锌浸出渣镓、锗的综合回收技术及进展

湿法炼锌厂的浸出渣是镓、锗的主要二发资源，本文综述了锌浸出渣中镓、锗的主要回收技术及国内外近年来的研究进展．为冶炼厂综合回收镓、锗提供了参考。     

从拜耳法母液中回收镓

引言 1871年,D·I·门捷列夫预言了镓的存在,他根据其周期系把它称为类铝。1875年,P·E·Lecog de Boisbaudran用光谱方法在闪锌矿中发现一种新的元素。后来,他把它分离,并研究其特征;它们与预言为类铝的物质完全相同。在化学上,镓呈酸性在pH=4和pH=9之间形成氢氧化物。从30～1900℃,金属镓呈液态。当伴生有砷或磷之类的元素时,它成为一种半导体。它的半导体性能比硅好,由于这个原因,被广泛地看作优良的微电子元件。     

从砷化镓废料中回收镓

砷化镓的单透射速率比硅快5倍，用于高速运转的资料处理系统，可提高效率和质量．由于GaAs的能带结构特点，它比硅有更好的光学性能和辐射强度．因此，GaAs的应用研究正在广泛地进行，例如高级计算机，激光，通讯设备及其附属设施，宇航和军事用途等．应用领域对GaAs的需求日益增长．但是，在GaAs品片的生产过程中，大量废料未经处理就被废弃（如韩国达到85％）．在GaAs废料中，Ga含量接近50％，其典型成分见下表：通常，金属像是铝工业和锌工业冶金过程的副产品，从废料中回收的镓很少．曾有关于从煤飞灰回收镓的报道，但这种飞灰镓含…     

烟尘中微量锗的测定

研究了Ge(Ⅳ)与槲皮素(Quercetin)、十二烷基苯磺酸钠(SDBS)、聚乙烯醇(PVA)混合体系的显色反应特性.在1.4～3.8 mol/L HCl范围内,最大吸收峰(λmax)为470 nm处、摩尔吸光系数ε470为1.8×105L·mol-1·cm-1.在SDBS和PVA混合表面活性剂存在下,配合物的组成比为Ge(Ⅳ)∶Quercetin=1∶3.0～20μgGe(Ⅳ)/50 ml范围内,服从比尔定律.在混合掩蔽剂存在下,几乎没有干扰离子.已成功地应用到测定烟尘中微量锗的含量,结果十分满意.     

从锌置换渣中分段浸出锌、铅、镓和锗

采用分段浸出方法从锌置换渣中选择性提取锌、铅、镓和锗.首段浸出过程通过控制合适的硫酸浓度与液固比条件,锌和镓的浸出率达到90％和99％以上,超过92％的锗留在硫酸浸出渣中;二段采用盐酸作为浸出剂选择性提取铅,铅的浸出率为99％,锗损失率小于2％;三段采用1 mol/L氢氧化钠作为浸出剂,通过破坏硅锗固溶体的结构,实现锗...     

谈谈含铅烟尘的综合回收设计

根据含铅烟尘的原料成分、性质等,通过技术方案比选,设计出综合回收含铅烟尘中的有价金属工艺流程及其控制参数的设备大小,可取得良好的环境效益。     

氧化锌烟尘中锗的浸出行为

针对锌浸渣烟化挥发产生的氧化锌烟尘中锗浸出率低、氧化锌烟尘浸出渣中锗含量高的问题,开展了锌浸渣烟化挥发过程不同收尘器收集的氧化锌烟尘中锗的浸出行为研究,分析了锗、铁、硅浸出的相关性,考察了锗的浸出行为、渣中锗的赋存状态,揭示了渣中锗难以被进一步浸出的原因。并在此基础上,对氧化锌烟尘浸出渣进行硫酸浸出分解铁酸盐-盐酸浸出解离硫酸铅-氢氟酸浸出解离硅酸盐的梯级强化浸出。结果表明：混合氧化锌烟尘中锗主要赋存于硅酸盐及固溶体中,尤其是锅炉尘中铁酸盐和硅酸盐较高,制约了锗浸出率的提高;影响锗浸出率的关键因素是氧化锌烟尘中铁、硅含量,渣中不溶锗主要赋存于难溶硅酸盐矿物及固溶体中,提高锗浸出率的关键是硅酸盐的解离;在硫酸体系下,采取高温高酸浸出解离难溶铁酸锌及含硅矿物,控制过程硅的浸出与沉淀,可进一步提高锗的浸出率。     

