Recovery of metal values from copper converter and smelter slags by ferric chloride leaching

A study of the recovery of copper, nickel and cobalt from copper converter and smelter slags by leaching with ferric chloride is reported. The converter slag from Ghatsila, India contained 4.03% copper, 1.99% nickel and 0.48% cobalt and the smelter slag contained 1.76% copper, 0.23% nickel and 0.19% cobalt. Various parameters including the effect of stirring, leaching time, leaching temperature, concentration of ferric chloride, solid-liquid ratio and particle size, on the extraction of copper, nickel and cobalt have been studied. 92% copper, 28% nickel and 24% cobalt could be extracted from converter slag under optimum conditions, whereas 54% copper, 71% nickel and 44% cobalt could be extracted from smelter slag.     

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.     

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.     

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。     

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%.     

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...     

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.     

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%.     

降低铜阳极泥分铜工序的有价金属损失探讨

在保证铜的回收率前提下,为了降低铜阳极泥硫酸化焙烧后脱硒渣分铜工序中有价金属银、碲的浸出损失,进一步富集贵金属,选择水浸分铜来取代酸浸分铜.主要考察了氯化钠添加量、反应温度、反应时间以及液固比对铜、银、碲浸出率的影响.结果表明,脱硒渣水浸分铜工序的优化条件组合为:添加脱硒渣量9 %的氯化钠,反应温度30 ℃,控制液固比4:1（单位为mg /L）,搅拌反应2 h.将上述优化条件组合应用于车间扩大试验中,无需升温加热,铜回收率为94.17 %,而银、碲浸出损失分别降低至0.08 %、2.39 %;金、银质量百分比由原来的0.24 %和10.64 %分别增至0.62 %和17.85 %.      

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。      

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。     

A nitric acid route for processing a nickel/copper sulphide concentrate

This paper is concerned with the processing of an indigenously available pyritic sulphide concentrate for the recovery of the associated nickel and copper values by nitric acid leaching. Two different processing schemes have been investigated. In the first, the concentrate as such has been acid leached at ambient pressure in a stainless steel vessel. The influence of time, temperature, and the quantity of acid in the leaching process has been studied. Data on acid regeneration have been collected. It has been possible to achieve high recoveries of nickel and copper with acid regeneration amounting to about 60% of the total input for leaching. In the second, the concentrate after pre-roasting has been leached using a smaller quantity of nitric acid as compared with the straight leaching procedure. The influence of various pre-roasting temperatures on the leaching behaviour has been studied. High recoveries of nickel and copper have been obtained by leaching the sulphide concentrate after pre-roasting at about 450°C. Based on these results an attempt has been made to propose a flowsheet for the treatment of sulphidic resources of nickel and copper.     

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.     

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。     

Thermodynamic Aspects of the Roasting Processes in the Pre-treatment of Nickelferrous Garnierites

Abstract

The chemistry of pre-calcination and reduction roast processes with H₂ + H₂O gaseous mixture was analyzed, in order to find the best nickel and cobalt recoveries after selective roasting of nickelferrous laterites

A thermodynamic analysis of the pre-reduction of garnieritic ores aiming NiO and CoO reduction showed that the low NiO activity in the ore demands highly aggressive reducing conditions to attain reasonable nickel recoveries. Between 650-850°C, the highest nickel recoveries through amoniacal leaching was obtained at 750°C with 60% H₂ + 40% H₂0. Tests at 900°C revealed an unexpected high nickel recovery probably due to the presence of metallic iron which acted as a solvent for metallic nickel, favoring in consequence its metallization.     

转炉渣含铜影响因素分析及生产措施

楚雄滇中有色金属有限责任公司产出的转炉渣含铜持续偏高,对后续铜渣浮选的生产操作和工艺指标控制均有不同程度的影响.针对此问题,公司从转炉渣化学成分、物相,铜金属在转炉渣中损失形式,转炉渣含铜数据进行了研究,并从入炉铜锍品位,冷料加入量、加入时机和粒度大小,石英熔剂加入量,造渣、放渣操作等方面进行了深入分析,提出了降低渣含...     

Characteristics of electrochemical reactions accompanying chlorinating annealing of copper sulfide concentrates

The mechanism for reactions accompanying the low-temperature roasting of a copper sulfide concentrate with potassium and sodium chlorides without the formation of sulfurous gases and their evolution into the atmosphere is suggested. The obtained cake is leached with water under pH correction in the vicinity of 6. Water-soluble sulfates transfer into the solution, while copper and iron hydroxides remain in the cake. The further leaching of the cake by an aqueous sulfuric acid at the final pH 2.5–3.0 makes it possible to completely transfer copper into the solution, while iron completely remains in the solid phase. The recovery of copper into the solution under the optimal annealing conditions (t = 450°C, τ = 1 h) and the above conditions of double leaching is no lower than 95%. Chlorinating annealing at temperatures below and above 450°C results in a decrease in the recovery of copper into the final product of copper sulfate. The found maximum is explained.     

Kinetics of galena dissolution in ferric chloride solutions

A leaching investigation of galena with ferric chloride has been carried out as a function of concentration of ferric chloride and sodium chloride, temperature, and particle size. Three size fractions were considered in this investigation, namely, 48 × 65, 35 × 48, and 28 × 35 mesh. The concentration ranges of ferric chloride and sodium chloride used in this investigation were 0 to 0.25 M and 0 to 3 M, respectively. The reaction rate mechanism has been discussed in terms of a shrinking core model developed for cubic systems. Mass transport of ferric chlorocomplex through the product sulfur layer appears to be responsible for establishing the overall leaching rate under most of the conditions used in this investigation. The apparent activation energy for the leaching of 28 × 35 mesh galena with 0.1 M FeCl₃, 1 M HC1, and 3.0 M NaCl was found to be about 8.05 kcal/mol (33.7 kJ/mol), which was partially contributed by diffusion and partially by the heat of reaction of the formation of ferric chlorocomplexes. Rate of dissolution at both 50° and 90 °C is greatly affected by ferric chloride concentration up to 0.2 M and is essentially constant with ferric chloride concentration above this value.     

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.     

Activities of CoS and FeS in copper mattes and the behavior of cobalt in copper smelting

The distributions of cobalt and iron between metallic copper and high copper mattes were measured at 1400 and 1500 K. A value of 0.40 ±0.02 was found as the Raoultian activity coefficient of CoS at infinite dilution in the Cu₂S-FeS-CoS mattes. The present activities of FeS in the Cu-saturated Cu₂S-FeS mattes were found to deviate more positively than those reported by Krivsky and Schuhmann at 1623 K, and the positive deviation from the Temkin’s ideality was greater at 1400 K than at 1500 K. Using the activity coefficient of CoS, the partitions of cobalt between copper mattes and fayalitic slags were calculated for various conditions of copper smelting. It was found that cobalt exhibits, in the matte-slag equilibria, chemical properties intermediate between nickel and iron, but much closer to iron than to nickel. The overall recovery of cobalt in blister copper depends on matte grade, and is as low as 3 pct at best. When a high cobalt recovery is desired, therefore, a copper concentrate rich in cobalt must not be processed by conventional pyrometallurgical technology in view of the inevitably high loss to slag. M. NAGAMORI, formerly Associate Professor, Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah.