrite （Fe S₂） and quartz （Si O₂）,etc.And antimony existed in a variety of forms,53%in the form of antimony sulfides and others were oxides.Moreover,the major antimony oxide was valentinite,and a few stibiconite and antimonate （Sb₂O₄）,which was coexisted with pyrite,arsenopyrite and other flocculent substances.In addition,the gold was mainly wrapped by compounds such as sulfides and silicates,however,only a small amount of gold existed in the form of bare or semibare;among them,gold wrapped by antimony sulfide had the highest risk of loss in leaching.The appropriate addition of Na₂S concentration could effectively improve the leaching rate of antimony,but too much S^2-would lead to the addition of S₂O₃^2-and Sn^2-in leaching solution,which accordingly increased the leaching rate of gold.Corresponding,the addition of Na OH could inhibit the hydrolysis of Na₂S;instead,too high Na OH might remarkably accelerate the conversion rate of S^2-to elemental sulfur,and restrain the dissolution and mass transfer of stibnite and antimony oxides.In view of the above,it was suitable to select Na₂S 100 g·L^-1+Na OH 100 g·L^-1 for pre-removing antimony from refractory gold concentrates in leaching process.The rising temperature could effectively improve the reaction kinetic conditions,and the most important,it also reduced the content of dissolved oxygen in leaching solution,which might accordingly promote the leaching rate of antimony and suppress gold’s dissolution.However,too high temperature dramatically intensified the decomposition of Na₂S,in turn reducing the leaching rate of antimony.An appropriate L/S reduced the viscosity of solution and speeded up the leaching rate of antimony,but excessive L/S also increased the dissolution of oxygen,resulting in the associated leaching of gold.Taken together,the proper leaching temperature was optimized at 75℃and L/S of 3∶1.Besides alkalinity,lowering solution potential could also avoid the oxidation of Na₂S.Because Sb⁵⁺was relatively stable in alkaline environment,which restricted the leaching of antimony to a certain extent,resulting in incomplete removal in leaching residue.In theory,Mn reacted with oxygen preferentially than S^2-，which effective prevented the oxidative hydrolysis of Na₂S to generate polysulfide and thiosulfate,and inhibited the dissolution of gold.The electrochemical and XPS analysis further revealed that Mn inhibitor had been oxidized to Mn²⁺,and gradually transformed into Mn OOH and Mn O（OH）₂ in solutions,which reduced the redox potential,effectively prevented the oxidation from S^2-to S₂O₃^2-and Sn^2-，and alleviated associated leaching of gold.Under the optimal leaching conditions of Na₂S 100 g·L^-1+Na OH 100 g·L^-1,L/S of 3∶1,Mn addition content of 5%,the antimony leaching rate reached 93.3%,leaching at 75℃for 30 min,and compared with no inhibitor,the associated-leaching rate of gold was reduced by 65.33%,the content of antimony in leaching residues was lowered down to 1.75%,and 96.01%gold was enriched in leaching residues,which effectively achieved the desired targets for antimony pre-removal and gold enrichment in leaching residue.更多还原