粗金粉中金的氯浸-控制电位还原精炼

某冶炼厂氰化金泥还原得到的粗金产品纯度较低,采用氯浸-还原工艺对粗金进行了精炼提纯。在生产工艺中采用盐酸+氯酸钠对粗金进行氯浸溶解,用焦亚硫酸钠控制电位选择性还原浸出液中的金。采用补水-冷却使银和铅从氯浸液充分沉淀析出,通过调整pH值、改变焦亚硫酸钠添加方式、精确控制还原电位等方法,产品金锭达到IC-Au99.99标准。两年的生产实践创造了明显的经济效益。     

重金属强化含金矿石的氰化浸出

通过分析铊、铋、汞和铅等重金属强化金氰化溶解的电化学原理,对含金氧化物矿石和难浸硫化物金精矿进行了重金属强化浸金研究.结果表明:重金属对金氰化溶解的阳极过程有显著的强化作用,但在常规供氧条件下,金的溶解速率并未显著提高;只有同时采用阴极强化措施,才能使重金属起到显著提高金溶解速率的作用;对于含金氧化物矿石,单独采用重金属强化即可明显提高浸金速率,如果在过氧化氢助浸的基础上添加重金属,金的浸出速率会有更大幅度的提高;对硫化物金精矿而言,单独采用重金属无明显强化效果,只有在添加过氧化氢作为辅助氧化剂的基础上,重金属对金的浸出才能起到强化的作用,该体系中过氧化氢起到了强化阴极过程和氧化硫化物的双重作用.     

难选氧化金矿氰化助浸试验研究

甘肃某金矿中金属矿物含量较少,以褐铁矿、黄铁矿为主,脉石矿物主要有石英、粘土矿物等.探索试验表明氰化浸出获得指标明显优于浮选、重选法.采用助浸剂可以提高金的氰化浸出率,其中混合助浸剂HZ可同时降低氰化钠用量,缩短浸出时间.采用优化工艺条件,在磨矿细度-74μm占90％,石灰用量3000 g/t,矿浆浓度40％,混合助浸...     

Review of gold leaching in thiosulfate-based solutions

Numerous non-cyanide leaching lixiviants have been developed, among which thiosulfate is considered the most promising alternative to cyanide due to its non-toxicity, low price, high leaching rate and excellent characteristics in dealing with carbonaceous and copper-bearing gold ores. The traditional copper−ammonia−thiosulfate system has been studied extensively. However, with many years of process development, there are still some problems and challenges with this gold leaching system. A series of studies using nickel-, cobalt- and ferric-based catalyst to substitute copper have been conducted with the purpose of reducing the consumption of thiosulfate. A variety of non-ammonia thiosulfate leaching systems including oxygen−thiosulfate, copper−thiosulfate, copper−EDA−thiosulfate, ferric− EDTA−thiosulfate, and ferric−oxalate−thiosulfate leaching systems have been also developed to eliminate the potential side-effect of ammonia. In this review, the basic theory and process development of some main gold leaching systems based on thiosulfate solutions were systematically summarized to illustrate the research status on thiosulfate leaching process. The potential effects of various additives such as organic ligands containing amino, carboxyl or hydroxy functional groups on gold thiosulfate leaching were described in detail. The potential opportunity and challenge for promoting the industrial development of thiosulfate-based gold leaching systems were also discussed.     

硫脲浸金电化学行为研究

采用循环伏安法(CV)、Tafel曲线和差分脉冲伏安法(DPV)等电化学方法对模拟硫脲浸金体系进行了研究.结果表明,硫脲浓度范围为0.005～0.04 mol/L,浓度增大有利于金的浸出;在Fe3+浓度为0.01～0.08 mol/L范围内,随着Fe3+浓度的增大,金腐蚀电位负移,腐蚀电流变大;适度升温可以提高金的腐蚀...     

