针铁矿除铁法在锌氧压浸出工艺生产的应用研究

当今锌氧压浸出工艺已成为锌冶炼的主要趋势,该工艺绿色环保,锌精矿中的硫元素以单质硫的形式回,从根本上解决了火法炼锌产出的二氧化硫等气体对环境的污染,针铁矿除铁工艺是整个锌氧压浸出工艺中关键核心技术之一,针铁矿工艺除铁渣产出量少、有价金属夹带少、过滤效果好等优势,在生成针铁矿同时,能够吸附系统溶液中的Ga、Ge、F、TOC等杂质,达到共脱除的效果。本课题对连续大规模针铁矿除铁法在锌氧压浸出湿法炼锌工艺的应用研究,分析了该工艺的控制要点,探索锌湿法冶炼除铁的发展和方向。     

硫化锌精矿氧压浸出过程中的沉铁机理

硫化锌精矿中的铁在氧压浸出过程浸出进入溶液后,在后续除铁的同时要向溶液中鼓压缩空气,利用其中的氧气将溶液中的亚铁离子氧化成三价铁离子进行针铁矿除铁,而针铁矿除铁系统庞大,生产成本高,尤其高海拔地区空气含氧量低,除铁效果也会大打折扣,从而影响后续工序的正常生产以及锌锭产品的品质。因此,找到硫化锌精矿氧压浸出过程中的沉铁机理,通过控制浸出工艺参数,尽量将铁在浸出过程中沉入渣中,对简化氧压浸出工艺流程具有重大意义。本文通过对硫化锌精矿氧压浸出锌冶炼过程中沉铁机理进行分析,为硫化锌精矿氧压浸出生产操作参数的确定提供参考。     

一种从硫化锌精矿直接浸出锌同时除铁的方法

介绍了一种从硫化锌精矿直接浸出锌同时除铁的方法,利用氧压浸出除铁原理。控制反应器温度压力及酸度,在浸出锌的同时将铁沉淀在浸出渣中,不需单独除铁工序,锌浸出率高,沉铁率高,与传统除铁方法比较,实现了浸出锌与沉铁在一个反应器中完成,具有清洁生产,节能环保的明显优势。     

热酸浸出—铁矾法除铁湿法炼锌工艺中锗的回收

本文以含锗锌精矿为处理原料,从热酸浸出-铁矾法除铁湿法炼锌流程中回收锗时采用从沉矾后溶液中中和沉淀回收锗的方案是可行的。可用CaO或焙砂作中和剂.     

硫化锌精矿焙烧浸出与直接浸出结合提锌同时除铁的方法

介绍了一种硫化锌精矿焙烧浸出与直接浸出结合提锌同时除铁的方法,利用硫化锌精矿氧压浸出除铁原理,浸锌同时除铁,取消了热酸浸出的除铁过程,简化了设备及工艺流程,提高了锌回收率,可以达到节能、环保、高效。     

高铁硫化锌精矿加压浸出研究及产业化

采用加压浸出技术处理高铁锌精矿,完成了小型试验、半工业试验和工业性试验并投入工业化生产。工业性试验的锌浸出率98.05%、铁浸出率29.22%,较好地实现了锌的选择性浸出;浸出液残酸39.15g/L,浸出液中的铁含量5.71g/L,可以用沉矾除铁工艺进行处理。     

采用加压浸出工艺优化传统湿法炼锌流程研究

用传统湿法炼锌厂的热酸浸出液在高压釜中浸出锌精矿。结果表明,在温度130℃,液固比14∶1,精矿粒度-50μm占96%,浸出时间3h,氧分压600kPa,添加木质素磺酸钙0.4%的条件下,锌浸出率达97%以上,浸出液中的铁含量低于2g/L,加压浸出液可直接返到传统湿法炼锌流程的中性浸出,同时精矿中的硫以元素硫形式进入渣相。该工艺流程易与传统湿法炼锌厂现有流程结合,具有同时浸锌除铁、工艺流程简单、对环境友好等优点。     

湿法炼锌浸出渣与锌精矿联合浸出工艺研究

开展湿法炼锌浸出渣和锌精矿联合酸浸试验,利用硫酸浸出湿法炼锌常规浸出渣中以铁酸锌等方式存在的锌,同时采用高铁锌精矿将浸出液中的三价铁离子还原为二价铁离子,实现锌精矿中锌的同步浸出。探讨锌浸出渣和锌精矿投料比、初始硫酸浓度、反应时间、液固体积质量比和浸出温度对锌及伴生金属铜、铟和杂质金属铁浸出率的影响。结果表明,在浸出终点浸出液中硫酸浓度20～40g/L、锌浸出渣与锌精矿质量比1∶0.25、原料粒度-0.074mm、液固体积质量比6mL/g、反应温度90℃、反应时间3h的条件下,锌、铟、铜的浸出率都在96%以上,浸出液中95%以上的铁被还原为二价铁离子,满足后续工艺的要求。     

