含砷电积脱铜液制备三氧化二砷的工艺研究

以含砷电积脱铜液为研究对象,采用SO_2还原其中的As(Ⅴ)制备As_2O_3,实现有价元素的回收。结果表明:反应温度为60℃、酸浓度18.00%、反应时间3 h,SO_2通入量20 L/h条件下,As_2O_3纯度为99.63%,As_2O_3直收率为88.05%,还原反应SO_2利用率为35.85%。     

CaCl_2溶液浸出高砷钴矿

为了解决高砷钴矿火法脱砷工艺过程劳动条件差、严重污染环境、付产品 As_2O_3中含钴及 As_2O_3的处理销售问题,提高钴的回收率,我们进行了利用氯化钙溶液浸出高砷钻矿的小型试验,取得了良好     

含砷烟尘制备三氧化二砷工艺研究

含砷烟尘经氢氧化钠溶液浸出、SO_2还原制备得到As_2O_3。研究结果表明:当氢氧化钠浓度为3.0 mol/L、硫磺与含砷烟尘质量比0.075:1、液固比6:1、浸出温度95℃、浸出时间2.0 h、搅拌速度400 r/min时,砷浸出率为99.27%。当初始砷浓度为100 g/L、初始pH=0、反应温度30℃、反应时间90 min、SO_2气体流量0.8 L/(L·min)、搅拌速度300 r/min时,砷回收率为86.13%,得到的产物中As_2O_3含量为95.79%。经热水溶解—重结晶,As_2O_3纯度达99.63%,质量达到了有色金属行业标准(YS-T99—1997)中As_2O_3-1标准。     

从冶金中间产品回收砷和固化砷

1975年日本矿业协会成立了一个研究委员会对砷无污染固化和回收的研究进行了不懈努力。在从As_2S_3沉淀回收As_2O_3的一些方法中,湿法冶金的方法被认为是比较无污染的方法。常常采取氧化浸出法随后进行As~(+3)离子的还原和As_2O_3的结晶。但由于包含氧化和还原,使过程复杂化。为避免这种复杂性,利用新型的萃取剂D2EHDTPA对As~(+3)离子进行萃取试验。结果表明在H_2SO_4水溶液内的As~(+3)离子容易被萃取。反萃采用Na_2CO_3碱液。     

粗锑碱性精炼的几个问题

一、碱性精炼的机理碱性精炼作业,系将計算好的純碱量加入熔融的銻液表面,随即插入鑄铁管鼓入压縮空气。当空气沿銻液上升时,部分銻和砷即按下式氧化。 2Sb+(2/3)O_2→Sb_2O_3…………………(1) 2As+(3/2)O_2→As_2O_3…………………(2) 根据Sb_2O_3的-ΔH_(298)=167.0(大卡/克分子),As_2O_3的-ΔH_(298)=156.8(大卡/克分子)可知道,这里并不存在着砷的优先氧化的問題,这一点根据有关純烟化(仅鼓入空气而不加純碱)的实践資料亦可     

以砷为填料AsC1_3精馏法除硒和硫的研究

一、前言 由于制备GaAs等化合物半导体需要基础材料高纯砷,特别是对砷中硒和硫等杂质的含量要求很低,所以,国内外对如何除去砷中的硒和硫进行了大量而系统的研究工作。其方法有十余种之多,例如铅熔池法、生长单晶法、砷的氧化法、As_2O_3升华法、As_2O_3在盐酸中重结     

砷与环境

一、砷在自然界的分布砷属于微量元素,地壳中砷的含量约为1×10~(-4)％左右。砷富集在自然界某些矿床内,主要呈硫化物存在。含砷的矿物约百余种,常见的有:雄黄(As_4S_4)、雌黄(As_2S_3)、毒砂(FeAsS)、砷铁矿(FeAs_2)、白砷石(As_2O_3)、砷钴矿(CoAs_2)、红砷     

新技术

一种锑冶炼砷碱渣的处置方法本发明涉及一种锑冶炼砷碱渣除砷的处理方法,是按以下步骤进行:a.碱渣浸洗、分离,获得碱液与锑渣,锑渣返回利用;b.碱液送去吸收冶炼排放烟气中的SO_2或用酸调pH值至5.0以下;c.碱液中添加Na_2S_2O_3并使As与Na_2S_2O_3之摩尔比达1:1.5—2;d.反应后进行沉降分离,渣为As_2S_3(As_3S_5).含As约     

砷酸钙与碳粉混合共热解过程解析

研究了砷酸钙与碳粉体系共热解反应过程。利用热重分析仪监测不同升温速率下,砷酸钙与碳粉质量比为4∶1混合物在氩气气氛、加热区间温度30～1 200℃过程中的失重情况,并采用XRD表征各失重阶段残余物。结果表明,混合体系失重过程分为三个阶段:第一失重阶段,温度240～325℃,Ca_2As_2O_7·H_2O脱水生成Ca_2As_2O_7;第二失重阶段,温度560～668℃,Ca_2As_5O_7到Ca_3(AsO_4)_2的晶型转变及Ca_5(AsO_4)_3OH和Ca(OH)_2失水生成Ca_5(AsO_4)_3和CaO;第三失重阶段,温度904～1 120℃,碳还原砷酸钙反应生成CaO和砷蒸气。动力学模型拟合结果表明:相边界反应动力学模型能较好地解释砷酸钙与碳粉共热解第三个失重阶段的反应机制。     

掺氧GaAs单晶的红外吸收研究

报道了掺 As_2O_3 和掺 Ca_2O_3+Cr 水平法生长的 CaAs 单晶中氧有关缺陷的红外吸收谱,揭示了氧缺陷吸收蜂的出现和样品电阻率的依赖关系,并对氧缺陷中心(O_i-V_(As))的负 U 特性进行了讨论。淬火实验表明,氧还可能以其它形态存在于 GaAs 晶体中。     

Reward structure as a moderator of the relationship between extraversion and sales performance.

