锌焙砂浸出制备铁酸锌研究

本文以含锌53.35%、含铁13.51%及铁酸锌13.97%的锌焙砂为原料,在对锌焙砂粒度分析、X-荧光多元素半定量分析、XRD分析及锌铁物相分析基础上,采用硫酸做浸出剂,研究始酸浓度、液固比、搅拌速度、浸出温度、浸出时间等因素对浸出渣物性的影响。结果表明,获取高含量ZnFe_2O_4浸出产品的试验条件为:始酸浓度100 g/L、液固比8∶1、搅拌速度400 r/min、浸出温度75℃、浸出时间120 min。     

锌冶金中铁酸锌研究概述

本文介绍了铁酸锌的软磁特性、吸波特性、催化性能等性质及其在磁性材料、隐形材料、太阳能转换材料、气敏材料等方面的用途,以及在锌冶金等过程中铁酸锌的形成及其危害;简述了工业上处理铁酸锌的典型火法工艺回转窑挥发法、常用湿法工艺热酸浸出法及其他方法如烟化法、Ausmelt法、碳酸盐焙烧法、硫化焙烧法、高压浸出法、微波碱浸法、多段浸出法、盐浸法、多酸浸出法以及碱浸法等,指出其处理锌冶金中铁酸锌的实质均是破坏铁酸锌的晶体结构,使铁酸锌分解转化为其他物质,通过冶金、化学或物理方法回收锌铁,这些方法存在着能源和材料消耗大、工艺流程复杂、残渣处理难度大、生产成本高、环境污染等问题。同时,结合铁酸锌的特殊性质,对锌冶金副产铁酸锌的高效利用进行展望,提出了在不破坏铁酸锌的晶体结构前提下,将铁酸锌从锌冶金过程中作为产品独立分离出来的新思路。     

Microwave caustic leaching of electric arc furnace dust

Electric arc furnace (EAF) dust is a waste product which is generated when steel scrap is melted in an electric arc furnace. It contains high concentrations of iron, zinc and lead. Numerous pyrometallurgical and hydrometallurgical processes have been developed to treat this material. Only a limited number of these have reached commercialization and the majority have been pyrometallurgical. However, the hydrometallurgical processes, such as caustic leaching, offer some potential advantages.In the present research, the application of microwave radiation at 2.45 GHz was employed, as the energy source, in the hydrometallurgical caustic leaching process for EAF dust treatment. The variables which were investigated were: leaching time, microwave power, caustic concentration and the solid to liquid ratio. The experimental results showed that the zinc recovery from the dust increased with a decrease in the solid to liquid ratio and an increase in the microwave power. The optimum caustic concentration for the maximum zinc recovery was 8M. The rates of zinc recovery were significantly higher under microwave conditions as compared to those observed with conventional leaching. Some possible mechanisms to explain this behaviour are discussed.     

新型抑制剂在稀土尾矿综合回收萤石重晶石中的应用

四川某稀土矿山选厂尾矿含泥量大,萤石、重晶石品位均很低,重晶石矿物粒度较细,难以综合回收利用。采用自主研发的抑制剂SDN作为重晶石抑制剂,经混合浮选-萤石重晶石分离工艺选别,可得到Ca F2品位为97.28%、回收率为80.33%的萤石精矿和Ba SO4品位为90.45%、回收率为75.98%的重晶石精矿。新型抑制剂SDN为离子型小分子药剂,不仅能有效抑制重晶石,实现萤石与重晶石高效分离,还能有效避免絮凝现象导致的回水黏度越来越大,有利于生产顺利进行。     

从锌浸出渣中强化浸出锌锗的试验研究

针对云南某湿法炼锌浸出渣,采用硫酸强化浸出对渣中锌、锗、铁的浸出效果进行研究。正交试验结果表明:最优浸出条件为:溶出温度160℃,硫酸浓度为1.5 mol/L,浸出时间1.5 h,液固比为6。最优浸出条件下,锌和锗的平均浸出率分别高达96.77%和70.86%,有害元素铁的平均浸出率仅为55.44%,在抑制铁浸出的同时,保证了锌锗元素的高效浸出。     

Extraction of zinc from zinc ferrites by fusion with caustic soda

Zinc ferrites are one of the major forms of zinc in some wastes, such as steel mill EAF dusts and the leaching residues of roasted zinc sulfide concentrates. These ferrites can be very difficult to chemically decompose so that the zinc can be recovered. This decomposition is the key to the recovery of zinc in these solid wastes. In this work, the recovery of zinc from synthetic zinc ferrite was investigated. It was found that around 75–80% of the zinc in zinc ferrite can be extracted after being fused directly with NaOH pellets and dissolved in an alkaline leaching solution. The recovery increased to over 90% when the ferrite was hydrolyzed with water or dilute NaOH solution prior to the fusion step.     

