Sn-Zn-Ag-Bi无铅钎料的成分设计

为了改善Sn-Zn钎料的性能,在Sn-Zn钎料中添加Ag、Bi两种合金元素.使用正交试验法,研究钎料成分变化时钎料润湿面积、剪切强度及腐蚀率的变化规律.3个影响因子分别为Ag的质量分数、Bi的质量分数和Zn的质量分数,每个影响因子设定3个水平,进行3因素3水平正交试验.以钎料的润湿面积、剪切强度及腐蚀率作为评价指标,分析试验结果,优化最佳的工艺参数,确定Sn-Zn-Ag-Bi钎料的最优成分是alB2C2,即质量分数Sn为91.5%、Zn为5%、Bi为3%、Ag为0.5%.结果表明,在该成分下,最优钎料各项指标与Sn-9Zn相比有较大的提高.     

Sn-Zn-Cu无铅钎料的组织、润湿性和力学性能

研究了(Sn-9Zn)-xCu无铅钎料的微观组织、润湿性能和力学性能.Cu的加入使得Sn-9Zn钎料中针状富Zn相逐渐转变为Cu-Zn化合物,当Cu含量为8%时,Cu6Sn5相生成.Sn-Zn-Cu合金熔点随着Cu含量增加而升高,同时润湿性随Cu的加入得到显著改善.使用中性活性松香钎剂,钎料与Cu箔钎焊时的润湿角显著减小.Sn-9Zn的润湿角为120°,而(Sn-9Zn)-10Cu的润湿角为54°.这是由于Cu的加入降低了Zn的活性,减少了Zn在钎料表面氧化,降低了液态钎料表面张力,使得钎料能获得较好的润湿性.合金在2%Cu时获得较高的强度,随着Cu含量的增加,Cu-Zn化合物相对增多,抗拉强度有所下降;而合金的塑性随着Cu的加入迅速下降.     

A pyrometallurgical alternative: The refining electrolysis of lead and solder

Conclusions  In refining electrolysis in hexafluorosilic acid with current densities of 100 A/m², it is possible to separate bismuth and antimony from prerefined lead bullion. Pure lead with less than 50 ppm bismuth and less than 100 ppm antimony was deposited at the cathode. The current efficiency was 99%, and the specific energy consumption was 30–40 kWh/t. Under the same conditions, a lead-tin alloy with less than 300 ppm antimony can be produced by refining a Pb−Sn−Sb alloy with 30% tin and up to 5% antimony. In this case, antimony remains in the anode sludge. Because of the high amount of anode sludge, the strong adhesion of the sludge on the anode surface, and its physical properties in the case of high antimony contents (i.e., more than 5% antimony in the anodes), some differences in the usual electrolysis technology are necessary to guarantee a long-term, stable, and trouble-free electrolysis. The tendency of anode passivation can be reduced by using a periodic current reversal technique. This technique results in a smaller amount of anode sludge, a reduced loss of lead in the anode sludge, and lower anodic polarization values.     

New Method for Destroying Organic Contaminants and Recycling Wastewater from PCB and MF Manufacturing Process Effluent Streams

This paper was recently published in the January edition of Industrial Environmental Management and is a modified version of an article published previously in Circuit World Vol.9 No. 4, 2003. The work was carried out as a CRAFT Project (ROCWAT-Thematic Priority F5 (Project number EEVK1-2001-30014). Part of the process involves dissemination to as wide an audience as possible through appropriate journals.     

引线框架铜合金材料与SnAg3.0Cu0.5的界面组织

采用扫描电镜和能谱分析等手段研究了3种不同引线框架用铜合金材料与SnAgCu钎料的界面结构,3种铜合金引线框架材料与SnAg3.0Cu0.5焊膏焊后未经时效的界面组织相似.焊点在160℃恒温时效300 h后,Cu-0.1Fe-0.03P合金、Cu-0.36Cr-0.03Zr合金、Cu-0.38Cr-0.17Sn-0.16Zn合金与SnAg3.0Cu0.5焊膏的界面金属间化合物厚度分别为8.7、7.4、6.2μm,其成分主要为Cu6Sn5,靠近铜合金一侧均有少量Cu,Sn生成.结果表明,Cu-0.38Cr-0.17Sn-0.16Zn合金比Cu-0.1Fe-0.03P合金和Cu-0.36Cr-0.03Zr合金具有更好的焊接可靠性能,Cu-0.38Cr-0.17Sn-0.16Zn合金中的Zn元素在焊点界面的富集有效减缓了界面处原子的相互扩散,使金属同化合物的增长速度降低.     

