Simultaneous extraction of gold and zinc from refractory carbonaceous gold ore by chlorination roasting process

A novel process based on chlorination roasting was proposed to simultaneously recover gold and zinc from refractory carbonaceous gold ore by using NaCl as chlorination agent. The effects of roasting temperature, roasting time and NaCl content on the volatilization rates of gold and zinc were investigated. The reaction mechanism and the phase transition process were also analyzed by means of SEM, EDS and XRD. The results demonstrated that under the optimal conditions of NaCl content of 10%, roasting temperature of 800 °C, roasting time of 4 h and gas flow rate of 1 L/min, the rates of gold and zinc were 92% and 92.56%, respectively. During low-temperature chlorination roasting stage, a certain content of sulfur was beneficial to the chlorination reactions of gold and zinc; and during high-temperature chlorination roasting stage, the crystal structure of vanadium-bearing mica was destroyed, and the vanadium-containing oxides were beneficial to the chlorinating volatilization of gold and zinc. Eventually, the chlorinated volatiles of gold and zinc could be recovered by alkaline solution.     

机械活化对从复杂硫化精矿中硫代硫酸盐浸取金的影响

采用机械活化提高复杂硫化矿CuPbZn中金的回收。研究研磨时间、球尺寸、球料比和球磨转速对金的硫代硫酸盐浸取的影响。在最优条件下（球磨时间1h,球尺寸20mm,球料比15/1,球磨速度600r/min）,矿石的非晶化度达到78%,颗粒尺寸从30μm下降到8um,比表面积从1.3m2/g增加到4.6m2/g,金的回收率从7.4%提高到73.26%。     

Bioleaching of refractory gold ore （ Ⅲ ）——Fluid leaching Jinya refractory gold concentrate by Thiobacillus ferrooxidans

A novel fluidized-bed reactor was designed and installed for bloleaching in a semi-continuous way, by which a process for biuleaching-cyanidation of Jinya refractory gold arsenical concentrate was studied. The arsenic extraction rate reaches 82.5 % after 4-day batch biooxidation of the concentrate under the optimized condition of pH 2.0, ferric ion concentration 6.Sg/L and pulp concentration 10%. And leached rate of gold in the following cyanida.tion is over 90%. The parameters of three series fluidized-bed reactors exhibit stability during the semi-continuous bioleaching of the concentrate.Armmic in the concentrate can be got rid of 91% after 6-day leaching. Even after 4 days, 82% of arsenic extraction rate was still obtained. The recovery rates of gold are 92 % and 87.5 % respectively in cyaniding the above bioleached residues.The results will provide a base for further commercial production of gold development.     

高砷难处理金精矿细菌氧化-氰化提金

通过在高砷金精矿中配入不同比例的低砷碳酸盐型金精矿,使其所含硫、砷及铁等主要矿物成分含量发生变化,研究给矿中铁砷摩尔比对难处理高砷金精矿细菌氧化一氰化浸出效果的影响.结果表明:含砷金精矿中铁砷摩尔比直接影响细菌预氧化的效果,同时也影响细菌的活性和溶液中铁砷摩尔比的变化,给矿中铁砷摩尔比越高,溶液中的铁砷摩尔比也越高,且随着给矿中铁砷摩尔比的增加,溶液中铁砷摩尔比的变化幅度加大,给矿中铁砷摩尔比介于4.6~2之间,有利于细菌预氧化和氰化浸出,铁、砷氧化率分别由6.14%和7.38%提高到89.90%和93.60%,金、银浸出率分别由64.18%和35.93%提高到97.78%和88.83%,较好地改善细菌氧化效果,稳定和优化细菌预氧化过程.     

