含铋高锑冶炼渣浸出液梯级分离回收砷、锑、铋

针对传统锑、铋分离过程中,砷、锑、铋分离不彻底,有价元素回收率不够高等问题,采用还原沉砷、水解沉锑、中和除氯、中和沉铋等方法对含铋高锑冶炼浸出液进行处理,对温度,反应时间等影响条件进行了考察。结果表明,在最佳条件下,通过加入次亚磷酸钠将砷酸根还原为砷单质,最后砷以氧化砷的形式被回收,回收率达到了91.99%;沉砷后液加水进行水解沉淀,锑以SbOCl的形式沉淀下来,沉淀率在95%左右;将SbOCl加入氨水中进行除氯,锑以氧化锑的形式沉淀分离,除氯率达到了96%;沉锑后液加入一定量的氨水来中和,铋以BiOCl沉淀的形式分离出去,沉淀率达到99%左右,实现了砷与锑、铋的梯级分离与回收。     

氧化协同浸出复杂铜碲铋渣中的碲及有价金属

以铜、铅阳极泥火法处理产生的铜碲铋渣为原料,采用中性浸出-氧化协同浸出-草酸沉铜-水解沉铋-亚硫酸钠还原碲工艺分离回收铜碲铋渣中的碲及有价金属。研究了硫酸浓度、双氧水用量、NaCl浓度、浸出时间、浸出温度、液固比对协同浸出铜、碲、铋浸出率的影响,草酸过量系数对沉铜效果的影响,终点pH值对铋沉淀率的影响以及Cl-浓度对碲还原率的影响。结果表明: 在硫酸浓度4 mol/L、双氧水用量0.6 mL/g、NaCl浓度2.5 mol/L、浸出时间1 h、浸出温度80 ℃、液固比3 mL/g时,铜、碲、铋浸出率分别达到98.2%、90.1%和99.3%; 草酸用量为理论量的1倍时,沉铜率达99.2%; 在终点pH=2时,铋沉淀率达97.72%; Cl-浓度0.8 mol/L,碲还原率达95.6%。铜以草酸铜形式回收,铋以氯氧铋形式回收,碲以碲粉形式回收。     

含砷铅铋渣综合回收铅铋的研究

试验对铅铋渣进行了较好的分离，确定了合理的工艺流程及最佳工艺条件，Pb、Bi的回收率均大于90％，砷90％以上富集于钙砷渣中。该工艺不仅综合回收了Pb、Bi等有价金属，而且消除了砷污染，治理了环境。因此，该工艺对铜冶炼过程中产生硫酸铅或氧化铅为主的物料综合回收具有指导意义。     

分银渣中有价金属高效回收利用

以锡、铅及砷含量较高的分银渣为原料, 研究了高效回收锡、铅、砷、锑等有价金属的工艺流程。采用分银渣制团-高温脱砷锑-还原熔炼-硅氟酸电解工艺, 考察了还原剂种类、还原剂加入量以及MeS加入量对高温脱砷锑过程的影响, 结果表明: 当还原剂R1加入量为8.8%, MeS加入量为2.4%时, 高温处理团矿后锡回收率达到87.64%, 脱砷锑效果好。经硅氟酸电解, 锡、铅以铅锡焊料形式回收, 锑以锑氧形式脱除, 银、铋等富集进入阳极泥。     

高砷铜烟尘中有价金属回收的实验研究

针对火法熔炼—湿法浸出工艺处理高砷铜烟尘有价金属回收率低,湿法浸出工艺处理高砷铜烟尘砷铁渣量大、会释放剧毒砷化氢气体的问题,采用低温硫化挥发的方法将砷与其他有价金属选择性地分离,实现了砷的去除和综合利用,砷以三氧化二砷产品的形式得以回收利用。挥发除砷后的焙砂采用加压硫酸浸出,浸出液中的铟采用P204萃取,反萃后利用锌粉置换得到海绵铟,萃铟后的浸出液采用锌粉置换得到海绵铜,锌通过浓缩的方式制成七水硫酸锌产品,锡铋铅入渣以铅冶炼原料得以回收。     

低冰镍加压酸浸工艺研究

本文研究了低冰镍湿法冶炼工艺流程,详细进行了低冰镍加压酸浸-萃取脱铜-中和除铁-中和沉镍的工艺研究。在优化试验条件下,加压浸出镍、铜的浸出率分别为91.56%,99.08%。浸出液经萃取脱铜-中和除铁-中和沉镍工艺使有价金属分别得到回收富集。     

