由氧化锌烟灰氨法制取高纯锌

开发了用NH3-NH4Cl水溶液浸出炼铅炉渣烟化炉氧化锌烟灰制取高纯锌的新工艺.Zn的浸出率＞96%,浸出液加H2O2后净化除Sb和As,然后采用加锌粉两段逆流除Cu,Cd,Pb,电积过程中电能消耗2 500～2 700 kW@h/t.电锌含Zn＞99.999%,杂质元素Cu,Cd,Co,Ni,Fe,As,Sb均小于0.0001%,Pb＜0.000 3%.     

CO还原氧化锌生成气态锌和CO2反应的平衡常数

用新方法测定了不同温度下ＣＯ还原ＺｎＯ生成Ｚｎ蒸气和ＣＯ２的反应的平衡常数,得到了该反应的ｌｇＫｐ＝－１０６３０／Ｔ＋６．９２关系式。将此式与文献报道的关系式进行比较,在１２５０Ｋ时,Ｋｐ最小值为０．０１２４,比本研究低０．０１３６;Ｋｐ最大值为０．０３２４,比本研究高０．００６４;其余的Ｋｐ值与本研究的结果比较接近,差值不超过０．００５,说明本研究结果是可靠的。     

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。     

电纺丝法制备氧化锌纳米纤维

以聚乙烯醇(PVA)与乙酸锌的混合溶液为前驱体,采用静电纺丝法制得乙酸锌/PVA复合纤维,经煅烧后得到直径分布均匀的ZnO纳米纤维.对所制得的复合纤维及ZnO纳米纤维分别采用了热失重、X射线衍射、红外光谱(IR)、扫描电镜(SEM)等分析测试手段进行了表征.研究了纤维平均直径受电纺丝溶液配比的影响.     

氧化锌烟尘中铟的挥发富集

针对含多种有价金属的还原挥发氧化锌烟尘,对各元素的挥发特性进行热力学平衡计算、实验室回转窑挥发和中试试验,验证铟镉铅选择性挥发效果,获得高铟物料和脱除氟氯的高锌焙砂的工艺路线。在实验室回转窑中,铟和铅的挥发率分别为93.20%和95.12%,同时,得到含锌67.36%、含氟0.013%和氯0.407%的焙砂。在中试试验中,挥发产物中铟的平均含量超过700g/t,较原料富集比超过2倍,铅的平均挥发率达到98.94%,焙砂中平均锌含量为64.16%,锌焙砂中氟和氯的含量分别降到了0.013%和0.211%,这说明从氧化锌烟尘中分离铟并获得可以满足电解锌要求的焙砂的挥发效果非常显著。     

一种实时掺氦生长P型氧化锌晶体薄膜的方法

本发明公开的实时掺氮生长P型氧化锌晶体薄膜的方法，是在金属有机化学汽相沉积过程中利用活化裂化高纯氮源气体产生氮原子进行实时掺氮的。步骤如下：先将衬底表面清洗后放入金属有机化学汽相沉积生长室中，生长室真空度抽到至少10^-4Pa，然后加热衬底，使衬底温度为350—950℃，将高纯氧源和用高纯载气将高纯有机锌源输入生长室中在衬底上生长氧化锌薄膜，高纯氧源和高纯有机锌源的摩尔流量分别为5～100000μmol／min和0．1～1000μmol／min，同时将用原子发生器活化裂化高纯氮源气体分离出的氮原子输入生长室，     

微波水热法制备氧化锌纳米粉体及其光催化性能

以ZnSO4·7H2O为原料,NaOH为矿化剂,采用微波水热法成功制备出氧化锌纳米粉体,研究了NaOH浓度对ZnO粉体的物相,形貌以及光催化性能的影响。XRD表明所得粉体均为纯相六方纤锌矿结构的氧化锌,晶粒尺寸介于39~58nm之间;FE-SEM和TEM表明,当NaOH浓度从0.5mol/L逐渐增大到4.0mol/L时,颗粒形貌由碎片状变为层片花状结构。利用300W高压汞灯作为光源,对质量浓度为20mg/L的罗丹明B溶液进行光催化降解实验,在光照120min后,不同矿化剂浓度下制备的氧化锌催化剂对罗丹明B的降解率均接近100%,说明当前条件下制备的ZnO粉体对罗丹明B具有较高的光催化活性。     

高比表面积氧化锌纳米线的制备

以聚乙烯吡咯烷酮作为络合剂与醋酸锌混合,并且加入适当催化剂,制得纺丝液.采用静电纺丝的方法,制得聚乙烯吡咯烷酮/醋酸锌复合纤维,通过热处理得到氧化锌纤维.对所制得的纤维成分、形貌、晶粒大小,分别采用X射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等分析测试手段进行表征.实验结果表明,500 ℃下煅烧得到表面粗糙、充满细小管道的纯氧化锌纳米纤维,平均晶粒尺寸5 nm,拥有超高比表面积.     