Selective recovery of Sn from copper alloy dross and its heat-treatment for synthesis of SnO2

Preliminary study on concentration and separation of tin (Sn) from copper alloy dross by selective dissolution method was conducted. The tin in the copper alloy dross did not dissolve in an aqueous nitric acid solution which could allow separation of tin from the copper alloy dross. The tin as H₂SnO₃ (metastannic acid) phase was precipitated in the solution with centrifuging process and transformed to tin dioxide (SnO₂) after drying process. The dried sample was heat-treated at low temperature and its phase characteristics, surface morphology and chemical composition were investigated.     

Microstructure,wetting property of Sn-Ag-Cu-Bi-xCe solder and IMC growth at solder/Cu interface during thermal cycling

The effects of adding small amounts of cerium (Ce) to Sn-3.3Ag-0.2Cu-4.7Bi solder on microstructure,wettability characteristic,interfacial morphology and the gr...     

循环经济理念下的再生资源产业

一、发展再生资源产业是建设循环经济的重要内容 循环经济是相对于传统的线性经济发展模式而言的.在传统的线性经济发展模式中,社会经济运行体系主要由生产系统和消费系统构成,自然资源通过生产系统转变为产品,产品又通过消费系统变成为废物,废物最终被抛弃进入环境中,造成对自然环境的污染和破坏.这种线性的经济运行模式导致的最终结果必然是自然资源的枯竭和自然环境的破坏,是一种不可持续的发展模式.     

硫氰酸盐法浸出废印刷线路板中的金

本文研究了一种从废印刷线路板(PCB)中提金的新方法.在酸性溶液(pH=1～2)中,去铜后的PCB粉末中加入氧化剂二氧化锰(二者质量比为1∶0.7),络合剂硫氰酸钠溶液(0.4mol/L,固液比为1∶22),室温(20℃)振荡(250r/min)3h获得了超过96%的高浸金率.硫氰酸盐作为浸金剂,性质稳定,基本不污染环境.     

Effects of AlN hydrolysis on fractal geometry characteristics of residue from secondary aluminium dross using response surface methodology

The effects of aluminium nitride (AlN) hydrolysis on fractal geometry characteristics of residue from secondary aluminium dross were studied using response surface methodology. The results show that the fractal dimensions of the residue can be significantly influenced by the AlN hydrolysis from secondary aluminium dross. The hydrolysis of AlN in the dross was spontaneous under temperatures of 303–373 K. The actual fractal dimensions of residue were significantly affected by the liquid–solid ratio (p<0.05) and changed from 1.16 to 1.80, which accurately aligned with those from the calculations. Moreover, the fractal dimensions of residue were significantly affected by the interactions between hydrolysis temperature and hydrolysis time, liquid–solid ratio and hydrolysis time, respectively (p<0.01). The minimum fractal dimensions of the residue reached 1.15 under the optimized conditions, which included a hydrolysis temperature of 30 °C, liquid–solid ratio of 5 mL/g and hydrolysis time of 10 min. The results suggest that response surface methodology can guide in optimizing the conditions of AlN hydrolysis in order to obtain the minimum fractal dimensions of residue for improving the reutilization of the dross.     

元素Ga,Bi对SnAgCu无铅钎料性能的影响

在SnAgCu无铅钎料中添加金属元素Ga,Bi,对其合金进行熔化温度、润湿性、力学性能和微观组织研究.研究表明,添加Ga,Bi有利于降低SnAgCu合金的熔化温度和改善润湿性,并可提高其力学性能.     

