Atmospheric oxygen-rich direct leaching behavior of zinc sulphide concentrate

The leaching behavior of main metallic sulphides in zinc concentrate under atmospheric oxygen-rich direct leaching conditions was studied through mineralogical analysis. The results show that the sulphides dissolve obviously except pyrite. Based on the relationship between elemental sulfur and the residual sulphides in the leaching residue, the dissolution of sphalerite, chalcopyrite, covellite and galena is assumed to follow the indirect oxidation reactions, where the acidic dissolution takes place firstly and then the released H2S transfers from the mineral surface into bulk solution and is further oxidized into elemental sulfur. The interface chemical reaction is further supposed as the controlling step in the leaching of these sulphides. The direct electrochemical oxidation reactions are assumed to contribute to the dissolution of pyrrhotite, which is controlled by the diffusion through elemental sulfur layer.

Pressure acid leaching of zinc sulfide concentrate

Effects of particle size of the zinc sulfide concentrate,leaching temperature,solid-to-liquid ratio and additive amount on pressure acid leaching process of the zinc sulfide concentrate were studied.The results indicate that the additive can improve the reaction kinetics and the conversion rate.And sulfur can be successfully separated from the zinc sulfide concentrate as elemental sulfur.The reasonable experiment parameters are obtained as follows:the leaching temperature 150℃,oxygen partial pressure 1 MPa,additive amount 1%,solid-to-liquid ratio 1:4,leaching time 2 h,initial sulfuric acid concentration 15%,and particle size less than 44μm.Under the optimum conditions,the leaching rate of the zinc can reach 95%and the reduction rate of the sulfur can reach 90%.

Recovery of gallium from zinc concentrate by pressure oxygen leaching

Zinc concentrate with high gallium content is one of the main resources of gallium.The gallium presents in the form of isomorphism in tetrahedron coordination with sulfur in sphalerite.The research was to investigate the amenability of zinc concentrate with high gallium to pressure oxygen leaching.The particle size,sulfuric acid concentration,oxygen partial pressure,additive amount,and time of reaction were studied.The extraction yields of gallium and zinc are 86%and 98%,respectively.The optimal condition is 100 g of zinc concentrate with particle size smaller than 38 lm,sulfuric acid concentration150 g L-1,leaching temperature 150℃,leaching time120 min,oxygen partial pressure 0.7 MPa,additive amount of 0.2 wt%.

Metallogeny of the Baiyangping Lead-Zinc Polymetallic Ore Concentration Area, Northern Lanping Basin of Yunnan Province, China

The Lanping Basin in the Nujiang-Lancangjiang-Jinshajiang （the Sanjiang） area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment-hosted Pb-Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India-Asia continental coUisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the oreforming elements in the east ore belt are mainly Pb-Zn -Sr-Ag, while Pb-Zn-Ag-Cu-Co elements are dominant in the west ore belt. Comparative analysis of the C-O-Sr-S-Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore- forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb-Zn mineralization age of both ore belts was contemporary and formed in the same metaliogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship.

ELECTROCHEMICAL NOISE ANALYSIS OF THE INFLUENCE OF THE Zn^(2+)IONS CONCENTRATION ON ZINC ELECTROPLATING

The influence of the concentration of Zn2+ ions on zinc electroplating process was investigated by means of electrochemical noise (EN) and cyclic voltammetry methods in conjunction with the scanning electron microscopy (SEM) technique. It was found that the EN generated during the electroplating of dentritic or large polymeric zinc deposit has large potential oscillation amplitude and positive potential drift while the compact zinc deposit possesses small noise amplitude and little potential drift. With the change of rate determining step from diffusion-control through mixed-control to activation-control, the maximum relative energy obtained from wavelet analysis defined from the region with larger scales to those with smaller scales, and the EDP (relative energy distribution plot) can be us, as 'fingerprints' of EN to characterize the electroplating process and the deposit structure. The results also showed that electrochemical noise technique can give more information about the electrodeposit structure than other normal electrochemical measurements, such as linear potential sweep method and cyclic voltammetry technique.

