氯化焙烧-水浸法从锂云母矿提锂(英文)

采用氯化焙烧-水浸法处理锂云母矿,并对氯化处理温度、时间、氯化剂的类型及用量进行研究。条件优化实验表明,在锂云母、氯化钠、氯化钠的质量比为 1:0.6:0.4,氯化处理温度为 880 °C,氯化处理时间为 30 min时,锂的提取率可达 92.86%,钾、铷、铯的提取率分别为 88.49%、93.60%和 93.01%,。采用 XRD 对锂云母原矿及焙烧后物料的物相进行分析。XRD 结果分析表明,当将锂云母和混合氯化剂一起焙烧(氯化钙及氯化钠)时,所得物相为 SiO2、CaF2、KCl、CaSiO3、CaAl2Si2O8、NaCl 和 NaAlSi3O8。     

Optimization of operating parameters and kinetics for chloride leaching of lead from melting furnace slag

The feasibility and kinetics of lead recovery from the slag of traditional lead melting furnace using chloride leaching were investigated. The effects of operating parameters such as leaching time, NaCl concentration, FeCl₃ concentration, liquid/solid ratio, stirring rate, temperature, and particle size on recovery of lead were studied and the optimization was done through the response surface methodology (RSM) based on central composite design (CCD) model. The optimum conditions were achieved as follows: leaching time 60 min, 80 °C, stirring rate 800 r/min, NaCl concentration 200 g/L, FeCl₃ concentration 80 g/L, liquid/solid ratio 16, and particle size less than 106 μm. More than 96% of lead was effectively recovered in optimum condition. Based on analysis of variance, the reaction temperature, liquid/solid ratio, and NaCl concentration were determined as the most effective parameters on leaching process, respectively. Kinetics study revealed that chloride leaching of galena is a first-order reaction and the diffusion through solid reaction product and chemical reaction control the mechanism. The activation energy of chloride leaching of galena was determined using Arrhenius model as 27.9 kJ/mol.     

银氧化锡合金废料电解综合回收工艺研究

采用直流电解法和化学法回收银氧化锡(AgSnO2)合金废料中的银和锡。优化得到的电解银工艺参数为:槽电压1.5~3.0 V,电解周期为24 h,电解液中Ag⁺浓度为150~260 g/L,HNO3浓度为15~20 g/L,同极距120~140 mm,极板排布为六阴极五阳极间隔交替排列。一个周期银氧化锡废料电解银直收率接近95%,主体纯银粉在阴极析出。富含氧化锡的阳极泥和残极用硝酸浸出少量残余银,不溶渣还原熔炼回收锡,硝酸浸出的含银溶液中加入氢氧化钠调节pH值到10,沉淀得氧化银,500℃焙烧得到单质银。废料中的银和锡均得到有效回收。全流程银的回收率不低于99%。     

双氧水协同硝酸浸出失效银催化剂中银的研究

在传统硝酸浸出含银废催化剂中银的基础上，研究了双氧水浸出银的影响。在2mol/L HNO₃，浸出温度70°C，浸出时间120min，固液比1:4条件下，通过逐次加入双氧水，银浸出率为99.76%，获得了较好浸出效果。浸出过程中，双氧水将Ag氧化为Ag₂O，可有效提高银的浸出率，同时硝酸与银反应产生的氮氧化物被双氧水氧化生成硝酸继续参加反应。采用硝酸-双氧水作为浸出剂保证了银高效浸出，减少了氮氧化物排放，为含银废催化剂绿色高效回收提供了理论基础及技术支撑。     

Role of oxygen and ammonium ions in silver leaching with thiosulfate–ammonia–cupric ions

The dissolution of silver with thiosulfate and copper ions was studied in a batch-stirred reactor at 25 °C in the absence and presence of various ammonium ions and oxygen concentrations in the aqueous solution. Leaching silver with 4 mg L-1oxygen in the aqueous solution requires high concentration of ammonium and thiosulfate ions. High silver dissolution is achieved at pH of high cupric tetraamine concentration, around pH 9.8, but a high degradation of thiosulfate ions is resulted from their oxidation by the presence of oxygen. When the oxygen concentration is below 1 mg L-1, dissolved silver thiosulfate species are fairly stable and the degradation of thiosulfate ions in the aqueous solution is low. Under these conditions,high silver dissolution is attained using low thiosulfate concentration. At the oxygen concentration of 4 mg L-1,dissolved silver thiosulfate species precipitate out of the aqueous solution significantly affecting silver dissolution.Precipitation of dissolved silver thiosulfate species occurs because of oxidation of the thiosulfate bonding to the silver.     

