阳极导电材料对铁钨锡合金粉电解铁的影响

研究阳极导电材料碳素钢、316L不锈钢、铅钙合金、石墨、钛涂钌板、钛板和铜板在硫酸盐和氯盐体系中对铁钨锡合金粉电解铁的影响。结果表明:电解24 h,上述阳极导电材料在氯盐中的阴极电流效率为90%、90%、66%、66%、54%、49%、33%,在硫酸盐中的阴极电流效率为90%、87%、82%、81%、73%、68%、54%。槽电压均逐渐升高,在氯盐体系中,石墨、铅钙合金、钛涂钌板和钛板作阳极导电材料时,电解液pH逐渐降低;碳素钢、316L不锈钢和铜板作阳极导电材料时,电解液pH逐渐升高。在硫酸盐体系中,铜板和碳素钢作阳极导电材料时,电解液pH基本不变;316L不锈钢作阳极导电材料时,pH逐渐升高;铅钙合金、石墨和钛板作阳极导电材料时,pH先升高后降低。基于槽电压、阴极电流效率,选择适宜的电解体系为硫酸盐体系,该体系中适宜的阳极导电材料为铅钙合金。     

以PEG为分散剂从废绿矾中回收Fe_3O_4（英文）

以CaOH为沉淀剂通过共沉淀从绿矾溶液中回收Fe_3O_4,研究分散剂PEG对Fe_3O_4磁分离的影响。结果表明,分散剂PEG对Fe_3O_4的回收有显著影响。在Fe_3O_4制备过程中添加PEG不利于Fe_3O_4的回收。当PEG-6000浓度从0增加到8 g/L时,Fe_3O_4产品的铁品位从65.58%降至57.79%,中值粒径从2.35μm降至1.35μm。然而,在混合产物的湿磨过程中添加PEG可促进随后的Fe_3O_4回收。当PEG-200用量从粉末质量的0%增加到4%时,Fe_3O_4产物中铁的品位从65.58%升高到68.32%。当PEG-200用量为4%时,改变PEG相对分子质量从200增加到20000,Fe_3O_4产物中铁品位从68.32%降至66.70%。     

铜电解液中砷的还原及脱除(英文)

探讨了反应温度、H2SO4浓度、CuSO4浓度、反应时间、SO2气流量等因素对SO2还原铜电解液中As(Ⅴ)的影响,并对浓缩共晶作用下铜电解液中As(III)的脱除行为进行了研究。研究表明:As(V)还原率随着反应温度和H2SO4浓度的升高而降低,随着SO2气流量的增大及反应时间的延长而升高。当反应温度为65°C,H2SO4浓度为203g/L,CuSO4浓度为80g/L,SO2流量为200mL/min,反应时间为2h时,铜电解液中As(Ⅴ)还原率为92%;铜电解液中的As(V)还原后,将铜电解液浓缩至H2SO4浓度为645g/L时,As、Cu、Sb、Bi脱除率分别达到83.9%,87.1%,21%,84.7%.XRD分析结果表明:结晶产物中含有As2O3和CuSO4·5H2O等物相。     

低温CO-SCR催化剂UiO-66制备及其脱硝性能EI北大核心CSCD

通过溶剂热法在不同调节剂种类、浓度条件下制备UiO-66改性催化剂,并利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、热重分析仪(TGA)等对催化剂进行表征。考察不同调节剂种类、浓度对UiO-66形貌、结构组成以及选择性催化还原(CO-SCR)性能的影响。结果表明:UiO-66-HCl催化剂具有良好的脱硝性能和分散性以及更多的路易斯酸性位点和CUS(不饱和金属位点)。CO-SCR催化性能测试结果显示,在对苯二甲酸(H_(2)BDC)与调节剂的摩尔比为1:4,脱硝温度为170℃时,UiO-66-HCl脱硝率达到95%。     

Industrial experiment of copper electrolyte purification by copper arsenite

Copper electrolyte was purified by copper arsenite that was prepared with AS2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m^2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m^2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper（GB/T467-97）.     

Hexagonal hematite platelets synthesized from pyrite cinders by hydrothermal process

Well-crystallized hexagonal hematite (α-Fe2O3) platelets were synthesized by hydrothermal process,using a highly concentrated ferric hydroxide as precursor.The precursor was prepared by adding ammonia to the ferric sulfate solution which was obtained by leaching pyrite cinders with sulfuric acid.Structure and morphology of the synthesized products were investigated by X-ray diffraction,scanning electron microscope,transmission electron microscope and selected area electron diffraction.The results reveal tha...     

新型复合引发剂APS-TEA引发DMDAAC的聚合及PDMDAAC的应用

用一步法合成DMDAAC单体，采用APS—TEA复合引发体系引发聚合得到PDMDAAC。实验取100mL质量分数为72％的DMDAAC溶液，通N2 30min后加入APS 0．548g、TEA0．352g、EDTA·2Na 15．04mg，当反应温度为42℃，反应时间为24h时，DMDAAC的转化率为82．26％，PDMDAAC的特征粘度为1．06dL／g。采用PFS（聚合硫酸铁）、PDMDAAC和PFS—PDMDAAC复合絮凝剂处理Cu^2＋、pb^2＋浓度均为10mg／L的模拟重金属污水，PFS—PDMDAAC复合絮凝剂处理效果最好。控制模拟污水的终点DH值约为8．5，使用PFS-PDMDAAC复合絮凝剂，当PFS剂量为5．52mg／L、PDMDAAC剂量为0．39mg／L时，处理后Cu^2＋、Pb^2＋去除率分别达到99．8％和99．9％。     

东江库区移民环境容量的回顾与评价

东江水库移民安置规划依据环境容量这一制约因素，以经济收入指标作为移民安装标准进行编制，保障了东江库区社会的稳定和经济的发展，使其资源得到了合理的开发。说明在市场经济体制下应把握价值规律，合理制定移民安置标准；应根据库区经济发展规律适时投资，以发展投入资金铁最大效益；还应注意移民文化素质的提高，以促进库区经济的发展。     

化学镀铜及其应用

综述了化学镀铜技术及其发展趋势,对化学镀铜的原理、工艺、镀液组成等方面进行了全面的分析,最后对化学镀铜今后的研究方向提出了一些见解.     

Novel technology of purification of copper electrolyte

The effects of arsenic with different valence states on the purification of copper electrolyte were studied and a novel technology of purification of copper electrolyte by copper arsenite was proposed. The results show that the purification performance of As（Ⅲ） compounds is better than that of As（Ⅴ） compounds. The purification technology by copper arsenite has the advantages of simple operation, high purification performance and low cost in comparison with other technologies and its appropriate purification conditions are that copper arsenite concentration is 18 g/L, reaction temperature is 65 ℃ and reaction time is 8 h. The removal rates of Sb and Bi are 53.22% and 58.67% respectively under these conditions. The purification principle show that a kind of yellow precipitate mainly composed of arsenic, antimony （ Ⅴ ）, bismuth and oxygen forms in electrolyte after copper arsenite is added, and consequently antimony and bismuth are removed from electrolyte.