Separation of sulfide lead-zinc-silver ore under low alkalinity condition

A complex lead-zinc-silver sulfide ore containing 2.98% Pb, 6.49% Zn and 116.32×10-4% Ag (mass fraction) from Yunnan Province, China, was subjected to this work. Research on mineral processing was conducted according to the properties of the lead-zinc-silver ore. Under low alkalinity condition, the lead minerals are successfully separated from the zinc minerals with new reagent YZN as zinc depressant, new reagent BPB as lead collector, CuSO4 as zinc activator and ethyl xanthate as zinc collector. The associated silver is mostly concentrated to the lead concentrate. With the process utilized in this work, a lead concentrate of 51.90% Pb with a recovery of 82.34% and a zinc concentrate of 56.96% Zn with a recovery of 81.98% are produced. The silver recovery in the lead concentrate is 80.61%. Interactions of flotation reagents with minerals were investigated, of which the results indicate that the presence of proper amount of Na2S can precipitate Pb2+ and has a sulfidation on oxidized lead minerals. The results also show that Na2CO3 and YZN used together as combined depressants for sphalerite can signally improve the depressing effect of new reagent YZN on sphalerite.

The mechanisms of paragenesis and separation of silver, lead and zinc in hydrothermal solutions

On the basis of an experimental study and thermodynamic calculation, the mechanisms of paragenesis and separation of silver, lead and zinc in the hydrothermal system have been studied. At acidic to nearly neutral pH, their chloride complexes are stable, and among them the chloride complexes of zinc are most stable. And the sulfide complexes are the dominant species at nearly neutral to alkaline pH, while the sulfide complexes of silver are most stable. With decreasing temperature, , f-{O-2} and increasing pH, the solubilities of silver, lead and zinc will decrease, leading to their deposition and separation. For sulfide complexes, the concentrations of reduced sulfur and pH are two important factors affecting their stabilities. Complexes of different forms and stabilities respond to the variation of conditions to different extents, which gave rise to the paragenesis and separation of silver, lead and zinc in the whole ore-forming process of dissolution, transport and deposition.

Thermodynamic analysis of separating lead and antimony in chloride system

In chloride system, thermodynamic analysis is a useful guide to separate lead and antimony as well as to understand the separation mechanism. An efficient and feasible way for separating lead and antimony was discussed. The relationships of [Pb2+][Cl-]2—lg[Cl]T and E—lg[Cl]T in Pb-Sb-Cl-H2O system were studied, and the solubilities of lead chloride at different antimony concentrations were calculated based on principle of simultaneous equilibrium. The results show that insoluble salt PbCl2 will only exist stably in a certain concentration range of chlorine ion. This concentration range of chlorine ion expands a little with increasing the concentration of antimony in the system while narrows as the system acidity increases. The solubility of Pb2+ in solution decreases with increasing the concentration of antimony in the system, whereas increases with increasing the concentration of total chlorine. The concentration range of total chlorine causing lead solubility less than 0.005 mol/L increases monotonically.

Analysis of non-ionized substance losses in experiments on plasma mass separation

Plasma mass separation requires a lot of diagnostic techniques that not only demonstrate the separation effect but also show the efficiency of the process.During the test experiments,plasma flux to be separated may contain neutral particles that avoid the separation process due to their insensitivity to electromagnetic field.We present the diagnostics of the lost substance in experiments on plasma mass separation.The obtained data of the diagnostics helps determine the law of particle evaporation from the plasma source.We show that neutral flux is unable to distort the result of separation diagnostics.The presented approach can be used in experiments aimed at enhancing the separation effect and achieving target productivity for industry applications.

Effectively Inhibit Phase Separation to Improve Efficiency and Stability of All-Inorganic Planar CsPbIBr2 Perovskite Solar Cells

The advancement in a power conversion efficiency(PCE)to reach 25%,the inorganic perovskites are being explored intensively as promising optoelectronic materials due to their excellent photovoltaic performance,i.e.,thermal stability and efficiency.Lately,the inorganic cesium lead halide perovskite is studied to show enhanced light absorption,however,it suffers from the phase separate into I-rich and Br-rich phase which leads to poor film quality due to difference of electronegativity.Herein,we propose a unique solution of controlling the rate of solvent volatilization followed by gel method to inhibit phase separation effectively to obtain the homogenous and pinhole-free CsPbIBr2 films with high crystalline quality.In this study,an inverted planar device based on a light absorber of CsPbIBr2 is prepared to achieve a power conversion efficiency of 8.8%(maintain a stabilized value of 8%in ambient air conditions).Surprisingly,the optimized cell without encapsulation shows excellent long-term stability,as it maintained 90%initial efficiency over 500 h and controlled storage at around 45%relative humidity and 25℃.

