低镉低铁锌的技术改造研究

随着锌用途的扩大,低镉低铁锌出现市场需求。生产中,粗锌通过铅塔、镉塔的精馏精炼得到精锌产品。对铅塔、镉塔进行局部技术改造达到降低成品锌中镉、铁含量的目的,从而满足市场需求。     

精镉提炼技术与生产实践

白银公司某厂用精馏法处理中间产品高镉锌产粗镉,粗镉碱性精炼产精镉。存在的问题:粗镉精炼周期长,精镉质量不合格。采取措施:精准配料,稳定熔化镉含镉品位在30%～40%;提升镉塔脱镉能力,充分富集镉,提高高镉锌含镉品位到30%～40%;搭配处理集团公司其他厂的高镉物料。实施后缩短了精炼周期,炼出合格精镉。     

高镉锌精馏塔的设计改进

<正> 在锌精馏生产过程中,镉塔冷凝器产出的半成品高镉锌,是一种除含锌和镉以外,几乎不含其它杂质的锌镉二元合金,含镉品位约5～10％。这种合金目前在金属材料工业中还没有实际使用价值。为了处理这种高镉锌,我厂于1977年10月修建了一座工业性的高镉锌精馏塔进行生产试验。该设计是采     

铅塔处理高铅镉和高品位高镉锌的工业试验

进行了含镉物料单塔处理一步产出粗镉的工业试验。采用1372大型铅塔处理含镉40%～90%的物料可使镉富集到98%左右,铅、锌及其它高沸点杂质金属的含量符合粗镉要求。     

铅塔处理高铅镉和高品位高镉锌的工业试验

进行了含镉物料单塔处理一步产出粗镉的工业试验。采用1372大型铅塔处理含镉40％-90％的物料可使镉富集到98％左右。铅、锌度其它高沸点杂质金属的含量符合粗镉要求。     

镉

一、镉的性质和用途镉与锌的性质很相似,并且常在天然化合物中与锌伴生。由於镉较锌易於挥发,故当锌矿石还原时,镉首先挥发,而藉此与锌分离开来。纯镉是一种白色金属,比重为8.6,熔点为321°。在电位次序表中,镉位於锌的下面,但在氢的上面,帮能从酸中排出氢来。在电气工业中用金属镉,制造受到滑动接触磨擦的导电体。加镉能改善铜的机械性能,增进导体的寿命,同时并不减低铜的导电能力。镉是很多易熔合金的组成成份。近来镉被广泛地用,以被覆钢铁(镀镉)。     

从高镉锌中回收镉

在锌冶炼过程中回收镉一般采用湿法,或湿法与火法联用,其缺点是流程长,加工费高。我厂采用密闭鼓风炉炼铅锌,烧结烟尘中镉未予回收,仍返回烧结。因此,原料中的镉大部份进入粗锌。在粗锌精炼过程中,镉以金属状态进入副产品高镉锌中。这种合金主要成份是锌和镉,其它杂质甚微,无工业用途。根     

镉

镉大部分靠回收含微量镉的锌精矿作为冶炼副产物获得。镉与锌有类似的性质,比锡硬,比锌软,富于延展性。具有比其他金属优越的密合性。耐大气腐蚀和电腐蚀。耐碱不耐酸,熔点低     

用高锌镉生产精镉工艺的改进

针对用高锌镉生产精镉工艺中存在的修炉停产时间长、加工费用高等问题,在化学法除锌时添加硝酸钠,可将高锌镉中的锌除至0．001%,不用精馏就可以生产精镉。     

日本三池厂锌精馏技术综述

一、锌精馏技术沿革该厂于1963年引进美国新泽西锌公司专利,建两座铅塔和一座镉塔,组成典型的三塔型塔组,以精炼其竖罐所产粗锌,生产能力为1500吨精锌/月。 1967年建一座处理无镉锌的铅塔,生产低成本的精锌,其生产能力为750吨精锌/月。至此,该厂总生产能力达2250吨精锌/月。 1969年利用处理无镉锌的铅塔产出的纯     

镉熔炼含氯烧碱渣在黄钾铁矾法炼锌中的再利用研究

通过热水溶解、液固分离工艺从炼锌回收镉所产生的含氯烧碱渣中回收镉。含氯碱液在沉矾前进入锌湿法系统,沉矾时用Cl-替代OH-,铜镉渣的热酸浸出及铜渣的低酸洗涤生产CuCl等以消除Cl-的危害;沉矾时用Na+代替NH4+,锌、镉回收率达到99.90%。试生产证明经济效益、环保效益良好。     

