硫精矿焙砂提金及铜锌综合回收试验研究

针对云南某矿山硫精矿焙砂中铜、锌、硫、砷含量高及铁氧化物包裹金等问题,开展了常规氰化浸出和酸浸—氰化浸出两种不同方案回收金的试验研究.结果表明,常规氰化浸出金的浸出率为84.52％,酸浸—氰化浸出的酸浸过程铜、锌浸出率分别为40.25％、38.79％,后续金的浸出率为85.82％.综合比较,酸浸—氰化浸出工艺更优,比常...     

Modeling and optimization of Carbon in leach (CIL) circuit for gold recovery

Carbon in leach (CIL) is an important step in gold processing that involves simultaneous adsorption and leaching. While the mechanism of leaching and adsorption are well known, the effect of different operating and design parameters on the dynamics and performance of CIL circuit are not yet studied. The focus of this paper is to study the effect of operating parameters like cyanide concentration, oxygen concentration and mean particle diameter on the overall efficiency of CIL circuit. A dynamic model based on first principles is developed for the entire CIL circuit. Suitable kinetic models for both leaching and adsorption are adopted from the literature. Customizable simulator is written in MATLAB to simulate the model. Simulation results are first validated using previously published results. The validated model is then used to perform sensitivity studies on different parameters that affect the gold extraction process. The key parameters are optimized by conducting a multi-objective optimization study using elitist non-dominated sorting genetic algorithm of MATLAB. The percent recovery and net profit are maximized, while minimizing the cyanide used in the process. Four decision variables are used viz. particle diameter, oxygen concentration, cyanide concentration and ore volume fraction in tanks. A Pareto-optimal solution for the process parameters is provided such that all the objectives are improved to a value above which their improvement will result in degradation of other objectives. As a result, high recovery, high profit and low cyanide concentrations can be achieved simultaneously.     

国外某低品位贫硫型金矿选冶试验研究与工业应用

国外某低品位贫硫金矿石含金1.24 g/t,在对矿石性质进行详细研究的基础上,开展了全泥碳浸、浮选+氰化联合工艺、粗粒堆浸+细粒碳浸三个工艺方案的试验并进行了经济技术指标的对比,最终推荐采用全泥碳浸方案。针对该矿石,在磨矿细度为-0.074 mm占65%的条件下,采用全泥碳浸方案,氰化浸出48 h,金浸出率达到86.41%,浸渣金品位为0.17 g/t,吨矿氰化钠耗量为0.15 kg,实现了该低品位金矿的高效回收,并进行了工业化应用,生产指标与小试指标高度吻合。试验结果可作为该低品位贫硫金矿10 000 t/d选冶厂的设计依据。推荐的工艺方案流程及药剂制度简单,数据重现性好,处理成本低且生产经济技术指标稳定,对相同或类似性质的低品位金矿石的开发利用具有一定的借鉴和参考作用。     

Improvement of cyanidation practice at Goldcorp Red Lake Mine

Goldcorp Red Lake Mine processes a mildly refractory high grade gold ore with 77.8 g/t Au and 1.9% arsenopyrite, 1.7% pyrite and 0.2% pyrrhotite at a grind of 77% −37 microns. A cyanidation study was conducted to determine the necessary retention time of the leach circuit and the optimal gold extraction and cyanide consumption. Results have shown that the gold leaching kinetics could be significantly improved by the addition 100–200 g/t lead nitrate directly in the grinding circuit, followed by a 6 h cyanidation. A 1 month trial indicated a throughput of 810 tpd can be sustained without detrimental effect on gold extraction. However, the mill is currently limited by the underground operation to a throughput ranging from 650 to 700 tpd for a 55 h retention time. In the event of future throughput increase over 810 tpd value, lead nitrate could become an essential part of the leaching efficiency. The experimental work indicated a gold extraction at 87.1–87.4% (tailings ∼9.8 g/t Au) which is similar to plant performance. The associated cyanide consumption was 0.7 kg/t. Gold dissolution can efficiently be conducted at an average cyanide concentration of 400 ppm. Previous control of cyanide concentration in the plant was 700 ppm in the first leach tank to 350 ppm NaCN at the end. Testwork realised in the mill allowed a 32% cyanide reduction predicted by the on-site cyanidation study. The new cyanide concentration is ranging between 500 ppm in the first leach tank and 300 ppm NaCN at the end of the leaching circuit. The cyanide consumption of the plant was reduced from 1.0 to 0.68 kg/t with reduction of effluent treatment costs. Grinding finer (91% −37 microns) slightly increased the gold extraction (tailings lower by 0.4 g/t) but lowers the leaching kinetics, increases cyanide consumption (35%) and the arsenic dissolution.     

某高砷高硫复杂难处理金矿选矿试验研究

为有效回收某高砷高硫复杂难处金矿中的金,分别开展了矿石的工艺矿物学分析,及浮选、焙烧、氰化浸出等试验研究。结果表明,以黄铁矿、毒砂为主的载金矿物嵌布粒度较细,多以包裹体赋存,采用常规的氰化工艺金的浸出率较低,仅为18%左右。而采用浮选的工艺,通过组合药剂的优化使用,可获得金品位为21.05 g/t、金回收率为92.58%的金精矿,金精矿再经焙烧氰化浸出,金的浸出率可达89.93%。最终矿石在“浮选-焙烧-水洗-氰化” 的联合工艺下,可使矿石中的金得到较好回收。     

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。     

磁处理提高广东某含铜金矿金浸出率的试验研究

广东某含铜浮选金精矿的金品位为8.312 g/t、铜含量为5.18％,工业上采用全泥氰化、浸出渣浮选回收铜的工艺流程.矿石中较高的铜含量不仅消耗大量的氰化物,还影响了金的浸出效果.为了进一步提高金的浸出率、降低氰化物用量,采用加温常压化学预氧化浸铜—浸铜渣氰化浸金工艺回收试样中的铜和金,并在磁处理条件下,考察了磁场强度...     

河南某难处理金矿石选冶工艺对比研究

针对河南某难处理金矿石品位低、黄铁矿含量高、部分载金硫化物氧化严重,以及金嵌布粒度极细的特点,开展了详尽的浮选及全泥氰化浸出试验。试验结果表明：采用浮选工艺,所得精矿的金品位和金回收率仅为18.72 g/t和72.55%;而采用全泥氰化浸出工艺,在磨矿细度为-0.074 mm占90%,矿浆液固比为2∶1,加石灰调浆5 h使矿浆pH值稳定在11.5左右,氰化钠用量为1 kg/t,氰化浸出时间为72 h的条件下,金的浸出率可达81.11%。因此,推荐采用全泥氰化浸出工艺处理该矿石。     

甘肃省某低品位金矿选矿试验研究

甘肃某金矿为低品位氧化矿石,金矿物为自然金,自然金颗粒以微细粒为主,且有37.04%以包裹金形式赋存。在矿石特征分析的基础上进行了常规浮选、重选、全泥氰化三种工艺流程对比,最终确定用全泥氰化工艺回收金。通过全泥氰化指标各影响因素的优化探讨试验,得出了最佳选别条件:磨矿细度-200目占85%、保护碱石灰用量为2000g/t、PH=10-11、氰化钠用量800g/t、浸出时间4h、矿浆浓度40%、底炭密度15g/L、吸附时间8h。在此条件下,进行氰化炭浸综合条件平行试验,可获得金浸出率93.15%、金吸附率99.45%、金总回收率92.63%的较好指标。     

Simulation study of the optimal distribution of cyanide in a gold leaching circuit

The mineral industry has been using cyanidation to recover gold from ores for more than a century; however, a systematic study of the best reactant addition strategy in a cascade of agitated leaching tanks is not available in the open literature. A phenomenological mathematical model of the gold cyanidation process, calibrated with a set of industrial data from an Australian plant, together with an economic performance index is used to analyze this problem. The simulated results show that the best compromise between the two antagonistic effects, cyanide consumption and gold recovery, which are both function of cyanide concentrations, leads to a reagent distribution that depends on the leaching and cyanide consumption kinetics, pulp feed characteristics, and economic factors such as the gold market value. For the specific studied plant, in the operating range of low cyanide consumption and fast gold dissolution, all the cyanide must be added in the first tank; however, in the operating conditions of high cyanide consumption, cyanide has to be distributed in the first, second and third tanks.     

