含氰污水的净化处理

<正> 金银氰化厂及堆浸厂的氰化溶液在循环使用一段时间后,当溶液中铜、锌及铁等的氰络合物及硫代氰酸盐的浓度超过容许值时,就会降低氰化溶液对金、银的溶解能力,因此需要排放部分氰化溶液。另外氰化尾矿浆及堆浸残渣中都含有大量的氰化物。氰化厂排出的污水中,氰化物含量约为     

夹皮沟金矿选矿工艺改造的比选

针对夹皮沟金矿选厂目前全泥氰化炭浆提金生产工艺产生的氰化尾渣和含氰废水处理污泥危害性大、经济效益低的问题,通过比较分析全泥氰化—无害化处理、浮选、重选—浮选、重选—浮选—金精矿氰化4种工艺的优缺点,从金回收率、投资费用、技术可靠性、安全环保等方面考虑,推荐采用全泥氰化—无害化处理和重选—浮选—金精矿氰化两种工艺作为原工艺改造的方向,并应结合实际进行优化。     

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。     

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。     

小型全泥氰化厂生产实践

本文介绍一座工艺流程简单、投资少、见效快、技术指标较好、无含氰污水排放、日处理量20吨的全泥氰化厂。该厂为小型全泥氰化厂的建设、生产及含氰污水处理提供了十分有益的经验。     

氰化浸出工艺中浸出槽串浆管径的选择

氰化浸出提取金银是目前国内外处理金银矿物的常用方法.氰化法提金工艺成熟,技术经济指标较理想.浸出槽是氰化浸出工艺中浸出反应的主要设备,但对浸出槽串浆管径的研究却很少.笔者就串浆管径的选择进行分析,以供氰化厂设计浸出槽时作参考.     

团结沟金矿金的赋存状态及工艺性质的研究

一.前言团结沟金矿氰化厂投产以来,由处理地表氧化矿逐步过渡处理较深部以原生矿为主的混合矿,其氰化浸出率逐年下降。为了弄清难浸的原因和提高金的氰化浸出率,对矿石的物质组成、金的赋存状态和工艺性质以及选冶过程中金的行为进行了较详细的研究。     

一种有效的炭解吸和全电解联合设备

在黄金生产全泥氰化炭浆厂中,最后一段流程的关键设备是解吸电解设备。1987年5月红花沟金矿150t/d炭浆厂建成,适用于全泥氰化炭浆法提金工艺的解吸电解设备也试制成功。其工艺流程如图1.500kg载金炭由贮炭槽     

金渠金矿氰化厂提高金洗涤率的实践

通过对生产中提高金洗涤率的技术改造和生产实践,完善了氰化厂的洗涤系统,提高了洗涤率,提高了经济效益.     

氰化法提金的工艺最佳化研究

很多科研人员在他们致于于改进金矿石的处理工艺时，经常谈到氰化法提金过程中某些参数的最佳效果问题，根据操作条件和金矿石物成分的不同，他们获得的结果也是各种各样的，虽然加拿大的氰化厂中近年提金工艺已得到明显改进，但仍在研究工艺的最佳化问题，为此，人们已进行过很多研究，以说明氰化提金某些重要参数作用，并为金的处理工艺研制出一种有效的药制制度，本文介绍了包括用两种等难浸矿石进行的实验室研究结果，并通过一种     

Recovery of copper cyanide from waste cyanide solution by LIX 7950

The use of the guanidine extractant, LIX 7950, to extract copper cyanide from waste cyanide solution has been investigated. Copper extraction is favorable at low pH while a high cyanide to copper molar ratio tends to suppress copper loading. The extractant also strongly extracted zinc and nickel from cyanide solution, but the extraction of iron was poor. The presence of thiocyanate ion significantly depressed copper extraction, but thiosulfate ion produced negligible impact on copper extraction. The preferential extraction of metal cyanide species to free cyanide has been noticed. The potential application of the recovery technique as a pre-concentration step for the treatment of cyanide effluent has been suggested, by which copper can be extracted and concentrated into a small volume of solution and the barren cyanide solution recycled to the cyanidation process.     

