甲醛和OP乳化剂对印刷电路板酸性半光亮镀锡的影响

印刷电路板(PCB)镀锡铝工序必不可少,但其对环境有污染,受到了各国的限制.以锡基液加表面活性荆对PCB电镀锡,采用SEM、法拉第定律、稳态极化曲线分别研究了甲醛、OP乳化剂对镀锡层形貌、镀液电流效率、锡电沉积阴极极化的影响.结果表明:甲醛和OP乳化剂均能显著细化晶粒和改变镀层形貌,当甲醛含量太低时,镀层颗粒呈鹅卵石状...     

铜电解液自净化研究进展

在铜电解过程中,粗铜中的有害杂质(主要是As、Sb、Bi)通过电化学溶解进入电解液并不断富集,从而严重危害阴极铜的质量及电解生产,电解液及时净化对阴极铜质量有着重要的意义.针对现行的铜电解液净化工艺中存在的能耗高、污染大、除杂效率低等缺点,对铜电解液自净化工艺进行了评述,详细介绍了目前国内外自净化除杂的实验室研究、工业应用及自净化机理的研究现状,并对其发展前景进行了展望.     

Purification mechanism of copper electrolyte by As（Ⅲ）

A new kind of precipitate, antimony arsantimonate, was found during the precipitation reactions in acidic solution containing As（Ⅲ）, Sb（Ⅲ） and Sb（ Ⅴ ） by means of chemical analysis, SEM, XRD and IR spectrometry. The results show that the As content in antimony arsantimonate increases with the increase of n（As（Ⅲ）/n（Sb） in solution and the content of component Sb（Ⅲ） and Sb（Ⅴ） remains almost constant with the variation of n（Sb（Ⅲ））/n（Sb（Ⅴ）） in solution. The antimony arsantimonate is a kind of floccules with size of 1-5 μm. The crystal performance of the compound gets better with the decrease of n（As（Ⅲ））/n（Sb）, the cell parameter of which is near to 10.33×10^-10m under different n（As（Ⅲ））/n（Sb） and As atom locates on the surface, not in the inner of the grain. The chemical bonds of As--OH, Sb---OH, As---O--Sb, Sb--O---Sb and O---H of the precipitate are included in the precipitate. The chemical structure of precipitate is described as Sb（OH）2---O--[Sb（OH）3--（O---As（OH）--O---Sb（OH）3）3]----O--- Sb（OH）2·xH2O. The structure analysis shows that the copper electrolyte can be purified by As（Ⅲ） because the antimony arsantimonate precipitate forms.     

大冶冶炼厂高电流密度铜电解工业试验

介绍了大冶冶炼厂在现有生产条件下进行的高电流密度铜电解工业试验。结果表明,高电流密度电解所得阴极铜外观质量较好,电流密度280A／m^2时高纯阴极铜合格率为98．15％-98．37％,290A／m^2时高纯阴极铜合格率为95．51％-98．29％。     

Recovery of copper sulfate after treating As-containing wastewater by precipitation method

The solid sodium hydroxide neutralized acidic As-containing wastewater till pH value was 6. Green copper arsenite was prepared after copper sulfate was added into the neutralized wastewater when the molar ratio of Cu to As was 2:1 and pH value of the neutralized wastewater was adjusted to 8.0 by sodium hydroxide. The arsenious acid solution and red residue were produced after copper arsenite mixed with water according to the ratio of liquid to solid of 4:1 and copper arsenite was reduced by SO₂ at 60 °C for 1 h. The white powder was gained after the arsenious acid solution was evaporated and cooled. Copper sulfate solution was obtained after the red residue was leached by H₂SO₄ solution under the action of air. The results show that red residue is Cu₃(SO₃)₂·2H₂O and the white powder is As₂O₃. The leaching rate of Cu reaches 99.00% when the leaching time is 1.5 h, molar ratio of H₂SO₄ to Cu is 1.70, H₂SO₄ concentration is 24% and the leaching temperature is 80 °C. The direct recovery rate of copper sulfate is 79.11% and the content of CuSO₄·5H₂O is up to 98.33% in the product after evaporating and cooling the copper sulfate solution.     

