复杂铜、铅、锌、银多金属硫化精矿综合回收利用研究

【作者】 俞小花；

【导师】 谢刚； 杨大锦；

【作者基本信息】 昆明理工大学 ， 有色金属冶金， 2008， 博士

【摘要】 有色金属冶金是典型的资源投入型产业,其生存与发展必须以矿产资源为依托。近年来,由于我国铜、铅、锌等冶金行业的快速发展,优质资源消费增加,资源逐渐枯竭,有色金属的发展受控于资源,有色金属的供应不能满足国民经济发展对其需求,为了保持有色金属的可持续性发展,必须开发利用有色金属的多种资源。我国三江成矿带将是我国重要的有色金属矿产资源地。该矿带的资源特点是各种有色金属相互共生、易浮难分选,获得的精矿相互互含,导致有色金属精矿质量不高,金属回收率低。为了实现资源的高效综合开发利用,必须开发此类共生有色金属精矿的冶炼新技术。本论文以复杂铜铅锌银多金属硫化精矿为原料,与传统冶炼工艺比较后,确定了处理该种类矿石的全湿法冶金新技术,通过实验室全流程的各单元过程系统研究,确定了处理复杂铜铅锌银多金属硫化精矿的全湿法冶金工艺流程。并对其中的主要工序进行了理论分析,主要包括以下内容:1、加压浸出在现有的热力学研究基础上,进行了复杂多金属硫化精矿加压浸出热力学的研究,绘制298K和423K下的CuFeS₂-H₂O系、ZnS—H₂O系、PbS-H₂O系、FeS₂—H₂O系的φ-pH图;在加压釜中通过加压酸浸对复杂多金属硫化精矿进行浸出,通过对温度、时间、硫酸用量、氧压、矿石粒度等条件的考察,确定了最佳浸出条件:对于复杂多金属精矿1:精矿粒度-0.038mm（-400目）≥96%,液固比4∶1,温度～150℃,总压力为1.2～1.4MPa,浸出时间为180min,始酸浓度为145～155g/L,木质素适量,搅拌转速850r/min。在此条件下,各金属的浸出率分别可以达到（%）:Zn～94%、Cu～97%;对复杂多金属精矿2:精矿粒度-0.033mm（-425目）≥99%,液固比4∶1,温度～150℃,总压力为1.2～1.4MPa,浸出时间为180min,始酸浓度为140～150g/L,木质素适量,搅拌转速850r/min。在此条件下,各金属的浸出率分别可以达到（%）:Zn～95%、Cu～96%。2、加压浸出液萃取分离铜首次对富含高铜和高锌的高酸加压浸出液采用萃取的方法进行铜和锌的分离。通过对M5640、LIX973、LIX984三种有机相负载铜能力,萃取温度、混合时间、萃取相比、反萃相比、反萃原液酸浓度等条件对铜萃取率影响的考察,确定适当的萃取剂和萃取工艺:选用M5640作为萃取剂,萃取的合适条件:相比（O/A）4∶1、有机相中萃取剂含量（V/V）25%、混合时间3min、萃取级数11级以上、萃取温度30-40℃;在此条件下,铜的萃取率＞95%。反萃的合适条件:相比（O/A）1∶1、反萃原液游离酸浓度＞250g/L、混合时间2min、反萃级数5级以上、反萃温度30～40℃;在此条件下,铜反萃率＞95%。3、加压浸出渣中元素硫的脱除对富含元素硫、铅、银的加压浸出渣先浮选富集其中的硫精矿,浮选的合适条件为:矿浆浓度为10-20%,粒度为原渣粒度,浮选时2号油用量为10g/t,采用一段粗选-二段精选-三段扫选流程。浮选硫精矿含硫＞60%,浮选硫回收率＞70%,浮选铜回收率＞65%,浮选锌回收率＞65%,浮选铅回收率～8%;对富集后的硫精矿进行蒸馏脱除元素硫,蒸馏温度460-480℃。元素硫挥发率＞98%,其它金属元素的损失率＜0.5%。4、浮选尾渣碳酸盐转化-硅氟酸浸出铅首次采用碳酸盐转化-硅氟酸浸出的方法处理富含硫酸铅的物料。对含铅的浮选尾渣采用碳酸盐进行硫酸铅的转化,通过对转化时间、转化剂用量、转化温度等条件的考察,确定合适的转化条件:温度20-25℃,时间30min（第一次）、30min（第二次）,碳酸氢铵用量为理论量的-0.9倍,氨水和碳酸氢铵摩尔比为1∶1;对转化渣采用硅氟酸浸出的方法进行浸铅研究,考察始酸浓度、浸出时间、浸出温度等因素对浸出过程的影响,确定合适的浸出条件:浸出时温度为-60^C,时间为30min,游离硅氟酸浓度为125-150g/L。通过对碳酸盐转化-硅氟酸浸出条件试验的研究,确定最后的浸铅工艺:转化-浸出-转化-浸出,在此条件下铅的浸出率＞94%;5、硫脲浸银在现有的研究基础上,对试验过程中产出的各种含银物料中的银进行了硫脲浸出的研究,并进行了热力学的研究,绘制298KAg₂S（Ag）-SCN₂H₄-H₂O系φ—pH图,并对硫脲浸银的机理和动力学进行了研究,建立了动力学方程;考察了硫脲浓度、Fe³⁺浓度、浸出时间、温度等因素对浸出过程的影响,并由此确定了浸银的工艺条件:两段浸出,浸出温度60-70℃,硫脲浓度:一段55g/L、二段20g/L,液固比（7.5-10）∶1,时间180min,Fe³⁺浓度～10g/L;在此条件下银的浸出率＞93%。论文的创新点:（1）论文自主研发了从复杂多金属硫化精矿中综合回收铜、铅、锌、银的全湿法工艺流程。（2）论文采用加压浸出的方法处理某地复杂铜铅锌银多金属硫化精矿,并取得很高的铜、锌浸出率。（3）论文研究了从含Cu～40g/L、H₂SO₄～70g/L、Zn100g/L的高铜高锌高硫酸溶液中萃取分离铜、锌,并根据条件试验研究结果,确定了多级逆流萃取工艺。（4）论文研究了采用碳酸盐转化-硅氟酸浸出的方法处理富含硫酸铅的浮选尾渣的过程,并确定了合适的工艺:两次转化-浸出工艺。（5）论文研究了硫脲浸银过程的动力学,建立了浸出温度、硫脲浓度和Fe³⁺浓度对其动力学影响的关系式。更多还原