含铜金精矿铅盐预处理浸金技术研究

为了降低氰化钠用量,对某含铜4.92%的金精矿开展了铅盐抑铜预处理研究。结果表明,在氰化浸出前加入醋酸铅可以抑制铜的浸出、增强金银浸出、降低氰化钠消耗。醋酸铅预处理金精矿-氰化浸出的优化条件为: 浸出前直接添加醋酸铅150 g/t,磨矿细度-0.037 mm粒级占95%,浸出时间48 h,氰化钠浓度0.5%,pH=12,矿浆浓度40%。在此条件下浸出渣中金品位降至1.20 g/t,金浸出率达97.55%,银回收率60.28%,氰化钠耗量14.37 kg/t。该工艺具有良好的经济效益。     

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。     

某高硫高砷含碳金矿选矿试验

某高硫高砷含碳金矿石金品位为4.21 g/t,含砷0.82%、含碳0.85%,呈细粒、微细粒嵌布。硫化物包裹金和裸露金占总金的98.31%,金多分布于黄铁矿与石英、绢云母等脉石矿物连生体中。为回收利用矿石中的金,分别进行直接氰化浸出、预处理-氰化浸出、浮选-预处理-氰化浸出试验。结果表明,直接氰化浸出、预处理-氰化浸出金回收指标均较差;原矿经一段磨矿（-0.074 mm 90%）-1粗3精2扫浮选-二段磨矿（-0.038 mm 93%）-1粗3精2扫闭路浮选-尾矿预处理-氰化浸出选别,浮选可获得金品位23.36 g/t、含银96.00 g/t的金精矿,金精矿回收率为6722%,金浸出率23.36%,金总回收率达90.58%,指标较好,可作为该金矿石选矿工艺流程。     

广西某低品位金矿氰化浸出助浸剂实验研究

广西某低品位金矿石含金量为1.29 g/t,脉石矿物以石英为主,有色金属铜、铅、锌等及有害元素砷的含量极低。对该矿石进行氰化浸金实验研究,分别考查磨矿细度、溶液pH值、氰化物用量、搅拌转速、浸出时间对金浸出效果的影响;通过单矿物氰化助浸实验,确定多种助浸效果较好的助浸剂,并按同一比例混合,获得了三种新型助浸剂A、B、C;针对广西某低品位金矿石,进行氰化浸出助浸实验。结果表明,矿样细度-0.074 mm 93.27%,溶液pH值为10.5,氰化钾用量为4 kg/t,搅拌转速为1500 r/min,浸出时间为24 h的实验条件下,金的浸出率为92.58%;而氰化钾用量减少至3 kg/t,其余条件不变的情况下,加入新型助浸剂A浸出18 h后,金的浸出率可达93%。新型助浸剂的加入有效地提高了金的浸出率,同时将氰化物的损耗降低了25%,浸出时间缩短了6 h以上。     

Low pH cyanidation of gold

Lime is used in CIP/CIL slurries to increase the pH, which partially stops the formation of aqueous hydrogen cyanide. Hydrogen cyanide gas can be evolved directly from the pulp surface or purged from the leach tank in oxygen or air that is sparged into the tanks to provide oxygen for the dissolution of gold.Savings in lime consumption can be achieved by leaching at a reduced pH, especially in aqueous solutions high in magnesium such as to be found in the Kalgoorlie Goldfields in Western Australia, but a greater percentage of cyanide is then present as aqueous hydrogen cyanide. Another proposed procedure to reduce lime consumption is closed tank leaching where a reduced pH or the natural pH of the ore is used and hydrogen cyanide loss is prevented by the closed vessel.The dissolution rate of pure gold as a function of pH for constant total cyanide concentration has been determined. Dissolution was directly proportional to the concentration of the cyanide ion present, with the contribution to dissolution from aqueous hydrogen cyanide too low to be measured.Ore leached in high magnesium, hyper-saline, process water showed increased gold dissolution at low pH compared to the pure gold. Reducing pH caused more cyanide to be consumed by the pulp but did not significantly increase the amount lost to the atmosphere.     

