响应曲面法优化硫脲浸出烧结灰中银的工艺研究

以炼铁烧结机头除尘灰(烧结灰)为实验原料,通过XRF、XRD、SEM-EDS手段对原料进行表征,采用酸性硫脲法浸出烧结灰提取银。在单因素实验的基础上,使用响应曲面法(RSM)对烧结灰中提取银的工艺条件进行优化,以炼铁烧结灰中银的浸出率为响应值,选取对硫脲浸出烧结灰提银过程有显著影响的变量(反应温度、硫脲浓度、浸出时间)作为考察因素,采用Central Composite Design(CCD)中心设计方案以三因素五水平设计实验,得到最优的提银工艺条件,并获得拟合度高的二阶多项式模型。结果表明:硫脲浸出烧结灰中银的最佳工艺为反应温度50℃、硫脲浓度22g/L、浸出时间90min;在最佳提取条件下,银浸出率的模型预测值为89.38%,实验真实银的浸出率为89.9%,其相对误差为0.52%,表明实际值与模型预测值接近,可用于预测烧结灰提取银的浸出过程。     

微波热解法制备的炭涂层对LiNi_（1／3）Mn_（1／3）Co_（1/3）O_2性能的影响

报道了炭包覆锂离子电池正极材料LiNi_（1／3）Mn_（1／3）Co_（1/3）O_2的新工艺。炭涂层由前驱体葡萄糖通过微波热解而形成。采用x射线粉末衍射（XRD）、扫描电镜、x射线荧光测试和恒流充放电测试来表征所制备的材料。XRD结果表明,炭包覆没有改变LiNi_（1／3）Mn_（1／3）Co_（1/3）O_2材料的相结构。SEM结果表明,炭包覆的LiNit／3Mnl／3Col／302颗粒表面变得粗糙。充放电测试结果显示,炭包覆的LiNi_（1／3）Mn_（1／3）Co_（1/3）O_2的循环性能与未包覆的相比得到提高。炭包覆的LiNi_（1／3）Mn_（1／3）Co_（1/3）O_2在0．2C倍率下循环50次的容量保持率由84．8％提升到95．5％,且高倍率下材料的容量保持率得到提高。     

采用硫化钠分离富集湿法炼锌渣中汞与硫（英文）

采用Na2S浸出-CO2沉淀法对浮选硫精矿中汞的分离和富集以及元素硫的回收进行研究。结果表明,在常温、Na2S浓度为1.5 mol/L、液固比为6:1、浸出时间为30 min的条件下,元素硫的浸出率可达98%以上,汞的平均富集率为98.13%,渣中汞含量为原矿石的5.23倍。向浸出液中通入CO2气体,充分搅拌溶液,在CO2流量为200 mL/min,通气时间为150 min的条件下,元素硫从溶液中析出,回收率可达到97.67%,获得的元素硫纯度为99.75%,符合GB/T2449—2006工业硫磺一等品标准。     

Removing chlorine of CuCl residue from zinc hydrometallurgy by microwave roasting

Most Zn hydrometallurgy factories adopt Cu2SO4 as a dechlorination reagent from zinc solution nowadays, thus much CuCl residue is produced. The existing process of treating this residue is washing with water or sodium carbonate solution, which would cause a lot of troubles to water treatment and waste discharge. A method of microwave roasting was adopted for dechlorination of CuCl residue. A 1.5 kW microwave roasting equipment with dust collection and tail gas adsorption systems was set up and applied during the experiment. By investigating the effect of temperature, heat preservation time, moisture content of raw material and grain size of samples on the dechlorination, the optimal experimental condition is obtained. When the samples with 2% moisture and 〈150 μm grain size are microwave roasted at 400 °C for 2 h, the Cl content turns from 14.27% to 1.35% and the dechlorination rate is as high as 90%, while that with conventional heating is only 60%-80%. The phase change of the roasting process investigated with X-ray diffraction verifies that CuCl in CuCl residue is removed by being transformed into CuO.     