锌中浸渣中锌和铟的SO_2还原浸出研究

目前湿法炼锌过程中的锌浸出渣处理工艺存在着有价金属回收率低、工艺技术指标差等问题。针对这些不足,开展了锌中性浸出渣的SO_2还原浸出研究。研究结果表明,与热酸浸出相比,采用SO_2还原浸出工艺能够显著提高原料中锌、铟的浸出率。用SO_2作还原剂,研究了温度,初始酸浓度,SO_2压力对中浸渣中锌、铟的浸出率的影响。在硫酸浓度为100g/L,反应温度110℃,液固比10∶1,时间120min,SO_2分压0.3MPa的浸出条件下,锌、铟的浸出率最高,分别为93.8%、92.3%。     

铁酸锌的应用现状及制备工艺

评述了近些年铁酸锌的应用现状,包括在处理工业废水、脱硫材料、高性能吸波材料、防腐涂料以及阻燃剂等方面。介绍了制备铁酸锌的机械化学合成工艺、溶胶-凝胶工艺、水热合成工艺、焙烧法工艺、共同沉淀工艺、金属有机盐热分解工艺等,概括出了各种工艺的原理、条件、优缺点以及发展状况。并指明了未来发展方向。     

高硅低铁锌焙砂中性浸出-液固分离试验研究

针对新疆某高硅低铁锌焙砂进行中性浸出—液固分离试验研究,详细考察了浸出时间、浸出液固比、浸出温度和始酸浓度对焙砂浸出和矿浆絮凝沉降的影响。结果表明,浸出温度、浸出时间和浸出液固比对锌的浸出影响较大,对硅的浸出影响不具明显规律;矿浆絮凝沉降受浸出条件影响较大,改变浸出液固比、初始酸度和矿浆浓度能够显著改善矿浆沉降性能。综合考虑锌、硅的浸出行为和矿浆沉降性能,最佳浸出工艺选择为:浸出温度70℃、浸出时间2.5h、液固比(mL/g)为8～10;中性浸出液初始酸度为40g/L时所得中性浸出渣含锌46.56%,渣率77.47%,锌的中性浸出率为45.06%,絮凝沉降矿浆浓度为4.5%。     

常压富氧浸出技术从含锗氧化锌烟尘回收锌和锗

针对湿法炼锌过程中稀散金属锗的浸出,以含锗氧化锌烟尘为原料,研究了采用常压富氧浸出技术从含锗氧化锌烟尘中回收锌和锗。通过氧化锌烟尘的XRD、SEM-EDS等分析,表明富锗氧化锌烟尘中除含有氧化锌烟尘外,还含有少量硫化锌与硫化铅,部分硫化锌与氧化锌混合形成致密颗粒。考察了铜离子浓度、时间、液固比、温度、氧压等因素对氧化锌烟尘浸出锌、锗的影响。结果表明,在常压富氧条件下,温度90 ℃、液固比7 mL/g时,采用二段浸出4 h,锌、锗的浸出率可超过90%;浸出渣主要物相为硫酸铅以及硫化锌。采用氧化锌烟尘做中和剂对酸浸溶液进行中和还原处理,控制溶液pH值为3~3.5,反应1 h,可将溶液中Fe3+浓度控制在0.02 g/L内,且该过程Ge不发生水解损失,有利于后续溶液中锗的高效分离。     

地电化学浸出动力学探讨

在地电化学浸出过程动力学分析的基础上,用2种矿化度的地下水为导电液,对2种岩性矿石样品的地电化学浸出试验数据进行动力学模型的数据处理,得到了以地下水为导电液的地电化学浸出动力学过程属于固膜扩散模型,而且是交叉的双直线模式的结论。     

Dynamic microbial populations in heap leaching of zinc sulphide ore

Polymerase chain reaction (PCR) technology was used to monitor the microbial population within two 6-m-high sulphide ore heaps where zinc was bioleached. Genomic DNA was isolated from microorganisms attached to the ore particles. The microbial population varied in diversity at different heap heights and at different stages of the leaching cycle. Nine bioleaching microorganisms were identified, including iron oxidizers, sulphur oxidizers, whether mesophiles, or moderate thermophiles. No bioleaching extreme thermophiles were detected. Moderate thermophiles were present at average heap temperatures of 40 °C or higher. No moderate thermophiles were present in the top 2 m of the heaps. Mesophiles were present throughout the lifetime of the heaps and at all heap depths. Cultures of Acidithiobacilluscaldus and Sulfobacillusthermosulfidooxidans originally introduced to inoculate the heaps did not proliferate but were instead displaced by other species; no benefits were obtained from heap inoculation. The most predominant species were Acidithiobacillus thiooxidans and Acidithiobacillus albertensis. Leptospirillum sp. was not predominant in the heaps, in contrast to the dominant role this organism plays in tank bioleaching operations.     