何家岩原生金矿石细菌预氧化提金工艺试验研究

何家岩原生金矿石中,金及金的载体矿物粒度微细,采用常规氰化浸出,金浸出率仅23%左右。对浮选金精矿采用细菌预氧化—氰化浸出工艺,金浸出率可达到92.73%。因此,采用浮选—浮选金精矿细菌预氧化—氰化浸出是处理该矿石较为适宜的工艺。     

Limits of the CIL circuit in copper–gold plants

This study examined the performance of the CIL (Carbon-in-Leach) circuit at Telfer, a copper–gold plant treating porphyry copper deposits containing gold associated with both copper and iron sulphides, with an objective to identify factors normally limiting the gold recovery in the CIL circuit in the presence of a small amount of copper after copper flotation, and then propose a means to improve it. Diagnostic leaching assessment and mineralogical analysis by MLA revealed that the occlusion of gold by other minerals and the fine grain size of gold associated with them may be the contributing factors to the low gold recovery in the CIL circuit. Fine grinding of the CIL feed increased gold recovery significantly from the leaching process. However, it is interesting to find that fine grinding increased the amount of released copper ions which complex with cyanide resulting in significantly higher cyanide consumption. It is therefore proposed that regrinding of the CIL feed followed by copper flotation is an appropriate pre-treatment method for the CIL circuit.     

某难处理金矿石提金工艺试验研究

针对某含砷高、含碳高、硫化物含量低的微细粒浸染型难处珲金矿石,进行了不同流程的提金工艺试验研究.对于金品位为2.98 g/t的原生矿,用常规氰化金的浸出率仅为0.68%;焙烧-氰化提金工艺,金的浸出率为80%左右;原矿浮选,金的浮选回收率为82.73%;浮选-金精矿生物氧化-炭浸提金工艺,金的总回收率74.72%;浮选...     

内蒙古某金矿尼尔森重选—低氰浸出试验研究

内蒙古某金矿含金2.83 g/t,目前采用氰化钠浸出—树脂吸附工艺提金,浸渣总氰含量高达50 mg/kg。为降低氰化物用量,使得浸渣氰化物浓度达到充填技术标准,采用尼尔森重选—重选尾矿低氰浸出工 艺对内蒙古某金矿进行提纯试验研究,重点考察重选尾矿的磨矿细度、金欣用量、氧化钙用量、液固比及浸出时间对浸出效果的影响。结果表明：①在磨矿细度为-0.043 mm占87%、分选G值为80 G、流态化水量为3 L/min、给矿浓度为50%的条件下,采用“1粗2扫”工艺流程进行尼尔森重选,金累计回收率达到55.91%,金累计品位为35.48 g/t,重选尾矿含金1.34 g/t。②对重选尾矿进行低氰浸出条件试验,确定适宜的磨矿细度 为-0.043 mm占79%,氧化钙用量为5 kg/t,金欣用量为1 200 g/t,浸出时间为36 h,液固比为1.5 mL/g,此时金浸出率为91.88%,重选—浸出工艺流程综合回收率达96.42%;在上述条件下,采用树脂吸附处理贵液, 金吸附率为86.94%,合计重选—浸出—吸附全流程的金综合回收率为91.13%,指标良好。试验最终获得的浸渣总氰浓度为0.50 mg/kg,达到尾矿充填技术标准。     

某高硫难处理金精矿超细磨提金试验研究

针对某高硫难处理金精矿中金大部分被黄铁矿包裹、直接氰化浸出金浸出率低的问题,采用超细磨-碱预处理-氰化浸出工艺处理金精矿,通过条件优化可获得金浸出率84.50%,氰化钠耗量控制在3 kg/t以内,该工艺简单、流程短、安全环保。