氰化尾渣中金银综合回收试验研究

金银共伴生矿物是重要的贵金属资源,其高效综合利用一直是研究的热点及难点。本文以云南某金银铁共伴生矿氰化尾渣为研究对象,工艺矿物学研究结果显示,银主要以类质同象的形式赋存于铁锰氧化物、尤其是铅硬锰矿中,直接氰化浸出的方式难以获得良好的浸出效果,只有通过破坏包裹矿物的晶体结构才能得到有效回收;通过系统研究,提出了尾矿“酸浸预处理-氰化浸出”工艺技术路线,获得了良好的工艺指标,金、银浸出率分别为55.73%和75.35%,有效回收尾矿中的金和银,对该尾矿资源综合利用提供了技术支撑,同时也对复杂难处理金银矿的高效利用提供了有益参考。     

Cyanide recovery in hydrometallurgical plants: use of synthetic solutions constituted by metallic cyanide complexes

Cyanide compounds are widely used in gold ore processing plants in order to facilitate the extraction and subsequent concentration of the precious metal. Owing to the high cyanide concentrations employed in gold processing, effluents generated have high contents of free cyanide as well as metallic cyanide complexes, which lend them a high degree of toxicity. The process under study, developed in laboratory scale with the use of a distillation apparatus, consists of highly decreasing the pH of the solution by adding sulfuric acid. Thus, the cyanide present in either free form or as a metallic complex is made volatile and the resulting cyanide gas is absorbed in an alkaline solution for reutilization. This work aims at recognizing the chemical relations between the cyanide and metals during distillation. The regeneration of cyanide from gold processing proved to be a viable procedure. Cyanide recoveries pointed to the fact that if a method for reutilization of cyanide contained in mining effluents is employed, the precious metal processing will become more efficient. Also, the environmental conditions in the area of the operation will be improved.     

Biological treatment of cyanide by natural isolated bacteria (Pseudomonas sp.)

Biological treatment is a proven process for the treatment of mining effluents such as tailings, wastewaters, acidic mine drainage etc. Several bacterial species (Pseudomonas sp.) can effectively degrade cyanide into less toxic products. During metabolism, they use cyanide as a nitrogen and carbon source converting it to ammonia and carbonate, if appropriate conditions are maintained. In this study, nine strains of Pseudomonas sp. were isolated and identified from a copper mine. Two (CM5 and CMN2) of the nine bacteria strains were used in a cyanide solution. Some important parameters in the biological treatment process were tested and controlled: pH, cell population and CN⁻ concentration. Tests were conducted to determine the effect of the type of bacterial strains on the treatment of cyanide. Laboratory results indicated that biological treatment with Pseudomonas sp. might be competitive with other chemical treatment processes. This paper presents the results of an investigation of a biological treatment system for cyanide degradation in a laboratory batch process.     

高浓度含氰废水处理的工程试验研究

采用降氰预处理与改进因科法联合处理工艺,对某公司含氰废水的工程试验研究。考察了改进因科法处理中的pH值、焦亚硫酸钠加入量、反应时间、硫酸铜投加量对除氰效果的影响;降氰预处理中的药剂投加量和反应时间对降氰效果的影响,并得到了最佳反应条件。在最佳反应条件下,利用联合处理工艺对含氰废水进行小型序批试验,结果表明,处理出水中总氰浓度、COD及pH值均达到排放标准的要求。     

氯化法提金工艺技术研究进展

氯化提金是一种重要的无氰提金工艺方法,因为其具有浸出率高、且不使用氰化物的优势而越来越被重视。2010年以来氯化提金研究呈现明显增加趋势,且液氯化提金研究文献更多。氯化法提金工艺诞生不久,氰化法相继问世,当时由于材料工业比较落后,氯化法面临的腐蚀问题限制了其发展,随之被氰化法所替代。2000年以来,材料科学得到了迅猛发展,先进的耐腐蚀材料为氯化法扫清了障碍,随着人类社会的发展,工业生产所带来的生态平衡和环境保护问题超过了工业发展的本身,因此,氯化提金工艺将会得到更大的发展。      