Anode oxidation of HCHO in THPED-containing electroless copper plating solution

The electrochemical mechanism of anode oxidation of HCHO in electroless copper plating solution with N, N, N', N'-tetrakis(2-hydroxypropyl)ethylenediamine (THPED) was investigated by measuring cyclic voltammetry curves and anodic polarization curves. Three different oxidation peaks occur at the potentials of-0.62V (Peak 1), -0.40V (Peak 2) and -0.17V (Peak 3) in the anode oxidation process of THPED-containing solution. The reaction at Peak 1, a main oxidation reaction, is the irreversible reaction of adsorbed HCHO with hydrogen evolution. The reaction at Peak 2, a secondary oxidation reaction, is the quasi-reversible reaction of adsorbed HCHO without hydrogen evolution. The reaction at Peak 3 is the irreversible oxidation of anode copper. The current density of Peak 1 increases gradually, that of Peak 2 remains constant and that of Peak 3 decreases with the increase of HCHO concentration. The current density of Peak 3 increases with the increase of THPED concentration and the complexation of THPED promotes the dissolution of anode copper.     

免费相册空间的“入侵”——把相册变成网络硬盘

现在各大门户的网站的免费相册的空间都大的惊人，新浪的有50M，而财大气粗的网易更是推出了无限容量的免费相册空间。但这类空间—般只允许上传扩展名为．gif和jpg的图片文件，其它类型的文件禁止上传，即使即私自将文件的扩展名改为．gif或jpg也是无法     

硝酸预处理对Pd/C催化剂微观结构的影响

采用不同浓度的硝酸对椰壳活性炭进行预处理,然后以浸渍法制备了精对苯二甲酸精制用Pd/C催化剂。通过SEM、TEM、EDS、XRD及比表面积和孔结构测试等手段,研究了硝酸预处理对Pd/C催化剂微观结构的影响,并探讨了其结构与催化活性的关系。SEM、TEM及孔结构测试的结果表明,适宜浓度(1.2 mol/L)的硝酸预处理可在一定程度上增大活性炭的平均孔径和中孔体积,减小Pd晶粒尺寸,提高Pd在载体上的分散性。EDS表征结果显示,硝酸预处理使催化剂表面新增7.57%(w)的氧元素。XRD表征结果显示,硝酸预处理对催化剂的物相基本无影响。硝酸预处理使活性炭载体表面产生含氧基团,增大载体孔径、中孔体积和有效负载面积,抑制Pd晶粒的增大,促进Pd的分散,从而提高其催化活性。     

难处理低品位铜钴矿的微生物浸出

以赞比亚某典型难处理低品位氧化铜钴矿为研究对象,配入适量硫化铜钴矿,采用人工调配的高效微生物浸矿菌群对铜钴矿进行微生物浸出,同时分别与摇瓶酸浸、搅拌酸浸和柱浸进行了对比.结果表明,采用微生物浸出难处理铜钴矿,随着温度升高和时间延长,铜浸出率增大.浸出温度为40℃时,微生物浸出铜浸出率为90.7%,高于摇瓶酸浸和搅拌酸浸浸出结束时浸出率(69.4%~73.2%)以及柱浸结束时浸出率(约85%).由于微生物浸出群落对该难处理铜钴矿作用时间周期较长,适用于堆浸生产.细菌的存在使得铁离子不断的在二价与三价间循环,通过具有强氧化性的Fe3+与硫化矿物相互作用,使得矿物分解,提高浸出率.     

磁微粒子Fe_3O_4纯化CdS纳米晶的实验研究

以L-半胱氨酸、醋酸镉为原料,在磁微粒子Fe3O4存在下,通过水热法合成出CdS纳米晶与磁微粒子连接混合体,利用磁微粒子的磁性对合成的CdS纳米晶进行分离纯化,然后加入聚乙烯吡咯烷酮(PVP)、3-巯基丙酸使磁微粒子与硫化镉纳米晶分离。对产品进行了详尽的XRD、SEM、HRTEM及EDS能谱表征分析,并测试了纯化前后样品的荧光激发谱与荧光发射谱,荧光光谱显示获得预期的纯化效果。