用浸出工艺回收酸性矿山废水沉淀渣中金属元素

酸性矿山废水沉淀渣的处置一直是废水处理工程面临的难题。以广东省大宝山矿槽对坑尾矿库外排废水处理厂产生的沉淀渣为例,开展沉淀渣中有价金属元素酸浸与回收试验。淀渣铁、锰、铜、锌、镍、铅品位分别为40 919.6,14 320.6,4 681.4,7 557.4,149.3,360.9 g/t,杂质成分主要为石英、方解石。在硫酸浓度为20%、固液比为0.33 g/mL、浸出时间为8 h、浸出温度为30 ℃条件下,铜、锌、镍、铅、锰和铁的浸出率分别为99.49%、21.41%、51.21%、4.45%、55.86%、34.25%。采用硫酸浸出工艺回收沉淀渣中有价金属元素在技术经济上可行,同时可缓解废水处理厂的环保压力。     

铁矾渣综合利用技术进展

在有色冶炼的沉铁过程中会产生大量的铁矾渣,直接堆存处理不仅会对环境造成危害,也是一种资源的浪费。目前国内外对于铁矾渣的处理处置方法,主要是通过火法工艺、湿法工艺、选矿工艺及联合工艺等回收Zn、Pb、Ag、In、Fe等有价金属,其次利用铁矾渣制作功能材料和建筑材料,以及最终无害化固化处置。认为在铁矾渣处置过程中减少二氧化硫和废水排放,避免重金属污染,实现主要有价金属回收的同时减少尾渣数量是今后研究的热点。      

Integrating sulfidization with neutralization treatment for selective recovery of copper and zinc over iron from acid mine drainage

The most commonly used commercial process for acid mine drainage (AMD) treatment today is lime neutralization. However, it is accompanied by the treatment of produced metal hydroxide precipitate. Because of the decrease in the capacity of landfill disposal site and the increase in the price of base metals such as copper (Cu) in recent years, it is expected that not only to treat but also to recover these base metals from AMD. For the subsequent smelting process, the major issue is how to separate the Cu and zinc (Zn) over iron (Fe) from AMD as selectively as possible.In this work, we attempted to achieve this objective by modifying the present lime neutralization treatment process with sodium hydrosulfide (NaHS) sulfidization. An AMD sample generated from an abandoned copper mine located in east Japan was utilized in this study. At first, lime neutralization was applied to the AMD to find the precipitation behaviors of Cu, Zn, and Fe. Next, NaHS sulfidization as well as the integration with lime neutralization were conducted to separately precipitate Cu, Zn, and Fe from the AMD. Finally, two modified treatment approaches for selectively recovering Cu and Zn over Fe from the AMD were proposed. The results of consecutive experiments for the two proposed approaches showed that Cu, Zn, and Fe in the AMD were removed and separated into individual precipitates, and that the concentrations of each heavy metal in the final effluent were also able to meet the Japanese effluent standards.     

全湿法回收银铋渣中有价金属的试验研究

针对火法和氯化法处理银铋渣的弊端，提出了全湿法处理银铋渣的新工艺。按照试验所确定的最佳条件，用稀硫酸浸锌、用硝酸浸其它金属，结合食盐沉银、中和水解沉铋、含铜ZnS04溶液的锌粉置换除杂和蒸发结晶等从浸出液中提取金属的手段，有效实现了Au、Ag、Bi、Zn、Cu等有价金属的分离回收，可获得金渣、银粉、次硝酸铋、工业硫酸锌和海绵铜产品，Au、Ag、Bi、zn、cu的直收率分别达到99．64％、98．23％、97．76％、96．37％和95．83％。全湿法新工艺工艺简单，加工成本低廉，适于中小型工业化生产。     

铜熔炼烟尘中铜的回收试验研究

为了回收铜熔炼烟尘中的有价金属,对某铜冶炼厂产生的高铜、高砷烟尘进行了性质分析,确定了烟尘中主要元素的赋存状态及含量。结果表明,烟尘中铜和锌主要以硫酸盐和氧化物的形式存在,砷主要以氧化物的形式存在,具有良好的浸出特性。采用低浓度酸浸—硫化沉淀法回收烟尘中的铜,并考察了絮凝剂对硫化物矿浆沉降性能的影响。结果表明：① 在初始硫酸浓度为40 g/L,浸出温度为50 ℃,浸出时间为90 min,液固体积质量比为4∶1 mL/g的条件下,Cu、Zn、As的浸出率分别为96.33%、96.52%和83.72%。② 硫化沉铜时,在硫化钠过量系数为1.3,pH值为3.0,反应时间为20 min的条件下,Cu的沉淀率可达到99.99%,硫化沉淀产物主要物相为CuS,其中铜的品位为56.90%,可直接用于工业生产。沉铜后液可继续回收Zn等有价金属。③ 加入絮凝剂可使硫化沉淀的粒径变大,加速矿浆的沉降并且有助于固液分离。     

Selective leaching of arsenic and antimony from a tetrahedrite rich complex sulphide concentrate using alkaline sulphide solution

