预浸出对硫化铜精矿硫酸化焙烧处理的影响

采用硫酸化焙烧-浸出-电积工艺来处理硫化铜精矿时增加预浸出可以使得铜浸出率增加,焙砂浸出液中影响铜电积的主要杂质元素Fe、Mn、Co等含量降低,预浸出段酸矿比0.3:1、温度50 ℃、时间3 h、液固比1:1时,Cu的最终浸出率大于99%,焙砂浸出液中Fe、Mn含量分别为0.12g/L和0.005g/L。通过预浸出段正交试验,确定了酸矿比对各个元素的浸出率影响最大,当酸矿比0.6:1,温度70 ℃,时间2 h,液固比1:1时,Fe的渣计浸出率为93.61%,Mn的渣计浸出率为59.50%,Mg的渣计浸出率为32.97%。     

The development of an environmentally friendly leaching process of a high C,As and Sb bearing sulfide gold concentrate

An environmentally friendly leaching process, consisting of the pretreatment of alkaline pressure oxidation and thiosulfate leaching, has been developed to efficiently extract gold from a high carbon, arsenic and antimony bearing sulfide gold concentrate. The Au extraction from the concentrate by direct cyanidation was very low mainly due to the encapsulation of gold by associated minerals and the preg-robbing effect of graphite and organic carbon. The pretreatments of permanganate oxidation and oxidative roasting both could effectively liberate encapsulated gold and eliminate the preg-robbing effect on cyanidation. However, the reagent dosage of permanganate oxidation was high and the final oxidation solution contained substantial quantities of toxic ions. The flue gas of oxidative roasting also contained a lot of poisonous oxides, and the extremely drastic reaction environment of roasting led to the secondary encapsulation of gold by newly generated oxides. The pretreatment of alkaline pressure oxidation effectively liberated encapsulated gold with less than stoichiometric reagent dosage and simultaneously relieved the secondary encapsulation of gold, but could not completely remove graphite and organic carbon. Because carbonaceous matter had a weak affinity for gold thiosulfate complex, the Au extraction by thiosulfate leaching after the pressure oxidation achieved 86.1% whilst the thiosulfate consumption was 35.3 kg/t-concentrate. This process of alkaline pressure oxidation–thiosulfate leaching neither used toxic reagent nor released poisonous gas, and furthermore its effluents contained few toxic ions.     

碱性硫化物浸出含锑金精矿过程中的抑金措施

在含锑难冶炼金矿碱性浸出脱锑生产工艺中的金伴随浸出是一种普遍的现象,此现象使金进入到锑浸出液中,造成了一定的损失。本文根据碱性硫化物在氧化环境中的不稳定性以及碱性多硫化物浓度对于金、锑浸出过程中的反应级数差等理论,并结合实际生产情况,研究了空气氧化、二段浸出对碱性硫化体系浸锑过程中的抑制金浸出的效果。在浸出矿浆中通入4.5L/（L*min）的空气,氧化浸出4h后,Sb浸出率63%,Au浸出率0.86%。采用两段浸出法,Sb浸出率为89%,Au损失率为浸出4.2%,相比一段浸出Au损失率降低6.0%。     

某高砷铜精矿压力浸出工艺研究

随着国内外铜资源的不断开采利用,矿石品位越来越低,难处理复杂铜矿增多,为传统铜冶炼工艺带来了处理效率低、污染严重等诸多问题。砷在冶炼过程中,常散布在焙烧或冶炼的各产物中,恶化粗铜质量、影响硫酸生产、污染大气、毒化环境。为探索高砷铜矿中合理的铜砷分离方法,本文对高砷铜精矿进行加压浸出试验研究,考察液固比、反应温度、氧分压和反应时间等对铜、砷浸出率的影响。结果表明:在优化试验条件下,铜的浸出率可达99%,固砷率约60%。     

Simultaneous sulfide oxidation and gold leaching of a refractory gold concentrate by chloride–hypochlorite solution

In this research, oxidation of sulfide and leaching of gold from a gold–bearing sulfide concentrate using chloride–hypochlorite solution has been investigated. Effects of calcium hypochlorite concentration, initial pH and sodium chloride concentration on the recovery of gold were examined. Two conditions were considered; the stability range of the gold complex (Eh > 900 mV) and formation of chlorine gas (pH < 3.5). During leaching, due to oxidation of sulfide and generation of acid, pH dropped. About 82% of gold was extracted from 200 g/L concentrate after 2 h using 200 g/L Ca(OCl)₂, 200 g/L NaCl at initial pH of 11, stirring speed of 600 rpm and temperature of 25 °C.     

