氧化锌矿的碱浸出

将处理氧化铝矿物的拜耳法移植于氧化锌矿的湿法处理形成"锌拜耳法",用浓碱浸出氧化锌矿,然后降低温度或浓度使锌以氢氧化锌的形式析出,析出母液经浓缩处理后返回浸出矿,研究氧化锌矿的碱浸出过程。研究结果表明:当氢氧化钠浓度为5mol/L,浸出温度为85℃,液固比为10:1,浸出时间为2h时,氧化锌矿中锌的浸出率为77%,铅的浸出率为9%,镉的浸出率为5%。     

黄铜矿的机械活化浸出

进行了机械活化后黄铜矿的物理化学性质变化及其对浸出速度影响的试验．结果表明,黄铜矿在行星磨中机械活化后晶格常数发生变化,晶格畸变增加,化学活性提高,与ＨＮＯ３反应的速度加快,经行星磨活化４０ｍｉｎ后黄铜矿与ＨＮＯ３反应的活化能由未活化时的８１．５ｋＪ·ｍｏｌ－１降至６５．３ｋＪ·ｍｏｌ－１,从而可在较低温度及较低浸出剂浓度下实现其有效浸出．     

机械活化对磁黄铁矿浸出动力学的影响

利用X线衍射仪、比表面积测试仪、扫描电镜和粒径分析仪对未机械活化和经振动磨机械活化后的磁黄铁矿进行分析和表征.在FeCl3-HCl体系中对未机械活化和经机械活化后的磁黄铁矿的浸出动力学进行研究.研究结果表明:机械活化增加磁黄铁矿的微观结构缺陷和比表面积,粉末粒度减小,形成的团聚体非常明显;与未活化的磁黄铁矿相比较,经机械活化10,20和40 min后的磁黄铁矿化学反应活性提高,反应速度加快,表观活化能降低,其中表观活化能由未活化时的150 kJ/mol分别降至58,49和45 kJ/mol.     

氧化锌的碱法浸出

根据等温溶解度法所研究的25℃、75℃和100℃时Na2O-ZnO-H2O三元水盐体系的平衡相图,借鉴氧化铝湿法生产工艺,探讨了氧化锌在碱性体系中的溶解和析晶过程.结果表明,对100℃、Na2O的质量分数wNa2O<34%的平衡体系,可采用稀释分解实现氧化锌的分离,完成该碱浓度下的氧化锌循环;对100℃、Na2O的质量分数wNa2O>29%的平衡体系,可采用冷却降温实现锌酸钠的分离,锌酸钠稀释后易得到氧化锌,从而完成在该碱浓度范围的氧化锌循环.     

机械活化碱分解独居石新工艺

运用我国在钨冶金领域中行之有效的机械活化碱分解工艺及设备进行稀土矿独居石的碱分解,全面研究了各种参数的影响．试验表明,当碱用量为理论量的１．６０～１．７２倍（精矿量的０．６５～０．７０倍）,温度为１６０℃,保温时间为２～３ｈ时,稀土分解率可达９９％以上．和现有工艺相比,本工艺能使碱用量减少３０％,回收率提高２％,有明显的经济效益．     

铵盐法处理氧化锌矿的研究

报道了用铵盐法处理含硅，铁高的氧化锌矿制取电解锌的工艺，试验表明，该工艺有流程短，技术条件易于控制，能耗低的优点，对含锌大于20％的氧化锌矿石，锌的浸出率可大于95％，锌电解直流电能耗为2380－2460kwh/t，阴极锌质量达到GB470－831＃号锌标准。     

铵盐浸出氧化锌矿动力学的研究

含硅、铁较高的氧化锌矿在NH4Cl-NH3-H2O体系中的溶解过程，遵循核收缩模型的动力学规律，浸出反应的表观活化能为34．57kJ／mol.浸出过程属于混合控制，即表面化学反应与通过不溶硅、铁矿物相的扩散为过程的控制步骤。     