Removal of impurity elements in copper metallurgy is one of the major problems encountered today since pure copper ore reserves are becoming exhausted and the resources of unexploited ores often contain relatively high amounts of impurity elements like antimony, arsenic, mercury and bismuth, which need to be eliminated. The present work is aimed at pre-treating a tetrahedrite rich complex sulphide concentrate by selective dissolution of the impurities, therefore, upgrading it for pyrometallurgical processing. To accomplish this, dissolution of antimony and arsenic by an alkaline sulphide lixiviant from the concentrate were investigated. The lixiviant proved selective and effective to dissolve these impurity elements from the concentrate with good recoveries. Further investigations on the factors influencing the leaching efficiency of the lixiviant were studied. The parameters considered were sulphide ion and hydroxide ion concentrations, mineral particle size, reaction temperature and leaching time. Analysis of the leach residue indicates that copper content of tetrahedrite has transformed into copper sulphides with the average chemical formula Cu_1.64S. The grade and economic value of the concentrate were improved greatly after sulphide treatment, and therefore, suitable as a feedstock for smelting. The impurities have been reduced to low levels which are tolerable in the smelting furnace and consequently reduce both the treatment and environmental problem encountered when such concentrate is processed pyrometallurgically.     

锌冶炼工艺技术及研究与发展方向探讨

锌精矿伴生有贵金属、稀散金属和其他有色金属。我国年消耗锌精矿约1070万t，其中约含有价金属资源量：铜42800t、镉32100t、钴321t、镍214t、镓963t、铟3210t、铊214t、锗963t、锡5350t、铅96300t、锑6420t、铋1070t、银856t、金1.07t，伴生金属资源量总价值达200亿元以上。简述了我国锌冶炼主要工艺技术特点，指出我国在锌精矿中的锌及其伴生的有价金属回收利用方面虽然取得了较大的成绩，但由于现有冶炼工艺存在有价元素镓、铟、铊、锗、锡、锑、铋、铝、铜、银、金、铅、锌等随铁渣走造成损失大的难题，以及低含量的有价元素不能富集回收利用的难题，致使经济效益损失巨大，并存在环境污染风险。未来锌冶炼工艺的研究与发展方向为资源利用率高、经济效益好及环境污染小的“高温高酸浸出——稀散金属循环累积富集——一渣两液三路分离回收有价金属法”。     

Bioleaching and recovery of metals from final slag waste of the copper smelting industry

Solid waste from the copper smelting industry may be harmful if disposed of in the environment, but it may be a valuable resource if metals can be recovered. The purpose of this study was to evaluate the acid bioleaching of metals from a sample of final smelter slag and the recovery of metals from the leach liquors. Bioleaching was tested in a continuously stirred tank reactor (CSTR) at 20-25 °C with 5% pulp density (particle size 75% <47 μm). The yields of metal solubilization after 29 days of contact were 41% Fe, 62% Cu, 35% Zn and 44% Ni. Metals were precipitated in a separate CSTR by titrating the leach liquors with sulfide-rich effluent from a sulfate-reducing fluidized-bed reactor (FBR) (25 °C) to desired pH values. Over 98% of the Cu precipitated at pH ? 2.8 and over 99% of the Zn precipitated at pH ? 3.9. The precipitation of Ni and Fe required higher pH values and was less efficient than Cu and Zn recovery. In addition, bulk precipitation of metals was also tested by feeding the leach liquor directly to another sulfate-reducing FBR. In order to reduce its toxicity and maintain stable sulfate reduction performance in the FBR, the leach liquor had to be diluted ten-fold and the pH adjusted from 0.6 to approximately 4.     

铜冶炼烟尘的综合利用

以铜转炉烟尘为原料, 采用高压酸浸工艺回收有价金属和脱除砷。结果表明, 在硫酸浓度4 mol/L、浸出温度100 ℃、浸出时间2 h条件下, 烟尘中砷、铁和铜浸出率分别为94.14%、93.80%、91.80%, 浸出渣主要物相为硫酸铅(PbSO₄);通过氧压沉砷处理浸出液, 使溶液中铁和砷形成臭葱石(FeAsO₄·2H₂O)而固化;沉砷后液主要物质为Cu²⁺和SO₄^2-, 可用于电解回收铜。该工艺可以实现铜烟尘中有价金属的综合回收, 同时将砷以臭葱石形式固化, 减少对环境的污染。     

湿法炼锌浸出渣湿法和火法联合处理工艺

为了综合回收锌浸渣中的有价金属,进行了弱酸渣酸浸减量化研究,减量后的渣进回转窑处理,酸浸混合液采用锌精矿还原处理－铁粉置换沉铜－锌焙砂预中和－氧化锌粉中和沉铟工艺来分离回收有价金属。采用酸浸工艺和回转窑工艺联合处理锌浸渣,可减少入窑渣量,降低能耗。结果表明,锌浸渣经酸浸可减量50%以上,锌粉中和沉铟工艺可实现锌回收率大于90%,铜回收率大于99%,沉铟后液铟小于5 mg/L。减量后的渣可富集铅、银等金属,该渣送回转窑挥发处理,产出的氧化锌烟尘可用于中和沉铟,中和过程既可使氧化锌中的锌预先浸出,又可进一步富集铟。该工艺可实现锌浸渣的无害化处理和资源综合利用。     