铜铅硫化混合精矿高效分离新工艺研究

铜铅硫化矿的高效浮选分离一直是选矿领域的重点和难点.针对铜铅硫化混合精矿,提出采用硫酸预处理—浮选分离新工艺,通过对黄铜矿和方铅矿单矿物硫酸处理前后的接触角测定、人工混合矿和实际铜铅混合精矿预处理—浮选分离试验研究,分析了硫酸对方铅矿和黄铜矿的作用机理,确定了最佳预处理条件.研究结果表明,硫酸预处理后方铅矿的表面接触角...     

Sulfuric acid leaching of Turkish chromite concentrate

In this work a high grade chromite concentrate obtained from Pinarbasi–Kayseri district of Turkey was reacted with a solution of sulfuric acid and perchloric acid. The effect of sulfuric acid concentration, temperature, duration, and perchloric acid addition on leach recovery was studied. At the end of leach reaction chromium appeared in the solution as Cr³⁺ and it did not change to environmentally hazardous Cr⁶⁺. The final product in the solution was chromium(III) sulfate obtained with about 83% maximum recovery, under the optimum leaching conditions of 175 °C, 2 h, 70% H₂SO₄ and 1/2 perchloric acid/chromite ratio.     

Thermophilic heap leaching of a chalcopyrite concentrate

Thermophiles have been shown to be the only micro-organisms to leach chalcopyrite successfully. Heap leaching may be a feasible alternative to conventional bio-reactors, providing a high temperature environment can be maintained within the heap without external heating.In the present study thermophilic heap leaching of a chalcopyrite concentrate coated onto inert support rocks (the GEOCOAT™ process) was studied in sets of small heated columns. The temperature was gradually increased to 70 °C, while successively introducing various mesophile and thermophile cultures. Individual columns were dismantled after progressively longer leach periods and the residual concentrates analysed. Copper extractions in excess of 90% were achieved within 100 days.On the basis of head and residue analyses the rate of reaction heat generated was calculated. A comprehensive heap heat conservation model was used to determine whether the experimental temperatures can be achieved and maintained in a full scale heap. Results indicate that operating hot heaps successfully is possible within a certain range of process parameters.     

铅盐在高铜金精矿氰化提金试验中的应用与工业实践

河台金矿原矿含0 2%～0 3%的铜,以原生硫化铜为主,含硫1%左右,属贫硫化物含铜金矿石。从1989年建厂至1998年一直采用单一混合浮选工艺,生产含铜3%～5%的混合金精矿,这样影响了企业的经济效益。经试验研究采用铅盐预处理工艺获得成功,并建成氰化冶炼厂,本文介绍铅盐在高铜金精矿氰化浸金应用中的试验与工业实践情况。     

The cyanide leaching of gold in solutions containing sulfide

A large proportion of the gold processed in the 21^st century will be recovered from sulfide ores. Since the sulfide minerals are to some extent soluble in cyanide solutions, there will always be some sulfur species present in the leach solution. It has been shown that soluble sulfide hinders the rate of gold leaching, forming a protective layer of the type Au/S_x. Electrochemical studies of the constituent half reactions: gold oxidation; and oxygen reduction, were consistent with this view. The effect of sulfide and cyanide concentrations on the leaching reaction were investigated, and it was shown that the sulfur formed is chemically attacked by cyanide, resulting in higher leach rates at higher cyanide concentrations. The effect of lead was also studied and is discussed in detail.     

山东某浮选金精矿氰化浸出实验研究

山东某浮选金精矿工艺矿物学研究表明,该精矿主要金属矿物为黄铁矿,铜、铅、锌、砷等金属元素含量都比较低,对该精矿采用氰化浸出金、银比较有利,浮选精矿含金品位平均为21.86 g/t,含银10.5 g/t、硫47.16％.矿物组成比较简单.实验结果表明,采用直接氰化搅拌浸出可以获得金浸出率为95.06％,银浸出率71.43％的良好指标.     

含铷云母精矿铷浸出试验研究

对含铷云母精矿进行多浸出方式探索对比试验研究,研究表明,精矿采用氯化钙为焙烧助剂,精矿:氯化钙配比1∶0.2,焙烧温度850℃焙烧时间30~40 min,焙砂磨细至-74μm≥95%,水浸条件以温度60℃、L/S=2.0~3.0、浸出30~40 min,采用二段焙烧-水浸,铷浸出率可达91.97%以上。浸渣中铷可降至600ppm以下。铷溶浸效果较为理想。     

Sulphuric acid leaching of mechanically activated copper sulphidic concentrate

In this study, the effect of mechanical activation was evaluated on the leaching efficiency of copper sulphidic concentrate in 0.5 M sulphuric acid medium. The mechanical activation of samples was performed by a high energy planetary ball mill under the atmospheric conditions. The results showed that there was an optimum time of MA, about 6 h, in which the leaching efficiency reaches its maximum value (42% for 7 h of leaching). The improvement of leaching efficiency due to mechanical activation can be attributed to the significant decrease of the size of particles and the intense structural disordering of particles.     