Behavior of calcium silicate in leaching process

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｇｅｎｅｒａｌ ,ａｌｕｍｉｎａｃａｎ ｔｂｅｐｒｏｄｕｃｅｄｅｃｏｎｏｍｉｃａｌｌｙｂｙＢａｙｅｒｐｒｏｃｅｓｓｉｎＣｈｉｎａｂｅｃａｕｓｅｔｈｅｂａｕｘｉｔｅｃｈａｒａｃｔｅｒ ｉｚｅｓｉｎｄｉａｓｐｏｒｅａｎｄａｂｏｕｔ 80 %ｂａｕｘｉｔｅｅｘｉｓｔｉｎｌｏｗｄｅ ｇｒｅｅｏｆｔｈｅｍａｓｓｒａｔｉｏｏｆａｌｕｍｉｎａｔｏｓｉｌｉｃａ(Ａ/Ｓ)ｗｈｉｃｈｖａｒｉｅｓｆｒｏｍ 4ｔｏ 9[1] .Ａｎｄａｂｏｕｔ 4 0 %ｏｆａｌｕｍｉｎａｉｓｐｒｏ ｄｕｃｅｄｂｙｓｉｎｔｅｒｉｎｇ…     

贵锑选择性氯化浸出富集金过程中铅的行为研究

本文系统分析了高离子强度下含Pb2 、Cl-、SO42-酸性溶液各离子间的平衡,计算出不同条件下PbCl2、PbSO4在高Cl-、SO42-的酸性溶液中的溶解度(mol/L).绘制出25℃下,氢离子浓度分别为7.5、5、2.5、1、0.1(mol/L)时,PbCl2、PbSO4的溶解度(mol/L)随总硫酸根浓度[SO42-]T 和游离氯离子浓度[Cl-]的关系曲面.PbCl2、PbSO4的溶解度曲面在高酸度的条件下有一交线.根据浓度积原理,将优先析出溶解度小的物质,即较低曲面所表示的物质.将各条件下,两曲面的交线对底面做投影,由投影得到的溶解平衡曲线图便可根据溶液的组成及温度条件判断出溶液中的Pb2 的析出形式.结果表明:在含Pb2 、Cl-、SO42-酸性溶液中,[H ]≥7.5mol/L、[Cl-]＞2.5mol/L时,溶液中PbCl2的溶解度小于PbSO4的溶解度,PbCl2较PbSO4优先析出;随着[H ]的减小,PbSO4 的溶解度逐渐减小, PbSO4较PbCl2优先析出的范围增大;[H ]=0.1mol/L时,仅仅在硫酸根浓度非常低,游离氯离子浓度非常高时,才可能优先析出PbCl2;[H ]≤ 0.01mol/L时,在[SO42-]T 、[Cl-]可能达到的范围之内,都将优先析出PbSO4.从而较好地解释了在控制电位选择性氯化浸出高品位含金物料工艺中,分离铅时,加入了大量的SO42-,而析出铅渣99%以上是PbCl2的事实.     

预浸-氰化浸出回收湿法炼锌渣中的银和金

某冶炼厂的锌浸出渣中银勘布粒度细,含银、金分别为381.3、1.02 g/t,可采用预浸-预浸渣氰化浸出工艺回收。重点研究了预浸条件对银、金浸出效率的影响。条件实验表明,药剂A比酸浸、氨浸具有更好的预浸效果;最佳预浸条件为药剂A浓度200 g/L、浸出液固比2:1、在50℃浸出3 h。综合条件实验得到的预浸渣渣率为66.2%,金、银的氰化浸出回收率分别为85.7%、92.9%。     

铅鼓风炉中铜、硫、砷和锑对银分布的影响(英文)

研究铅鼓风炉中杂质对银分布的影响。将含有不同Cu、S、As和Sb含量的铅烧结块在管式炉中于1573K下进行烧结,然后随炉冷却。烧结气氛为还原性的CO+CO2气体(p(CO)/p(CO2)=2.45)。采用SEM-EDS对所得样品进行表征。结果表明:烧结样品中含有5种不互溶的相,即炉渣(CaO,FeO,SiO2)、冰铜(S,Cu,Fe)、硬渣(As,Fe,Cu)、Cu-Sb相和铅块。银在Cu与Sb形成的熔体中的溶解度比在液态铅中的高。S与Cu形成冰铜,As与Cu形成硬渣。S和As能减少Cu-Sb合金的生成量,从而降低铅块中银的损失。     