氰化尾渣综合回收利用工艺优化研究

鉴于国家环保政策的调整,环保部等三部委已将“采用氰化物进行选矿过程中产生的氰化尾渣”定为危险废物,而即将执行的新环保税法将对危险废物征收1000元/吨的环境保护税,氰化废物的经济消解是未来氰化厂主要研究课题和发展方向。山东某氰化尾渣中含有一定品位的铅、锌、铜,该氰化尾渣不进行回收处理,不仅会造成资源的浪费,也会对环境造成污染。如果对这部分多金属进行回收,会产生良好的经济效益。从氰化尾渣中回收有价金属元素不同于从原矿中回收有价金属元素,回收其中的有价元素较困难。为解决此问题,根据该氰化尾渣的性质,采取代表性的尾渣矿样,拟采取确定合理的选矿工艺回收尾矿中的有价金属,采用先浮铅锌再浮硫的优先浮选工艺流程试验,该试验流程能够取得较好的有价金属元素回收效果。结果表明,在原矿含铅2.62%,含锌0.98%,含铜0.19%的条件下,采用一粗两精两扫的浮选工艺流程选择铅锌,一粗两精两扫选选硫流程,处理改氰化尾渣,获得了含铅品位19.77%,回收率21.50,锌品位19.69%,回收率71.07%,铜含量1.43%的铅锌精矿,硫品位45.27%,回收率35.92%的硫精矿。新工艺流程工艺指标更优、药剂成本更低、工艺更简洁,不仅铅锌精矿中铅、锌均得到有效的回收,其中伴生硫的指标也得到了改善,为氰化尾渣中铅锌铜硫的回收提供了方案。     

Effects of free cyanide and cuprous cyanide on the flotation of gold and silver bearing pyrite

At gold and silver mineral processing plants, cyanide species are always present in the process water recycled to flotation circuits, despite the cyanide destruction process. The effect of cyanide, in particular, cuprous cyanide on gold and silver flotation has not been well understood. In the present study, free cyanide and cuprous cyanide species were isolated and their effects on the flotation of a pyritic ore were evaluated. It was found that free cyanide depressed gold and silver flotation through their carrier, pyrite. Cuprous cyanide mainly in the form of Cu(CN)₃²⁻ depressed pyrite flotation similarly as free cyanide. Electrochemical studies including open circuit potential (OCP), cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques were carried out to understand the underpinning depression mechanism of cyanide species on pyrite flotation using xanthate as collector. It was found that all surface electrochemical reactions were inhibited by either free cyanide or cuprous cyanide. The surface layer as a result of xanthate adsorption on pyrite was completely removed in the presence of these cyanide species, which was suggested to contribute to the hydrophilic pyrite surface.     

The effect of salinity on the capacity and selectivity of ion exchange resins for gold cyanide

Despite the success of several resin-in-pulp pilot plant operations in the Western World and large scale plants in the former Soviet Union the process of extracting gold from slurries using ion exchange resins is yet to gain recognition as a viable alternative to the carbon-in-pulp process. An experimental research program has investigated the potential use of anion exchange resins containing a variety of quaternary ammonium functional groups in highly saline process water such as that found in Western Australia. The effect of univalent and bivalent ions on gold adsorption has been studied. It was shown that the selectivity of the resin for gold cyanide was enhanced with increasing ionic strength. It has been proposed that the degree of hydration, polarisation and size of the adsorbing species are factors that contribute to the observed change in selectivity of the ion exchange resin at different salinity. It was observed that in highly saline solutions copper cyanide did not load significantly on any of the experimental resins studied. Furthermore, it has been shown that an existing commercial non-selective resin loads no significant amount of copper cyanide under saline conditions. It is proposed that the apparent change in selectivity of resins for gold cyanide is caused by anions that have a stronger affinity for the resin in these highly non-ideal solutions as well as a possible change in the distribution of copper cyanide complexes in solution. The results of this study demonstrate that the selectivity of ion exchange resins in highly saline water is significantly improved and as a consequence the resin-in-pulp process may be more efficient than carbon-in-pulp in process streams of high salinity.     

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.