含铜金矿的压力氧化浸出及其机理

含铜金矿在氧气分压为o.45 MPa、温度约为110℃条件下于高压釜中氧化一定时间,浸出铜后,渣氰化浸金,获得的铜、金浸出率分别为90.3%和96.55%.通过分析X射线衍射谱及CuFeS2-H2SO4-NaCl-H2O体系在25℃下的ψ-pH图,确定了载金矿物的氧化机理,分析了浸出体系的酸度、温度及氯化钠浓度对含铜金矿预氧化及浸出过程的影响规律.结果表明:硫化矿的氧化溶解首先是磁黄铁矿,其次是铜的次生硫化矿,再次是黄铜矿,最后是黄铁矿;载金黄铜矿的氧化首先是铁从黄铜矿的晶格中氧化溶解出来,生成中间产物CuS2和CuS;较高的酸度和氯化钠浓度有利于单质硫的生成、三价铁的水解和铜的浸出,进而有利于金浸出率的提高.     

水合肼还原-重量法测定氯化浸金液中金含量

采用水合肼还原氯化浸金液(氯金酸溶液)中的金,称量析出海绵金的质量,实现了海绵金的准确测定,考查了反应温度、试液金浓度、水合肼使用量等对于测定结果的影响,并与其它测定方法进行了比对。调整氯化浸金液金浓度约为40 g/L,加入水合肼(用量1.5 mL/g-Au)还原后加热溶液微沸20 min,损失在滤液中的金量可忽略。测定结果的相对标准偏差(RSD)小于0.2%。方法操作简便,可满足生产分析的要求。     

从废弃印刷线路板中回收金的试验

试验研究了采用硫脲法有效地从废弃印刷线路板中回收金。试验结果表明，硫脲回收金的主要影响因素有：温度、硫脲质量浓度、Fe^3＋质量分数、浸出时间、硫酸体积分数；合适的浸出条件是：固液比为1：5，浸出温度为35℃，硫脲质量浓度为10g／l，Fe^3＋抖质量分数为0．3％，浸出时间为1h，硫酸体积分数为5％。     

预浸-氰化浸出回收湿法炼锌渣中的银和金

某冶炼厂的锌浸出渣中银勘布粒度细,含银、金分别为381.3、1.02 g/t,可采用预浸-预浸渣氰化浸出工艺回收。重点研究了预浸条件对银、金浸出效率的影响。条件实验表明,药剂A比酸浸、氨浸具有更好的预浸效果;最佳预浸条件为药剂A浓度200 g/L、浸出液固比2:1、在50℃浸出3 h。综合条件实验得到的预浸渣渣率为66.2%,金、银的氰化浸出回收率分别为85.7%、92.9%。     

Co-intensification of gold leaching with heavy metals and hydrogen peroxide

Co-intensification was researched to accelerate gold leaching with regards to its electrochemical nature by using anodic intensifiers of heavy metal ions (Pb2+, Bi3+, Tl+, Hg2+ and Ag+) on the basis of hydrogen peroxide assistant leaching on three different types of materials which were classified as a refractory sulphide gold concentrate, an easily leachable sulphide gold concentrate, and a low grade oxide gold ore according to their leaching characteristics. The results showed that, favorable co-intensification effects on the three materials were obtained and leaching time of gold was effectively shortened to no longer than 12 h from 16 to 24 h for hydrogen peroxide assistant leaching. For the five tested heavy metal ions, Bi3+and Tl+ presented co-intensifying effect on all the three materials, and Hg2+ caused co-intensifying effect on both refractory and easily leachable sulphide gold concentrates, and Pb2+ and Ag+ only had co-intensifying effect on the easily leachable sulphide gold concentrate.     