钢铁厂烧结机头灰中铅的配位浸出行为与综合回收

针对钢铁厂烧结机头灰中富含铅、铁、碳、钾、氯等多种有价元素的特点,根据氯离子与铅配位的特性,采用配位浸出的方式实现铅与铁、碳等元素的选择性分离回收。SEM-EDS、XRD等研究分析表明,烧结机头灰中铅主要以絮状的KPb₂Cl₅等物相吸附于铁氧化合物、硅铝酸盐和碳颗粒表面,铁主要以Fe₂O₃和Fe₃O₄物相存在。实验考察了溶液pH值、温度、氯离子浓度、浸出时间和液固比等因素对铅浸出率的影响。研究表明,在溶液pH值为3.0,浸出温度为80℃,氯离子浓度为6 mol/L,液固比(mL/g)为10:1,浸出时间为2 h的优化条件下,烧结机头灰中铅化合物与氯发生配位溶解反应生成PbCl_i^2-i(i=1～4)等易溶解的络合离子,实现铅的浸出,铅浸出率为95.7%;而烧结机头灰中对钢铁冶炼有用的铁、碳、硅、铝等元素不被浸出,富集在浸出渣中,较好地实现了选择性浸出。浸出液中的铅经冷却结晶、洗涤纯化后,获得纯度为99%的氯化铅产品...     

从铅银渣中回收金银概况

为实现铅银渣中金银的综合回收,对铅银渣物理化学性质、有价金属含量、赋存状态、铅银渣中金银的回收方法、研究进展及其应用情况进行综述。铅银渣粒度细、酸度强、可溶物含量高,渣中矿物经历过相体转化由硫化物转变成氧化物,以再造矿物形式存在,选矿难度大;铅银渣有价金属铜、铅、锌、金、银含量较高,经济价值可观。目前,从铅银渣中回收金银的主要方法为浮选法、湿法、火法、湿法-火法联合、选冶联合等。通过分析各种方法优缺点,指出单一的浮选法流程简单、成本低,但金银回收率低;湿法、火法或湿法-火法工业应用良好,但是存在工艺复杂、成本高;选冶联合方法金属回收率高、流程适应性强,便于连续操作,具有较好的发展应用前景。     

Preparation of pure SbCl3 from lead anode slime bearing high antimony and low silver

A novel treatment process of lead anode slime bearing high antimony and low silver was developed by a potential-controlled chloridization leaching and continuous distillation.The experimental results show a high Sb 3+ concentration,489.2 g/L,in the leaching solution for two-stage countercurrent leaching process,and the leaching rates of Sb,Cu,Bi more than 99% when the potential is controlled at 450 mV.When the leaching solution is distillated and concentrated at 120°C,almost all the silicon compound is evaporated into the concentration distillate and exists as amorphous hydrated silica.By the continuous distillation,high pure SbCl3 could be prepared,and AsCl3 is enriched in the distillate while metals Bi,Cu are enriched in the continuous distillation residue.As a result,the recovery rate of Sb is more than 95%.     

Thermodynamic analysis and process optimization of zinc and lead recovery from copper smelting slag with chlorination roasting

An efficient chlorination roasting process for recovering zinc (Zn) and lead (Pb) from copper smelting slag was proposed. Thermodynamic models were established, illustrating that Zn and Pb in copper smelting slag can be efficiently recycled during the chlorination roasting process. By decreasing the partial pressure of the gaseous products, chlorination was promoted. The Box−Behnken design was applied to assessing the interactive effects of the process variables and optimizing the chlorination roasting process. CaCl₂ dosage and roasting temperature and time were used as variables, and metal recovery efficiencies were used as responses. When the roasting temperature was 1172 °C with a CaCl₂ addition amount of 30 wt.% and a roasting time of 100 min, the predicted optimal recovery efficiencies of Zn and Pb were 87.85% and 99.26%, respectively, and the results were validated by experiments under the same conditions. The residual Zn- and Pb-containing phases in the roasting slags were ZnFe₂O₄, Zn₂SiO₄, and PbS.     

Anti-tarnish property of sterling silver alloy with yttrium addition

It has been demonstrated that sterling silver alloy is a widely used material in the jewelry industry.The anti-tarnish property is one of the most important properties of this material.In this work,the effect of yttrium on the corrosion resistance,and tarnish resistance properties ofsterling silver alloy were investigated with the use of CIE-LAB uniform color scale,which gained acceptance as an effeetive way to assess color.To better understand the mechanism of the effect,the distribution of yttrium in the alloy was analyzed by mainly segregating in gaps among dendrite crystals and grain boundary.An increase in yttrium content in sterling silver alloy resulted in a decrease in the amount of eutectic structure.The tarnish and corrosion resistance of sterling silver were improved with yttrium content increase.However,too high yttrium conteut will lead to poor anti-tarnish properties.     

Kinetic process of oxidative leaching of chalcopyrite under low oxygen pressure and low temperature

Kinetic process of oxidative leaching of chalcopyrite in chloride acid hydroxide medium under oxygen pressure and low temperature was investigated. The effect on leaching rate of chalcopyrite caused by these factors such as ore granularity, vitriol concentration, sodium chloride concentration, oxygen pressure and temperature was discussed. The results show that the leaching rate of chalcopyrite increases with decreasing the ore granularity. At the early stage of oxidative reaction, the copper leaching rate increases with increasing the oxygen pressure and dosage of vitriol concentration, while oxygen pressure affects leaching less at the later stage. At low temperature, the earlier oxidative leaching process of chalcopyrite is controlled by chemical reactions while the later one by diffusion. The chalcopyrite oxidative leaching rate has close relation with ion concentration in the leaching solution. The higher ion concentration is propitious for chalcopyrite leaching.     