Recylex暂停氧化锌的生产

法国金属回收公司Recylex暂停了旗下位于德国的子公司Harz Metall公司的氧化锌生产 公司于12月5日表示，经济环境逐渐恶化使公司作出了停产决定。     

Recovery of valuable metals from zinc leaching residue by sulfate roasting and water leaching

Zinc leaching residue (ZLR), produced from traditional zinc hydrometallurgy process, is not only a hazardous waste but also a potential valuable solid. The combination of sulfate roasting and water leaching was employed to recover the valuable metals from ZLR. The ZLR was initially roasted with ferric sulfate at 640 °C for 1 h with ferric sulfate/zinc ferrite mole ratio of 1.2. In this process, the valuable metals were efficiently transformed into water soluble sulfate, while iron remains as ferric oxide. Thereafter, water leaching was conducted to extract the valuable metals sulfate for recovery. The recovery rates of zinc, manganese, copper, cadmium and iron were 92.4%, 93.3%, 99.3%, 91.4% and 1.1%, respectively. A leaching toxicity test for ZLR was performed after water leaching. The results indicated that the final residue was effectively detoxified and all of the heavy metal leaching concentrations were under the allowable limit.     

Zn（Ⅱ）-NH3-Cl--H2O体系的优势区图（英文）

采用化学平衡模拟软件GEMS预测了锌湿法冶金过程中涉及的锌在Zn(Ⅱ)-NH3-H2O和Zn(Ⅱ)-NH3-Cl--H2O体系中的溶解度,并构建了其含锌物种分布图和优势区图。采用平衡实验方法测定了相同条件下锌的溶解度,其结果与预测结果相吻合。含锌物种的分布图和优势区图表明,在弱碱性条件下,2个体系均为以锌氨和羟基锌氨配合物为溶液的主要物种,其中Zn(NH3)24-为主要优势物种;在Zn(Ⅱ)-NH3-Cl--H2O体系中,锌氨氯三元配合物的形成能有效增大锌在中性条件下的溶解度,在该体系中存在Zn(OH)2、Zn(OH)1.6Cl0.4和Zn(NH3)2Cl23种固相,固相产物的形成取决于体系中总锌、总氨和总氯浓度。这些热力学平衡图表明了体系中各种物种之间的相互影响作用,并预测了总氨和总氯浓度的变化对锌溶解度的影响,为锌湿法冶金提供了热力学数据。     

Dissolution kinetics of low grade complex copper ore in ammonia-ammonium chloride solution

The leaching kinetics of Tang-dan refractory low grade complex copper ore was investigated in ammonia-ammonium chloride solution. The concentration of ammonia and ammonium chloride, the ore particle size, the solid-to-liquid ratio and the temperature were chosen as parameters in the experiments. The results show that temperature, concentration of ammonia and ammonium chloride have favorable influence on the leaching rate of copper oxide ores. But, leaching rate decreases with increasing particle size and solid-to-liquid ratio. The leaching process is controlled by the diffusion of the lixiviant and the activation energy is determined to be 23.279 kJ/mol. An equation was also proposed to describe the leaching kinetics.     

低品位氧化铜矿氨-硫酸铵体系过硫酸铵氧化浸出

以过硫酸铵为氧化剂,研究低品位氧化铜矿在氨-硫酸铵体系氧化浸出工艺。讨论氨/铵离子摩尔比、总氨浓度,氨、硫酸铵和过硫酸铵的浓度,反应温度,液固比,反应时间和搅拌速度等操作条件对铜浸出的影响。结果表明:在92.8%的矿样粒径小于0.045 mm,氨、硫酸铵和过硫酸铵浓度分别为2.4、1.8和0.100 mol/L,浸出时间为90 min,温度为30℃,液固比(mL/g)为5:1,搅拌速度为500 r/min时的优化条件下,低品位铜矿的铜浸出率达87.7%。     