【Abstract】 Great progress had been achieved in copper,lead,zinc metallurgical industries in China.Along with national economy developing,the consumption of nonferrous products is more and more.Chinese is primary country of product and consumption of copper,zinc and lead.So the following problems are arised,the consumption of the excellent resource is increasing,the resource gradually dries up,the development of nonferrous metals is controlled by resource,and the providing of nonferrous metals can’t satisfy the development of national economy.All kinds of resources of nonferrous metals must be exploitate and utilize in order to keep continuable development of nonferrous metals.The three rivers ore area is the important resource area of nonferrous minerals in China.The characteristics of these minerals are that all kinds of nonferrous metals reciprocally accrete,floatation is ease but separation is difficult,the reciprocal holding of the metals in the obtained concentrate from dressing leads to the concentrates’ quality is bad,and the recovery rate is low.The new metallurgical technique which is used to treat complex polymetallic concentrates must be exploitate in order to actualize high-performance and compositive exploitating and utilizing.The raw material is complex polymetallic sulfide concentrate containing copper, lead,zinc and silver.Compared with the traditional metallurgical processing,the new hydrometallurgical technology of treating this kind of concentrate was determined.The conditions experiments of every chief segment in the whole flowsheet have been systematically investigated in the laboratory,then the whole hydrometallurgical processing flowsheet which treated complex polymetallic sulfide concentrate containing copper,lead,zinc and silver was determined.And the theoretical analysis has also been carried out.The main contents are followed as:1.Pressure leaching.Based on the existing thermodynamic research,the pressure leaching thermodynamics of treating complex polymetallic sulfide concentrate was studied,and the potential—pH diagrams for the system of CuFeS₂-H₂O,ZnS-H₂O,PbS-H₂O,FeS₂-H₂O at 298K and 423K were drawn. Complex polymetallic sulfide concentrate was treated using pressure leaching in autoclave,the optimal leaching conditions are determined after reviewed the conditions of leaching temperature,time,the dosage of sulfuric acid,oxygen pressure,granularity of concentrate.Complex polymetallic concentrate 1: granularity of concentrate was -0.038mm（-400 screen mesh）≥96%,ratio between liquid and solid was 4:1,temperature was about 150℃,the oxygen pressure was 1.2～1.4MPa,leaching time was 180min,the beginning acid concentration was 145～155g/L,sodium lignosulfonates was proper amount,stirring speed was 850r/min.Under these conditions,the leaching rates of every metal were Zn-94% and Cu-97%.Complex polymetallic concentrate 2:granularity of concentrate was -0.033mm（-425 screen mesh）≥99%,ratio between liquid and solid was 4:1, temperature was about 150℃,the oxygen pressure was 1.2～1.4MPa,leaching time was 180min,the beginning acid concentration was 140～150g/L,sodium lignosulfonates was proper amount,stirring speed was 850r/min.Under these conditions,the leaching rates of every metal were Zn-95%and Cu-96%.2.Extracting copper from the liquid of pressure leaching.For the first time,the copper has been extracted from the leaching liquid which contains high concentration of copper,zinc and sulphric acid.Through the test of following conditions:loading copper ability of organic phase,extraction temperature,mixing time,phase ratio of extraction,phase ratio of stripping,acid concentration of stripping liquid,the suitable extraction processing was obtained that suitable conditions of extraction were phase ratio（O/A）4:1,the content of extractant in organic phase（V/V）25%,mixing time 3min,extraction series over11,extraction temperature 30-40℃;Under these conditions,the extraction rate