科明科Trail锌厂的氧压浸出

科明科Trail锌厂是世界上第一个锌氧压浸出厂。它于1981年开始生产,每天处理190吨沙利文锌精矿。锌精矿在有四个室的高压釜中进行高温氧压浸出,获得硫酸溶液和元素酸。锌浸出率大于98％,酸化物转化为元素硫的转化率大于95％。     

锌氧压渣中铁复相强化溶出规律及浸出动力学

在锌冶炼的氧压浸出工艺中,由于铁复杂相的存在,使得铁浸出率不高,导致锌氧压浸出渣中仍存在一定量铁资源未能有效回收。以广东某冶炼厂锌氧压渣为研究对象,首先进行详细的工艺矿物学研究,然后采用硫酸化焙烧-溶液浸出的方法对锌氧压渣中的铁复相进行强化分解及高效溶出。得到了较优的试验条件为:焙烧温度300℃、酸渣质量比0.4、焙烧时间2.0 h、浸出时间1.0 h、浸出温度80℃,液固比L/S=5/1,此时铁浸出率为83.31%,锌浸出率达到97.06%。最后,对铁复相的溶液浸出动力学进行了研究,得到了浸出反应的表观活化能为23.18 kJ/mol,并建立了半经验动力学方程。     

Reaction mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust

Abstract

The experiments in this paper were performed to research the mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust. The reduction potential of zinc during cementation was determined to investigate the morphology of products. Residues after the cementation process from zinc sulphate solution were analyzed by SEM and EPMA to investigate the morphology of products. Different temperature will cause different structure of particles. The reaction mechanism of cobalt removal by zinc dust is thought to be as follows: first, the Co2+ forms Co–Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; second, the Co–Zn alloy continues reacting to Co with Co2+, which is the control process of the whole reaction.     

Reduction roasting of high iron bearing zinc calcine for recovery of zinc and iron

High iron bearing zinc sulphide ore is an important resource for zinc, and the reserve is very great in the world. It is very difficult to effectively obtain zinc and iron from the source by traditional technology. In this study, a novel method was proposed for recovery of zinc and iron from high iron bearing zinc calcine, and the key procedure, reduction roasting, was investigated. The effects of CO concentration, CO₂ concentration, temperature and time on reduction roasting were studied respectively. The experimental results show that the content of soluble zinc and magnetic susceptibility reached 91·15% and 4·1×10^?4 m³ kg^?1 under the optimum conditions respectively. About 90%Zn and 9·5%Fe were dissolved from the reduction roasted zinc calcine by low acid leaching, and simultaneously, 84·3%Fe was recycled to the iron concentrate containing iron of 53·2% from zinc leaching residue by low intensity magnetic separation.

Le minerai de sulfure de zinc à haute teneur en fer est une ressource importante du zinc et il en existe une grande quantité dans le monde. Il est très difficile d’obtenir efficacement le zinc et le fer de cette source par la technologie traditionnelle. Dans cette étude, on propose une nouvelle méthode pour la récupération du zinc et du fer à partir de produit calciné de zinc à haute teneur en fer, et on examine la procédure clef, le grillage réducteur. On a étudié respectivement les effets de la concentration de CO, de la concentration de CO₂, de la température et de la durée sur le grillage réducteur. Les résultats expérimentaux montrent que la teneur en zinc soluble et la susceptibilité magnétique atteignaient respectivement 91·15% et 4·1×10^?4 m³ kg^?1 en conditions optimales. Environ 90% du Zn et 9·5% du Fe étaient dissous à partir du produit calciné de zinc de grillage réducteur par lessivage à acide faible, et simultanément, 84·3% du Fe était recyclé en concentré de fer contenant 53·2% de fer à partir du résidu de lessivage du zinc par séparation magnétique à faible intensité.     

Effect of high amounts of dietary zinc and age upon tissue zinc in young chicks

Weight gains of younger broiler chicks were not reduced by up to 2400 p.p.m. added zinc fed to four weeks of age. Tissue zinc was not changed significantly by 600 or 1200 p.p.m. supplemental dietary zinc, but at 2400 p.p.m. added zinc, blood, kidney, and liver zinc were significantly elevated (P less than 0.05). In the heart, zinc was not affected by the added dietary zinc but increased over time with all diets. Unlike the calf and weanling pig, the metabolism of zinc in the young chick does not appear to change appreciably with increasing maturity. Thus, the homeostatic control mechanisms of the young chick are effective for up to 1200 p.p.m. dietary zinc, but are partially overcome by 2400 p.p.m. added dietary zinc.     

