脱除铜阳极泥中贱金属的预处理工艺

提出用碱性NaOH体系加压氧化浸出和硫酸浸出相结合的工艺预处理铜阳极泥,即铜阳极泥在碱性NaOH体系加压氧化浸出,使As和Se氧化后溶解,Cu和Te被氧化后沉淀,然后用硫酸溶液浸出碱性浸出渣中的Cu和Te,实现铜阳极泥中贱金属的有效脱除.研究结果表明:无论碱性直接浸出或酸性直接浸出,都不能有效分离铜阳极泥中的有价金属;不同强化方式下的碱性KOH体系浸出过程,都不能达到同时脱除As和Sb的目的;碱性NaOH体系加压氧化浸出在NaOH浓度为2.0 mol/L和温度为200℃时,不仅在碱性浸出过程As和Se的浸出率都达到99.0％以上,而且碱性浸出渣硫酸浸出时Cu和Te的浸出率分别达到95.64％和77.38％.     

铜阳极泥预处理连续加压酸浸工艺开发研究

绍了新开发出来的一种具有较好工业应用前景的铜阳极泥预处理新工艺,小型及半工业试验结果表明,铜阳极泥直接加压酸浸,可以充分利用生阳极泥中水溶性铜离子的催化氧化作用,提高反应速度;在连续浸出过程中Ag,Se,Te走向与间断浸出过程差别明显,使浸出效果优于间断加压浸出预处理工艺,有利于提高有价元素的综合回收。     

稀硫酸浸出处理铅阳极泥

采用焙妙氧化－稀硫酸浸出处理铅阳极泥，技术可行，流程合理，银、铜的直收率均在９８％以上。     

杂铜阳极泥硫酸化焙烧-浸出工艺提取Cu和Ni的试验研究

杂铜阳极泥中含有大量的贵金属和稀有金属元素,是提取贵金属和稀有金属元素的重要原料,杂铜阳极泥处理的第一步即是提取Cu、Ni等贱金属,以富集贵金属和稀有金属元素.采用硫酸化焙烧-浸出工艺,从杂铜电解产生的阳极泥中提取Cu和Ni.考察焙烧温度、焙烧时间、浸出液固比、浸出硫酸浓度以及浸出时间等因素对Cu、Ni和Sn浸出率的影响.结果表明：当焙烧温度为400℃、焙烧时间3 h,浸出时液固比为4：1,100 g·L^-1硫酸、温度为80℃的条件下,Cu、Ni的浸出率>96.6%,可以有效地实现杂铜阳极泥中Cu和Ni的提取,而Sn的浸出率为13.0%,浸出渣可以作为提取Sn和贵金属的原料.     

难处理铜钴合金的氧化酸浸出

采用硫酸和盐酸的混合酸在有氧化剂存在的常压条件下对磨细后的铜钴合金进行浸出.试验结果表明:在溶液初始酸度为5.0～6.5 mol/L,硫酸与盐酸摩尔比较低,酸过量系数φH为1.2,氧化剂加入量ψn为理论量的1.2倍,反应温度为80 ℃,反应时间为70 min,搅拌速度为200～300 r/min的条件下,铜钴浸出率均能达到97%以上,浸出过程中不会有硅胶产生,过滤性能良好,实验重现性好.     

铜阳极泥预处理富集金银的研究

对铜阳极泥预处理富集金银进行研究。先经硫酸预浸脱铜,当反应温度为353K,H2SO4与Cu的物质的量比n(H2SO4):n(Cu)为1.5,液固比为3:1,反应时间为1.5h时,铜浸出率达到90%;脱铜阳极泥再与碳酸钠进行球磨转化后硝酸浸出脱铅;当球磨时间为3h,Na2CO3与Pb的物质的量比即n(Na2CO3:n(Pb)为2.5,液固比为2:1,球料比为8:1,HNO3与Pb的物质的量比即n(HNO3):n(Pb)为6.0,浸出时间为0.5h,浸出温度为296K时,铅浸出率为69.5%。研究结果表明:经上述预处理后阳极泥金、银含量分别从0.152%和7.81%增加到0.31%和13.7%,阳极泥量减少一半,大大提高了回转窑生产能力,并减少了SO2的排放量。     

