Effect of impurities in recycling water on Pb-Ag anode passivation in zinc electrowinning process

Effect of impurities in recycling water on Pb-Ag anode passivation in zinc electrowinning process was investigated by linear scan voltammetry.Results show that passivation process would be affected in the presence of Cl^-and F-in recycling water.It was highly advantageous to take H2SO4 concentration as 180g/L,Mn^2＋ concentration as 3-5 g/L and F-less than 42mg/L.However,passivation process would not be affected when Cl^-concentration was less than 13mg/L without any other ions,or when mass ratio of Mn^2＋ to Cl^-existing in electrolyte was 8,where Cl^-concentration could reach up to 625mg/L.

EXPERT OPTIMIZED CONTROL TECHNIQUE FOR ELECTROLYTIC DEPOSITION PROCESS OF HYDROMETALLURGY OF ZINC

ＥＸＰＥＲＴＯＰＴＩＭＩＺＥＤＣＯＮＴＲＯＬＴＥＣＨＮＩＱＵＥＦＯＲＥＬＥＣＴＲＯＬＹＴＩＣＤＥＰＯＳＩＴＩＯＮＰＲＯＣＥＳＳＯＦＨＹＤＲＯＭＥＴＡＬＬＵＲＧＹＯＦＺＩＮＣ①ＹａｎｇＣｈｕｎｈｕａ，ＧｕｉＷｅｉｈｕａ，ＹｅＷｅｎｗｕＩｎｆｏｒｍａｔｉ...

Intelligent optimal control for lead-zinc sintering process state

The intelligent integrated predictive model of synthetical permeability was established using the fuzzy classifier to combine the time sequence predictive model with the craftwork parameter predictive model. Then, the estimation model of burn-through point(BTP) based on pipe stress point(PSP) method and the predictive model of BTP were proposed. The optimal control of permeability and heat states was implemented by using the fuzzy expert controller with self-studying mechanism. The application of the intelligent control technique suppresses 17% of the fluctuation of synthetical permeability and 12% of the fluctuation of BTP, stabilizes the output and quality of sinter and settles the basis for the optimization of output and quality of sintering process.

The Processing Mineralogy for Lead and Zinc Oxide Ore in Sichuan

Using variety of modern testing methods, the processing mineralogical characteristics for a lead and zinc oxide ore in Sichuan were studied systematically. The chemical analysis result shows that the lead and zinc oxide content exceeding the minimum industrial grade and iron ore, total iron content reaches a minimum industrial grade and associated with gold and silver; The mineralogical analysis result shows that lead and zinc mineral composition and configuration are very complexity. The zinc minerals and zinciferous minerals are sphalerite, hemimorphite, Smithsonite, Hydrozincite, zinc chlorite, limonite, zinc dolomite and zincocalcite; lead minerals and plumbiferous minerals are mainly galena, cerussite, anglesite, limonite and Coronadite; The minerals disseminated grain size are very fine and mineral dissemination characteristics are very complex ; expected theoretical recoveries for lead and zinc were 72% and 67% respectively. The results of this study provide basic data and theoretical basis for ore dressing.

Expert fault diagnosis system for leaching process in zinc hydrometallurgy

Leaching process is the first step in zinc hydrometallurgy, which involves the complex chemical reactions for dissolving zinc bearing material in dilute sulfuric acid. Ensuring the safe running of the process is a key point in the operation. An expert fault diagnosis system for the leaching process was proposed, which has been implemented in a nonferrous metals smeltery. The system architecture and the diagnosis procedure were presented, and the rule models with the certainty factor were constructed based on the empirical knowledge, empirical data and statistical results on past fault countermeasures, and an expert reasoning strategy was proposed which employs the rule models and Beyes presentation and combines forward chaining and backward chaining. [

Investigation of Formation Process of the Chrome-free Passivation Film of Electrodeposited Zinc

The feasibility was investigated to substitute chrome-free passivation treatment of electrodeposited zinc in a titanium bath for chromate passivation treatment. The formation mechanism of the chrome-free passivation film was further analyzed. The surface mor- phologies and the elemental compositions of the treated samples with varied immersion times were observed by scanning electron mi- croscopy （SEM） and determined by energy dispersion spectrometry （EDS）, respectively. The electrode potential of the sample surface was recorded in the film formation process. The changes of the electrode potential are in accordance with that of SEM and EDS of the sample surface. The results of X-ray photoelectron spectroscopy （XPS） show the chrome-free passivation film composed ofZnO, SiO2, TiO2, Zn4Si207（OH）2, and SrF2. The anode zinc dissolution and the local pH value increase due to the cathode hydrogen ion reduction process result in the formation of the chrome-free passivation film. The macro-images of the chrome-free passivation films formed on electrodeposited zinc show that the color of the film changes from blue to iridescence with the increase of the immersion times.