Mechanism of Pb Removal from Brass Scrap by Compound Separation Using Ca and NaF

The Mechanism of Pb removal from brass scrap by compound separation using Ca and NaF addition was investigated. Because large Ca-Pb compound particles formed by Ca addition rise to the surface of the molten brass, they can be skimmed off from the molten brass. However, fine Ca-Pb compound particles remain in the molten brass because of low buoyancy. By subsequent NaF addition, the reaction between Ca-Pb compound and NaF takes place at their contact regions, resulting in the formation of solid CaF2, liquid Pb and Na gas. Pb is mainly present at the Ca-Pb compound-CaF2 interface. CaF2 acts as a binder for aggregation of fine Ca-Pb compound particles, resulting in the formation of light and large composite compounds, which rise to the surface of the molten brass. A high Pb removal rate is achieved by skimming off.

The Kinetics of Pb Removal from Brass Scrap Using Compound Separation

2 wt% Ca was added to molten brass containing 3.2 wt% Pb. The composition and grain size of the formed Ca-Pb compound were examined in detail using SEM-EDS and XRD. This revealed that the composition of the Ca-Pb compound depends on the grain size of the liquid phase Pb and the diffusion phenomenon of the Ca in the Ca-Pb compound formed on the surface of the Pb. When the Pb has a fine grain, a compound composed only of Ca-Pb compounds is formed. When the grain size of the Pb is several μm, Ca-Pb compounds containing unreacted Pb in the center are formed. These compounds aggregate into a larger compound grain. From the evaluation of the floating force (the resultant force of the weight and buoyancy of the Ca-Pb compounds formed) and the rising terminal velocity of the Ca-Pb compound within the molten brass, it was found that the floating force and rising terminal velocity depend on the composition and grain size of the Ca-Pb compound. It was found that since Ca-Pb compounds with a floating force greater than 10-6 g ·cm/s2 have a very large rising terminal velocity, they reach the surface of the molten brass in a short time after compound formation and then continue to float on the surface of the molten brass. Thus they can be removed by skimming. The effects of the grain size of the Ca-Pb compound on the floating force and the rising terminal velocity were greater than those of the composition of the Ca-Pb compound.

玻璃分相联用机械化学法脱除废旧含铅玻璃中重金属铅

传统分相法采用热酸浸提工艺脱除CRT锥玻璃分相产物中重金属铅,酸浸过程强酸消耗量大,废酸无法回用,易引发酸污染。目的 为了绿色、高效回收CRT锥玻璃分相产物中重金属铅,方法 采用乙二胺四乙酸(EDTA)作为浸提剂,通过机械化学法研究锥玻璃中重金属在快速分相和机械活化浸出过程中的迁移转化规律,揭示影响重金属脱除率的主要因素和作用机制。结果 结果表明:在分相处理过程中锥玻璃所含Pb,K,Ca等元素主要富集在呈连通结构的富B_(2)O_(3)相中。在随后湿法球磨浸提过程中,分相产物中富B_(2)O_(3)相在机械活化作用下快速溶解到水中,同时富B_(2)O_(3)相中所含金属离子与EDTA形成可溶络合物,且可从分相产物中脱除。锥玻璃所含Pb,K,Ca等金属脱除率随EDTA添加量增大、球磨转速提高、球磨时间延长等不断提升,但随液固比增大呈先升高后降低趋势。当EDTA添加量(质量分数,下同)为80%,球磨转速500 rpm,液固比0.8时,球磨处理30 min,分相产物中Pb,K,Ca,Al脱除率分别达到98.79%,94.92%,95.17%,65.71%,获得SiO_(2)质量分数超过92%的高硅氧玻璃粉末。结论 研究结果可为含重金属玻璃绿色、高附加值利用提供借鉴与参考。

云南某低品位铅锌硫化矿选矿试验研究

云南某低品位硫化铅锌矿含Pb0.42%、Zn0.39%,矿物组成较复杂,含有方铅矿、白铅矿、闪锌矿、氧化锌矿等多种矿物。采用铅锌混合浮选抛尾—铅锌分离选矿流程回收利用该铅锌矿。结果表明,采用该处理工艺可获得Pb品位70.34%、Pb回收率84.06%的铅精矿,Zn品位45.74%、Zn回收率80.65%的锌精矿。