盐酸和氯酸钠浸出铜阳极泥中金的研究

以铜阳极泥为原料,采用盐酸和氯酸钠为浸出剂,根据同时平衡原理,对浸出过程进行了热力学分析,考察了浸出时间、液固比、氯酸钠浓度和盐酸浓度对金浸出率的影响。研究结果表明,总金浓度[Au]T的降低和总氯浓度[Cl-]T的增加均有利于金的浸出。随着总氯浓度的增加,体系中含金物种的主要存在形态发生Au~(3+)→AuCl_3(aq)→AuCl_4~-→AuCl_2~-的转变,理论最佳浸出剂组成为盐酸与氯酸钠摩尔浓度比为6∶1。在搅拌速度为400r/min、液固比为4∶1、浸出时间为3h、盐酸浓度为3.0mol/L、氯酸钠浓度为16g/L、反应温度为25℃的条件下,金的最大浸出率为98.89%。     

添加锌电解阳极泥对ZnS浸出过程的影响

在锌焙烧烟尘热酸浸出过程中,来自于铁酸锌溶解的三价铁离子被用作焙烧烟尘中ZnS浸出的氧化剂.为了提高锌的浸出率,研究了在浸出过程中加入锌电解阳极泥对ZnS浸出的影响.考察的浸出条件包括阳极泥加入量、温度、硫酸浓度和反应时间.试验结果表明,阳极泥中的MnO2有助于焙烧烟尘中ZnS的氧化浸出.在最佳的条件下,通过加入阳极泥(锰加入量为焙烧烟尘质量的4%)可将锌的浸出率由94%提高到97%以上.     

黑铜泥碱性浸出工艺及机理探讨

以黑铜泥为原料,研究黑铜泥碱性浸出的工艺条件,从而使Cu、Sb、Bi和As有效分离,并探讨浸出过程的动力学机理.实验结果表明:在最佳碱浸条件下,黑铜泥中As的浸出率为92.84%,Cu的浸出率为1.43%,Sb的浸出率为2.92%,Bi的浸出率为1.26%.黑铜泥碱浸出过程在动力学上符合液-固反应的收缩性未反应核模型,...     

富硼渣硫酸浸出试验研究

以富硼渣为原料，在１．５ｍ＾３浸出罐中进行硫酸浸出试验，硼的浸出率主要与富硼渣的结构，粒度，加酸量及浸出时间和温度等因素有关，试验结果表明，富硼渣中硼只要以遂安石晶体存在，粒度在０．１８～０．１６ｍｍ加酸量为８０％，浸出时间９０ｍｉｎ温度９５～１００℃硫酸浸出率可大于９０％。     

Ultra fast microwave-assisted leaching for the recovery of copper and tellurium from copper anode slime

The decomposition of copper anode slime heated by microwave energy in a sulfuric acid medium was investigated. Leaching experiments were carried out in a multi-mode cavity with microwave assistance. The leaching process parameters were optimized using response surface methodology (RSM). Under the optimized conditions, the leaching efficiencies of copper and tellurium were 99.56% ±0.16% and 98.68% ±0.12%, respectively. Meanwhile, a conventional leaching experiment was performed in order to evaluate the influence of microwave radiation. The mechanism of microwave-assisted leaching of copper anode slime was also investigated. In the results, the microwave technology is demonstrated to have a great potential to improve the leaching efficiency and reduce the leaching time. The enhanced recoveries of copper and tellurium are believed to result from the presence of a temperature gradient due to the shallow microwave penetration depth and the superheating at the solid-liquid interface.     

Alkaline pressure oxidative leaching of bismuth-rich and arsenic-rich lead anode slime

A new alkaline pressure oxidative leaching process(with NaNO3 as the oxidant and NaOH as the alkaline reagent)is proposed herein to remove arsenic,antimony,and lead from bismuth-rich and arsenic-rich lead anode slime for bismuth,gold,and silver enrichment.The effects of the temperature,liquid-to-solid ratio,leaching time,and reagent concentration on the leaching ratios of arsenic,antimony,and lead were investigated to identify the optimum leaching conditions.The experimental results under optimized conditions indicate that the average leaching ratios of arsenic,antimony and lead are 95.36%,79.98%,63.08%,respectively.X-ray diffraction analysis indicated that the leaching residue is composed of Bi,Bi2O3,Pb2Sb2O7,and trace amounts of NaSb(OH)6.Arsenic,antimony,and lead are thus separated from lead anode slime as Na3AsO4·10H2O and Pb2Sb2O7.Scanning electron microscopy and energy-dispersive spectrometry imaging revealed that the samples undergo appreciable changes in their surface morphology during leaching and that the majority of arsenic,lead,and antimony is removed.X-ray photoelectron spectroscopy was used to demonstrate the variation in the valence states of the arsenic,lead,and antimony.The Pb(IV)and Sb(V)content was found to increase substantially with the addition of NaNO3.     

