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 ozonein 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 inhydrochloric acid was employed and the influences of temperature,liquid/solid ratio,HCl concentration and stirring speed on theextraction of antimony were investigated.High antimony extraction(93.75%)is achieved under the optimized conditions.After thepretreatment by ozone,the antimony is recovered efficiently and the gold is enriched in the leaching residue.

Pretreatment and thiosulfate leaching of refractory gold-bearing arsenosulfide concentrates

A hydrometallurgical process for refractory gold-bearing arsenosulfide concentrates at ambient temperature and pressure was presented, including fine grinding with intensified alkali-leaching （FGIAL）, enhanced agitation alkali-leaching （EAAL）, thiosulfate leaching and displacement. Experimental results on a refractory gold concentrate showed that the total consumption of NaOH in alkaline leaching is only 41% of those theoretically calculated under the conditions of full oxidization for the same amount of arse- nides and sulfides transformed into arsenates and sulfates, and 72.3% of gold is synchro-dissoluted by thiosulfate self-generated during alkaline leaching. After alkaline leaching, thiosulfate leaching was carried out for 24 h. The dissolution of gold is increased to 91.9% from 4.6% by cyanide without the pretreatment. The displacement of gold by zinc powder in the solution gets to 99.2%. Due to an amount of thiosulfate self-generated during alkaline leaching, the reagent addition in thiosulfate leaching afterwards is lower than the normal.

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 S2- or [S2]2- to [SO4]2-; sulfur in the core is in a reduction state, S2- or [S2]2-, but exists in an oxidation state S6+ 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.

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 bioleaching in a semi continuous way, by which a process for bioleaching 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 6.5?g/L and pulp concentration 10%. And leached rate of gold in the following cyanidation is over 90%. The parameters of three series fluidized bed reactors exhibit stability during the semi continuous bioleaching of the concentrate. Arsenic 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.

Mode of Occurrence of Gold in Micro-Disseminated Strata-Bound Sb-Au Deposits, Qinling Region, China

Optical studies, backscattered electron images, secondary ion spectrometry and highprecision transmission electron imaging demonstrate that gold is strongly correlated with arsenic on a microscopic scale in the sediment-hosted micro-disseminated gold deposits. The positive correlation between Au and As, despite varying Au/As ratio, is persistent in arsenian pyrite overgrowths and arsenopyrite. It is found that gold occurs in native state as submicro beads in association with arsenic-bearing sulfides. The extremely small grain size of gold may indicate a very rapid process of deposition.

甘肃某含砷锑难处理金矿选矿试验研究

针对甘肃某含砷锑难处理金矿现场浮选过程中选别指标低的问题,开展了矿石工艺矿物学研究。在此基础上,进行了重选、浮选、中矿再磨再选、尾矿氰化浸出等试验研究,最终形成了尼尔森重选—中矿再磨再选—尾矿氰化浸出的联合工艺流程。采用该流程,精矿金品位可达50.05 g/t,金综合回收率可达93.89%。较单一浮选工艺流程,该联合工艺流程的金回收率提高30百分点以上,为现场工艺流程改造提供了可行的技术方案。

某高硫含砷低品位金精矿选矿工艺研究

为提高某高硫含砷低品位难处理金精矿选别指标,分别采用尼尔森离心重选和高效旋流器分级工艺进行金精矿分选试验研究。试验结果表明:在保障金精矿冶炼净返系数等级的基础上,采用试验条件为重力倍数60G、反冲洗水量4 L/min、给矿速度400 g/min的尼尔森离心重选工艺,可获得金品位为30.97 g/t,金回收率为19.97%的重选精矿;采用试验条件为矿浆浓度20%、沉砂口直径22 mm的高效旋流器分级工艺,可获得金品位为26.02 g/t,金回收率为12.50%的溢流。尼尔森离心重选、高效旋流器分级工艺可使最终精矿产品的金回收率分别提高1.6%~1.9%和0.7%~1.0%。考虑到尼尔森离心重选工艺成熟工艺少、后期投资高,故推荐高效旋流器分级工艺进行该金精矿分选试验,以提高该金精矿利用价值。