硫酸铵焙烧法浸出镍磁黄铁矿中有价金属

将镍磁黄铁矿与(NH4)2SO4混合后在高温下焙烧,考察(NH4)2SO4用量、浸出温度、浸出时间和稀硫酸浸出液的pH值对焙烧产物中金属元素浸出率的影响,并在氨水-(NH4)2SO4混合溶液中浸出焙烧产物。结果表明:在不同情况下,Ni和Cu的浸出率较高,Mg和Fe的浸出率较低;氨性溶液有利于Ni和Cu的浸出,总氨浓度为7 mol/L时,Ni和Cu的浸出率分别为89.56%和79.35%;低pH值的稀硫酸溶液有利于Mg和Fe的浸出,pH值为0.5时,Mg和Fe的浸出率分别为61.39%和62.56%。由扫描电镜-能谱分析和XRD分析可知,矿样中Ni和Cu大部分被浸出;由于焙烧产物中部分Mg和Fe以铁酸钙和硅酸镁等形态存在,Mg和Fe的浸出率较低。     

氨络合物体系电积锌的阴极过程

采用CHI650电化学工作站测定了在锌氨络合物体系中锌电沉积的稳态阴极极化曲线及电流-时间暂态曲线.结果表明:锌的阴极电结晶过程是以瞬时成核方式进行的,随外加电位负移,晶体的向外生长速率增大;添加剂的加入不会改变锌阴极电沉积的成核方式,但将大大减小晶体的向外生长速率.通过对不同NH3浓度下测得的阴极极化曲线的分析,可获得各条件下的平衡电位,以及阴极过程动力学参数(交换电流密度J°、传递系数α),进而推导出溶液中存在的主要离子为Zn(NH3)2 4,在阴极直接放电的络离子为Zn(NH3)22 .     

Ida~(2-)-H_2O体系浸出低品位氧化锌矿(英文)

采用Ida2--H2O体系(亚氨二乙酸盐水溶液)处理高碱性脉石型低品位氧化锌矿,考察浸出时间、液固比、配体总浓度、温度及pH值对矿物中主金属Zn及杂质元素Ca、Mg、Cu、Ni、Fe、Pb、Cd的溶出影响。结果表明:在弱碱性Ida2--H2O体系中,Ca、Mg、Fe不会被大量溶出,有价金属Cu、Ni、Pb、Cd可部分随主金属Zn溶出而进入浸出液;在浸出时间4h、液固比5:1、配体总浓度0.9mol/L、温度70℃、pH8的优化条件下,锌浸出率为76.6%。     

Corrosion of hot-dip-galvanised steel and zinc alloy-coated steel in ammonia and ammonium chloride

There are many potential causes of corrosion in animal buildings. Animals exhale large quantities of moisture into the air creating high relative humidity in the building if the moisture is not properly vented. High humidity increases the potential for condensation. In addition, ammonia may be found in large quantities in animal buildings. Ammonia is released from manure and urine. In addition, ammonium chloride is used as a nitrogen source in fertilisers. In this study, the atmospheric corrosion of hot-dip-galvanised steel and zinc alloy-coated steel such as zinc–aluminium and zinc–aluminium–magnesium has been studied in atmospheres containing different levels of ammonia. Investigations have also been conducted at different levels of ammonium chloride. The results are discussed in view of the mechanisms of corrosion of zinc and zinc alloy-coated steel in ammonia and ammonium chloride-containing environments.     

Selective recovery of zinc from zinc oxide dust using choline chloride based deep eutectic solvents

Deep eutectic solvents (DESs) are a kind of potential lixiviant for selective metal processing due to their versatile complexation properties. In this study, we investigated the recovery of zinc from zinc oxide dust using choline chloride−urea− ethylene glycol (ChCl−urea−EG) DESs. The zinc extraction efficiency can be up to 85.2% when the slurry concentration is 50 g/L, leaching temperature is 80 °C and stirring speed is 600 r/min. The leaching process is controlled by the diffusion and the corresponding activation energy is 32.1 kJ/mol. The resultant solution was directly used for the electrodeposition of zinc. The pure zinc deposit is obtained with a current efficiency of 82.6%. Furthermore, the ChCl−urea−EG DESs can be recycled. This approach is shown to be promising for the recycling of zinc from the zinc-containing dust.