Reduction-roasting and ferric chloride leaching of copper converter slag for extracting copper,nickel and cobalt values

In a previous investigation the optimum conditions for recovering copper, nickel and cobalt from converter slag through ferric chloride leaching have been described. The study of various parameters revealed that nickel and cobalt recovery could not be improved beyond 24 to 26% respectively from converter slag, though more than 90% of the copper could be extracted. Further attempts were made to bring the metal values completely into solution through reduction-roasting followed by ferric chloride leaching of the slag. The present work comprises a study of various experimental conditions such as concentration of ferric chloride, duration of leaching, duration of reduction-roasting, temperature and nature of reducing agent, to arrive at the optimal recovery of the metal. Under identical experimental conditions a decrease in copper recovery, but an increase in nickel and cobalt recovery has been observed above a roasting temperature of 750°C. The decrease in copper recovery has been attributed to copper ferrite formation which has been confirmed both by leaching experiments with synthetic mixtures and by X-ray diffraction studies with both slag samples and synthetic mixtures. Recovery of nickel has also shown little decline when solid reductants were used above 850°C whereas cobalt recovery remains nearly the same even above 850°C. Under optimum conditions 80% copper, 95% nickel and 80% cobalt could be recovered by reducing the slag at 850°C with 10 wt % furnace oil, followed by leaching with ferric chloride.     

Pressure leaching of copper converter slag using dilute sulphuric acid for the extraction of cobalt, nickel and copper values

In our earlier studies [1–4], conditions were optimized for leaching converter slag with ferric chloride/dilute sulphuric acid for the recovery of cobalt, nickel and copper. By using both leachants most of the copper, nickel and cobalt values could be solubilized. Subsequent treatment of the leach liquors for separation and recovery of metals was difficult due to the presence of large quantities of iron in relation to other metal concentrations. In the present work, an attempt has been made to develop a process based on pressure leaching of the slag with dilute sulphuric acid in which iron contamination could be minimized by oxidation and hydrolysis. Various parameters including leaching time, pulp density, particle size, concentration of acid and oxygen partial pressure were studied to optimize the solubility of metal values. Under optimum conditions about 90% copper and more than 95% each of nickel and cobalt could be extracted with only 0.8% extraction of iron.     

转炉渣富钴镍浸出液镍钴分离工艺研究

以某厂镍电解生产净化工序氯气除钴产生的钴渣为氧化剂,除去转炉渣浸出液电积脱铜后液中的钴,实现转炉渣富钴镍浸出液中镍钴分离。结果表明,在钴渣含三价镍与钴量摩尔比为4～5,反应温度70～80℃,反应时间120min,终点pH 4.8～5的条件下,分离富集钴后的二次钴渣镍钴比可降为1～1.5,可用于生产钴产品。除钴后液可直接并入镍电解系统。     

高铁硫化矿选择性浸出铁的研究

将镍钴火法冶炼转炉渣进行还原硫化,制备成富含镍钴铜的高含铁硫化矿,并采用加压选择性浸出其中的铁。对铁的浸出行为进行了研究。结果表明,随着铜浸出率从98%降到-42%,铁浸出率从3%升到43%左右,选择性浸出后液含铁越来越高,而且以二价铁居多,这是造成高铁硫化矿难以进行加压选浸的主要原因。     

Processing of Cobalt-Copper-Arsenic Complex Ore Concentrate

Extraction of cobalt from complex ore flotation concentrates obtained from the Blackbird Mine. Idaho. USA is reviewed. After flotation of a primary copper concentrate, a bulk concentrate is recovered containing major amounts of cobalt, arsenic, and iron, with minor amounts of copper and nickel. This concentrate can be upgraded during flotation by removing iron, but with considerable cobalt loss. Chemical extraction difficulties are caused by the high arsenic and iron content of the concentrate. The historical approach, including a short lived plant, has been pressure oxidative leaching followed by ferric arsenate precipitation, solution purification, and cobalt electrowinning. Smelting and sulfation roasting followed by leaching are unsatisfactory but also discussed. The most recent studies, showing some promise, have been on oxygen-calcium chloride leaching and on biooxidative leaching at moderate pH with simultaneous iron hydrolysis and ferric arsenate precipitation.     