铜铅混合精矿硫酸预氧化-浮选分离参数优化试验研究

方铅矿与黄铜矿的分离一直是选矿领域的难点,使用硫酸预氧化可选择性抑制方铅矿表面可浮性,使得两种矿物可浮性产生差异,实现浮选分离。针对铜铅混合精矿硫酸预氧化-浮选分离工艺进行了系统的参数优化。首先,利用单因素试验,分析了预氧化硫酸浓度、温度、时间等关键因素对铜铅混合精矿浮选分离效果的影响;其次,利用正交试验分析,建立了预氧化过程中各影响因素与浮选指标之间的数学模型;通过模型求解,得到最佳预氧化条件为硫酸浓度5 mol/L、时间40 min、温度100℃。最后在上述条件下进行了混合精矿预氧化-浮选闭路试验,获得了铜精矿Cu品位18.03%,Cu回收率94.52%;铅精矿Pb品位47.12%,Pb回收率为91.29%的良好指标,铜铅分离效果显著,对铜铅硫化混合精矿的浮选高效分离提供了一定的借鉴。

矿浆难免离子对铅锌硫化矿分离的影响研究进展

这是一篇矿物加工工程领域的论文。矿浆溶液中普遍存在一些难免离子,并且其中存在的难免离子对铅锌硫化矿的浮选分离有着重要影响。矿浆中难免离子主要来源于选厂用水、矿物自身溶解、活化剂或者抑制剂解离以及流体包裹体释放引入的原生离子和磨矿过程中引入的次生离子。本文对矿浆中引入的原生离子以及磨矿体系引入的次生难免离子对铅锌硫化矿浮选分离的影响进行了总结分析发现,不论是原生离子还是次生离子对铅锌硫化矿浮选行为的影响均较为明显,较多的学者针对这种现象进行了大量的研究。通过药剂调控以及改变磨矿环境等方法已经取得了较大的突破,为后续研究者提供了重要的研究思路。本文的关注点是将前人的研究成果与现场工艺紧密结合,在不影响工业经济情况下如何从源头消除难免离子,如何从现场工艺中降低难免离子对浮选指标的影响仍是未来研究的重要方向。

基于马蹄涡前缘吸气控制的压气机叶栅流动机理

为探究从源头抑制角区分离的流动控制方法,采用数值模拟方法,以NACA65叶栅为研究对象,利用叶栅前缘端壁吸气技术控制马蹄涡,结合拓扑分析对叶栅通道内的三维流动结构进行精确重构,以研究前缘端壁吸气控制马蹄涡进而改善叶栅通道流场结构的机理。结果表明:叶栅前缘端壁吸气技术可以有效推迟马蹄涡形成并削弱其强度,同时在吸气狭缝末端形成一对反旋流向涡对,在向下游发展过程中与通道涡相互作用;前缘端壁吸气通过控制马蹄涡,降低端壁边界层厚度,叶栅前缘通道涡发展受限,由回流组成的叶表分离被抑制;前缘及压力面侧吸气(EPS)直接作用于马蹄涡压力面分支,通道涡强度进一步被削弱,角区分离模式由闭式分离转为不完全闭式分离。最后,对比最优吸气系数下不同方案出口总压损失,发现当吸气量为进口质量流量的0.2%时,EPS方案出口截面总压损失降低5.8%;并且通过调整吸气系数,可以获得较好的变工况控制性能。

转子叶顶间隙值及改型对压气机性能影响的数值模拟

为了分析转子叶顶间隙值和改型对压气机性能的影响,以典型轴流跨声速压气机NASA stage 35为对象,对不同叶顶间隙值的压气机进行数值模拟。结果表明:叶顶间隙增大并且泄漏流强度提高,会导致脱体激波位置前移,转子吸力面激波作用位置后移,前缘溢流现象减弱,叶尖泄漏涡与激波作用增强,间隙区域涡量增加,靠近前缘的涡核向下游移动,但附面层与激波之间的作用减弱;不同叶顶间隙值的压气机失速机制不同,在小间隙下压气机失速是由叶尖泄漏涡和转子吸力面附面层分离共同作用引起的,在大间隙下压气机失速是由叶尖泄漏涡引起的;在研究的变化范围内,叶顶间隙值为0.50τ时,压气机性能最好,峰值效率和稳定裕度分别提高了0.16%和2.39%;将最优间隙改型成平行扩张式和正弦波间隙后,压气机性能提高,脱体激波后移,叶尖泄漏涡与激波作用程度减弱,转子吸力面附面层分离减弱,改型间隙能够减少叶片制作材料,减轻发动机质量。

硫化铅锌矿浮选分离研究进展

铅锌分离目前仍是选矿领域的一大难题,介绍了闪锌矿和方铅矿的晶体结构与可浮性,指出了优先浮选、混合浮选、等可浮浮选和异步浮选等传统工艺以及电化学浮选、分支浮选、载体浮选和高浓度浮选等新工艺的特点和适用对象;综述了硫化铅矿捕收剂、硫化锌矿捕收剂、硫化铅锌矿调整剂的研究现状;分析指出了浮选分离工艺的发展方向为高浓度浮选工艺、低碱工艺和无氰工艺等绿色工艺,优化药剂制度和研发环保高效新药剂是未来硫化铅锌矿选矿药剂研究的重要方向。