活化焙烧强化盐酸浸出红土矿的镍

通过X线衍射、红外光谱、差热、扫描电镜和液氮吸附等方法考察活化焙烧对红土矿矿相结构变化和有价金属浸出的影响。研究结果表明:该矿在277℃左右发生了针铁矿脱水转变为赤铁矿,在610℃发生蛇纹石去羟基化作用,该结果与通过XRD表征的在不同温度下进行焙烧的矿石中主要矿相的晶型转变结果一致;矿物在300℃焙烧时,比表面积为21.04 m2/g,在610℃焙烧时,比表面积为26.45 m2/g,比原矿的比表面积16.03 m2/g有较大提高,有助于后续的浸出过程;在300℃焙烧后,矿样浸出可以获得最大的镍浸出率,达93%,而铁的浸出减少,进一步升高焙烧温度不利于有价金属镍的浸出。     

锗烟尘中氧化锌浸出过程动力学研究

对锗烟尘中氧化锌酸浸的动力学和反应机制进行了研究。结果表明,锗烟尘中氧化锌酸浸属于生成固体产物层的“未反应核缩减型”模型,动力学方程遵从1—2α／3-(1-α)^2／3=kt,锗烟尘中氧化锌酸浸的反应为一级反应,其表现活化能11．442kJ／mol,浸出过程为扩散步骤所控制。提高酸的浓度、温度、搅拌强度均可加快锌浸出速度,提高浸出率。     

含炭难处理金矿石碘法浸出

用非氰试剂——碘从矿石中浸出黄金，目的是研究碘化浸金取代剧毒氰化物提金的可行性；采用了热力学方法对碘-碘化物溶金的可能性进行了简单分析，用碘-碘化物溶液对含炭难处理金矿石进行了浸出工艺条件实验及与氰化浸出的对比实验，取得了较理想的实验结果：浸出4h金浸出率达到95％，氰化法直接浸出12h金浸出率80％；碘化法浸金速度快，金浸出率高。     

氧化锌矿浸出锌的优化实验研究

采用响应曲面法(Response Surface Methodology,RSM),选取Quadratic模型,进行了Box-Behnken实验设计优化在NH_3-(NH_4)_2SO_4-H_2O体系浸出氧化锌矿的实验工艺参数,建立了回归方程.回归分析模型的"ProbF"值为0.0023,小于0.05,模型模拟精度高,回归方程的全体自变量与因变量之间是显著的,回归方程可信.模型分析发现,液固比、浸出温度、浸出时间三个因素对锌的浸出率影响较为显著,对响应面和等高线图进行分析,液固比和浸出时间的交互作用较为显著.RSM法优化最佳浸出实验参数液固比12.81、浸出温度30℃、浸出时间4.15h、总氨浓度7.5mol·L~(-1),预测浸出率86.2%.综合考虑操作的可行性,在采用NH_3-(NH_4)_2SO_4-H_2O体系浸出氧化锌矿工艺中,选取液固比13、浸出温度30℃、浸出时间4h、总氨浓度7.5mol·L~(-1),测得浸出率为86.0%,与理论预测值相比误差为0.23%.     

氧化锌矿物浸出渣中铅、锶的提取及动力学分析

NH₄HCO₃ conversion followed by HCl leaching was performed and proven to be effective in extracting Pb and Sr from zinc extracted residual. The mechanism and operating conditions of NH₄HCO₃ conversion, including molar ratio of NH₄HCO₃ to zinc extracted residual, NH₄HCO₃ concentration, conversion temperature, conversion time, and stirring velocity, were discussed, and operating conditions were optimized by the orthogonal test. Experimental results indicate that NH₄HCO₃ conversion at temperatures ranging from 25 to 85°C follows the shrinking unreacted core model and is controlled by inner diffusion through the product layer. The extraction ratios of Pb and Sr under optimized conditions reached 85.15% and 87.08%, respectively. Moreover, the apparent activation energies of Pb and Sr were 13.85 and 13.67 kJ·mol?1, respectively.     

Extraction and kinetic analysis of Pb and Sr from the leaching residue of zinc oxide ore

NH_4HCO_3 conversion followed by HCl leaching was performed and proven to be effective in extracting Pb and Sr from zinc extracted residual. The mechanism and operating conditions of NH_4HCO_3 conversion, including molar ratio of NH_4HCO_3 to zinc extracted residual,NH_4HCO_3 concentration, conversion temperature, conversion time, and stirring velocity, were discussed, and operating conditions were optimized by the orthogonal test. Experimental results indicate that NH_4HCO_3 conversion at temperatures ranging from 25 to 85°C follows the shrinking unreacted core model and is controlled by inner diffusion through the product layer. The extraction ratios of Pb and Sr under optimized conditions reached 85.15% and 87.08%, respectively. Moreover, the apparent activation energies of Pb and Sr were 13.85 and13.67 k J·mol~(-1), respectively.     