从锌精矿焙烧电尘中提取镉

对从锌精矿焙烧电尘中回收镉的工艺进行了研究,比较了水浸、酸浸及氧化酸浸3种浸镉方法,指出氧化酸浸-除砷-置换-压团-熔铸是回收镉的最佳流程,用这种方法处理含镉电尘,镉的浸出率大于90%,粗镉品位99.10%。     

镉钴砷及其同类杂质离子对长周期锌电积的影响

镉离子、钴离子、砷离子是对长周期锌电积过程有重要影响的金属离子,简要介绍了它们对长周期锌电积过程的作用:镉离子对析出锌质量影响较大;钴离子对降低锌的电流效率有较为明显的作用;砷离子对降低电流效率最为剧烈.同时也分析了与它们相似离子对长周期电积锌的影响.     

单竖罐蒸馏炉"油改气"工程生产实践

介绍了长沙库厂单竖罐蒸馏炉“油改气”工程的主要内容及生产实践。通过改造，不仅改善了锌厂环境，而且大幅度降低了蒸馏锌生产成本，提高了经济效益。     

竖罐炼锌炉的改进

介绍了葫芦岛有色金属集团有限公司炼锌竖罐的运行情况，发现了目前该窑竖罐所存在的问题．针对这些问题，提出了一系列的改造措施．改进了设备，以延长炉体寿命．提高冷凝效率。     

铅冶炼烟尘浸出液中镉的电积行为的规律

镉常伴生于锌矿、铅锌矿和铜铅锌矿石中,约95%的镉作为铅锌冶炼过程中的副产品被回收,其中冶炼烟灰是镉回收的主要原料之一。本文以铅冶炼烟尘为对象,研究了其硫酸浸出液中镉的电解沉积行为,主要考察了电流密度、温度以及镉离子的浓度对电流效率、单位电耗、阴极镉纯度及形貌的影响规律。结果表明:在电流密度150 A/m2、温度30 ℃、浸出液中镉浓度40 g/L的条件下,电沉积4 h的电流效率可达96.14%,单位电耗为1.769 kW·h/kg,阴极镉的纯度可达到97.75%。升高温度、增大电流密度、镉离子的消耗都在不同程度上降低了电流效率并增加了单位电耗。电极反应动力学表明,镉离子在阴极区的还原过程受离子扩散控制。      

The inert gas effect on the rate of evaporation of zinc and cadmium

An experimental study has been made to investigate the effect of argon and helium on the rate of evaporation of zinc and cadmium under one atmosphere pressure at temperatures ranging from 500 to 850°C. The experimental results were compared with the maximum rates calculated using the effusion formula as well as with values obtained using two different types of equations based on kinetic theory, diffusion theory, and empirical data. Equations have been derived for expressing the rate of evaporation of zinc and cadmium in both argon and helium as functions of temperature of the liquid zinc and cadmium. It was found that the rates of evaporation of zinc and cadmium were higher in helium than in argon, with the difference increasing with increasing temperature. It was also found that the experimental results obtained in argon agree with the calculated values better than those obtained in helium.     

锰粉代替锌粉去除硫酸锌溶液中铜镉研究

湿法炼锌过程中,溶液净化过程中需要进行除铜镉操作,传统除铜镉方法以锌粉为还原剂去除铜镉,锌粉耗量高,产出铜镉渣品位较低.为了降低除铜镉工序物料消耗,提高铜镉渣品位,研究了用锰粉替代锌粉进行硫酸锌溶液中铜镉的去除,研究结果表明,金属锰粉代替锌粉除铜镉工艺可行.除铜镉速率及去除效果均优于电炉锌粉,同时也达到了降低成本的效果...     

竖罐炼锌残渣回收技术的现状及展望

介绍了利用旋涡炉技术回收竖罐炼锌残渣的现状及工艺特点 ,分析了竖罐炼锌企业残渣处理的重要性和残渣处理技术的发展趋势 ,论述了利用奥斯麦特技术处理竖罐炼锌残渣同时冶炼铜精矿生产冰铜这一新技术的可行性。     

The diabetic foot]

The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 micromol/kg CdCl2). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 micromol/kg ZnAc), given 24 h prior to 20 micromol/kg CdCl2 administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible reproductive organs.