Modeling, Optimization, and Control of Solution Purification Process in Zinc Hydrometallurgy

The solution purification process is an essential step in zinc hydrometallurgy. The performance of solution purification directly affects the normal functioning and economical benefits of zinc hydrometallurgy. This paper summarizes the authors' recent work on the modeling, optimization, and control of solution purification process. The online measurable property of the oxidation reduction potential(ORP) and the multiple reactors, multiple running statuses characteristic of the solution purification process are extensively utilized in this research. The absence of reliable online equipment for detecting the impurity ion concentration is circumvented by introducing the oxidationreduction potential into the kinetic model. A steady-state multiple reactors gradient optimization, unsteady-state operationalpattern adjustment strategy, and a process evaluation strategy based on the oxidation-reduction potential are proposed. The effectiveness of the proposed research is demonstrated by its industrial experiment.

Establishment of water quality index(Na^+,Ca^(2+)) for purified water reused to zinc electrolysis process

The effects of Na+ and Ca2+ in the purified water on the conductivity of zinc electrolyte and the current efficiency of zinc electrolysis were studied by the alternating current bridge method and the simulated electrolysis experiments,and the water quality index of reused water was established. The results show that the conductivity of the solution and the current efficiency decrease as these two kinds of positive ions are added in the electrolyte. The effect of Ca2+ is much more remarkable than that of Na+. ρ(Na+)≤ 8 g/L and ρ(Ca2+)≤20 mg/L are the quality indexes in the zinc electrolysis process and the concentrations of Na+ and Ca2+ in the purified water reused to the process should be less than the limited values,i.e. the water quality index of the purified water should be controlled by its reused amount.

锌浮渣干湿法处理工艺对比与干法处理工艺关键设备选型及应用

在湿法炼锌的工业生产中,电解阴极锌片在熔锌感应电炉内熔化除杂时产出副产品锌浮渣,锌浮渣中含锌约80%,其中70%以上锌以单质形态存在。本文对比了干法和湿法两种处理工艺的优缺点,重点介绍了干法处理工艺中关键设备选择和能力计算,并结合实际生产情况对投产后的工艺设备进行改进和完善。

氧化锌对钠钙玻璃的抗菌性及工艺性能的影响

采用高温熔融法制备钠钙玻璃,研究不同量的氧化锌对钠钙玻璃抗菌性和工艺性能的影响。采用贴膜法分析玻璃的抗菌性,测试包括表面张力、高温黏度和熔化澄清的工艺性能。结果表明:当氧化锌引入的质量分数大于3%时,玻璃对大肠杆菌和金黄色葡萄球菌的抗菌性达到90%以上;氧化锌的引入降低了玻璃的表面张力和高温黏度,使高温玻璃熔体中气泡的排出速率增大,气泡数量减少,利于玻璃熔体澄清,适用于工艺生产。

改性黑药类捕收剂强化浮选玉龙铅锌矿中伴生银的无碱工艺研究

针对玉龙铅锌矿浮选过程中伴生银矿物回收率不高等问题,进行了新型捕收剂下无碱铅银浮选工艺研究。研究结果表明,在磨矿细度为-74μm占65%时,抑制剂采用亚硫酸钠与硫酸锌,捕收剂采用改性黑药类捕收剂CY-1,可实现无碱条件下铅银精矿中银回收率的显著提升。闭路实验获得了含Pb 52.05%、Ag 4 866 g/t的铅银精矿,铅、银回收率分别为91.76%和84.43%。与乙硫氮+丁铵黑药为组合捕收剂时的高碱工艺相比,铅、银回收率分别提高了2.5和6百分点。该工艺消除了浮选过程中石灰对银矿物的抑制,有助于强化铅锌矿伴生稀贵金属的综合回收,提升资源的综合利用效率。

锌湿法冶炼渣污染物及综合利用研究

锌湿法冶炼是一种常用的锌冶炼工艺,它在生产过程中会产生大量的渣污染物。这些渣污染物主要包含氧化锌、氧化铁、浸出渣、净化渣等。由于这些渣含有大量有价值的金属元素和资源,对其进行综合利用具有重要意义。本文通过详细分析渣污染物形成过程、组成及含量,介绍常用的渣污染物处理方法,探讨综合利用渣污染物的技术方法,能为相关领域提供参考,并促进该领域技术与应用的进一步发展。