Microbial oxidation of refractory gold sulfide concentrate by a native consortium

A defined mesophilic consortium including an iron oxidizing bacterium and a sulfur oxidizing bacterium was constructed to evaluate its ability for bioleaching a flotation concentrate from Andacollo mine in Neuquén, Argentina. Experiments were performed in shake flasks with a pulp density of 10% (w/v), using a basal salt medium containing ferrous iron at pH 1.8. The leaching solutions were analyzed for pH, redox potential (using specifics electrodes), ferrous iron (by UV-Vis spectrophotometry) and metal concentrations (by atomic absorption spectroscopy). The results showed that the consortium was able to reduce the refractory behavior of the concentrate, allowing 91.6% of gold recovery; at the same time, high dissolution of copper and zinc was reached. These dissolutions followed a shrinking core kinetic model. According to this model, the copper solubilization was controlled by diffusion through a product layer (mainly jarosite), while zinc dissolution did not show a defined control step. This designed consortium, composed of bacterial strains with specific physiological abilities, could be useful not only to optimize gold recovery but also to decrease the leachates metallic charge, which would be an environmental advantage.     

难冶金精矿焙砂和烟尘氰化浸金的差异（英文）

采用对比方法研究难冶金精矿焙砂和烟尘氰化浸金的差异。结果表明,直接氰化时焙砂和烟尘中金的浸出率分别为85.31%和54.30%。砷、碳含量及其存在形式是导致两者金浸出率差异的主要原因。对于NaOH预处理后氰化浸金,焙砂和烟尘中金的最大浸出率分别为87.70%和58.60%。有害元素的脱除、碱浸预处理过程中金的损失及铁氧化物的阻碍共同决定碱浸预处理后焙砂和烟尘中金的浸出率。经H₂SO₄预处理后,焙砂和烟尘中金的最大浸出率分别达到94.96%和80.40%。碳质物的影响是焙砂和烟尘中金浸出率差异的主要原因。基于这些差异,提出两种适宜工艺,焙砂和烟尘中金的浸出率分别达到94.91%和91.90%。     

难处理金矿预处理及金回收技术进展

随着优质金矿不断被开发消耗,难处理金矿占比不断地提高,从难处理金矿中回收金是金产业未来发展的必然趋势。本文简要分析了难处理金矿浸出困难的原因,介绍了焙烧氧化法、热压氧化法、生物氧化法、机械活化法、微波法5种预处理技术和氰化法、硫脲法、硫代硫酸盐法、卤素法、火法5种金回收技术的研究进展,并比较了5种预处理技术和4种湿法金回收技术的优势与不足。在此基础上对难处理金矿预处理和金回收技术的前景进行了展望。     

基于BP网络的臭氧和硫酸铁预氧化难选冶金精矿的氧化率预测

使用神经网络模型预测难选冶金精矿在臭氧和三价铁氧化条件下的铁浸出率。神经网络的输入结点是6个操作参数：臭氧浓度,三价铁离子浓度,液固比,氧气量,氧化时间,反应温度;神经网络的输出结点是难选冶金精矿中铁的氧化率。基于误差反向传播算法的多层前向神经网络使用33组实验值,采用6-11-1的网络结构经过反复训练得到一个良好模型,其相关系数R2为0.966。对神经网络与常规的多元线性回归2种模型进行对比。神经网络的计算结果表明：在所有操作参数中,温度是最重要的影响因素,臭氧为第二重要的影响因素。神经网络模型能够准确地预测黄金冶炼厂的难选冶金矿的预处理步骤中铁的氧化率,并可用来优化工艺参数。     

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(…     

碳质金矿的碳质物及生物氧化预处理研究现状

碳质金矿是一种重要的难处理金矿。研究发现,其碳质物主要包括元素碳、有机酸和烃类物质。在氰化浸金过程中碳质物可通过类活性炭的吸附方式将已溶解的金劫走。目前,已有的预处理方法主要有高温焙烧法、生物氧化法、化学氧化法、竞争吸附法、覆盖抑制法、微波加热法。生物氧化法因具有条件温和、流程简单、能耗低、环境友好等优点得以迅速发展。与生物氧化预处理有关的微生物主要有氧化亚铁硫杆菌、氧化硫硫杆菌、氧化亚铁钩端螺旋菌等化能无机自养菌。有关黄孢原毛平革菌、假单胞菌、多毛链霉菌在碳质物降解和钝化方面的研究也已展开。最后,分析了该技术存在的问题,并对其应用前景进行了展望。     