碱性氧化铜矿产氨菌浸出特性

为了研究碱性氧化铜矿产氨菌浸出特性,分析了产氨菌浸矿过程对矿石的作用.将云南某矿的碱性氧化铜矿置于含菌培养液、去菌培养液和氨水等5种浸矿溶液中,在同一条件下进行摇瓶浸矿实验,剖析溶液中各可能的浸矿因子.研究结果表明:产氨菌产氨能力较强,尿素培养液中氨质量浓度最大达8.93 g·L-1;产氨量与细菌含量呈正相关关系,细菌含量越高,产氨量越大;产氨菌主要通过产氨间接浸矿,此外产氨菌和其代谢产物都能直接作用于矿石,浸矿能力细菌产氨>细菌>细菌代谢产物,三者比值约为12:5:4.     

稀土钙钛矿氧化物的合金化制备

采用机械合金化方法合成了稀土钙钛矿型氧化物SmCoO3,并利用XRD和Raman谱对其结构进行了测试,确定了合成单相SmCoO3的合金化条件及累积球磨一定时间后样品的Raman谱特征.     

硫氧混合铅锌矿中锌的氧化氨浸动力学

常压低温条件下在NH3-(NH4)2 SO4体系中使用过硫酸铵作为氧化剂对硫氧混合铅锌矿中的锌进行浸出实验,系统研究了搅拌速度、浸出剂浓度、氧化剂浓度与温度对于锌浸出率的影响.结果表明,在最优条件下锌的浸出率可达93.2%,且浸出过程中几乎没有其他离子进入溶液,实现了锌的选择性高效浸出,从而简化了后续的浸出液净化与材料制备过程.动力学研究表明,硫氧混合铅锌矿中锌的氧化氨浸过程遵循固体产物层扩散控制的未反应核收缩模型,浸出反应的表观活化能为17.89 kJ·mol-1.     

稀土钙钛矿氧化物的合金化制备

采用机械合金化方法合成了稀土钙钛矿型氧化物SmCoO3,并利用XRD和Raman谱对其结构进行了测试,确定了合成单相SmCoO3的合金化条件及累积球磨一定时间后样品的Raman谱特征。     

Sulfuric acid leaching of high iron-bearing zinc calcine

Sulfuric acid leaching of high iron-bearing zinc calcine was investigated to assess the effects of sulfuric acid concentration, liquid-to-solid ratio, leaching time, leaching temperature, and the stirring speed on the leaching rates of zinc and iron. The results showed that the sulfuric acid concentration, liquid-to-solid ratio, leaching time, and leaching temperature strongly influenced the leaching of zinc and iron, whereas stirring speed had little influence. Zinc was mainly leached and the leaching rate of iron was low when the sulfuric acid concentration was less than 100 g/L. At sulfuric acid concentrations higher than 100 g/L, the leaching rate of iron increased quickly with increasing sulfuric acid concentration. This behavior is attributed to iron-bearing minerals such as zinc ferrite in zinc calcine dissolving at high temperatures and high sulfuric acid concentrations but not at low temperatures and low sulfuric acid concentrations.     

Thermodynamics and kinetics of extracting zinc from zinc oxide ore by the ammonium sulfate roasting method

Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by (NH₄)₂SO₄ roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the zinc oxide ore and (NH₄)₂SO₄ in a temperature range of 573-723 K. The effects of reaction temperature and particle size on the extraction rate of zinc were also examined. It is found that a surface chemical reaction is the rate-controlling step in roasting kinetics. The calculated activation energy of this process is about 45.57 kJ/mol, and the kinetic model can be expressed as follows:1-(1-α)1/3=30.85 exp(-45.57/RT)·t. An extraction ratio of zinc as high as 92% could be achieved under the optimum conditions.