高纯硫酸盐溶液微量硅脱除工艺研究

采用氢氧化铁吸附脱除硫酸盐溶液中的微量硅。结果表明,在下述优化条件下:反应温度60℃,终点pH=5.5,氧化剂双氧水用量2mL,反应时间60min,絮凝剂用量0.1g/L,溶液中锌、铁含量稳定,硅含量由10×10-6降至1×10-6左右。     

酸碱滴定法快速测定硅锰铝合金中硅

利用氟硅酸钾溶解于沸水中生成氢氟酸的原理。试样以硝酸、氢氟酸溶解，硅转化为硅氟酸，加入硝酸钾生成氟硅酸钾沉淀。经过滤、洗涤沉淀中的游离酸后，溶解于中性沸水中，生成氢氟酸，以溴麝香草酚蓝为指示剂，用氢氧化钠标准溶液滴定游离出的氢氟酸，借此测定硅锰铝合金中硅含量，其相对标准偏差小于0．0796％。     

钼蓝分光光度法快速测定硅在硅铝钙钡合金中的应用

将经典的氟硅酸钾沉淀碱滴定法改为钼蓝分光光度法快速测定硅。试样熔融酸化浸取，定容后，在0．15—0．6mol／L的微酸性溶液中，钼酸铵与硅酸作用生成黄色硅钼络离子，以草酸配位铁使溶液透明并破坏磷、砷等元素与钼酸铵生成的杂多酸，消除其干扰。用硫酸亚铁铵还原剂将生成的黄色硅钼络离子还原为硅钼蓝，其蓝色的强度与硅含量成一定比例关系，借此可用分光光度法测定硅含量，方法选择性强，且缩短了分析周期。     

炼铁厂降硅途径探讨

降低生铁含硅是一项系统工作。近年来南钢高炉强化水平不断提高，利用系数稳定在3.5以上，但生铁含硅多年来未取得进步。本根据低硅冶炼的特点，结合高炉目前的原燃料条件和生产的具体状况，对影响高炉降低铁水含硅的各项因素进行全面系统的分析，以探讨为高炉降硅创造条件的可能性，寻求适合我厂条件的降硅途径。     

中锰渣摇包法生产高硅锰硅的研究

通过对中锰渣摇包法生产高硅锰硅合金工艺开发性试验总结，确定了摇包生产的各项参数，为高硅锰硅合金生产提供了一种全新方法。应用该工艺生产高硅锰硅节能、无污染、产品质量好。     

原料对硅氧化物纳米球形成的影响

以硅、二氧化硅为硅源探讨了水热沉积条件下原料对硅氧化物纳米球形成的影响。实验表明,硅、二氧化硅的混合物在水热沉积硅氧化物纳米球时效果最好,所得纳米球直径小、分布较均匀;仅以硅为原料时所得球状结构尺寸大,直径分布范围宽;仅以二氧化硅为原料时则得不到球状结构。二氧化硅对于硅氧化物纳米球的形成起到了重要作用。     

酸分解试样氟硅酸钾容量法测定硅锰合金中的硅

介绍了酸分解试样，氟硅酸钾容量法测定硅锰合金中硅的方法，选择了最佳试验条件，方法简便、快速、准确，具有较好的精密度，已用于硅锰合金中硅的测定，结果满意。     

75硅铁[Si]含量的控制

1前言硅系铁合金产品是三大系列铁合金产品之一，目前国内生产量最大的是75硅铁。75硅铁主要用做炼钢生产的脱氧剂和合金剂，其主导元素是硅。国内各企业执行的GB2272－87国家标准，牌号规定硅含量72．0％～80．0％。75硅铁是高能耗产品，仅电费一项在我厂生产成本占60％以上。产品含硅量过高，质量过剩，会带来原材料及能耗的升高，使生产成本增加，产品含硅量过低达不到要求，产生不合格品，同样给企业带来损失。我厂75硅铁大部分供出口，个商要求产品含硅量≥75％，而且以实际重量计量，进一步造成质量损失。产品硅含量的适度，对于生产…     

