电选法回收废印刷线路板中金属Cu的研究

采用破碎机和高压电选机对废印刷线路板中金属Cu进行回收.结果表明,破碎产物粒度<0.9mm时金属的单体解离度较高,可以作为分选的原料.物料在电选过程中的动力学分析表明,影响电选效果的主要因素为电极电压、滚筒转速、电晕电极距及物料粒度.经正交实验优化影响参数后,-0.9+0.074mm粒级的破碎产物一次电选所得精料中Cu的富集情况较好,Cu品位由32.0%富集到63.6%,回收率为78.7%.     

A review on transient stability of DFIG integrated power system

With the increasing penetration of doubly fed induction generators (DFIGs), the impact of the DFIG on transient stability attracts great attention. Transient stability is largely dominated by generator types in the power system, and the dynamic characteristics of DFIG wind turbines are different from that of the synchronous generators in the conventional power plants. The analysis of the transient stability on DFIG integrated power systems has become a very important issue. This paper reviews the current research on the issue from two aspects. One is to describe the methods to improve the fault ride through capability of DFIG wind turbines and the other is to analyse the impact of the DFIG wind farm on transient stability of power systems.     

印制电路板废水处理技术应用实践

针对印制电路板废水的特点,根据清污分流、先预处理再综合处理的原则进行合理的细化分类,对不同的水质进行分类物化处理。该处理技术具有工艺合理、可操作性好、自动化程度高等优点,处理后出水水质达到广东省《水污染物排放限值》(DB44／26—2001)一级标准。     

国内外传爆药装药结构研究的发展动向

对国内和国外关于传爆药装药结构的研究现状和研究成果进行总结,分析了国内研究的一些不足,并提出了一些意见和该领域今后的研究方向.     

电感性本质安全电路L/R的选择原则

基于电感性本质安全电路放电电流线性衰减模型,引入最小建弧电压的概念,得到了放电时间不含未知参数的表达式,利用电感电路的本质安全性能判别式,确定了电感电阻比L/R的选取原则.     

PROFILE: Indigenous Institutions and Environmental Assessment: The Case of Ghana

/ The search for sustainable development provides the impetus forexamining the role of indigenous institutions and their ecological knowledgein environmental assessment and local sustainability. This paper attempts totrace the evolution of environmental assessment in Ghana. Focusing on theAshanti Region, the paper further discusses the nature and operations ofindigenous institutions, their ecological knowledge, beliefs, practices, andsocial norms that are relevant to environmental assessment process in thecountry. Some of the challenges that emerge from the discussions arehighlighted. There is a need to establish environmental assessment andcooperative management boards that would include representatives ofindigenous institutions. In addition, the introduction of technicaldictionaries and training manuals based on indigenous ecological knowledgeand their humane environmental practices will further improve theenvironmental assessment process in Ghana.KEY WORDS: Environmental assessment; Indigenous institutions; Indigenousecological knowledge; Sustainable development; Environmental assessmentboards     

硫化氢气体的监控和防护

叙述了海上低凝固点及气液比很小的稠油试生产中对硫化氢气体的监控和防护概况。指出油、气、水流程均应采取全密闭式，其监控系统应包括硫化氢探测装置和报警系统，防止人体伤害的防护系统应有多种设备、仪器。此外，还应注意凡上岗工作人员均应事先加以培训，合格后才可正式工作。在采取以上所有监控防护措施后，在日常的安全生产中，未停产一次，也未伤一人。     

基于模糊熵和非对称贴近度的安全预警研究

针对道床漏泄严重导致道砟电阻和分路电阻发生变化、继而引起"红光带"与分路不良故障的问题,以ZPW-2000 A轨道电路为例,建立预警指标体系。采用模糊模式识别法对轨道电路状态进行预警。首先,计算各预警指标的隶属度函数和隶属度矩阵,利用模糊熵理论确定各预警指标的权重;其次,采用非对称贴近度原则对预警决策进行识别,以判决系统所属安全等级;最后,以长沙电务段新开铺站为例进行实例验证。结果表明,基于模糊非对称贴近度的轨道电路分路不良预警是可行的,其对轨道电路的安全等级划分更精细,故障预警更精确。     

涡电流分选富集线路板中有价金属研究

文章采用涡电流分选方法对废旧线路板经破碎和风选后的精矿产品、尾矿产品进行了试验研究。结果表明,涡电流分选工艺对富集线路板中有价金属有着较好的优势。涡电流分选的精矿产率与该分选设备的工作场强、分选筒的转速和入料颗粒的大小有着密切的关系。合理调节涡电流分选设备的工作参数,能获得质量较好的金属富集体。     

阴离子交换萃取体系对废旧电子线路板中铜的提取

主要研究了三异辛胺(N235)的阴离子交换萃取体系对废旧电子线路板中铜的提取。萃取体系的组成为N235(40％)-异辛醇(20％)-煤油(40％)，在HCI介质中对铜进行萃取，在实际样品的应用中，有较为满意的结果。得到了99．06％的硫酸铜晶体。