钴冰镍常压浸出工艺研究

以镍转炉渣还原硫化熔炼得到的钴冰镍为原料,在常压下于硫酸体系中进行浸出,考察了硫酸浓度、液固比、浸出时间及浸出温度对钴冰镍中有价成分浸出率的影响。结果表明,液固比和硫酸浓度对钴、镍、铁的浸出率影响较大。当硫酸浓度为1.6mol/L、液固比5、浸出时间2.5h、浸出温度85℃时,铁浸出率达到69%,镍、钴浸出率分别控制在1%和5%以内,取得了很好的选择性浸出效果。     

氯化铁溶液浸出低冰镍提取镍铜的研究

利用三价铁离子(Fe3+)的氧化性,采用氯化铁溶液浸取低冰镍,提取其中的镍、铜元素。本研究考察了浸出液固比、浸出温度、浸出时间、氯化铁溶液浓度对镍和铜浸出率的影响。动力学研究表明:氯化铁溶液浸出低冰镍时,镍元素的浸出过程由化学反应控制,铜元素的浸出过程由混合反应控制,经计算镍的浸出活化能为70.26 kJ/mol、铜元素的浸出活化能为38.62 kJ/mol。低冰镍和浸出渣的物相分析结果表明,浸出反应发生时,低冰镍中的硫元素被氧化成单质硫。本研究避免了传统工艺中的含硫气体污染问题。      

Organic acid leaching of base metals from copper granulated slag and evaluation of mechanism

A hydrometallurgical method is discussed to selectively extract base metals such as copper, cobalt, nickel and iron from the copper granulated slag (0.53% Cu) at atmospheric pressure. It involves first-stage leaching of slag with organic (citric acid) to selectively recover cobalt, nickel and iron. The residue containing high copper was subjected to second-stage leaching with inorganic (sulphuric) acid. Leaching parameters such as acid concentration, pulp density, temperature and time were optimised to extract metals from the granulated slag. A maximum recovery of 4.47% Cu, 88.3% Co, 95% Ni and 93.8% Fe were obtained in first-stage leaching with 2?N citric acid at room temperature using 10% pulp density (w/v) in 8–9?h. On subjecting the leach residue to the second-stage leaching with 2?M sulphuric acid, 66–72% Cu was recovered in 4?h. The kinetics of the metal leaching from the slag was established by the XRD and SEM–EDAX studies of the residues.     

碘-乙醇非水体系分离—重铬酸钾滴定法测定炉渣中金属铁与氧化亚铁

对炉渣中的金属铁与氧化亚铁的测定进行了研究。通过考察与金属铁反应而不与氧化亚铁反应的5种弱酸盐溶液(醋酸铅溶液、醋酸铜溶液、三氯化铁-醋酸钠-醋酸溶液、碘-碘化钾溶液、三氯化铁溶液)和非水溶液(碘-乙醇溶液)对金属铁的浸取效果,选取了碘-乙醇溶液作为炉渣中金属铁的浸取剂。实验结果表明,0.200 0 g炉渣样品用50 mL碘-乙醇溶液浸取40min, 采用重铬酸钾滴定法分别测定浸取液中铁量和浸取后残渣中的亚铁量,得到炉渣中金属铁和氧化亚铁量, 金属铁的浸取率在97 %以上,而氧化亚铁不被浸出。与经典的三氯化铁浸取剂相比,本浸取剂对金属铁的浸取效果好,金属铁与氧化亚铁分离完全,避免了用三氯化铁溶液作浸取剂时亚铁与金属铁的酸溶干扰。以碘-乙醇溶液浸取钢渣和脱磷渣后采用重铬酸钾滴定法测定,金属铁的测定结果的相对标准偏差(RSD)分别为4.2%和4.6 %,氧化亚铁测定结果的相对标准偏差(RSD)分别为0.72%和0.62%。     