Recycling of Ammonia Wastewater During Vanadium Extraction from Shale

In the vanadium metallurgical industry, massive amounts of ammonia hydroxide or ammonia salt are added during the precipitation process to obtain V₂O₅; therefore, wastewater containing a high level of NH₄⁺ is generated, which poses a serious threat to environmental and hydrologic safety. In this article, a novel process was developed to recycle ammonia wastewater based on a combination of ammonia wastewater leaching and crystallization during vanadium extraction from shale. The effects of the NH₄⁺ concentration, temperature, time and liquid-to-solid ratio on the leaching efficiencies of vanadium, aluminum and potassium were investigated, and the results showed that 93.2% of vanadium, 86.3% of aluminum and 96.8% of potassium can be leached from sulfation-roasted shale. Subsequently, 80.6% of NH₄⁺ was separated from the leaching solution via cooling crystallization. Vanadium was recovered via a combined method of solvent extraction, precipitation and calcination. Therefore, ammonia wastewater was successfully recycled during vanadium extraction from shale.     

Dissolution of Nickel in Copper Residue Generated from Nickel Matte Refining

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以废铅酸电池铅膏制备超细氧化铅粉末

以柠檬酸为主要浸出剂,在室温下合成柠檬酸铅前躯体,将其低温焙烧生成超细PbO/Pb粉末.结果表明:废旧铅蓄电池铅膏的主要成分PbO_2、PbO和PbSO_4都能生成柠檬酸铅,铅回收率均在98%以上;由PbO与PbO_2生成的前躯体与标准柠檬酸铅晶型基本相同,结构呈堆积条状,粒径为20～30 μm,而由PbSO_4得到的前躯体可能含较多结晶水,与标准柠檬酸铅晶型有较大区别,呈鳞片状结构,粒径为1～10 μm;3种前躯体都能在低温焙烧下得到超细PbO/Pb粉末,粒径为200～500 nm;采用柠檬酸湿法浸取铅膏直接制备电池生产用超细PbO粉体的新工艺,为废旧铅酸电池的回收技术提供了一种新的思路.     

Technological, Economic, and Environmental Optimization of Aluminum Recycling

The four strategic directions (referring to the entire life cycle of aluminum) are as follows: production, primary use, recycling, and reuse. Thus, in this work, the following are analyzed and optimized: reducing greenhouse gas emissions from aluminum production, increasing energy efficiency in aluminum production, maximizing used-product collection, recycling, and reusing. According to the energetic balance at the gaseous environment level, the conductive transfer model is also analyzed through the finished elements method. Several principles of modeling and optimization are presented and analyzed: the principle of analogy, the principle of concepts, and the principle of hierarchization. Based on these principles, an original diagram model is designed together with the corresponding logic diagram. This article also presents and analyzes the main benefits of aluminum recycling and reuse. Recycling and reuse of aluminum have the main advantage that it requires only about 5% of energy consumed to produce it from bauxite. The aluminum recycling and production process causes the emission of pollutants such as dioxides and furans, hydrogen chloride, and particulate matter. To control these emissions, aluminum recyclers are required to comply with the National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production. The results of technological, economic, and ecological optimization of aluminum recycling are based on the criteria function’s evaluation in the modeling system.     

Recycling of electronic control units from end-of-life vehicles in China

In China, electronic control units (ECUs) from end-of-life vehicles (ELVs) are either discarded carelessly or smashed into pieces along with the vehicles for material recycling. With the rapid growth of vehicle population and ECUs in automobiles in China, this recycling scheme poses a serious pollution threat to the environment and wastes resources. This paper presents a new high value-added reuse scheme of ECUs from ELVs and develops a technology roadmap in accordance with China’s actual conditions.     

瓦斯灰回收有色金属及再资源化(续)

4．提锌残渣湿法提铟工序铟生产规模12t／a：产物化学成分见表8。主要技术经济指标：     

从再生资源回收市场管理说起

"十五"期间,国家把实施可持续发展战略放在更加突出的位置.实施可持续发展战略要求节约资源,保护环境,正确处理好经济发展与资源,环境的关系问题.     

钢铁厂粉尘回收锌技术

本文评述了近年来我国从钢铁厂含锌粉尘中综合回收锌技术研发的某些进展,并进行了相关分析,提出几篇参考文献.