of copper＞95%. The suitable conditions of stripping:phase ratio（O/A）1:1,the acid concentration of stripping＞250g/L,mixing time 2min,stripping series over 5,stripping temperature 30～40℃;under these conditions,the stripping rate of copper＞95%.3.Deprive the element sulphur in the slag of adding pressure leaching.The sulphur concentration was enriched through floatation from the leaching slag which contained high concentration of element sulphur,lead and silver.The suitable conditions of floatation were ore pulp concentration 10～20%,granularity of raw ore, 2# oil 10g/t,use the process of first stage rough dressing—two stage fine dressing—three stage scavenger.The sulphur content of floating sulphur concentration was＞60%,recovery rates of floating were sulphur＞70%,copper＞65%,zinc＞65%,lead～15%.Element sulphur was deprived from the enriched sulphur concentration using distillation,the conditions were temperature 460～480℃, volatilization rate of element sulphur＞98%,other metal element’s loss＜0.5%.4、Carbonate conversion -silicofluoric acid leaching on flotating gangue.It was the first that treated the material which containing lead sulfate using carbonate conversion-silicofluoric acid leaching.Lead sulfate was converted using carbonate treating floatation gangue.After testing these conditions:the conversion time,the dosage of conversion agent,conversion temperature,the suitable conversion conditions were determined:temperature20-25℃,time 30 min（first time）, 30min（second time）,the dosage of ammonium acid carbonate is 0.9times of theoretical value,the mol ratio of ammonium acid carbonate and ammonia liquor is 1:1.conversion slag was leached using silicofluoric acid,after testing the elements of the beginning acid concentration,leaching time,leaching temperature,suitable leaching conditions were determined:leaching temperature～60℃,time 30 min, extricated silicofluoric acid concentration 125～150g/L.through the study of carbonate conversion-the experiment of silicofluoric acid leaching conditions,the last process of leaching lead was determined: conversion-leaching-conversion-leaching,the leaching rate of lead under these conditions is＞94%.5、Leaching silver using thiourea.Based on the existing study,thiourea leaching silver from floating tailing and the thermodynamics ware studied,then theφ—pH diagram of Ag₂S（Ag）-SCN₂H₄-H₂O at 298Kwas drawn.The mechanics and kinetics of Leaching silver using thiourea were studied,and the kinetics equations were set up.After testing the elements of thiourea concentration,Fe³⁺concentration,leaching time,temperature,the processing of leaching silver was determined:two-stage leaching,leaching temperature 60-70℃,thiourea concentration:first stage 55g/L, second stage 20g/L,the ratio of liquid and solid is（7.5-10）:1,time 180min, Fe³⁺concentration～10g/L;the silver leaching rate under these conditions is＞93%.The following contributions have been made:（1）The whole hydrometallurgical flowsheet of synthetic recovery copper,lead, zinc,silver from complex polymetallic sulfide concentrate has been developed;.（2）Using pressure leaching to treat complex polymetallic sulfide concentrate containing copper,lead and zinc was studied,and the good leaching rates of copper and zinc was obtained.（3）Separation copper and zinc from the solution of high concentration of copper,zinc,sulfuric acid using extraction was studied,in which the concentration are Cu～40g/L、H₂SO₄～70g/L、Zn100g/L,according to the result of experiment study,many stage countercurrent extraction processing was determined.（4）The process of using carbonate conversion -silicofluoric acid leaching to treat the floating gangue which contain high concentration lead sulfate was studied, and suitable processing was determined:Two times conversion -leaching.（5）Kinetics process of leaching silver using thiourea was studied,kinetics equations on the elements of leaching temperature,thiourea concentration, Fe³⁺concentration were set.更多还原