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。     

对边磨边浸氰化提金工艺的探讨

通过理论及分析边磨边浸氰化提金选矿试验及国外的生产实践,该工艺可强化浸出效果,缩短工艺流程,减少设备基建投资和能耗。     

难浸金矿加石灰焙烧-氰化浸金工艺方法

对丹寨含砷硫难浸金矿加石灰焙烧－氰化浸金研究表明,在最佳焙烧条件（６００～６５０℃,ａ＝１．１～１、．２,２ｈ,空气流量２００ｍｌ／ｍｉｎ）,可固定９９％以上的硫和砷,金氰化浸金率从直接氰化浸出的０％提高到９４％。加石灰焙烧是１种新的无污染预处理工艺。     

某氰化渣的改性石硫合剂法浸金研究

某氰化渣中金的品位为12.03 g/t,氰化渣里游离金的颗粒极细,并且被铁氧化物包裹,难以解离,属于难浸类金矿。采用改性石硫合剂对氰化渣进行了浸金研究,考察了超细磨时间、氧化剂用量、矿浆p H和搅拌时间对金浸出率的影响。优化实验条件为:超细磨时间2 h、氧化剂Ca O2用量0.78 g/500 g、矿浆p H≈11.5、液固比2:1、搅拌浸出时间24 h,金的浸出率达78.57%。     

难浸氰化尾渣浮选精矿的常温常压碱浸预处理

某氰化尾渣浮选精矿采用超细磨-氰化方法处理,在＜37μm占99.5%的磨矿细度下浸出24h,金的浸出率仅有1.80 %,极难浸出.采用常温常压碱浸强化预氧化工艺处理后,在NaCN用量6kg/t、氰化时间24h的条件下,金的浸出回收率提高到85.82%,炭吸附率99.66%.     

氰化尾渣还原焙烧酸浸提铁及氰化浸金新工艺

以氰化尾渣为原料,采用还原焙烧酸浸工艺对其进行处理。当还原温度为850℃、加入煤粉质量为氰化尾渣质量的13%、还原时间为100 min时,对氰化尾渣进行还原,氰化尾渣中Fe2O3转化为Fe3O4或FeO。还原后采用硫酸浸出,当硫酸浓度为50%、硫酸用量系数为1.2、反应温度为105℃、反应时间为3 h时,铁的浸出率达到93.66%。还原焙烧渣在600℃氧化焙烧2 h经过脱碳后氰化浸金,当氰化钠用量为4 kg/t、反应时间为28 h、液固比为2:1时,金的浸出率达到92.4%。经过还原焙烧、硫酸浸出、氧化焙烧及氰化浸金,氰化尾渣渣量减少了38.8%。     

黄金洞焙砂浸金率低的原因分析

采用ＴＧ－ＤＴＡ热分析法、Ｘ射线衍射法对黄金洞焙砂的结构进行了研究,结果表明,黄金洞焙砂中仍含有８％的硫,并以单质硫,Ｆｅ１－ｘＳ,Ｆｅ１－ｘ－ｙＳ和ＦｅＳ２等形式存在。由于硫化物包裹的金不能暴露于氰化液中,以及这些物质的存在会大量消耗氰化过程中所需要的氧,因而导致黄金洞焙砂浸金率低。而此焙砂分别经３００℃,５８０℃焙烧处理后,焙砂氰化浸金率相应地提高到９１．７％和９３％。因此黄金洞焙砂浸金率低的原因是脱硫阶段氧化气氛不足,脱硫不完全,是焙砂欠烧而非过烧造成的。     

难冶金精矿烟尘中铁砷碳的脱除对氰化浸金的影响

以难冶金精矿烟尘为原料,研究了氢氧化钠浸出、硫酸浸出以及硫酸与氢氧化钠联合浸出对烟尘中砷、铁和碳脱除及氰化浸金的影响。结果表明:在氢氧化钠浓度为6mol/L时,砷、碳脱除率分别为99.66%和60.63%,金浸出率为58.90%,较直接氰化浸出仅提高4.60%,砷的有效去除不能有效提高金的浸出率。在硫酸质量分数为15%时,铁、砷和碳脱除率分别为33.65%、80.38%和12.59%,金的浸出率为80.40%,与氢氧化钠浸出相比,硫酸浸出解离铁能有效提高金的浸出率。烟尘分别经过质量分数为15%硫酸浸出后氰化浸金,两次2 mol/L氢氧化钠浸出和氰化浸金后,烟尘中铁、砷和碳的总脱除率分别为33.65%、95.63%和79.60%,渣率为80.33%。此时,金的总浸出率为91.90%,氰化渣中金的含量为3.31g/t。与烟尘直接氰化浸出相比金的浸出率提高37.60%。     

低温条件下全泥氰化炭浆浸金工艺的生产实践

结合生产现场工艺设备条件与氰化浸出理论，摸索出低温条件下氰化浸金工艺的生产经验和醋酸铅作为预浸剂的应用经验，达到延长选厂生产时间的目的，提高企业综合效益。     

Co-intensification of cyanide leaching gold by mercury ions and oxidant

The effects of mercury ions on gold cyanidation were studied. The results show that under low cyanide concentration, gold cyanide process is controlled by CN^? transfer, while at higher cyanide concentration, there forms passivation on gold surface. Therefore, chemical oxidation of gold in cyanide solution of higher concentration is controlled by surface reaction. Small quantity of additions of mercury ions bring about great increases in anodic gold dissolution rate, decreases the passivation and reduces the equilibrium activated energy. In addition, they also markedly change the effect pattern of cyanide concentration. Mercury ions show positive effects on cathodic reduction of oxygen and raise the rate of electrochemical step of the cathodic reduction of oxygen. Addition of a certain amount of hydrogen peroxide is confirmed to be an effective way for intensification of cathodic process on gold electrode. Active potential range and current peak on anodic dissolution are enlarged when being co-intensified with Hg²⁺ and hydrogen peroxide. Co-intensifying effect may be obtained and gold leaching rate is considerably increased on cyanide leaching of gold from gold concentrates.     

四川某低品位微细粒氧化金矿非氰浸出试验研究

对金品位为2.02 g/t的某低品位氧化微细粒金矿开展了全泥浸出提取金的试验研究。优选出非氰浸出剂CC-1,确定了相应工艺参数,在此基础上开展了3个粒级柱浸试验,对柱浸含金溶液进行了活性炭吸附试验,研究表明该矿石适宜于利用非氰浸出剂CC-1堆浸回收金。矿石磨至-200目占80%、矿浆液固比2:1、石灰用量3000 g/t原矿、CC-1浓度0.10%、浸出时间30 h条件下金浸出率92.75%;在石灰用量3000 g/t、CC-1浓度0.10%、浸出时间10 d时-10 mm矿样Au浸出率92.46%,浸出时间15 d时-20 mm及-30 mm矿样Au浸出率分别为91.49%、89.24%。采用CC-1作为浸出剂的含Au溶液活性炭吸附率为95.72%~97.11%。     

失效汽车催化剂中铂族金属的加压氰化浸出

研究了加压氰化法从失效汽车催化剂中选择性浸出铂族金属, 考察了加压氰化过程影响金属浸出率的各种因素. 实验结果表明 对200 g处理批量的小实验铂族金属氰化浸出率分别达到Pt98%, Pd99%, Rh96%; 千克级放大实验可完全重现小实验结果, 且该工艺也适应于其他类型失效催化剂的处理.     

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...     

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.     

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%。     

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...