综合利用含锑砷金精矿关键集成技术试验研究

针对某含锑砷金精矿,通过直接氰化试验、两段焙烧氰化试验、直接氰化—浮选回收锑—浮选尾矿两段焙烧氰化试验等工艺技术进行试验研究。结果表明,采用一级直接氰化、二级氰化尾矿浮选富集锑精矿、三级为锑浮选尾矿两段焙烧氰化关键集成技术方法,含锑含砷金精矿直接氰化金、银浸出率分别为31.22%、85.19%,氰化尾矿浮选产出锑含量为38.80%的锑精矿,精矿产率为10.50%,锑回收率达到90.94%,锑浮选尾矿采用两段焙烧氰化金、银回收率分别达到90.07%、52.70%,该关键集成技术方法使金、银、锑的综合回收率分别达到93.56%、92.99%、90.94%,显著提高了有价金属资源的综合回收效果,实现了含锑砷金精矿资源的高值化、资源化利用。

塔吉克斯坦某难处理金精矿低温二段焙烧预处理试验研究

高砷高硫金精矿中的金矿物被毒砂(As_(2)O_(3))和黄铁矿(FeS_(2))包裹,直接氰化浸出浸出率较低,其预处理工艺一直是研究关注的热点。本文以塔吉克斯坦高砷高硫金精矿为研究对象,在热重分析和热力学分析的基础上采用二段焙烧法进行预处理,脱除大部分砷、硫、有机碳等有害杂质,并对工艺参数进行优化。试验考察了添加剂及焙烧温度、时间对金精矿中碳、硫、砷脱除率的影响,并在最终焙烧产物物相分析基础上进行了焙烧-氰化浸出验证试验,得到以下主要结论。一段焙烧采用弱氧焙烧气氛焙烧脱砷,不需使用添加剂,较优工艺参数为焙烧温度500~550℃、焙烧时间2 h;二段焙烧采用富氧气氛焙烧脱硫,较优工艺参数为焙烧温度650~700℃、时间2 h;在上述较优工艺参数下的焙烧-氰化浸出的碳脱除率、硫脱除率和砷脱除率分别为91.16%、96.93%和92.52%,金浸出率达到95.30%。该结果相对于直接氰化浸出,金浸出率提高了20%,一定程度上实现了资源的高值化利用,为难处理金精矿高效提金提供了技术依据。

矿浆电解法炼锑的工业实践

高砷锑金精矿的湿法处理是目前锑行业内普遍存在的问题,矿浆电解技术是一种有效且工艺流程短的处理方法,并有相应的工业应用。文章综述了高砷锑金精矿矿浆电解反应原理,介绍了工业试验的现状,以及试验运行中存在的问题和在产业化推进过程中需要改进的建议。

难处理含金硫精矿的焙烧氧化-硫代硫酸盐浸出

为了提高难处理含金硫精矿中金的浸出率,采用同步热分析仪研究在马弗炉中焙烧氧化难处理含金硫精矿的最佳条件,通过优化实验确定硫代硫酸盐浸出的最佳工艺参数。结果表明:在马弗炉中焙烧氧化难处理含金硫精矿最佳条件为在700℃温度下焙烧2 h,难处理含金硫精矿硫的去除率可达94.7%。焙烧后,金的浸出率大幅度提高。使用组成为0.03 mol/L CuSO4、1.0 mol/L NH3·H2O、0.3 mol/L Na2S2O3、0.1 mol/L(NH4)2SO4和0.3 mol/L Na2SO3的硫代硫酸盐溶液作为浸出剂,最佳浸出工艺参数如下:浸出时间18 h、液固比2:1、振荡速度250 r/min、浸出温度50℃。在此浸出工艺参数下,金浸出率达71.2%。

高砷硫金精矿提金研究

广西贵港金精矿含15%～22%As,并含碳、铅等不利于氰化的元素,金直接氰化率8%～36%。采用催化氧化酸浸法预处理后,金氰化率可达92%～98%,氰渣浮选后精矿的金总收率达97%～99%。预氧化工艺在中温自热、低压、低酸操作条件下进行,废渣、废液符合环保要求。多批次小型试验及扩大试验结果表明该工艺技术指标稳定,经济可行。

高砷锑金精矿矿浆电解生产实践

由北京矿冶研究总院设计的年产1 000t锑的高砷锑金精矿矿浆电解生产线于2013年5月投料生产。工业实践表明,对不同品位物料,锑浸出率大于98%、砷浸出率小于1%,阴极锑含砷约0.3%,金几乎全部富集于浸出渣中,绝大部分砷和硫均留置在渣中,从根本上避免了大量砷碱渣的产生和低浓度SO2的危害。