白及多糖锌的结构表征及其抗氧化活性评价

该试验以白及多糖(Bletilla striata polysaccharide,BSP)和ZnSO_(4)为原料制备白及多糖锌(Bletilla striata polysaccharide-zinc,BSP-Zn),对其进行结构表征,并考察其体外抗氧化活性。以BSP-Zn的复合率为指标,在单因素试验的基础上结合响应面法优化BSP-Zn的制备工艺,采用傅里叶变换红外光谱、X射线衍射、扫描电镜和热重分析对BSP-Zn进行结构表征,通过测定DPPH自由基、ABTS阳离子自由基以及羟自由基的清除能力来综合评价BSP-Zn的体外抗氧化活性。结果显示,最佳工艺条件为BSP与锌的质量比25∶1、反应体系pH值为7.8、反应温度70℃,反应时间2 h,此条件下制备的BSP-Zn中锌含量为(27.96±0.84)mg/g。红外光谱以及扫描电镜结果表明,多糖中O—H、C—H、C—O—C和C O等官能团与Zn^(2+)发生复合,X射线衍射结果显示BSP和BSP-Zn均为无定型结构,热重分析结果显示,多糖与Zn^(2+)结合提高了其自身的热稳定性。抗氧化实验结果显示,与BSP相比,BSP-Zn对各自由基的清除能力均有显著性增加,表明BSP与Zn^(2+)结合,使BSP-Zn抗氧化活性增强。研究结果可为BSP的高效利用以及BSP-Zn功能性膳食补充剂的开发提供一定的理论基础。

锌精矿氧压浸出技术研究进展

传统湿法炼锌工艺存在烟气处理成本高、综合回收率低等问题,近年来,氧压浸出技术因其原料适应性强、锌回收率高、环境污染小等优点被应用于锌冶炼工业。介绍了锌精矿氧压浸出的生产工艺,论述了浸出过程反应的基本原理,以及离子催化、温度、酸度、分散剂等条件对浸出过程离子行为的影响与机理。讨论了锌精矿中伴生元素铁、镓、锗、铟、银等的浸出行为及在不同浸出条件下浸出行为的变化。

氰化尾渣综合回收利用工艺优化研究

鉴于国家环保政策的调整,环保部等三部委已将“采用氰化物进行选矿过程中产生的氰化尾渣”定为危险废物,而即将执行的新环保税法将对危险废物征收1000元/t的环境保护税,氰化废物的经济消解是未来氰化厂主要研究课题和发展方向。山东某氰化尾渣中含有一定品位的铅、锌、铜,该氰化尾渣不进行回收处理,不仅会造成资源浪费,也会对环境造成污染。如果对这部分多金属进行回收,会产生良好的经济效益。从氰化尾渣中回收有价金属元素不同于从原矿中回收有价金属元素,回收其中的有价元素较困难。为解决此问题,根据该氰化尾渣的性质,采取代表性的尾渣矿样,拟采取确定合理的选矿工艺回收尾矿中的有价金属,采用先浮铅锌再浮硫的优先浮选工艺流程试验,该试验流程能够取得较好的有价金属元素回收效果。结果表明,在原矿含铅2.56%、含锌0.95%、含铜0.19%的条件下,采用一粗两精两扫的流程浮选铅锌、一粗两精两扫的流程浮选硫的工艺,处理该氰化尾渣,获得了含铅品位19.77%、回收率21.50%,锌品位19.69%、回收率71.07%,铜含量1.43%的铅锌精矿,硫品位45.27%、回收率35.92%的硫精矿。新工艺流程指标更优,药剂成本更低、工艺更简洁,不仅铅锌精矿中铅、锌均得到有效的回收,其中伴生硫的指标也得到了改善,为氰化尾渣中铅锌铜硫的回收提供了方案。

云南某锌浸出渣工艺矿物学及银回收技术研究

本文以云南某锌湿法冶炼厂锌浸出渣为研究对象,通过化学多元素分析、MLA、扫描电镜等测试分析方法,对该冶炼渣的化学组成、矿物成分、主要矿物的解离度特征、共生关系、粒度分布及银矿物的赋存状态等工艺矿物学性质进行了详细研究。研究结果表明,该锌浸出渣含银280 g/t,矿物组成以锌赤铁矿为主,主要金属矿物单体解离度差且粒度细小。结合原矿的性质,通过“一粗两精两扫结合中矿再选”的闭路浮选流程,获得了Ag品位6 096.26 g/t, Ag回收率75.22%的银精矿,实现了对该锌浸出渣中银矿物的有效回收。