聚四氟乙烯杯溶解试样测定硅铝铁合金中硅

本文介绍了用聚四氟乙烯杯代替铂金皿溶解试样后，以钼蓝光度法测定硅铝铁合金中硅的试验方法和结果，对试验结果进行了讨论，并用实例说明。     

16MVA硅铬电炉生产锰硅合金的实践

通过对硅铬电炉和锰硅电炉参数、冶炼原理的分析，以及正确的生产过程控制，硅铬电炉在不改变参数的情况下，可以转产锰硅合金，技术指标较好。     

过氧化物促进作用的研究和探讨

探讨了H2O2和CaO2在去离子水、矿浆和氰化浸出液中的稳定性和去毒作用．通过对H2O和CaO2放氧速度的测定，得出；H2O2在弱碱性条件下的稳定性较好；在强碱性条件下，CaO2的稳定性较好；在矿浆和氰化浸出液中，H2O2能迅速分解而放氧，而CaO2却以相对较为缓慢的速度放氧．通过测定溶液和矿浆中的游离CN－，得出：在溶液中H2O2和CaO2的去毒作用随pH值的增大而减小；在矿浆中只要控制过氧化物的适宜用量，不但不会引起去毒作用，反而会节省大量氰化物．以此为依据，对全泥氰化和金精矿氰化的两个典型矿石进行了试验，表明利用H2O2或CaO2助浸均可提高浸出速度，缩短浸出时间．通过试验和理论分析证明，浸出速度得以提高的原因是溶解氧和过氧化物本身作为氧化剂都参与了浸金反应．本文最后对过氧化物促浸法进行了评价，并提出了应用前景．     

过氧化氢氧化的锑白溶液中SbⅢ,SbⅤ和过氧化氢的测定

报道了在盐酸介质中测定用过氧化氢氧化锑白的溶液中Sb(,Sb(和过氧化氢的分析方法。利用H2O2既具有还原性又具有氧化性这一特殊性质,用硫酸铈滴定法测定溶液中H2O2和Sb(的总量,用碘量法测定溶液中H2O2和Sb(的差量,用硫酸铈滴定法在近沸温度下测定溶液中的总Sb量,最后计算得出H2O2,Sb(和Sb(的量。讨论了滴定温度、H2O2/Sb(含量的比值和NaHCO3用量对测定结果的影响。方法用于过氧化氢氧化的锑白溶液中Sb(,Sb(和过氧化氢的测定,相对标准偏差分别为0.25%,0.28%和0.38%;     

双氧水脱硫技术在倾动炉的应用实践

双氧水脱硫技术在各行业被广泛应用,该技术被应用在贵溪冶炼厂倾动炉杂铜冶炼烟气中SO2治理,烟气经文丘里洗涤器降温、除尘后进入脱硫塔,利用双氧水强氧化性将烟气中的SO2在脱硫塔内与稀释的双氧水发生化学反应达到脱除的目的,含酸雾烟气经电除雾脱除酸雾后达标排放。该工艺具有流程短、脱硫效率高、精确控制、阻力小等优点,同时产生的稀酸可回收利用,无二次污染。     

废水处理石膏工序离心机给液方式的探索

介绍了废水处理石膏工序原有的离心机高位槽给液方式,并根据实际生产情况对其存在的问题和弊端进行了分析。为了提高离心机给液效率,结合已有经验加装2台离心泵输送石膏浆液,用于替代原有的高位槽给液方式,其控制模式也进行了相应调整。投入运行后取得了良好的效果,解决了原系统存在的效率低、管线复杂、管道易堵塞、能耗高等缺点。     

从废Pd-C催化剂中回收钯的研究

采用甲酸代替碱性甲醛溶液作还原剂、过氧化氢－盐酸混合溶液代替王水作溶剂回收废Ｐｄ－Ｃ催化剂中的钯。考察了影响钯收率的诸因素,确定了最佳回收条件,其收率远高于文献法,达９５％左右,且减轻了环境污染。     

Recent Applications of Peroxygen Reagents in Hydrometallurgy

The paper reviews development made over the past decade in the application of peroxygnn reagents in hydrometallurgical processes. The reagents are hydrogen peroxide, H₂0₂, Caro’s acid, H_2MS0₅, and calcium peroxide, CaO₂. Their chemical properties and methods for on-site storage or production are outlined.

Most progress has been made in the gold extraction industry, where hydrogen peroxide and calcium peroxide have been used to enhance oxygen availability in the cyanide leaching of gold ores, in both agitated and heap leach systems. Properly controlled, the use of these reagents can lead to increased rates of gold extraction and savings in cyanide consumption. Hydrogen peroxide is also widely applied for the oxidative destruction of cyanide in gold mill effluent solutions and tailings ponds. Caro’s acid can also be used for this purpose, with advantage in certain situations, which arc discussed. Caro’s acid has found industrial application in the leaching of uranium ores in Australia at the Nabarlek mine and this operation is described. Other applications discussed include the separation of cobalt from nickel by oxidative hydrolysis with Caro’s acid and the reclamation and recycle of tungsten using hydrogen peroxide.     

