氰化提金工艺的新进展

评述了近年来氰化提金工艺的新进展,重点讨论了强化氰化浸出、吸附浸出及富氧浸出工艺的特点、现状及今后开发的重点。     

加压氧化—氰化浸出法从氰化尾渣中回收金

山东某金矿为高硫多金属矿床，矿石中的伴生元素为Ag、Fe、Cu、Pb、Zn、S等元素，该矿采用浮选法将矿石中的金富集，生产的金精矿再磨后直接氰化浸出。生产实践表明，在氰化尾渣中金的品位高达3～4g／t，这不但浪费了国家资源，还影响了企业经济效益的提高。本文运用加压氧化-氰化浸金的原理，采用一种加压氧化-氰化浸金设备，对氰化尾渣进行了加压氧化-氰化浸金工艺试验。     

乌干达某金矿选矿试验研究

东非乌干达Busia金矿为中等硫化物石英脉型含金矿石,通过“重选-重选尾矿浮选”、“重选-重选尾矿全泥氰化”和“重选-重尾浮选+浮选精矿氰化”三种工艺流程的对比,最终确定用“重选-重尾全泥氰化”或者“重选-重尾浮选+浮选精矿氰化”工艺来回收金。其中“重选-重尾全泥氰化”工艺得到：在磨矿细度-320目占80%,氰化时间24小时,金回收率92.23%；“重选-重尾浮选+浮选精矿氰化”工艺得到：再磨细度-400目占85%,氰化时间48小时,精矿浸出率90.07%,金回收率85.02%。     

张家口金矿石充氧氰化浸出研究

对张家口金矿石进行充氧氰化浸出，使矿浆的溶解氧浓度成倍增加，可以克服常用规机械搅拌氰化浸出在起始阶段存在的矿浆溶解氧供给不足，加快金的溶解速度，缩短浸出时间，充氧氰化浸出１２ｈ，浸出率可达９４．５８％，而常规机械搅拌氰化浸出２４ｈ，其浸出率仅有８６．１８％。     

强化氰化浸出的机理探讨

黄金氰化浸出过程中，溶解氧起着使反应向生成物方向移动和加快反应速度的作用。在常规机械搅拌自然卷入空气的氰化浸出中，由于电化反应、吸附、硫化物氧化反应 等耗氧反应和扩散阻障，溶解氧供给经常处于“饥饿”状态。因此，在工业生产和研究中多采用充空气、充氧、加过氧化物和充加压空行的方法。本文应用物理化学、表面化学及胶体化学和溶液化学的理论分析讨论了氰化过程，从理论上进一步肯定了提高矿浆溶解氧浓度改善浸出指标     

药剂预处理金精矿氰化工艺研究与实践

对河台金矿金精矿氰化工艺，通过采用药剂X预处理的方法，提高了氰化浸出速度，优化了相关作业条件，增加了氰化处理能力。同时该法使用后，降低了材料消耗与处理成本，提高企业经济效益。     

新疆难处理金精矿焙烧预氧化—氰化提金工艺试验研究

对新疆某难处理金精矿进行工艺矿物学研究和焙烧预氧化—氰化提金工艺研究。试验结果表明,通过对该金精矿进行焙烧预氧化处理后,氰化金的回收率达91.42%,比常规氰化回收率提高了50.60%。这对于该类型金矿资源的充分利用有着重要意义。     

浮选金精矿充氧氰化浸出研究

以黑土沟浮选金精矿为研究对象,探索充氧对氰化浸出速度的影响。研究结果表明,充氧氰化浸出的速度几乎比常规氰化浸出快3倍,比充空气氰化浸出也快出许多。常规氰化过程中,特别是对于大容积浸出槽,矿浆严重缺氧,导致浸出速度减缓。充氧可以克服矿浆缺氧现象,并成倍提高溶解氧浓度,从而提高氰化浸出速度。     