硫化锌精矿氧压浸出过程中硫回收率的影响机制

锌氧压浸出特点是硫化锌精矿直接湿法浸出,硫不进入烟气,而是直接转化成单质硫回收。该工艺生产流程更简单,环境友好,综合能耗低,硫磺产品相对更容易储存、运输及销售。因此该技术的推广应用对锌冶炼行业节能减排乃至碳达峰碳中和目标的实现意义重大。从精矿矿物特征及金属的浸出率、浸出过程中硫元素的酸化率、硫磺结晶过程控制、硫浮选效率以及硫精矿热过滤温度等方面着手,研究其对硫磺回收率的影响机制。

甘肃某细粒铅锌矿工艺优化试验研究

甘肃某铅锌矿中铅品位为0.74%,锌品位为3.72%,为了实现该矿产资源的高效回收利用,针对铅锌矿物嵌布关系紧密,粒度较细,造成铅锌精矿互含量较高,影响浮选指标的问题,在原矿性质研究的基础上,进行了4种不同方案的工艺流程对比试验。试验结果表明:采用铅锌优先浮选—铅、锌粗精矿均再磨的工艺流程,最终获得的铅精矿铅品位为58.42%,铅回收率为79.95%,锌精矿锌品位为56.27%,锌回收率为93.05%。相较于方案2,锌精矿锌品位提高了3.03个百分点,锌回收率提高了2.75个百分点;相较于方案1现场生产工艺,铅、锌主品位提高,铅、锌互含量显著降低,锌回收率提高了4.15个百分点。

硫化钠体系中异极矿表面的硫化特性及硫化产物解析

通过多种分析检测方法揭示硫化钠体系中异极矿表面的硫化特性和机理,并对异极矿表面硫化产物进行分析测试。研究结果表明,硫化钠浓度对异极矿表面的硫化效果具有显著影响,即提高硫化钠浓度能促进矿浆溶液中硫组分与矿物表面反应,从而提高异极矿表面硫化产物的含量及矿物表面的疏水性。XPS和ToF-SIMS分析表明,异极矿表面的硫化产物并非单一的硫化物,而是由硫化物(S^(2−))和多硫化物(S_(n)^(2−))组成,且矿物表面多硫化物含量随硫化钠浓度的增加而增加,从而增强异极矿表面硫化产物的活性。

Reductive leaching of zinc and indium from industrial zinc ferrite particulates in sulphuric acid media

Zinc ferrite is the principal constituent in zinc neutral-leach residue（NLR） which is commonly treated by hot-acid leaching in electrolytic zinc plants. Reductive leaching of zinc ferrite with sphalerite concentrate as a reducing agent was performed. It was found that leaching of zinc ferrite in the presence of sphalerit concentrate was a viable process that effectively extracted zinc and indium and converted Fe^3＋ into Fe^2＋ at the same time. Reflux leaching tests by two stages were performed to achieve extractions of 98.1% for zinc and 97.5% for indium, and a Fe^2＋/Fe^3＋ molar ratio of 9.6 in leach solution was also obtained. The leaching behaviors of other elements, such as iron, copper and tin were also studied. The results showed that iron and copper were completely leached, whereas tin presented lower extraction values.

不同锌源叶面喷施对冬小麦和夏玉米产量及籽粒营养品质的影响

为探明不同锌源叶面肥喷施对小麦和玉米产量、籽粒矿质元素含量及锌、铁生物有效性的影响,对冬小麦-夏玉米轮作体系开展不同叶面肥喷施试验。小麦季设置去离子水(CK1)、尿素(CK2)、尿素+纳米氧化锌(U+ZnO)、尿素+壳聚糖纳米锌(U+ZnCNP)、尿素+普通七水硫酸锌(U+Zn)5种叶面肥处理;玉米季增加尿素与锌铁硒多元混合喷施处理(U+Zn/Fe/Se)。结果表明:各叶面肥喷施处理对小麦和玉米籽粒产量均无显著影响,但对籽粒微量元素含量有显著影响。不同锌源与尿素混合叶面肥对小麦籽粒锌含量强化效果由弱到强依次为U+ZnCNP<U+ZnO<U+Zn。与CK2处理相比,处理U+Zn使小麦籽粒锌含量显著提高77.7%(从22.80 mg·kg^(-1)增加至40.52 mg·kg^(-1))、籽粒植酸与锌(PA/Zn)摩尔比显著下降42.1%,使籽粒锌生物有效性(TAZ)显著提高74.5%。对于玉米,与CK2处理相比,处理U+Zn/Fe/Se使籽粒锌含量提高32.3%(从14.93 mg·kg^(-1)增加至19.60 mg·kg^(-1))、硒含量显著提高12.7倍(从17.66μg·kg^(-1)增加至242.04μg·kg^(-1))、籽粒PA/Zn摩尔比显著下降27.0%,使籽粒TAZ显著提高36.9%,使整个植株或玉米秸秆磷与锌(P/Zn)和磷与铁(P/Fe)摩尔比降低。研究表明,叶面喷施普通七水硫酸锌是提高小麦、玉米籽粒锌含量和生物有效性的最佳形式,其强化小麦籽粒锌效果优于玉米。叶面喷施尿素与锌铁硒混合溶液可同时提高玉米籽粒锌、硒含量及锌、铁生物有效性(籽粒、全株、秸秆),是解决人体或动物微量元素营养缺乏的有效农艺强化措施。