Extraction of vanadium from vanadium slag by high pressure oxidative acid leaching

To extract vanadium in an environment friendly manner, this study focuses on the process of leaching vanadium from vanadium slag by high pressure oxidative acid leaching. Characterizations of the raw slag, mineralogy transformation, and the form of leach residues were made by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The result shows that the vanadium slag is composed of major phases of fayalite, titanomagnetite, and spinel. During the high pressure oxidative acid leaching process, the fayalite and spinel phases are gradually decomposed by sulfuric acid, causing the release of vanadium and iron in the solution. Meanwhile, unreacted silicon and titanium are enriched in the leach residues. With the initial concentration of sulfuric acid at 250 g·L-1, a leaching temperature of 140℃, a leaching time of 50 min, a liquid-solid ratio of 10:1 mL·g-1, and oxygen pressure at 0.2 MPa, the leaching rate of vanadium reaches 97.69%.     

Sulfuric acid leaching of high iron-bearing zinc calcine

Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.     

Sulfuric acid leaching kinetics of South African chromite

The sulfuric acid leaching kinetics of South African chromite was investigated. The negative influence of a solid product layer constituted of a silicon-rich phase and chromium-rich sulfate was eliminated by crushing the chromite and by selecting proper leaching conditions. The dimensionless change in specific surface area and the conversion rate of the chromite were observed to exhibit a proportional relationship. A modified shrinking particle model was developed to account for the change in reactive surface area, and the model was fitted to experimental data. The resulting model was observed to describe experimental findings very well. Kinetics analysis revealed that the leaching process is controlled by a chemical reaction under the employed experimental conditions and the activation energy of the reaction is 48 kJ·mol-1.     

漂浮阳极泥中铋的提取与三氧化二铋的制备

漂浮阳极泥经过盐酸浸出、稀释水解、氢氧化钠中和得到氯氧铋,氯氧铋经过氢氧化钠转化制备得到三氧化二铋.当盐酸浓度为6mol/L,固液比为1∶5,反应温度为80℃,反应时间为1h时,漂浮阳极泥中锑和铋浸出率分别达到99.17％和99.08％.当稀释比为8∶1时,盐酸浸出液中锑水解率为98.13％,铋水解率仅为8.8％.稀释后液中加入氢氧化钠溶液,当pH为1.5时,铋水解率达到99.5％,水解产物氯氧铋(BiOCl)中铋、氧、氯的质量分数分别为54.23％,19.30％和14.61％.氯氧铋再次经过盐酸浸出,稀释水解,氢氧化钠沉淀得到氯氧铋.除杂后氯氧铋经过硫酸洗涤、氢氧化钠转化,当氢氧化钠浓度为6mol/L,液固比为3∶1,反应温度为80℃时,反应2h后过滤,用0.5mol/L盐酸洗涤得到形貌为纤维状、晶型为单斜的α-Bi2O3,氧化铋纯度达到99.81％.     

碱性氧化铜矿产氨菌浸出特性

为了研究碱性氧化铜矿产氨菌浸出特性,分析了产氨菌浸矿过程对矿石的作用.将云南某矿的碱性氧化铜矿置于含菌培养液、去菌培养液和氨水等5种浸矿溶液中,在同一条件下进行摇瓶浸矿实验,剖析溶液中各可能的浸矿因子.研究结果表明:产氨菌产氨能力较强,尿素培养液中氨质量浓度最大达8.93 g·L-1;产氨量与细菌含量呈正相关关系,细菌含量越高,产氨量越大;产氨菌主要通过产氨间接浸矿,此外产氨菌和其代谢产物都能直接作用于矿石,浸矿能力细菌产氨>细菌>细菌代谢产物,三者比值约为12:5:4.