Electroplating process of amorphous Fe-Ni-Cr alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅａｍｏｒｐｈｏｕｓａｌｌｏｙｓａｒｅａｎｅｗｋｉｎｄｏｆｍａｔｅｒｉ ａｌｓｗｉｔｈｓｈｏｒｔ ｒａｎｇｅｏｒｄｅｒａｎｄｌｏｎｇ ｒａｎｇｅｄｉｓｏｒｄｅｒ .Ｔｈｅｙｄｉｓｐｌａｙｍａｃｒｏｓｃｏｐｉｃｕｎｉｆｏｒｍｉｔｙａｎｄｉｓｏｔｒｏｐｙ .Ｂｅｃａｕｓｅｏｆｔｈｅｉｒｅｘｃｅｌｌｅｎｔｐｈｙｓｉｃａｌ,ｃｈｅｍｉｃａｌａｎｄｍｅ ｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓ ,ｔｈｅｒｅｓｅａｒｃｈａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆｔｈｅａｍｏｒｐｈｏｕｓａｌｌｏｙｓｂｅ…     

Fundamental study on utilization of tin and zinc-bearing iron concentrate by selective chlorination

The feasibility and technologies of comprehensive recovery of tin, zinc, arsenic and iron from the complex iron ores by selective chlorination roasting were studied by thermodynamic analysis and roasting experiments. Investigation shows that the product pellets with the compression strength of 2 625 N/P, the tumble index of 97. 26%, the abrasion index of 1. 35%, tin, arsenic and zinc residue of 0. 043%, 0. 046% and 0.058% respectively can be achieved if bailing a concentrate containing 0.39 % tin, 0.40% arsenic and 0.28% with addition of 8% coke breeze and 0. 5% CaCl2 and roasting the pellets at 1 060 - 1 080℃ for 40 min. The volatilization of tin, arsenic and zinc is 91.75 %, 93.42 % and 81.12 % respectively. The performances of the product pellets are able to meet the requirements of blast furnace ironmaking.     

粗金粉中金的氯浸-控制电位还原精炼

某冶炼厂氰化金泥还原得到的粗金产品纯度较低,采用氯浸-还原工艺对粗金进行了精炼提纯。在生产工艺中采用盐酸+氯酸钠对粗金进行氯浸溶解,用焦亚硫酸钠控制电位选择性还原浸出液中的金。采用补水-冷却使银和铅从氯浸液充分沉淀析出,通过调整pH值、改变焦亚硫酸钠添加方式、精确控制还原电位等方法,产品金锭达到IC-Au99.99标准。两年的生产实践创造了明显的经济效益。     

铟的还原浸出动力学及分步沉淀选择性分离（英文）

开展硫化锌精矿还原浸出高铁锌浸出渣高效浸铟及浸出液中铟选择性分离的研究。结果表明：在固体物料粒度74～105μm、反应温度90℃、浸出时间300 min、硫酸浓度1.4 mol/L的条件下,铟的浸出率达95%以上。采用收缩核模型对还原浸出动力学进行分析,不同条件下的浸出实验结果表明反应受穿过固体产物层的扩散控制,活化能为17.96 k J/mol,相对于硫酸浓度的反应级数为2.41。铁粉置换沉铜过程铜和砷的沉淀率均达99%以上。98%以上的铟从含高亚铁离子浓度的硫酸锌溶液中选择性分离,获得铟含量约为2.4%的富铟渣,经酸浸-萃取-电积工艺流程进一步处理后可得到纯铟。     

氧化锌贫矿提锌渣中铅和银的氯盐一步浸出

运用X射线衍射、扫描电镜和X射线能谱等分析手段,对山东某地深度氧化锌贫矿提锌后渣进行工艺矿物学特征分析可知,矿物中金属赋存状态复杂,属难选矿物。开发出氯盐一步法浸出铅和银的新工艺,考察反应温度、NaCl浓度、添加剂用量、液固比、HCl加入量和浸出时间对浸出过程的影响。结果表明:加入添加剂对铅的浸出率没有影响,但可以显著提高银的浸出率。条件试验研究得出最佳工艺条件如下:浸出温度90℃、NaCl浓度390 g/L、添加剂用量15 mL、液固比(质量比)7?1、HCl加入量3 mL、浸出时间3 h。在此最佳工艺条件下,铅的浸出率达到95%左右,银的浸出率达到90%左右。