锌浸渣浮选银精矿还原焙烧-低酸浸出脱锌

以某湿法炼锌厂产出的锌浸渣浮选银精矿为原料,采用回转炉还原焙烧—低酸浸出工艺进行脱锌研究。结果表明:在碳粉加入量10%、焙烧温度600℃、时间120 min、原料粒度-0.1 mm、回转炉转速5 r/min的条件下,铁酸锌还原焙烧分解效果最优,焙烧产物中可溶锌率达到85.83%。在硫酸终点pH为2、液固比5 mL/g、浸出温度70℃、浸出时间90 min优化条件下,对焙烧产物进行选择性浸出,锌和铁的浸出率分别为84.23%和34.71%。浸出渣中未溶解铁锌氧化物主要为还原焙烧过程中团聚成块的大颗粒及被硫酸铅熔化包裹形成的颗粒。

某复杂低品位铜锌硫化矿工艺矿物学研究

针对某复杂低品位铜锌硫化矿,为降低选矿成本及为生产提供指导依据,进行了工艺矿物学研究。采用化学多元素分析、矿物自动分析仪(MLA)、光学显微镜等分析手段,查明了矿石的元素组成及矿物组成、主要矿物的嵌布特征、共生关系、粒度分布及解离度特征。结果表明,矿石中Cu品位为0.60%,锌品位为0.25%;含铜矿物主要为黄铜矿,含锌矿物主要为闪锌矿;铜锌硫矿物嵌布关系复杂,嵌布粒径大小悬殊,主要矿物单体含量低,黄铜矿及闪锌矿的单体解离度分别为37.92%、32.43%、单体解离度不高;矿石中存在极细粒黄铜矿且细粒级黄铜矿包裹于黄铁矿、磁铁矿、闪锌矿、脉石中导致铜回收困难,部分闪锌矿粒度极细且铜锌硫矿物共生关系紧密,相互包裹,共同赋存于脉石中导致铜锌分离困难。

有源层溅射工艺及后退火温度对IZO TFT电性能的影响

为了提高氧化物薄膜晶体管的器件性能,以掺In氧化锌(IZO)为有源层,原子层沉积法(ALD)沉积的Al2O3薄膜为栅介层,制备了基于IZO的薄膜晶体管(IZO TFT),研究了IZO薄膜制备工艺中溅射气体氩氧流量比、溅射压强和后退火温度等工艺参数对TFT器件电学性能的影响。结果表明,在恰当的氩氧比和反应气压以及相对较高的退火温度下制备的IZO TFT具有良好的电学特性,当氩氧流量比为60:20 sccm、溅射压强为0.5 Pa、空气气氛中以250℃退火1 h时后,IZO TFT器件的整体电学特性表现较优,其迁移率高达31 cm^(2)/(V·s),开关电流比大于108。相对过低或过高的氩氧比会导致IZO有源层中氧空位含量过低或过高,从而降低TFT器件性能。过低的退火温度不足以使栅介质的Al-OH转变成Al-O以及空气中的氧扩散进入IZO体内钝化氧空位,因此器件性能较差。

Z-200体系下Pb^(2+),Zn^(2+)对黄铜矿可浮性的影响及其机理

这是一篇矿物加工工程领域的论文。黄铜矿、方铅矿和闪锌矿通常会相互伴(共)生,为了探究Pb^(2+)和Zn^(2+)对黄铜矿浮选行为和表面性质的影响,本研究对黄铜矿进行了单矿物浮选实验,并利用溶液化学计算、Zeta电位和XPS检测等方法,对比研究了Pb^(2+)和Zn^(2+)对黄铜矿浮选行为和表面性质的影响。黄铜上的Zn^(2+)。矿石可浮性影响的差异。测试结果表明,Pb^(2+)和Zn^(2+)都会吸附在黄铜矿表面,改变黄铜矿表面的Zeta电位,抑制黄铜矿的可浮性,并且随着pH值的升高,抑制作用增强;结合浮选实验结果可知,浮选所处的矿浆pH值范围内,锌主要以Zn(OH)2沉淀的形式吸附在黄铜矿表面从而对黄铜矿的浮选产生抑制效果,所以Zn^(2+)对黄铜矿浮选的抑制效果要比Pb^(2+)显著;且XPS分析结果表明,Pb^(2+)和Zn^(2+)都能在黄铜矿表面形成沉淀物,并以化学吸附的形式出现在黄铜矿表面,从而抑制黄铜矿的可浮性。