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%。     

锌粉置换回收锑精矿碱浸液中的金

锑精矿碱浸液是湿法处理锑精矿产生的中间产物含有少量的金,必须回收。以山东某公司锑精矿碱浸液为原料,经多种提取剂对比,采用锌粉置换回收其中的金。考察了锌粉用量、料液pH、浸出温度、时间的影响,得到的最佳工艺条件为:锌粉用量4.0 kg/m³,溶液pH=11,反应时间3 h,反应温度80 ℃,多批次试验金回收率88%。工艺过程简单,经济性可行,有效解决了资源浪费问题,为锑精矿碱浸液回收金提供了一条新的工艺。     

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.     

响应曲面法优化NaClO浸出贵州难浸金矿中的金

采用响应曲面法(RSM)优化NaClO浸出贵州难浸金矿中的金,探究了Na ClO浓度、温度、液固比、p H值4个因素之间的交互作用及其对金浸金率的影响,并进行了参数优化。RSM分析表明,各因素对金浸出率的显著程度为：NaClO浓度>液固比>p H>温度,NaClO浓度和p H之间的交互作用较为显著;得到较优的浸金工艺条件为：反应时间3 h,Na ClO浓度0.9 mol/L,初始pH=13.4,液固比8.2,温度27℃,在此条件下金的浸出率为93.4%。     

Mineralogical characterization and pretreatment for antimony extraction by ozone of antimony-bearing refractory gold concentrates

The mineralogical characterization of antimony-bearing refractory gold concentrates and the antimony extraction by ozone in HCl solution were investigated. The mineralogical study shows that there exist stibnite(Sb₂S₃), arsenopyrite(FeAsS), pyrite(FeS₂) and quartz in the concentrates, and the gold is mainly (67.42%) encapsulated in sulfides. The antimony extraction by ozone in hydrochloric acid was employed and the influences of temperature, liquid/solid ratio, HCl concentration and stirring speed on the extraction of antimony were investigated. High antimony extraction (93.75%) is achieved under the optimized conditions. After the pretreatment by ozone, the antimony is recovered efficiently and the gold is enriched in the leaching residue.     

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。     

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。     

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...     

微波焙烧预处理难浸含金硫精矿

对难浸含金硫精矿进行微波焙烧,考察微波功率、矿量(即样品质量)和焙烧时间对样品质量损失率和浸出率的影响。结果表明:当微波功率为16 k W、焙烧时间为50 min、矿量为900 g时,样品质量损失率可达28.12%,浸出率可达71.56%,较原矿直接碘化浸出率(9.82%)有了大幅提高。利用XRD和SEM技术分析焙烧前后样品的成分和表面形貌,微波焙烧后的样品较原矿更为松散、多孔,更利于浸出。     

XPS characteristics of sulfur of bio-oxidized arsenic-bearing gold concentrate and changes of surface nature of bio-oxidation residue

During bio-oxidation of sulfides, the chemical state change of sulfur is a complex and key factor. It is not only an indicator of the extent and intensity of the bio-oxidation, but also controls the property of bio-leaching medium and the period of oxidation. The chemical state of sulfur in sulfides oxidized by leaching bacteria was studied with XPS. Sulfide minerals in the arsenic-bearing gold concentrate consist of pyrite, arsenopyrite, chalcopyrite, galena, sphalerite and so on. In order to probe the pattern of the chemical state change of sulfur in the bio-oxidation residue of arsenic-bearing gold concentrate, the structure of the grains, and the surface nature of the residue, XPS test was carried out through different sputtering duration. The study of XPS clearly shows that: sulfides is progressively oxidized from the surface of minerals to the core by leaching bacteria; the chemical valence of sulfur changes from S^2- or [S2]^2- to [SO4]^2- ; sulfur in the core is in a reduction state, S^2- or [S2]^2- , but exists in an oxidation state S^6 on the surface; due to the chemical state change of sulfur, mineral phase of the bio-oxidation residue is also changed(sulfides inside, while sulfates outside); the layered structure is found in the grains of the bio-oxidation residue.