云南某金精矿氰化浸出试验研究

云南某金精矿工艺矿物学研究表明,该矿石为含金氧化矿—石英脉型岩金矿。金品位为38.23 g/t,银品位为28.82 g/t,金银可以一起进行综合回收,铜、砷、锑等杂质元素含量不高,碳含量较高,它的存在将会对金、银的浸出带来不利影响。试验结果表明,采用直接氰化搅拌浸出可以获得金浸出率为93.12%的良好指标。     

锌精矿氧压浸出过程伴生硫铁矿的转化行为

以硫铁矿为研究对象,研究浸出过程初始硫酸浓度、温度、氧分压、矿物粒度、反应时间对硫铁矿氧压浸出行为的影响。结果表明：硫铁矿氧压浸出过程反应初期为耗酸反应,硫酸的消耗速率大于硫酸的生成速率,反应后期主要是元素硫氧化转化生成硫酸;反应初期浸出液中的铁主要为二价铁离子,反应后期发生铁离子的氧化,且在高温酸性溶液中,三价铁离子可水解沉淀为赤铁矿和铁钒;硫铁矿中的硫元素在氧压浸出过程大部分转化为硫酸并以硫酸根的形式存在溶液中,而少部分以单质硫形式存在于浸出渣中,附着于浸出渣表面,形成包裹层。     

富氧焙烧对高铜低硫精矿浸出率和脱硫率的影响

针对高铜低硫精矿的特点,采用了富氧焙烧的技术。通过进行条件实验研究得到,当焙烧时间为8 h,焙烧温度为750 ℃,焙烧富氧浓度为30 %时,焙烧效果最好,在该条件下脱硫率为70 %,焙砂浸出率为97.5 %。通过实验对比富氧焙烧与非富氧焙烧可以得出,采用富氧焙烧可以有效的缩短焙烧时间,降低焙烧所用温度,大大提高了焙烧效率。通过进行重复性验证和工业扩大化研究得出在该最佳条件具有良好的重复性,对实际生产具有一定的指导意义。     

Interfacial properties of liquid sulfur in the pressure leaching of nickel concentrate

The effects of sulfur dispersing agents in the oxygen pressure leaching of nickel concentrate at medium temperature were investigated by interfacial studies. Liquid sulfur–aqueous solution interfacial tensions and liquid sulfur–sulfide mineral contact angles were measured at 140 °C, 690 kPa overpressure by nitrogen. The effects of sulfur dispersing agents including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid were evaluated by the calculation of the work of adhesion in the liquid sulfur–sulfide mineral–aqueous solution systems. It was found that the sulfide mineral surface is sulfophobic at pH from 4.1 to 4.5 due to the hydrolysis of nickel (II) ions to nickel hydroxide and the deposition of nickel hydroxide on the mineral surface. These findings apply to four different sulfide mineral systems, including pentlandite, nickeliferous pyrrhotite, pyrrhotite, and chalcopyrite. Lignosulfonate, Quebracho, and humic acid were found to significantly reduce the work of adhesion indicating they should be effective sulfur dispersing agents. OPD is ineffective in changing the work of adhesion of sulfur on the mineral sulfides indicating that it is not a good candidate for sulfur dispersion.     

The role of metal-cyanide species in leaching gold from a copper concentrate

The cyanidation of copper-gold ores is a difficult issue owing to the ready formation of copper cyanide complexes during gold leaching. Moreover, the speciation of other metal cyanides in leach slurries and the interaction between them have not been researched extensively, and are of fundamental importance to gold mills.In this paper the role of the cyanide complexes of copper, silver, nickel, iron and zinc in gold leaching was investigated by examining the leaching of a copper concentrate. It was found that copper-cyanide and other metal cyanide species, including Ag, Fe, Ni and Zn, all play an important role in gold cyanidation under conditions of zero free cyanide. These species dissociate, and the cyanide made available by the dissociation leaches gold. These metals species then precipitate, usually as a hydroxide under typical leaching conditions. Silver is an exception, which may precipitate as a metal or AgCN species. When cyanide is present, the mechanism of copper-cyanide assisted gold leaching is the dissociation of the weakly bound fourth ligand of Cu(CN)₄³⁻. The cyanide made available can then be used to leach gold and other metals.