Production of electrolytic manganese dioxide from purified solutions after the leaching of manganese-bearing slurry

The production of electrolytic manganese dioxide from purified solutions after the leaching of manganese-bearing slurry is investigated. The influence of the anodic current density on the electrolysis of manganese-bearing solutions is determined. The preliminary purification of manganese-bearing solutions before electrolysis is discussed. Purification of the solution at pH 6.5–7.0 ensures the maximum deposition of all the impurities that interfere with electrolysis: copper, zinc, nickel, cobalt, aluminum, phosphorus, arsenic, antimony, iron (III), and iron (II). After impurity deposition, the pulp is filtered; the hydrate deposits are washed; and the filtered liquid is sent for electrolysis to obtain electrolytic manganese dioxide. The samples of electrolytic manganese dioxide are studied by means of X-ray fluorescent analysis, X-ray phase analysis, and scanning electron microscopy. The results show that the electrolytic manganese dioxide obtained in the laboratory with anodic current density I_a = 150–200 A/m² meets all the requirements on a highly active product: the content of the basic component (MnO₂) in the experiments is 95.0–96.5 wt %.     

An investigation of the effect of the electrolyte composition on the consumption of fired anodes during electrolytic aluminum production

The effect of adding CaF₂, AlF₃, and KF into electrolyte on the consumption of fired anode during aluminum electrolysis is investigated. The CaF₂ content varied from 5 to 10 wt % in the electrolyte of the industrial composition. Correspondingly, the concentration of AlF₃ and KF varied from 4 to 10 and from 0 to 4.7 wt % in the modified electrolytes. Based on the procedure used, the total consumption of carbon and the amount of carbon transported into the gas phase (m _g) and foam (m _f) were determined. Electrolysis duration was 12 h, the distance between the poles was 40 mm, the temperature was 960°C, and the current density was 0.85 and 1.2 A/cm². It is established that adding CaF₂ and AlF₃ increases the consumption of anode, while adding KF decreases it. For CaF₂, ?m _f/?[CaF₂] is larger than ?m _g/?[CaF₂], 15.4 and 6.6 kg/(t_Al wt %) CaF₂, respectively. For AlF₃, ?m _f/?[AlF₃] is also larger than ?m _g/?[AlF₃] and equals 6.8 and 4.2 kg/(t_Al wt %) AlF₃. For KF, ?m _f/?[KF] is smaller than ?m _g/?[KF], being ?11.3 and ?8.1 kg/(t_Al wt %) KF.     

削减电解金属锰工艺废水的生产实践

结合生产实际,分析了电解金属锰废水产生量大的原因。介绍了采用电解金属锰工艺废水全过程控制技术对金旭冶化有限责任公司5 000 t/a电解金属锰生产线进行的改造。生产实践表明:通过改造,电解液和钝化液挟带量削减65%,废水水量削减80%,通过离子交换几乎全部回收废水中的Mn²⁺、Cr（Ⅵ）,将其回用到生产工艺中,有效解决目前电解金属锰废水处理中存在的铬渣二次污染问题。     

提高电锌质量的实践

分析了影响电锌质量的主要原因,介绍了生产中提高电锌质量的实践与改进措施,取得了明显的效果.     

银电解精炼中铋的行为分析

从理论和实践的角度分析论述了银电解精炼过程中杂质铋的行为,提出了银电解过程中对杂质铋的控制措施,介绍了在生产中应用效果。     

铜电解过程中的节能措施与效益

本通过对影响铜电解综合成本的电耗及蒸汽耗进行了深入的分析，并结合珠铜公司的生产实际情况，采取了有效的措施，取得了显的经济效益。     

Variation of the porous structure and leakage currents of anodes of niobium condensers in electrolytic oxidation

Conclusions Shaping of the anodes results in a large reduction of the total volume and dimensions of the pores. The magnitude of this reduction is determined unambiguously by the dispersion of the initial powder and oxidation voltage. Shaping results in the formation of a certain number of closed pores.Formation of closed porosity is accompanied by a large reduction of the leakage currents. This is explained by a reduction of the number of impurity atoms concentrated mainly on the surface of sintered anodes. Therefore, the high-dispersion powders which contain, per unit mass, approximately the same amount of impurities as the standard powders can be used to produce anodes with permissible leakage currents at low sintering temperatures.Translated from Poroshkovaya Metallurgiya, No. 3(339), pp. 56–59, March, 1991.     