广西金牙难浸金矿的工艺矿物学研究

为了给含砷金矿的提金工艺流程提供理论依据,对广西金牙金矿的矿石开展了工艺矿物学研究.该矿是典型的含砷难浸复杂金矿,矿石含Au为6.28 g/t,含Ag为1.37 g/t.As的质量分数为0.58%,S的质量分数为3.10%,C的质量分数为1.76%,其中有机碳的质量分数为0.21%.金精矿含Au为52.61 g/t,含Ag为6.00 g/t.As的质量分数11.32%,S的质量分数为29.32%,C的质量分数为0.35%.矿石中的主要金属矿物为毒砂、黄铁矿,其次有方铅矿、闪锌矿和黄铜矿等.载金矿物主要有毒砂、黄铁矿;金的赋存形态为次显微金;矿石的有害组分为砷、碳质和黏土矿物.含砷矿物是以毒砂、雄黄、雌黄形式出现.矿石的特征结构构造为细粒状结构和微细浸染状构造.

湖南某难处理金矿的加压预氧化-氰化浸金试验研究

针对湖南某难处理金精矿进行预处理技术研究.该矿含砷(质量分数)为11.28%,金的直接氰化浸出率为21.91%.矿石中的砷以毒砂形式存在.载金矿物为毒砂和黄铁矿等硫化物,金为微细浸染型被毒砂和黄铁矿包裹.通过加压预氧化,对矿石进行氰化浸金试验研究.加压氧化最佳条件为初始酸度1 mol/L,木质素磺酸钠5 g/t,硝酸硫酸比7∶1,氧压0.6 MPa,搅拌速度300 r/min,时间100 min,温度100℃,矿浆浓度20%.试验表明经过加压试验后,金的氰化浸出率达到90.87%,与未预处理相比提高了68.96%,达到了较好的试验效果.

碱性硫化钠浸出含锑金精矿过程中金锑行为

考察碱性硫化钠体系浸出某难处理含锑金精矿过程中金锑分离和综合回收,探讨浸出条件对金和锑浸出的影响,重点对该体系中金的浸出机理进行考察。结果表明,在硫化钠80g/L、氢氧化钠20g/L、常温条件下锑的浸出率达到95.3%,有10.3%的金伴随浸出,同时揭示了金浸出率随电位及温度变化的规律。

含砷难处理金矿的磁场强化氰化浸出试验研究

含砷金矿是主要难处理金矿类型之一 ,该类金矿石常规氰化浸出率一般很低。通过在浸出过程中引入磁场进行强化 ,明显促进了金的浸出。试验结果表明 ,在相同浸出条件下 ,磁场强化浸出可比常规氧化浸出提高浸出率 33.0 8个百分点 ;在减少氰化钠用量及缩短浸出时间的情况下 ,磁场强化浸出仍可使浸出率提高 2 8.37个百分点。

高砷锑金精矿矿浆电解连续扩大试验

采用矿浆电解技术对高砷锑金精矿进行半工业试验。结果表明,锑的回收率达97%以上,金几乎全部富集于渣中,砷和硫绝大部分留置于渣中,从根本上避免了砷害和SO2危害。盐酸和电能消耗较少,每吨锑的盐酸消耗量为286kg,总电耗为3 389kWh,其中电解电耗1 318kWh。

广西某难处理金矿金的赋存状态研究

研究了广西某难处理金精矿的化学成分、矿物成分、粒度分布和金的赋存状态。研究表明金的品位为 1 44g/t,银的品位为 35g/t,砷含量为 2 2 5 %。金、银含量在各粒级中分布不均匀 ,不同粒级金、银品位不同 ,在 <74μm粒级中金的品位最高达 1 5 4 0g/t,银的品位为 45g/t,砷为 2 4 6%。金的载体矿物主要是毒砂 ,其次是黄铁矿 ,金以超微细粒和次显微金包裹于毒砂和黄铁矿中。

富砷锑金矿石浮选分离试验研究

对某富砷锑金矿石进行了浮选分离试验研究。在弱酸性条件下,以硝酸铅作活化剂,以丁基铵黑药作捕收剂,采用浮锑抑砷工艺,最终获得含锑63.18%、回收率95.05%的锑精矿和含金9.02 g/t、含砷9.32%、金回收率为65.06%、砷回收率为64.97%的金砷混合精矿。