微波加热技术在典型冶金工艺中的应用研究进展

阐述了微波加热的基本原理,讨论了矿物在微波场中的升温特性和吸波特性。微波在矿物处理方面的应用研究进展,主要包括微波预处理、微波干燥、微波焙烧、微波碳热还原、微波辅助浸出等典型冶金工艺的研究现状。分析了目前微波加热技术在典型冶金工艺中的应用与研究进展,并对微波加热技术在冶金工艺中的应用前景进行了展望。     

微波加热再生废弃针剂用活性炭的性能

采用微波加热再生废弃针剂用活性炭, 通过响应曲面法中模型的优化设计和分析, 研究了再生过程中的3个影响因子(再生温度、再生时间以及物料厚度)对所再生活性炭亚甲基蓝值和得率的影响, 并通过方差分析(ANOVA)研究了各个实验因子或交互作用对活性炭性能的影响。得到实验优化工艺条件为:再生温度700℃, 再生时间18min, 物料厚度20mm, 所再生活性炭亚甲基蓝值和得率分别为187.5mg/g, 65.20 %。此外, 再生活性炭比表面积高达962m²/g, 总孔体积为1.02mL/g, 平均孔径为4.27nm。     

Dielectric Properties and Oxidation Roasting of Molybdenite Concentrate by Using Microwave Energy at 2.45 GHz Frequency

Metallurgical and Materials Transactions B - Conversion of electromagnetic energy into heat depends largely on the dielectric properties of the material being treated. Therefore, determining the...     

Effects of ZrO2 Coating on LiNi1/3Mn1/3Co1/3O2 Particle with Microwave Pyrolysis

In this paper, ZrO₂-coated LiNi_1/3Mn_1/3Co_1/3O₂ is successfully prepared by the microwave pyrolysis method. The structure and electrochemical properties of the ZrO₂-coated LiNi_1/3Co_1/3Mn_1/3O₂ are investigated using x-ray diffraction, AC impedance, and charge/discharge tests, indicating that the lattice structure of LiNi_1/3Co_1/3Mn_1/3O₂ is unchanged after the coating but the cycling stability is improved. As the coating amount is 2 wt.%, initial capacity of the coated LiNi_1/3Co_1/3Mn_1/3O₂ decreases slightly. However, the cycling stability increases remarkably over the cut-off voltages of 2.75~4.3 V and the capacity retention reaches 93.1% after 50 cycles. Electrochemical impedance spectra results show that the increase of charge transfer resistance during cycling is suppressed significantly by coating with ZrO₂.     

辉钼精矿在微波场中的升温行为研究*

考察了辉钼精矿在微波场中的升温行为,研究了物料厚度、微波功率及物料量对辉钼精矿升温行为的影响。研究结果表明,辉钼精矿具有良好的微波吸收性能,物料在微波场中升温与微波功率呈正比关系,而与物料 厚度和物料量成反比。在微波功率为2.6 kW,物料厚度为2 mm条件下,微波加热13 min后,辉钼精矿可升温至 600 ℃。采用微波氧化焙烧辉钼精矿是可行的。     

湿法炼锌氯化亚铜渣的介电特性研究

开发了微波焙烧湿法炼锌氯化亚铜渣脱氯的新工艺,为解决其综合利用提供了新的选择方案。阐述了微波焙烧脱氯新工艺的基础,即氯化亚铜渣的介电特性。通过分析微波焙烧前后物料物相的变化,表明微波焙烧有很好的除氯效果;然后采用谐振腔微扰法对微波焙烧前后原料或产物介电系数进行了测量,并研究了氯化亚铜渣密度和粒度对其介电系数的影响,在此基础上计算了微波对氯化亚铜渣的穿透深度。最后根据这些参数发现氯化亚铜渣粒度在20～100目并且密度在2g/cm3以上时铜渣的吸波性最好。