边界约束及分离面宽度对铅切割索分离性能的影响

为研究舱体边界约束及分离面宽度对铅切割索分离性能的影响,采用数值模拟的方法,对铅切割索爆炸后射流分离靶板的影响因素进行分析,得到了自由边界约束、固定边界约束和分离面削弱槽宽度对铅切割索分离性能的影响规律。结果表明,铅切割索分离铸铝等脆性材料是切割索射流侵彻和高压爆轰产物共同作用结果,边界约束对射流侵彻的影响较小,固定边界约束和自由边界约束对相同切割索射流侵彻深度的偏差小于5%;不同的边界约束对靶板的崩裂过程影响较大,固定边界约束会在切割索分离时限制材料的形变位移,进而限制高压爆轰产物对铸铝等脆性材料的崩裂作用,导致后续分离难度加大。增加分离界面削弱槽宽度,可有效降低分离装置边界约束对切割索分离性能的影响,提高切割索的分离可靠性,当削弱槽宽度≥12 mm时,2.7 g·m^(-1)铅切割索能够可靠分离4.5 mm厚的ZL114A材料。

黑龙江某钼矿选矿工艺优化试验研究

针对黑龙江某大型斑岩型钼矿生产的钼精矿铜、铅杂质超标的问题,在完成矿石性质研究基础上,开展了选矿工艺优化研究。结果表明,对含钼0.122%的原矿,采用自主研发的钼高效捕收剂PM和粗磨—钼分步浮选—钼铜混合浮选—钼铜粗精矿再磨—铜钼分离工艺流程处理,全流程闭路试验取得了钼品位54.32%、钼回收率90.69%、杂质铜含量0.048%、铅含量0.062%的较好钼精矿指标。相较于原工艺流程,新工艺得到的钼精矿铜含量降低了0.322个百分点、铅含量降低了0.348个百分点。优化工艺有效地降低了钼精矿中铜、铅杂质含量,研究结果可为该矿石的开发利用提供依据。

湖南三十六湾铅精矿提质降砷组合药剂浮选方法试验研究

针对南方矿业玉岭多金属铅精矿品位低且砷含量超标的问题,通过采用MLA检测分析了矿物组成及其嵌布关系,确定磨矿细度-0.074mm、pH=10的条件下,以丁铵黑药+乙硫氮为捕收剂、硫酸锌+亚硫酸钠+氯化铵为抑制剂的组合药剂体系,并开展了系列试验。工业应用后不仅有效实现铅精矿提质降砷,还提高了Sb、Ag、Sn等共伴生有价金属回收效果。

AGM隔板的装配压力对阀控式铅酸蓄电池性能的影响

研究了AGM隔板的注液量、注液种类、纤维直径、增强隔板以及初始压力等因素对装配压力的影响。实验证明,注液量为饱和吸液量的90%,装配压力控制在60 kPa左右,可以明显改善阀控式铅酸蓄电池的循环寿命。

河北某难选铅锌矿可选性实验

这是一篇矿物加工工程领域的文章。河北某铅锌矿中主要有价元素为铅、锌,品位分别为1.07%、2.08%。矿石中的铅主要赋存于方铅矿中,另有白铅矿、硫酸铅、铅铁矾等含铅矿物,锌主要赋存于硫化物闪锌矿中,占总锌的66.96%,其次为氧化锌矿物,锌氧化率较高。在实验研究中,确定了在-0.074 mm 65%的磨矿细度条件下,优先浮铅再浮锌的工艺。浮选产品中,铅精矿产率1.74%,铅精矿中铅、锌、铜品位分别为51.73%、10.86%、3.81%,回收率分别为83.93%、8.98%、68.20%;锌精矿产率为2.26%,锌精矿中铅、锌、铜品位分别为1.25%、51.64%、0.73%,回收率分别为2.63%、55.42%、16.97%。

河南某钼铅混合精矿分离试验研究

为高效利用河南某钼铅矿,针对其混合精矿钼铅分离困难、钼精矿中铅含量超标的问题,在对该混合精矿矿石性质研究的基础上,通过单因素条件试验,确定了分离粗选的关键技术参数,并采用正交试验法,以粗选水玻璃、DP-1和巯基乙酸钠用量作为自变量因素,选矿效率作为因变量因素,确定了钼铅分离的最佳抑制剂药剂制度。研究结果表明:当水玻璃用量3 kg/t、DP-1用量5kg/t、巯基乙酸钠用量18 kg/t时,选矿效率最优,并在此基础上进行1粗2扫7精闭路试验,最终获得了钼品位53.28%、含铅1.07%、钼回收率91.56%的钼精矿,实现了钼、铅的高效分离和回收。