离子选择电极法测定电铅灰中的氟与氯

使用SevenMulti 型PH/电导率/离子综合测试仪检测电铅灰中氟、氯含量。用加入了过氧化氢的柠檬酸与硝酸的混合酸溶解电铅灰,硝酸与过氧化氢可以消除硫离子对氯含量测定的干扰,柠檬酸与氟总离子强度调节缓冲溶液可以消除电铅灰中铁、铝对氟含量测定的干扰。测试结果显示,该方法精密度（相对标准偏差）F-小于1.50%,Cl-小于0.65%。准确度（加标回收率）F-在102.1%~105.3%之间,Cl-在93.0%~109.3%之间,电铅灰中共存离子对F-和Cl-的测定无干扰。该方法用于电铅灰中氟和氯的同时测定,具有很好的可行性和实用性。     

矿山含铜氰废水资源化利用工艺研究

采用"活性炭吸附—解吸联合工艺"处理某矿山的含铜氰废水。吸附阶段考察了吸附液pH和吸附方式对含铜氰废水中铜吸附率的影响,解吸阶段考察了解吸方式、时间、解吸液的硫酸和双氧水浓度对含铜炭中铜解吸率的影响。结果表明,先将含铜氰废水pH调至8左右,然后在5级串联吸附条件下吸附1.5h,铜的吸附率均稳定在90%以上,吨炭铜含量为31.4kg;所得含铜炭采用淋滤解吸,并在解吸液的双氧水和硫酸浓度分别为2g/L和3%条件下解吸7h,铜解吸率为87.60%,整个工艺铜的直收率达78%以上。     

Hydrogen peroxide decreases pHi in human aortic endothelial cells by inhibiting Na+/H+ exchange

Postischemic endothelial dysfunction may occur as a result of the effects of endogenous oxidants like hydrogen peroxide. Since endothelium-dependent vasodilator function may be affected by pHi, the effect of hydrogen peroxide on endothelial pHi was examined. Hydrogen peroxide (100 micromol/L for 10 minutes) decreased pHi from 7.24+/-0.01 to 7.02+/-0.02 and inhibited recovery from an ammonium chloride-induced intracellular acid load in carboxy SNARF 1 (c-SNARF 1)-loaded human aortic endothelial cells in bicarbonate-free solution. Prior inhibition of Na+/H+ exchange with 5-(N-ethyl-N-isopropyl)amiloride (10 micromol/L), by removal of extracellular Na+, or by glycolytic inhibition with iodoacetic acid blocked the subsequent effect of hydrogen peroxide on pHi. A 2-minute exposure to 100 micromol/L H2O2 decreased intracellular ATP levels by approximately 40%; this was prevented by 3-aminobenzamide and nicotinamide (1 mmol/L each), inhibitors of the DNA repair enzyme poly(ADP-ribose) polymerase. Both 3-aminobenzamide and nicotinamide significantly inhibited the hydrogen peroxide-induced intracellular acidification and the effect of hydrogen peroxide on recovery from an intracellular acid load. Hydrogen peroxide decreases pHi in human endothelial cells by inhibiting Na+/H+ exchange. This appears to be mediated by activation of the DNA repair enzyme poly(ADP-ribose) polymerase and subsequent depletion of intracellular ATP. Since a decrease in pHi in this range may alter the activity of NO synthase or affect the synthesis of vasodilator prostaglandins, the effect of hydrogen peroxide on the endothelial Na+/H+ exchanger may be important in the pathogenesis of postischemic endothelial dysfunction.     

Kinetic Model for Removal of Phenol by Horseradish Peroxidase with PEG

A kinetic model has been developed to simulate horseradish peroxidase-catalyzed polymerization of phenol in the presence of polyethylene glycol based on the following kinetics. The phenol conversion expression is a second-order Michaelis–Menten equation with respect to the concentrations of phenol and hydrogen peroxide. The enzyme inactivation is attributed to the polymer and hydrogen peroxide simultaneously. The inactivation by polymer is an apparently second-order reaction, first-order in each of enzyme and phenol, whereas the inactivation by peroxide is also an apparently second-order reaction, first-order in each of enzyme and hydrogen peroxide. The rates of consumption of hydrogen peroxide and polyethylene glycol are directly proportional to the rate of conversion of phenol. Experimental data show that the model output can predict the phenol removal and activity depletion realistically under a variety of reaction conditions. The model has been verified by predicting some independent experimental results on reaction stoichiometry, horseradish peroxidase dose effect, and semibatch operation with respect to hydrogen peroxide.