锌氧压酸浸硫精矿和硫尾矿的矿物学特征与环境活性

采用电感耦合(ICP-OES)、X射线衍射(XRD)、扫面电镜-能谱(SEM-EDS)、红外光谱(FTIR)及差热差重(TG-DTA)等多种检测方法对锌氧压酸浸硫精矿和硫尾矿的化学组成、粒度分布、物相结构等进行研究,并采用毒性浸出程序(TCLP)法考察其短期环境活性。研究结果表明:硫精矿1和硫精矿2主要以球状的单质硫存在,其中,少量硫精矿1以小颗粒的闪锌矿、黄铁矿等附着于块状的铁矾颗粒上,平均粒径为22.1μm;少量硫精矿2以块状的闪锌矿、黄铁矿和小颗粒存在,平均粒径为59.2μm。2种硫精矿在185~340℃时会剧烈燃烧,热稳定性较差。2种硫尾矿主要以块状的铅黄铁矾和黄钠铁矾存在,其中,硫尾矿1平均粒径为21.1μm;硫尾矿2含一定的赤铁矿(16.86%),平均粒径为5.3μm。硫精矿和硫尾矿中锌和镉元素在弱酸条件下不稳定,硫尾矿1中锌和镉的浸出量分别超标1.93倍和2.50倍;硫精矿2的分别超标2.03倍和6.56倍,硫尾矿1的分别超标3.46倍和5.94倍,硫尾矿2的分别超标11.10倍和8.28倍。

水系锌离子电池宽温域性能的电解质改性策略研究进展

在资源短缺、能源需求倍增的当今世界,水系锌离子电池(AZIBs)作为一种大规模储能技术以其具有高安全性、低成本、高容量和快速充放电等优势脱颖而出。随着对能源多元化应用场景的增加,AZIBs被开发并应用于多种极端环境。然而,电池中的自由水分子会引发一系列的不良反应,导致电池出现容量下降和寿命缩短的问题。在低温条件下,溶剂水的冻结会引起AZIBs的离子电导率降低、电荷转移阻抗增加,导致电池速率性能下降。在高温条件下,溶剂水的快速蒸发会产生气泡和气体膨胀,水诱导的副反应加剧,同时电极材料也会出现腐蚀和溶解,从而影响电池寿命。针对这些挑战,在这篇综述中,分别总结了针对水系锌离子电池在高温与低温下的研究进展,提出了适用于低温、高温以及同时适用于高低温的电解质策略,重点研究了高浓度电解质、凝胶电解质、电解质添加剂和共晶电解质降低电解质凝固点、提高低温电化学性能的机理,并对进一步提高水系锌离子电池的宽温域性能和工业应用进行了展望。

某铅锌浮选厂颗粒物浓度分布及其影响研究

铅锌浮选厂在生产过程中产生大量颗粒物,污染工作环境。以某铅锌浮选厂为研究对象,对厂房内、外颗粒物浓度分布情况进行测试分析,并对其污染状态及健康影响进行深入研究。结果表明:粒径小于10μm颗粒物其厂房内数量浓度高于厂房外,且数量浓度随粒径变小而增加,厂房内、外颗粒物的数量浓度比平均值大多大于1。PM_(10)、PM_(2.5)和PM1的厂房内质量浓度显著高于厂房外,厂房内PM_(10)、PM_(2.5)分别超过一级标准5.333倍和6.313倍,超过二级标准2.614倍和2.134倍。厂房内对厂房外颗粒物浓度有较大影响,颗粒物的分布和浓度也有所不同,环境因素对粉尘污染有较大影响。研究结果可为矿山环境颗粒物的有效控制提供数据参考价值。

