铜氨液制备新方法

介绍了我厂合成氨系统新建 16万t/a铜洗再生系统开车前铜氨液的制备方法。此方法与传统铜氨液制备方法对比 ,显示出其优越性、实用性。     

醋酸铜氨液中二价铜及铜比的测定

醋酸铜氨液的稳定运行,是保证合成车间铜洗和合成系统正常生产的关键。因此,除了保证醋酸铜氨液中各组分达到指标外,还必须严格控制醋酸铜氨液的铜比,以使生产能稳定运行。然而,要准确控制铜比,必须在知道总铜的情况下精确测定二价铜。目前测定二价铜多采用碘量法,而碘量法存在的主要问题有：一是由于Cu．＋的易氧化性,在注入试样时取样管必须插至烧杯底部,且试样必须要吹尽,否则会造成Cu．２＋．测定结果偏高;二是滴定过程中,如滴定掌握不好,造成碘化淀粉的生成,使测定结果偏低;三是当铜液中Cu２＋．含量过高时,加入的KI…     

铜液加酸加氨方法的改进

我厂是1970年建成投产的年产4.5万吨(现扩改为6万吨/年)合成氨厂。在生产过程中,我们对原设计调整铜液成份所用的加冰醋酸、氨的方法进行了改进。一、加氨方法的改进原设计是将1.6MPa的液氨充入加氨设备称氨缸中,经减压后把0.2 MPa左右的低压液氨注入铜洗再生系统内。我们现在省去了这套设备,直接在再生氨冷器出口氨管上     

硫钠法测定铜液中总氨含量

本文较详细地介绍了用硫代硫酸钠法测定合成氨铜液中总氨的含量,并对测定结果进行讨论。     

非掩蔽测定铜氨液中低价铜方案

一种非掩蔽测定铜氨液中低价铜方案。用锌置换铜氨液后用EDTA滴定,计算低价铜。特点是溶液清亮,终点显明,费用低。可非氧化快速测定总铜。     

氨碱性蚀刻液中铜溶解过程的化学动力学

氨碱性溶液是印制电路板工业中采用最为广泛的蚀刻溶液,但是关于溶液中铜溶解过程的动力学研究还比较缺乏。研究利用模拟实验的方法,定量地研究了铜溶解反应的化学动力学性质。当速度梯度G值大于7 570 s~(-1)时,铜溶解速率不受混合强度影响的传质速率限制;在反应前120 s内,平均单位面积铜溶解质量与反应时间呈线性关系,反应的速率常数约为0.137 3 mg/(cm~2·s);溶液Cu~(2+)浓度低于0.8 mol/L时,铜溶解速率随Cu~(2+)浓度增大而线性增大,此区间反应符合一级反应动力学;Cu~(2+)浓度约为1.0 mol/L时溶解速率最大;温度对反应速率的影响非常显著,升高温度反应速率增加较快,50℃时溶解速率可达21.106μm·L/(min·mol);溶解反应的Arrhenius活化能Ea约为23.7 k J,频率因子A约为1.43×10~5。     

Anodic Oxidation of Carbon Fibres in Diammonium Hydrogen Phosphate Solution

Anodic surface treatment of high tensile-carbon fibres under galvanostatic conditions has been performed in diammonium hydrogen phosphate solution, containing an addition of ammonium rhodanide.

The oxidized fibres have been characterized by monofilament tensile strength, XPS measurements and surface energetic analysis. Additionally, the acid-base interactions have been evaluated by wetting with aqueous solutions of different pH values.

An addition of ammonium rhodanide to the diammonium hydrogen phosphate anodization bath affects the oxidation of carbon fibres in terms of decreasing both the amounts of the surface oxides as well as that of degradation by-products. At the optimal treatment conditions (I = 100 mA) no changes in the tensile strength or BET-surface area of the fibre have been observed. The rise in ILSS values of amine cured epoxy composites is not dependent on O_ls/C_ls ratio or surface free energy of the reinforcing fibres, but on the acidic as well as nitrogen functional groups on their surface.     

Back-extraction Of Pu4 From 20% Tributyl Phosphate - 20% Mixed Trialkyl Phosphine Oxides/kerosene In The Presence Of

Back-extraction of Pu^4 +  from a mixture of 20% tributyl phosphate (TBP) and 20% mixed trialkyl phosphine oxides (TRPO) in kerosene in the presence of UO²⁺₂was studied. The back-extractants investigated may be divided into three groups: carboxylic acids and salts, amino polycarboxylates, and phosphonic acid. The distribution coefficients of both Pu^4 +  and UO²⁺₂using a number of different back-extractants were measured and compared. The results obtained suggest that the only practical back-extractants are carboxylic acids. Among the carboxylic acids tested, oxalic acid is suitable when the UO²⁺₂ concentration in the organic phase is less than 2 g/L. For UO²⁺₂concentrations between 2 and 10 g/L, oxalic acid-nitric acid mixtures may be used. For UO²⁺₂concentrations greater than 10 g/L, the only practical back-extractant is glycolic acid. The results obtained here may be used to further develop a new process for separation of Pu^4 +  and UO²⁺₂ from TBP-TRPO/kerosene mixture.     

The Effect Of Preozonation,Ozone/Hydrogen Peroxide Treatment,And Nanofiltration On The Removal Of Organic Matter From Drinking Water

Pilot scale experiments were performed to evaluate the ability of ozonation, ozone/hydrogen peroxide treatment and nanofiltration to reduce levels of organic matter, mutagenicity, total adsorbable halogens, color and turbidity from purified and bank-filtered surface water rich with humic material.

Ozonation and ozone/hydrogen peroxide decreased the amount of organic material from drinking water by about 20 percent measured as TOC and COD_Mn. Color and turbidity level reductions were 49 and 11 percent, respectively. Ozonation reduced the AOX concentrations formed during postchlorination from 150 μgL^?1 to 75 μgL^?1. The addition of hydrogen peroxide further improved the removal to 37 and 26 μgL^?1 depending on the ratio of H₂O₂/O₃. The mutagenicity reduction followed the same pattern: without ozonation the chlorination-derived mutagenicity was 1,450 net revertant L^?1 after the ozonation 700 and after the H₂O₂/O₃ treatment from <100 to 400 net revertant L^?1 depending on the H₂O₂/O₃ ratio. Nanofiltration appeared to be the most effective way to remove organic material. The removal of TOC was 68%, COD_M 72%, color 90%, turbidity 68%, AOX 88%, and mutagenicity 85%.