锌粉置换镓锗渣草酸浸出过程

考察锌粉置换镓锗渣草酸浸出过程中,草酸浓度、浸出时间、液固比、浸出温度、双氧水浓度对镓、锗、锌、铁、铜、硅浸出率及浸出料浆过滤性能的影响,揭示在草酸浸出体系下添加双氧水促进镓、锗浸出的作用机理。结果表明,采用草酸和双氧水为浸出剂,不仅可实现镓、锗的选择性浸出,还可显著改善浸出料浆的过滤性能。双氧水促进镓、锗浸出的机理为其作为氧化剂使镓、锗单质及其硫化物氧化为可溶的氧化物;草酸与镓、锗可生成稳定络合物,而与硅的作用较弱,从而促进镓、锗的浸出,同时使浸出渣的过滤性能得以改善。在草酸浓度为110 g/L、双氧水浓度为0.12 mol/L、液固比(L/S)为8、搅拌速度为 300 r/min、浸出温度为40 ℃、浸出时间为30 min 的条件下,镓和锗浸出率分别为99.32%、98.86%,而铜、锌、硅的浸出率分别在0.82%、0.84% 、0.43%,且浸出料浆的过滤速度由常压硫酸浸出体系下的0.48 mL/min 提高到100 mL/min。     

Recovering germanium from coal ash by chlorination with ammonium chloride

A new process of enriching germanium from coal ash was developed.The process involves in mixing the coal ash and ammonium chloride and then roasting the mixture to produce germanium chloride that is then absorbed by dilute hydrochloric acid and hydrolyzed to germanium oxide.The germanium recovery reached to 80.2% at the optimum condition:mass ratio of NH4Cl/coal ash is 0.15,roasting temperature 400℃ and roasting time 90min.     

含锗真空炉渣在HCl-CaCl2-H2O体系中浸出锗的动力学研究

为提高真空炉渣中锗的浸出率提供理论依据,对含锗真空炉渣在HCl-CaCl2-H2O体系中锗的浸出动力学进行了研究。结果表明,浸出过程属于生成固体产物层的\"未反应核收缩模型\",其宏观动力学方程为:1–2/3x–(1–x)2/3=4.66×10-3CHCl1.027CCaCl21.046d-0.862exp(–21068/RT)t,表观活化能为21.068kJ/mol,浸出过程受灰分层扩散控制;提高盐酸的浓度、氯化钙浓度、浸出温度、液固比及减小矿物粒度均可加快锗的浸出速度,提高锗的浸出率。     

锌粉置换镓锗渣硫酸浸出过程

考察锌粉置换镓锗渣硫酸浸出中,硫酸浓度、温度、液固比、浸出时间和添加剂对Ga、Ge浸出率及浸出渣过滤性能的影响,揭示添加硝酸钠和十二烷基磺酸钠促进浸出过程的作用机理。结果表明:浸出液中添加适量硝酸钠或十二烷基磺酸钠,均可促进Ga、Ge浸出;此外,十二烷基磺酸钠还可改善浸出渣的过滤性能。添加剂的作用机理为硝酸根能使Ga、Ge单质及其硫化物氧化,从而促进Ga、Ge浸出;十二烷基磺酸钠则通过促进溶液中硅胶的絮凝,减少其对Ga、Ge的吸附,同时,使浸出渣的过滤性能得以改善。在温度为90 ℃、液固比为10 mL/g、搅拌速度为300 r/min、浸出时间为4 h、硫酸浓度为156 g/L、硝酸钠浓度为52.29 g/L、十二烷基磺酸钠浓度为20.5 g/L的条件下,Ga和Ge的浸出率可分别达到97.01%和90.45%,浸出料浆过滤速度由未添加十二烷基磺酸钠时的0.48 mL/min提高到30.65 mL/min。     