The proposition that the relationship between extraversion and sales performance is moderated by reward structure was investigated. Specific hypotheses were tested with data obtained from 152 sales representatives. One group of sales representatives was rewarded primarily for obtaining new sales and another primarily for retaining customers. Data pooled across the 2 groups showed that extraversion did not correlate significantly with either new sales or customer retention. However, moderator analysis revealed that extraversion was positively associated with the dimension of performance that was explicitly rewarded but not with the nonrewarded dimension. A significant correlation between conscientiousness and new sales, but not between conscientiousness and customer retention, was found with the pooled data. As expected, relationships between conscientiousness and sales performance were not moderated by reward structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Plansee down

Austria's Plansee Group reported a decline in sales during the fiscal year 2002/2003, which closed at the end of February. After eight years with sales increasing by an average of 15 per cent, last year's sales dropped by 9 per cent to €528 million.This is a short news story only. Visit www.metal-powder.net for the latest metallurgy industry news     

Review of A company guide to the selection of salesmen.

Reviews the book "A company guide to the selection of salesmen" by M. Mandell. This report discusses current practices of 180 manufacturing firms in selecting salesmen. The report is, in effect, a manual for sales managers and relatively untrained sales personnel workers. Research evidence is conspicuous by its absence. The personnel psychologist, however, will be pleased to note the repeated pleas made by Mandell for sales organizations to base their selection programs on the results of personnel research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Magnetic resonance imaging of acute cerebellar ataxia: report of a case with gadolinium enhancement and review of the literature

INTRODUCTION: Intervention studies to reduce cigarette sales to minors have been conducted primarily in suburban settings. Little is known about sociocultural factors influencing cigarette sales to minors in urban settings. This study sought to determine sociodemographic and cultural factors that may play a role in cigarette sales and in efforts to reduce sales to minors in urban areas. METHODS: Merchant education and follow-up surveys were conducted in small local stores in predominantly African-American urban census tracts in Baltimore. The stores had prior evidence of cigarette sales to minors. RESULTS: Merchants reported hostility (66%) and foul language (64%) when they requested youth identification. Youthful-oriented advertising of cigarettes was highly prevalent in all stores and moreso in stores owned and staffed by Asian merchants. Advertising with specific youthful content was predictive (OR = 3.97; 95% CI = 1.70, 9.23; P = .0014) of higher requests for cigarettes from minors. CONCLUSIONS: Youth-oriented cigarette advertising is a prevalent environmental risk for urban youth. Differences between Asian and African-American merchants suggest socioethnic factors may be an influential component of illegal sales and educational campaigns to reduce smoking among minors.     

企业竞争力的核心--市场营销

对中国加入WTO后企业面临的新市场环境下的市场营销策略进行了分析探讨,认为企业必须全面地应用现代化市场营销的观点和理念对现有营销模式进行改造和完善,转变观念,紧紧抓住企业竞争力的核心——市场营销,才能与用户构建互利互赢的长期稳定的销售伙伴关系。     

产品销售管理信息系统与VPN技术结合实现远程销售管理

本文介绍了管理信息系统结合VPN技术在白银有色集团公司销售管理中的应用,实现了公司总部和各驻外销售站点日常业务处理、信息查询、分析统计和产品销售信息的共享,加强了公司在销售中监督和管理,规范了销售流程。     

销售预测模型在ERP系统中的应用

ERP系统是当今国际上先进的企业管理模式。目前，该管理模式正在逐步为国内企业采纳。简要介绍了ERP系统中销售预测模型的作用。较为详细的介绍了销售预测方法中的时间序列分解法，以及该模型在ERP系统中的实现方法，并以某铝材厂1999－2001年销售数据为实例对所采用的销售模型予以验证，同时给出了用ERP软件实现的2002年预测结果。篇中给出了部分程序脚本（节选自笔者参与开发的ERP软件），系用PowerBuilder7.0编写。     

宝钢供应链管理中的综合销售计划模型

供应链是描述企业采购、生产、销售过程中各实体和活动及其相互关系动态变化的网络。综合销售计划系统是供应链管理在销售部分的重要模块，其核心是主计划模型和效益优化模型。文章主要讨论宝钢供应链管理(SCM)的综合销售计划系统、主计划模型和效益优化模型。     

国内钢材销售渠道策略的分析与探讨

从介绍宝钢、安钢等钢铁企业典型销售渠道模式入手,对各类销售渠道及其激励措施进行了深入分析,指出：钢铁企业的销售渠道、策略应根据主客观形势的发展而变化,在不同销售区域所采取的渠道策略及其配套激励措施也应有所不同,既要保持相对稳定性,又要随销售形势的发展及时修订,依靠销售政策创造企业自身特色的营销模式。     

基于边际贡献的销售绩效考核设想

怎样对产品种类繁多、产品盈利能力差别很大的企业销售人员进行绩效考核，正确评价这些销售人员的业绩，是生产产品种类繁多、产品盈利能力差别很大的企业人力资源管理面临的一个重要课题。本文试图通过建立基于边际贡献的销售绩效考核体系这一方法，给相关类似企业提供一点思路。