用搅拌磨湿法超细磨得金精矿的氰化浸出工艺研究

研究了搅拌磨湿法超细磨得金精矿（-20μm＞97%）的氰化浸出工艺,探讨了影响金精矿氰化浸出的因素,并与常规滚动式球磨机湿法磨得金精矿氰化浸出指标进行对比。结果表明,通过优化氰化浸出各种因素,可大大缩短氰化浸出时间,氰化钠和碱石灰用量分别降低了1 kg/t、1.47 kg/t,金的浸出率提高了0.49个百分点,浸渣含金量降低了0.21 g/t,效果显著。     

金回收技术的研究

银洞坡金矿选一厂氰化浸出过程中存在着金浸出率低、泡沫外溢造成的金的流失和氰化尾渣含泥高严重影响氰化尾渣综合回收等主要问题。针对这些难题,提出并研究了磨矿与药剂组合的新工艺,使浮选金精矿品位由39 43g/t提高到53 19g/t,金浮选-氰化浸出总回收率由80 92%提高到90 54%;解决了所存在的三大难题。     

青海某难选冶金矿提金工艺试验研究

青海某金矿为中硫、含砷和碳的微细粒难选冶金矿。在查明矿石物质组成的基础上，对矿石进行了选矿方法、工艺条件及流程方案试验研究，确定采用浮选—重选—精矿焙烧—氰化浸出提金工艺，获得了满意的技术经济指标。该成果已被建厂设计采用，建成投产后经济效益较好。     

硫脲浸金新工艺的研究

近年来，用硫脲对含金矿石进行无毒浸出－同步电解提金是人们研究的热点之一。本文作者系统地研究了硫脲电解浸金的影响因素，考查了含金贵液电解时硫脲的再生情况，并与传统的氰化浸金进行了对比，得到了较好的结果，对我国黄金选矿具有一定的借鉴作用。     

Solvent extraction of gold(I) from alkaline cyanide solutions by the cetylpyridinium bromide/tributylphosphate system

This paper explores the solvent extraction of KAu(CN)₂ from alkaline cyanide solutions using quaternary ammonium cetylpyridinium bromide (CPB) as an extractant with the addition of tributylphosphate (TBP) as a modifier. It also investigates the influence of several variables on gold extraction, including the molar ratio (β) of CPB to Au(I), the volume percentage of TBP (φ_TBP), NaCl concentration, phase ratio (AQ/ORG), and gold concentration in the aqueous phase. The results indicate that nearly all of the Au(I) (>98%) was transferred from the aqueous phase into the organic phase when β = 1 and φ_TBP = 30 vol%. We also carried out experiments for treating 20 L synthetic aurocyanide solution containing 10 mg/L Au(I) with column-shaped extraction equipment. The results demonstrated the recovery of more than 94.5% of Au(I) after two successive stages of extraction, and the Au(I) concentration in the raffinate was less than 0.5 mg/L. KSCN solution was used to strip the gold-loaded organic phase, and about 90% of Au(I) could be reverse extracted into the aqueous phase when the KSCN concentration reached 3.0 mol/L. The results obtained in this paper establish that the CPB/TBP extraction system has potential for practical application in the extraction and separation of gold from alkaline aurocyanide solutions.     

The novel application of ferricyanide as an oxidant in the cyanidation of gold and silver

Low gold and silver extractions have often been observed in the traditional gold–silver cyanidation process. The reactivity and availability of oxidant is a potential limitation for gold and silver dissolution in cyanide solution, especially in heap leaching operations. The oxidant reactivity seems to have more of an effect on silver extraction due to the different mineralogy of gold and silver in the ores. For example, the occurrence of silver sulfides such as acanthite (Ag₂S) typically results in low overall silver extraction which may be due to slow kinetics of oxygen reduction on the acanthite mineral. The leaching of metallic gold and silver sulfide in the novel ferricyanide–cyanide leaching medium was investigated. The potential application of ferricyanide as a supplemental oxidant in gold–silver cyanidation process was proposed and the possible reagent regeneration methods were discussed.     