黄磷电炉电尘浆提取镓的预处理

根据在电炉还原炼磷过程中, 磷灰石中的镓在电尘浆中高度富集, 成为可供利用的镓资源, 提出了一种提取镓的预处理技术：用浓硫酸熟化电尘, 将其中的镓先转化成水溶性化合物, 再从预处理物料中浸出镓。 考察了预处理过程中电尘的化学和矿物学变化以及影响镓提取率的因素, 并给出了适宜的预处理条件;在最佳质量比电尘∶水∶硫酸=1∶1∶1, 200℃下熟化2h。 实验结果表明, 在优化条件下将预处理的电尘在80℃浸出1h, 镓的浸出率可达90%以上。     

Leaching of gallium from corundum flue dust using mixed acid solution

In order to extract gallium from a high-silica-content flue dust generated in corundum production, a mixed acid solution of H₂SO₄ and HF was used for leaching, and test parameters of the leaching process were optimized. Experimental results show that the leaching rate of gallium was only 38% when H₂SO₄ was used as leaching agent. Composition analysis results of micro areas in this corundum flue dust indicate that the content of gallium in silica-enriched phases was high; this portion of gallium was insoluble in H₂SO₄ solution. The leaching rate of gallium increased significantly with addition of HF due to corrosion of silica. Effects of reaction time, temperature, and concentrations of HF and H₂SO₄ on leaching rates of gallium were investigated. The leaching rate of gallium reached 91% when this corundum flue dust was leached in a mixed acid solution of H₂SO₄ and HF for 4 h, at a temperature of 80 °C, with a liquid-to-solid ratio of 5:1 (mL/g). The optimal concentrations of H₂SO₄ and HF in the mixed acid solution were 1.5 and 6.4 mol/L, respectively.     

锌粉置换镓锗渣高压酸浸的浸出机理

研究锌粉置换镓锗渣的高压酸浸过程,考察硫酸浓度、液固比、浸出时间、浸出温度、助浸剂种类和添加量对Ga、Ge浸出率以及浸出渣过滤性能的影响。结果表明：增加硫酸浓度有利于Ga、Ge的浸出,但硫酸浓度超过156 g/L后,反而不利于Ge的浸出。浸出时间和温度对Ga、Ge浸出率影响较小,但增加浸出时间或提高反应温度均有利于改善浸出渣的过滤性能。添加硝酸钠或硝酸钙均可促进Ga、Ge的浸出,且硝酸钙的添加还可改善浸出渣的过滤性能。在硫酸浓度156 g/L、助浸剂硝酸钙60 g/L、液固比8、浸出温度150 ℃下浸出3 h,Ga、Ge浸出率可分别达到98%和94%以上,且浸出料浆过滤速度较常压酸浸时的提高近20倍。     

Recovery of gallium from phosphorus industry flue

The flue dust generated during electric furnace production of elemental phosphorus was investigated for the recovery of gallium. Then the flue dust was slurried with water and blended with concentrated sulfuric acid, followed by ageing. The gallium in the dust was thereby converted to soluble sulfate. The factors affecting the dust curing were investigated to understand the process chemistry of the pretreatment. The optimal curing conditions are determined as follows: the mass ratio of dust to water and acid is 1 : 1 : 1, ageing temperature and time are 200℃ and 2h, respectively. Almost all the gallium available to acid dissolution in the dust, about 90% gallium, can be extracted by leaching the cured dust at 80℃ for 1h.     

Hydrochloric acid recovery from rare earth chloride solutions by vacuum membrane distillation

The possibility of the recovery of hydrochloric acid from rare earth （RE） chloride solutions was first experimentally studied by batch vacuum membrane distillation （VMD）. The recovery by continuous VMD was also studied to devise methods that enabled the operation of VMD setup in a stable condition as well as to increase the membrane-operating life The results indicated that HCl separation with RE by VMD was possible, and the recovery ratio of 80% could be achieved by batch VMD. In continuous VMD, when the temperature of circular solutions, circular rate, and downstream pressure was 62-63℃, 5.4 cm/s, and 9.33 kPa, respectively, the HCl concentration in circular solutions and the processing capacity per membrane area were obtained. The mathematical results were in accordance with the experimental ones.