Oxidation leaching of copper smelting dust by controlling potential

A study was conducted for metal extraction from copper smelting dust using the oxidation leaching and control of potential technology. The effects of H₂O₂ dosage, H₂O₂ feeding speed, initial HCl concentration, leaching temperature, liquid-to-solid ratio and leaching time on metals leaching efficiencies were investigated. The following optimized leaching conditions were obtained: H₂O₂ dosage of 0.8 mL/g (redox potential of 429 mV), H₂O₂ feeding speed of 1.0 mL/min, initial H₂SO₄ concentration of 1.0 mol/L, initial HCl concentration of 1.0 mol/L, leaching temperature of 80 °C, initial liquid-to-solid ratio of 5:1 mL/g and leaching time of 1.5 h. Under the optimized conditions, copper and arsenic can be effectively leached from copper smelting dust, leaving residue as a suitable lead resource. The average leaching efficiencies of copper, arsenic and iron are 95.27%, 96.82% and 46.65%, respectively.     

H2SO4分解铁-FeCl3浸出焙烧金精矿中金

采用硫酸分解焙烧金精矿,金从黄铁矿中解离的同时金得到了富集,可采用氯化铁溶液非氰浸出金。研究了硫酸浓度及过量系数、分解温度对铁分解率的影响,优化工艺条件为,焙烧温度180 ℃,反应时间90 min,硫酸过量系数1.2,在此条件下,铁分解率为92.14%,金含量从原来的51.7 g/t提高到106.1 g/t;研究了反应温度、液固比对氯化铁溶液浸出硫酸浸出渣中金的影响,优化浸出条件为,液固比1.5,80 ℃浸出90 min,在此条件下,金浸出率96.8%。     

白云母对氰化浸金的吸附效应研究

采用多种手段研究了金矿石中白云母对氰化浸出液中的金吸附效应。吸附试验考察了不同粒级白云母对溶液中金吸附率的影响,结果表明,白云母粒度越细,溶液中金的吸附率越高,吸附率由1.29%提高至5.35%;电化学溶解实验表明,白云母粒度越小,金的溶解速率越大;对浸金产物的扫描电镜(SEM)和能谱(EDS)分析表明,金的氰化络合物易吸附在白云母端点处;红外光谱分析显示,金氰化物与白云母存在化学吸附。密度泛函理论(DFT)模拟计算结果显示,金氰化物与白云母(001)表面的吸附强度为[Au(CN)2]-?AuCN。     

高岭石对氰化浸金的影响及助浸研究

采用电化学实验研究了在氰化浸金过程中常见矿物高岭石对金溶解速率及对溶液中金的吸附效果的影响。结果表明,高岭石的存在会使金的溶解速率加快,随着高岭石粒度逐渐降低金的溶解速率提高,且高岭石对溶液中金的吸附率增加。氰化浸出实验结果表明,高岭石存在时金的浸出率由93.21%降低到91.76%,采用柠檬酸三钠、过氧化镁和十二烷基硫酸钠助浸时,金浸出率升高至94.42%。能谱分析(EDS)发现浸出物中高岭石表面有金元素存在,表明高岭石会吸附溶液中的金。红外光谱分析和密度泛函理论计算表明,高岭石与金发生化学吸附作用,氢原子为高岭石的活性位点,C6H5O7^3-会优先吸附于高岭石(001)表面,加入助浸剂可降低高岭石与金的吸附强度,提高金的浸出率。     

铜-氨-硫代硫酸盐体系金溶出影响因素的电化学研究

铜-氨-硫代硫酸盐浸金体系中,金的溶出本质上是电化学过程。采用交流阻抗和Tafel曲线分析硫代硫酸盐、铜离子、氨浓度对金的溶出影响。结果表明:在金的溶出过程中,硫代硫酸盐和铜离子可能会导致钝化,尤其使铜离子浓度增大会导致钝化加剧,这种钝化会交替出现;氨水不会导致钝化;对金溶出速率的影响,硫代硫酸盐最大,铜离子最为复杂,氨影响相对最小。     

Intensified alkaline leaching pretreatment of refractory gold concentrates at common temperature and pressure