Drainage at Abandoned Mine Sites: Natural Attenuation of Contaminants in Different Seasons

Since 1996, hydrogeochemical surveys have been carried out in the abandoned Montevecchio Pb-Zn mining district (Sardinia, Italy), where mine drainages discharge directly into the local streams, to investigate variations in the aqueous occurrence of contaminants. Natural attenuation in dissolved contaminants occurs downstream of the abandoned mines. Iron is removed first (about 2 km downstream); lead, aluminum, and copper follow (about 4 km downstream). Other metals, such as zinc, cadmium, nickel, and rare earth elements, decrease further downstream. At high flow, natural attenuation is mainly due to dilution by rainwater. At low flow, natural attenuation processes are dominated by solid phase precipitation, efflorescent salt formation due to evaporation, and dilution by uncontaminated surface and/or groundwater inflow. Overall, concentrations of sulphate, Zn, Cd, Pb, Cu, Ni, and Co were less in 2010 than in 1996. The concentrations of dissolved sulphate and metals are lowest when the water is less acidic. However, despite ongoing natural attenuation, very high concentrations of toxic metals continue to be observed 15 years after the underground workings flooded. The amount of contaminants reaching the Marceddì lagoon increases as runoff increases following heavy rains.     

Dissolution behaviour of a Turkish lateritic nickel ore

The atmospheric pressure sulphuric acid leaching characteristics of Adatepe (Eski?ehir, Turkey) laterite ore that has recently been put into operation was investigated. The effects of sulphuric acid concentration (5-95%), temperature (20-95 °C) and time (30-240 min) on leaching were determined by nickel, iron and arsenic analyses. The amounts of Ni, Fe and As in solution were observed to increase with increase of temperature from 20 °C to 70 °C for sulphuric acid concentrations between 5% and 95%. Further increase of temperature to 95 °C showed that the dissolution of Ni, Fe and As were increased until 60% sulphuric acid concentration and over 60% a decrease in the dissolution percentages was observed due to the probable formation of nickel and silicon containing ferric sulphate type compounds that cause nickel loss from the leach solution. Experimental results showed that maximum nickel dissolution of 99.2% at 95 °C could be reached in 120 min of leaching time for a sulphuric acid concentration of 60%. The congruency of Ni dissolution with respect to Fe was found to be congruent over about 25% Ni and 15% Fe dissolution values. XRD analyses on the residues obtained after leaching showed that it was not required to dissolve all goethite phase to reach maximum dissolution of nickel contained in the sample. An activation energy of 30.36 kJ/mole was determined for Ni dissolution showing that leaching is controlled by external diffusion and chemical reactions.     

高镁低品位铜镍矿氧压硫酸浸出液综合回收研究

针对高镁低品位铜镍矿氧压硫酸浸出液特点,提出“Lix984萃取提铜-MgO中和黄钠铁矾法沉淀除铁-MgO中和沉镍”综合回收工艺。结果表明,采用Lix984可选择性萃取99.79%的铜,其他金属离子基本不萃取,经模拟工业贫铜电解液反萃,铜反萃率达98.13%,得到富铜电解液,可电积制备金属铜; 萃铜余液通过MgO中和黄钠铁矾法沉淀除铁,铁沉淀率达99.20%,镍损失率仅0.60%; 沉铁后液通过MgO中和沉淀回收镍,镍沉淀率为99.91%,并得到镍含量24.13%的氢氧化镍粗产品; 沉镍后的高浓度硫酸镁沉淀后液,可用于回收镁。     

铋精矿加压氧化氨浸高效分离铜、硫和铋

针对湖南柿竹园铋精矿火法冶炼过程中存在的成本高、低浓度SO₂和散烟排放污染环境、有价金属综合回收率低等问题, 以柿竹园铋精矿为原料, 提出了加压氧化氨浸分离铋与铜、硫的新工艺, 研究了氨水加入量、浸出温度、浸出时间、浸出压力及浸出液固比等因素对铜、硫、铋浸出率的影响。在氨水用量1.8 mL/g_铋精矿、液固比4∶1、釜压2.8 MPa、浸出温度160 ℃、浸出时间5 h、搅拌速度600 r/min的优化工艺条件下, 铜、硫浸出率分别达93.57%和92.87%, 铋不浸出并以氧化铋形态全部入渣, 实现了铜、硫与铋的高效分离。