铜转炉渣湿法回收钴研究

通过对铜转炉渣的多元素、物相分析,提出湿法处理工艺。考察物料粒度、初始酸浓度、温度、液固比、浸出时间、搅拌速度、通气速度等因素对铜、钴浸出率的影响。结果表明,采用先筛选粗粒度铜精矿后再硫酸浸出,有利于提高铜回收率,铜的累计回收率达到95%左右,钴与铁的累计回收率达到98%以上。     

Studies on Processing of an Alnico Scrap

This paper presents the results of research and development work on processing of alnico scrap, a secondary resource of nickel and cobalt, generated during the manufacturing of alnico magnets. The scrap contains 8–10% nickel, 10–12% cobalt, 32–50% of iron, 8–10% aluminium, 2% copper and remaining silica. Various processes such as acid leaching, aqueous chlorine leaching, salt roasting and cupric chloride leaching were studied in detail. Of these cupric chloride leaching was found to be most effective with respect to recovery and purity. It has been possible to obtain pure nickel and cobalt salts by cupric chloride leaching of the scrap, solvent extraction and precipitation of the salts. The overall recovery by the above process was almost 99%.     

Leaching of manganese nodules in ammoniacal medium using glucose as reductant

Polymetallic Indian Ocean nodules can be leached in ammoniacal solution in the presence of glucose. The various parameters chosen for leaching studies were: amount of glucose, time, pH, temperature, concentrations of ammonia and ammonium salt, and particle size. The percentage extraction of copper, nickel and cobalt decreases when the glucose concentration is increased to more than 0.4 gramme per gramme of nodule at 338 K and 0.2 g/g at 358 K. The dissolution of copper has been found to be dependent more on the pH of the solution than on the total molarity of ammonia and the ammonium ion. Leaching temperatures above 373 K are disadvantageous for the extraction of copper and cobalt, whereas nickel extraction is about 95% even at 433 K. The rate of leaching for all three metals is independent of the particle size in the range studied. All the copper, about 90% of the nickel and 60% of the cobalt can be extracted under the following leaching conditions: temperature 358 K, time 4 h, initial ammonia concentration 2.5 M, ammonium chloride concentration 0.37 M and glucose 0.2 gramme per gramme of nodule.     

Studies on Processing of an Alnico Scrap

Abstract

This paper presents the results of research and development work on processing of alnico scrap, a secondary resource of nickel and cobalt, generated during the manufacturing of alnico magnets. The scrap contains 8-10% nickel, 10-12% cobalt, 32-50% of iron, 8-10% aluminium, 2% copper and remaining silica. Various processes such as acid leaching, aqueous chlorine leaching, salt roasting and cupric chloride leaching were studied in detail. Of these cupric chloride leaching was found to be most effective with respect to recovery and purity. It has been possible to obtain pure nickel and cobalt salts by cupric chloride leaching of the scrap, solvent extraction and precipitation of the salts. The overall recovery by the above process was almost 99%.     

赞比亚某铜钴矿金属回收试验研究

赞比亚地区铜钴矿资源品位较低,铜钴赋存状态复杂,浸出和回收技术不成熟.某冶炼厂对此地区铜钴矿采用“浸出-萃取-净化-沉钴”工艺生产粗制氢氧化钴,浸出工段在生产过程中水量过剩,在净化工段前,萃余液中钴难以富集,造成资源浪费.本文采用酸浸还原-Lix984萃取-HBL110萃取工艺对此铜钴矿进行了试验,取得了满意效果:采用...     

Recovery of cobalt,nickel and copper from converter slag through roasting with ammonium sulphate and sulphuric acid