从云南某锌浸出渣中回收锌锗的试验研究

对锌浸出渣中锌、锗和铁进行高压选择性浸出,采用P204萃取去除浸出液中铁元素,使浸出液中的锌、锗元素得到富集。高压选择性浸出试验结果表明,锌的平均浸出率高达96.77%,锗的平均浸出率高达70.86%,而铁的平均浸出率仅为55.44%。萃取除铁试验表明,经三级萃取后,三价铁离子的萃取率大于99.5%,萃余液中三价铁离子浓度小于0.01 g/L,可循环进入湿法炼锌工艺中使用。     

锌中浸渣-硫化锌精矿协同浸出锌、铟的研究

本文在硫酸体系下对锌中浸渣-硫化锌锌精矿协同浸出工艺与锌中浸渣直接热酸浸出工艺进行了对比。实验结果表面：添加锌精矿进行协同浸出能够有效提高锌中浸渣中有价金属锌、铟和铁的浸出率。在实验的基础上,对锌中浸渣-锌精矿协同浸出机理进行了探讨,为协同浸出提供了理论依据。     

难处理复杂氧化锌烟尘碱洗渣浸出试验研究

对铅冶炼难处理复杂氧化锌烟尘碱洗渣进行了"中性浸出—酸浸"工艺试验研究。结果表明,碱洗渣中性浸出时,锌、镉的浸出率先随浸出温度、液固比、搅拌速度和时间的增加而提高,后增速变缓;中浸渣酸浸时,液固比对锌、铟的浸出率无明显影响。锌、铟的浸出率随初始酸度、浸出温度和时间的增加先增加后变缓。中性浸出最佳条件为:温度338K、液固比5∶1、搅拌速度400r/min、浸出时间1h,此条件下,锌、镉的浸出率分别为80.3%和76.3%。中浸渣酸浸最佳条件为:初始酸度100g/L、浸出时间2h、浸出温度363K、液固比5∶1,在该条件下,锌、铟的浸出率分别为97.1%和85.5%。     

Bioleaching and chemical leaching as an integrated process in the zinc industry

This work sought to integrate bioleaching and chemical leaching as a cost-effective process to treat zinc sulphides. The continuous bioleaching of a sphalerite concentrate, assaying 51.4% Zn, 1.9% Pb, 31.8% S and 9.0% Fe with mesophile iron and sulphur-oxidizing bacteria followed by chemical leaching of the bioleaching residue were assessed. In the bioleaching step, the first reactor was used to produce Fe(III) concentrations as high as 20 g/L. This solution was fed to the subsequent bioleaching reactors to oxidize sphalerite. It was possible to achieve 30% zinc extraction for 70 h residence time. In chemical leaching experiments, carried out with the residue of the bioleaching step, the effects Fe_total and acidity on zinc extraction were studied. It was noticed that Fe(III) concentrations over 12 g/L did not affect zinc recoveries. Furthermore, the higher the acidity, the larger the zinc recovery, for experiments carried out up to 181 g/L sulphuric acid. The results have demonstrated that it is possible to devise a new process capable of achieving 96% zinc extraction, similarly to the conventional roasting–leaching–electrolysis process.     

浮选柱在锌系统浸出渣选银中的应用

主要介绍了浸出渣的性质、工艺试验、选择浮选柱的理由,通过浮选柱三年的生产运行,精矿银回收率达到71.25%,银品位7 828 g/t,年创效益3 000余万元。浮选柱在生产实践中的成功应用对于企业提高技术经济指标、节能降耗、增加效益具有重要借鉴意义,值得大力推广。     

锌冶金副产铁酸锌颜料制备防腐涂料及其性能研究

针对工业副产铁酸锌资源高效利用问题,利用锌冶金副产铁酸锌为颜料制备一种防腐涂料。采用XRD、SEM等方法对颜料进行表征,研究不同颜基比条件下制备的涂料涂层的硬度、附着力等物理性质,及其耐酸性、耐碱性以及耐盐水性等。结果表明,采用锌冶金副产铁酸锌产品作为防腐颜料是可行的。使用该铁酸锌颜料能明显增加涂料涂层的硬度和附着力,及其涂层的耐酸性、耐碱性和耐盐水性。     

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。     

锌浸出渣银浮选回收实验初探

某锌浸出渣中含银228.24g/t,该浸出渣具有粒度细、酸性强、银的物象分布复杂等特点。针对该浸出渣,实验采用添加乳化煤油选择性絮凝矿浆中的微细颗粒增大表观粒度,并通过洗矿调节矿浆PH值以及降低矿浆中锌离子的浓度。实验结果表明：在PH=5.47的条件下,以六偏磷酸钠为分散剂,丁铵黑药为捕收剂,MIBC为起泡剂,采用一粗二扫浮选工艺流程,可获得含银3439g/t,回收率为76.54%的浮选精矿。