Effect of high dietary zinc upon zinc metabolism and intracellular distribution in cows and calves

Changes in the metabolism of zinc were investigated in mature nonlactating Holstein cows and 4-mo old calves fed high but nontoxic amounts of dietary zinc. Increasing dietary zinc of calves from 42 to 642 ppm elevated the zinc content of liver and pancreas 600% and 1400%, respectively. The elevated zinc in liver and pancreas involved a substantial increase in all intracellular fractions, with by far the largest amount associated with a 10,000 molecular-weight protein in the soluble cell fraction. This zinc-binding protein may protect the cell against damage from increased zinc. A comparable increase in dietary zinc of mature cows did not affect zinc content of liver or kidney nor alter the intracellular distribution of zinc in the liver. In mature cows, homeostatic control mechanisms which regulate the zinc content of tissue are much more effective than in calves. Accordingly, mature cows probably are able to tolerate higher concentrations of dietary zinc.     

预焙烧处理高氟氧化锌矿的研究

一种高氟氧化锌矿采用预焙烧脱氟———焙砂酸浸———浸液净化———净液电解流程生产锌。做了预焙烧和酸浸出试验，获得了良好的脱氟效果和较高的锌浸出率     

Performance and tissue zinc and metallothionein accumulation in chicks fed a high dietary level of zinc

Four experiments were conducted to identify several factors that might improve the accuracy and reproducibility of Zn bioavailability assays for chicks. Response of tissue Zn and metallothionein (MT) concentrations to various elevated levels and soluble sources of dietary Zn were measured, as well as the effect of delaying high Zn administration until 7 d posthatching to alleviate the detrimental effect of Zn sulfate on feed intake to 3 wk of age. Bone Zn increased (P < 0.01) in all experiments in response to increasing dietary Zn concentrations. Liver and pancreas MT were affected (P < 0.01) by a source by age interaction and variability that made this criterion unsuitable for bioavailability assays. Lastly, 1-d-old chicks were used to study the effect of delaying feeding of a high-Zn diet up to 7 d of age. The basal diet was fed continuously for 21 d as a control. A diet containing 1,000 ppm Zn was either fed continuously from Day 1, or started on Day 3, 5, or 7. Chicks given high Zn on Day 3, 5, or 7 decreased (P < 0.01) feed intake within 24 h of feeding. Delayed feeding of high dietary Zn might help to alleviate decreased feed intake observed in previous studies. Delaying the onset of high Zn feeding by several days may help alleviate feed intake problems observed with Zn sulfate. Use of either Zn gluconate or Zn acetate as a standard in assays or use of MT synthesis as a bioavailability criterion will probably not be useful to improve accuracy of the estimates.     

The simultaneous electrowinning of manganese dioxide and zinc from purified neutral zinc sulphate at high current efficiencies

A process that enables electrolytic-grade manganese dioxide and zinc to be electrowon simultaneously at high anodic and cathodic current efficiencies from purified neutral leach liquor from a zinc plant is described. Experimental results that show the effects on the anodic and cathodic current efficiencies of temperature, anodic and cathodic current densities, initial sulphuric acid concentration, initial zinc-ion concentration, initial manganous-ion concentration, and addition of a polyelectrolyte smoothing agent are presented and discussed.     

喷射成形高锌Al-Zn-Mg-Cu合金的时效行为

系统研究了喷射成形高锌Al-Zn-Mg-Cu合金在不同时效处理条件下的显微组织与力学性能.结果表明自然时效合金在晶界处已析出强化相;单级时效合金随时效时间的延长,晶内和晶界析出相逐渐粗化;双级时效合金的析出相进一步粗化,并且晶界析出相为断续特征;回归再时效合金具有较细的晶内组织及类似于双级时效的晶界组织.同时发现,双级时效合金的抗拉强度比峰时效合金的强度下降了13%左右,而回归再时效合金的强度优于峰时效合金的强度.     

锌精矿常压浸出与加压浸出工艺比较

比较了常压浸出与加压浸出两种工艺的机理、流程、技术经济指标、投资以及存在的问题。试验和生产数据表明,加压浸出在技术上和工艺上都更具有吸引力。     

锌精矿常压浸出与加压浸出工艺比较

比较了常压浸出与加压浸出两种工艺的机理、流程、技术经济指标、投资以及存在的问题。试验和生产数据表明,加压浸出在技术上和工艺上都更具有吸引力。