Roasting of copper converter slag containing 4.03% copper, 1.98% nickel and 0.48% cobalt with ammonium sulphate open to atmosphere has been carried out in order to achieve sulphation of copper, nickel and cobalt followed by leaching of the metal values as soluble sulphates with water. The effect of parameters such as temperature (200–600°C), time (15–120 min), and amount of ammonium sulphate (0.5–2.5 times stoichiometric) has been studied. Under atmospheric conditions, using 2.5 times the stoichiometric requirement of ammonium sulphate, the recovery of copper, nickel and cobalt was found to be 85%, 81% and 85%, respectively. Similar studies were carried out with sulphuric acid. The influence of experimental variables such as the amount of sulphuric acid (0.25–2 times stoichiometric), roasting temperature (100–300°C) and time (15–120 min) has been studied. Under optimum conditions, i.e., at 150°C and a roasting time of 60 min with the stoichiometric amount of sulphuric acid, recoveries of copper, nickel and cobalt were 95, 90 and 99%, respectively, along with a contamination of 60–80% iron. Removal of most of the iron from the leach liquors has been effected with ammonia liquor and lime as precipitants. A two-stage roasting operation using sulphuric acid, first at 150°C and then at 650°C, has resulted in bringing the iron content down to about 3% in the sulphation product without much affecting the recovery of other metal values.     

Factors affecting the leachability of Ni/Co/Cu slags at high temperature

An oxidative pressure acid leaching process was investigated for the extraction of Ni/Co/Cu/Zn metal values from base metal smelter slags. The process is applicable to smelting furnace dump slags, as well as to mid-stream converter slags. In addition to the economical advantages, extracting the base metal values from the dump slags produces an environmentally benign residue. To produce high level of extraction for the metal values, it is necessary to have the slag in crystalline structure. This, in turn, requires cooling the molten smelter slags sufficiently slowly during solidification. It was shown that if the same slags are quenched in water thereby producing an amorphous structure, the resulting metal extractions are substantially lower. The role of oxygen in the leaching reactions was also tested. The presence of oxygen is necessary for successful leaching of the metal values. After fine grinding, the slags were subjected to pressure acid leaching at 250 °C with an oxygen overpressure of 520 kPa. Sulfuric acid at a typical 0.3 acid to slag ratio was employed. Extractions higher than 90% of each of the nickel, cobalt, copper and zinc were achieved. Operating at 250 °C ensures that the concentration of Fe and Al impurity metals in leached solution remains very low. It was finally found that for high concentrations of divalent metals (Ni + Co + Cu + Mg) in the slag, a much higher quantity of sulfuric acid than the stoichiometric value is required. The latter is due to the drop of hydrogen ion concentration due to bisulphate formation.     

The leaching of nickeliferous laterite with ferric chloride

Several experiments were conducted to investigate the extraction of nickel from nickeliferous laterite by ferric chloride solutions as a function of pulp density, solution composition, and temperature. Solubility relationships for goethite and nickel laterite in aqueous solution were reviewed in terms of leaching rates and reaction mechanisms. Generally, the amount of nickel extracted increased with temperature, the amount of “free acid,” and ferric chloride concentration; however, the amount was inhibited by ferrous chloride. In this investigation, as much as 96 pct of the available nickel was extracted by ferric chloride solution. Nickel extraction was found to be more dependent on ferric chloride concentration than on the concentration of hydrochloric acid. Mechanistically, nickel extraction occurred by the formation of an intermediate ferric chloride complex, which was then hydrolyzed to hematite.     

铜锰渣酸浸及选择性硫化沉淀法回收铜工艺

系统开展了铜锰渣的H2SO4浸出及酸浸液Na2S2O3选择性沉铜研究,通过单因素实验,分别探究了2个工艺过程的影响因素.实验结果表明:铜锰渣酸浸的较优条件为:H2SO4用量200 g/L,液固体积质量比(mL/g)7:1,反应温度80℃,反应时间2 h,该条件下铜、钴、锌、锰的浸出率分别为99.81％,99.54％,9...     

低品位多金属钴渣选择性浸出新工艺研究

采用碱性体系下化学抑制—选择性浸出新工艺对钴渣中的有价金属进行浸出和分离,通过考察浸出温度、液固比、抑制剂用量、pH对浸出率影响的单因素及优化扩大试验,钴、锌、铜的浸出率可以分别达到94%、95%、96%以上。     

镍精矿加压酸浸新工艺研究

研究了金川镍精矿加压一步全浸镍、钴、铜新工艺,浸出液中和除铜后萃取分离镍钴,镍、钴、铜的浸出率可分别达到99.5%、98%和98%以上。该工艺与硫酸选择性浸出相比具有金属浸出率高、分离彻底、易分别回收等优点。