难处理金矿热压氧化工艺研究

本试验以国内某超细微难处理金矿为研究对象,开展酸性热压氧化工艺研究;分析了温度因素对硫化矿物氧化、元素迁移和金氰化浸出等的影响。试验结果表明,通过温度变化可影响黄铁矿和砷黄铁矿氧化反应速率,进而对S、Fe和As元素的迁移状态产生影响。反应温度越高黄铁矿和砷黄铁矿氧化越彻底,有利于金的氰化浸出;完全氧化后金的浸出率约为94%。浮选金精矿中的黄铁矿、砷黄铁矿逐渐氧化转变为砷酸铁盐、铁砷硫硅等多元素共沉物质,未发现有碱式硫酸铁或铁矾物相,反应生成的各种沉淀产物对浸出率无显著影响。      

某浮选金精矿的氰化浸出工艺研究

研究了某浮选金精矿的氰化浸出过程，考察了金精矿粒度、氰化钠浓度、氧化钙浓度、浸出时间及液固比等对该浮选金精矿氰化浸金率的影响。在最佳浸出条件下，其氰化浸金率可达到97％以上。     

The use of ion exchange resins for the treatment of cyanidation tailings part 1––process development of selective base metal elution

This work investigates the use of oxidative acid eluents for the elution of base metals from strong base ion exchange resins. Eluents composed of a mixture of H₂O₂ and H₂SO₄ were tested for eluting base metals from resins loaded with mixtures of base and precious metal cyanides. This process removed 100% of Cu and Zn loaded on the resin, without affecting the precious metal loading. It was found that copper could be removed separately from the other base metals. The elution technique was not effective for removing iron from the resin. Cyanide associated with base metals was recovered as NaCN. Some oxidation of cyanide was noticed, subject to the elution conditions.This oxidative acid elution process could be used in commercial operations for the selective elution of base metals from a strong base ion exchange resin bed operating in alternative adsorption/base metal elution cycles. Thus, virtually all metal cyanide species could be recovered from cyanide leached solutions or slurries to give relatively clean tailings without compromising precious metal recovery efficiency. The process also caters for cyanide recovery and recycling.     

提金尾渣的再利用

对于黄金矿山来说，氰化尾渣中尚有可回收的金、银、铜、铅等有价金属元素。综合回收这些金属，既可以为矿山创造经济效益，同时减少了尾矿对环境的污染，是宝贵的二次资源。     

The effect of anaerobic processes on the leachability of an arsenopyrite refractory ore

Gold is commonly liberated from sulfide minerals via oxidative destruction techniques. To circumvent the formation of sulfuric acid and to reduce the amount of energy required for these processes two alternative anaerobic processes based on sulfate reducing bacteria are investigated for arsenopyrite in this study. The first alternative, “bio-reduction” is expected to alter the structure of arsenopyrite via reduction of the mineral-sulfur to hydrogen sulfide, yielding a sulfur depleted residue that probably contains the gold. The second alternative “anaerobic oxidation” focuses on the mineral-arsenic which under anaerobic conditions can be oxidized to arsenite and subsequently precipitates as orpiment, which may contain the gold.Both alternatives were investigated with gas lift loop reactor experiments performed at pH 5 and 35 °C. These experiments showed that sulfate reducers were able to reduce sulfate from the reactor fluid, but that they were not able to use arsenopyrite as an electron acceptor (bio-reduction) or donor (anaerobic oxidation) under the selected conditions. As a result the gold leachability of the ore concentrate was not improved. To make the mineral more accessible for the leach solution the solubilization of lattice constituents from arsenopyrite that can be biologically reduced/anaerobically oxidized, should be stimulated. In addition, the concentration of arsenite needs to be limited to preserve the activity of sulfate reducing bacteria.     

金矿氰化浸出助浸剂的研究

介绍了柠檬酸作氰化浸出助浸剂,分别对罗山金矿浮选精矿、鹿尔坝金矿焙砂、鹰嘴山北金矿进行助浸试验的结果。研究结果表明,柠檬酸作为助浸剂可改善氰化浸出环境,提高浸出速度,缩短氰化浸出时间,降低氰化物用量。