锌精矿与锌浸出渣加压协同助浸过程优化及动力学研究

针对现有锌精矿加压浸出过程氧气利用率低、闪锌矿溶解缓慢等问题,利用锌浸出渣中Fe^(3+)的强氧化性以及Fe^(2+)/Fe^(3+)氧化还原离子对输氧效能,提高闪锌矿中S2-的高效氧化和O2利用率,实现锌精矿与锌浸出渣协同强化浸出。研究结果表明,Fe^(3+)可以提高氧气溶解度,同时Fe^(2+)/Fe^(3+)的往返变价行为加速了浸出体系中闪锌矿(ZnS)的氧化溶解,锌的浸出速率和浸出率得到显著提升。以锌浸出渣形式向体系添加6.1 g/L Fe^(3+)、在初始硫酸浓度95 g/L、氧分压0.8 MPa、反应温度160℃、反应时间120 min的优化条件下,锌浸出率可以达到98.60%,同时92.47%的铁沉淀入渣。锌精矿与锌浸出渣协同助浸受外扩散控制,表观活化能为15.61 kJ/mol,协同浸出的动力学方程为:1-(1-α)^(1/3)=4.78×10^(-3)×{[exp(-15610/8.314T)]×c(H_(2)SO_(4))1.21×P(O_(2))0.33×c(Fe^(3+))0.43×t}。

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。

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。

一种低成本的非水系高浓盐锌离子电解液

非水系电解液理论上可以与锌金属负极兼容,使其保持高化学稳定性和电化学可逆性,但目前对该体系的研究仅局限于低浓度体系。研究发现了一种低成本的三氟乙酸锌和乙腈的高浓锌离子电解液,其浓度最高可达到15 mol·kg^(-1)。利用该体系探究了浓度对电解液离子溶剂化和电化学性能的影响。在非水系电解液中,浓度的增加降低了与锌负极的兼容性,库伦效率降低至55.35%,但在中等浓度(5 mol·kg^(-1))时实现锌均匀平整沉积。高浓电解液中乙腈和CF_(3)COO^(-)阴离子全部参与Zn^(2+)的溶剂化结构,形成大量聚集离子对。最后与Na_(3)V_(2)(PO_(4))_(3)正极构建全电池进行测试。此外,研究中发现锌盐的低缔合常数并不是高溶解度必要条件。

电感耦合等离子体质谱法同时测定锌精矿中镓、锗、铟的含量

为准确快速测定锌精矿样品中镓、锗、铟的含量,提出了提示方法,并在溶样体系、目标元素同位素、内标元素选择以及共存元素、试剂干扰及消除方面进行了探讨。将样品过筛后,用硝酸-氢氟酸-高氯酸体系加热溶样,在所得溶液中滴加25%(体积分数,下同)硫酸溶液后再加入50%(体积分数)硝酸溶液溶解盐类,定容,过滤,根据实际样品中目标元素和共存元素铜含量稀释滤液,供电感耦合等离子体质谱仪分析。结果显示:硝酸-氢氟酸-高氯酸体系可以充分溶解样品,避免了镓和锗挥发损失、硅化合物夹杂、包裹性硫球夹杂的影响;在待测溶液中滴加25%硫酸溶液,能避免了样品中铁形成铁氧化物析出;以内标元素同位素^(103)Rh校正^(71)Ga、^(74)Ge,^(187)Re校正^(115)In,消除了大部分共存元素带来的干扰;以进一步稀释样品溶液消除铜质量分数不小于8%时内标校正带来的偏差;以在线/离线公式校正了^(74)Se对^(74)Ge以及^(115)Sn对^(115)In的干扰。镓、锗、铟标准曲线的线性范围为0.20~50.00μg·L^(-1),检出限(3s)为0.0026~0.0105μg·g^(-1)。方法用于标准物质和实际样品的分析,标准物质中镓、锗、铟的测定值和认定值基本一致,加标回收率为95.0%~106%,测定值的相对标准偏差(n=11)为2.6%~8.2%。和文献方法进行比对,两种方法的测定值基本一致。

艾萨磨在某高硫铜锌混合粗精矿铜锌分离中的应用

某高硫铜锌混合粗精矿在铜锌分离过程中难以获得铜品位18%以上的铜精矿,为解决铜精矿品位偏低的问题,进行了艾萨磨再磨工艺与现场球磨+水力旋流器再磨分级工艺对比试验研究。试验结果表明:采用艾萨磨工艺,铜锌分离作业可获得铜品位20.52%、锌含量2.38%、铜回收率89.32%的铜精矿,与现场球磨再磨工艺相比,铜精矿品位提高了2.82个百分点,锌含量降低了1.17个百分点,铜回收率提高了3.98个百分点。

高浓度快速浮选技术在铅锌硫化矿浮选中的研究与应用

采取高浓度快速浮选技术,解决了在不改变选矿工艺的情况下原矿处理量增大对生产指标的影响。技术改造后,铅、锌金属回收率分别提高了1.75%和1.61%,伴生银回收率提高了8.60%,药剂成本下降了1.36元/t,降低了选矿生产用水量,年创造经济效益约511.80万元,保护了生态环境。