工业锰粉氮化工艺的试验研究

以氮化锰粉氮含量为目标,采用单因素试验方法考查氮化温度、锰粉粒度以及氮化时间对氮含量的影响;采用XRD对氮化锰粉的结构进行了分析,并在此基础上应用二次回归正交试验设计方法建立二次方程优化氮化锰粉的制备工艺,经过F检验,回归方程显著性好。结果表明,最佳工艺条件是:氮化温度为836℃,氮化时间8h,氮气压力为1.72P°(101.3kPa),可获得含氮量高达8.35%(质量分数)的氮化锰产品。     

The quality of the discharge planning process: the effect of a liaison nurse

Nitric oxide (NO) in brain has been implicated in neuronal regulatory processes and in neuropathologies. Previously we showed that NO modified quinpirole-induced yawning, a behavioral measure of dopamine (DA) D3 receptor activation in rats. The aim of this study was to characterize the effect of nitro-L-arginine methyl ester HCl (NAME) and L-arginine HCl on reactivity of rats to the DA D1 receptor agonist SKF 38393 and DA D1 antagonist SCH 23390 in intact and neonatal 6-hydroxydopamine (6-OHDA)-lesioned rats (134 micrograms of base ICV at 3rd day after birth). L-arginine HCl (300 mg/kg i.p.) increased the oral activity response in 6-OHDA-lesioned rats, like SKF 38393, and induced catalepsy in intact control rats, like SCH 23390. In contrast, NAME had no effect on oral activity or catalepsy, but fully attenuated SKF 38393-induced oral activity. These findings indicate that L-arginine HCl has no apparent effect at the DA D1 receptor, but that NAME is effective in attenuating a DA D1 agonist-induced effect. Consequently NO may be an intracellular second messenger for supersensitized receptors associated with DA D1 agonist-induced oral activity.     

Influence of particle surface area on the toxicity of insoluble manganese dioxide dusts

The objective of this study was to examine the influence of specific surface area on the biological activity of insoluble manganese dioxide (MnO2) particles. The biological responses to various MnO2 dusts with different specific surface area (0.16, 0.5, 17 and 62 m2/g) were compared in vitro and in vivo. A mouse peritoneal macrophage model was used to evaluate the in vitro cytotoxic potential of the particles via lactate dehydrogenase (LDH) release. In vivo, the lung inflammatory response was assessed by analysis of bronchoalveolar lavage after intratracheal instillation in mice (LDH activity, protein concentration and cellular recruitment). In both systems, the results show that the amplitude of the response is dependent on the total surface area which is in contact with the biological system, indicating that surface chemistry phenomena are involved in the biological reactivity. Freshly ground particles with a specific surface area of 5 m2/g were also examined in vitro. These particles exhibited an enhanced cytotoxic activity, which was almost equivalent to that of 62 m2/g particles, indicating that undefined reactive sites produced at the particle surface by mechanical cleavage may also contribute to the toxicity of insoluble particles. We conclude that, when conducting studies to elucidate the effect of particles on the lung, it is important for insoluble particles such as manganese dioxide to consider the administered dose in terms of surface area (e.g. m2/kg) rather than in gravimetric terms (e.g. mg/kg).     

二氧化锰沉淀分离重铬酸钾滴定法测定活性二氧化锰生产液中氯酸纳

由于活性二氧化锰生产液成分复杂,采用目前测定纯NaClO3的方法分析活性二氧化锰生产液中氯酸钠时,共存组分对测定存在严重干扰.因此,本文就消除干扰组分,优化测定条件做了一些试验,确立了用二氧化锰沉淀分离锰后,重铬酸钾滴定法测定活性二氧化锰生产液中氯酸钠.本法可用于生产过程监控、测定.NaClO3回收率达99.5%～100.5%,相对标准偏差为0.33%.     

Obtaining manganese dioxide under conditions of diaphragm-free electrolysis

The conditions of obtaining manganese dioxide using diaphragm-free electrolysis are investigated. The optimum mode of obtaining the product is established, depending on the current density, process duration, and acidity.     

"卡特尔"定价不是良策--论电解金属锰行业组织的功能定位

电解金属锰行业组织很容易陷入联合定价的圈子，但对成员企业违背“卡特尔”联合定价的欺骗行为没有任何的强制力，“卡特尔”联合定价是与市场经济不相符的，更何况为制度，法律所不允许。行业组织应该加强其信息，技术的服务功能，弱化其价格联盟功能。     

基于过程方法的质量资源整合

主要介绍了菜钢结合多年来推行的IS09000系列标准质量管理体系的理论基础和实践经验,利用其核心的“过程方法”,对质量资源进行识别、确认,构建了持续改进的闭环过程控制模型,再对整合质量资源的过程进行分析与评价,策划过程控制方案,建立了建立质量问题决策和预警机制、质量预控模型和过程控制机制、“预防为先”的质量控制机制,对莱钢内部的质量信息、质量技术和质量检验资源和外部资源进行了整合,公司的产品实物质量水平、顾客满意度、质量信誉和品牌效得到有效提升,达到了提高管理效能和产品质量效益的双重目的.