1　INTRODUCTIONWhenaproportionofgoldcontainedinasulfidicconcentrateisinsolidsolutionwithinarsenopyrite ,ultra finegrindingmaynotresultincomplete goldliberation ,andoxidativedestructionofthesulfidesmaybenecessary .Theoptionsareroasting ,pressureoxidationorbacterialoxidation[1] .Conventionalmethodsofalkalineleachingofgoldarsenosulfidecon centratesinanautoclaverequireexpensiveequipmentaswellashigh costenergyandreagents .Rossovsky[2 ] reportedanalkalineleachingmethodwhichcontainsfinegrinding(…     

老挝某金矿石重选-环保药剂浸金研究

针对老挝某蚀变岩型金矿石开展了尼尔森重选和重选尾矿环保药剂浸金实验。在磨矿细度-0.074 mm占75%,尼尔森选矿机重力值为60 G’s,水量为3.8 L/min,给矿速度600 g/min条件下,重选精矿可回收原矿中47.2%的金。重选尾矿磨矿至-0.074 mm占90%,矿浆浓度为40%,石灰用量2000 g/t,铁氰化钾助浸剂用量100 g/t,预处理2 h,金蝉环保药剂用量2000 g/t,浸出32 h的条件下,重选尾矿浸出回收率92.0%,可回收原矿中48.6%的金。最终金总回收率95.8%。     

Behavior of S2O32- And SO32- In sulfur-bearing aqueous solution system for gold leaching

The concentrations of S₂O₃^2? and SO₃^2? were measured in gold leaching systems, including thiosulfate system, polysulfide system and the modified lime sulfur synthetic solution (ML) system in the process of chemical reaction. The interactions among S₂O₃^2?, SO₃^2? and S^2? were discussed. The behavior mechanism of sulfur-bearing reagents was proposed to describe the process reactions and their Gibbs free energy. The proper quantity oxygen and SO₃^2? reduce decomposition of S₂O₃^2? and react with sulfur derived from the decomposition of S_X^2?. So, SO₃^2? ions have action to stabilize sulfur-bearing system and are favorable to leach gold.     

碘化物对金精矿碘化浸出过程的影响

采用碘-碘化物浸出体系,从碘初始含量、碘与碘化物摩尔比和浸出液pH值3个影响因素入手,考察不同碘化物(碘化铵、碘化钾和碘化氢)对金精矿碘化浸出过程的影响。结果表明:在碘初始含量为1%,碘与碘化物摩尔比为1:8,浸出液pH值为7,液固比为4:1,搅拌速度为600 r/min,浸出时间为4 h,温度为25℃的条件下,用碘化铵或碘化钾作为碘化浸金的络合剂,金的浸出率均能达到90%左右,而用碘化氢(其水溶液为氢碘酸)作络合剂时,金的浸出率仅有75%。考虑到不同碘化物浸金效果差异及工业应用的可行性等因素,确定碘化钾为适宜的金精矿碘化浸出络合剂。     

卡林型金矿的HClO4-FeCl3浸出及正交试验研究

采用HClO4预氧化、FeCl3进一步氧化络合方法联合浸出品位低、成分杂的卡林型金矿中的金。机理分析认为,在浸出前期加入HClO4将金属硫化物中的硫以高价态硫酸根离子、硫酸氢根离子等形式进入溶液而脱除,减少单质硫形成钝化膜包裹从而阻碍金属硫化物的解离,同时保证体系中一定初始浓度的[Fe³⁺]、[Cl^-],有利于后续FeCl3浸金。正交试验研究表明,选定的4个因素对金浸出率的影响顺序为HClO4体积分数＞FeCl3浓度＞浸出温度＞HClO4预氧化时间,得到的较优浸出条件为HClO4体积分数6%、预氧化时间1 h、FeCl3浓度1.8 mol/L、40℃浸出5 h,在该条件下卡林型金矿金的浸出率为71.02%。