浮选处理＜0.25mm粒级废弃印刷电路板的试验研究

从废弃印刷电路板微细颗粒中富集有用金属是目前环境污染防治领域中的前沿课题,采用浮选方法对废弃印刷电路板破碎后的微细物料进行探索性浮选试验研究.借助Design-Expert7.0软件进行了废弃印刷电路板金属回收的4因素3水平浮选试验设计和结果分析,讨论了搅拌速度、充气量、矿浆温度及矿浆质量浓度对浮选效果的影响,给出了金...     

顶流式变径液固流化床的流场分布与分选实验研究

为解决变径水介质分选床中颗粒堆积及细粒级废弃电路板的有效物理分选,在现有的变径水介质分选床下壁面添加了多组顶流管,引入上升水流,加强了壁面堆积物料的松散与分选效果。详细分析了倾斜床体液固两相流的流型变化与特征,并采用ANSYS FLOTRAN CFD软件进行数值模拟,得到了介质流场的压强分布变化规律:流场压强自床体底端至顶端递减,自顶流孔给入的水流可以在床体顶流孔附近形成局部强压区,使分布在床体下壁面的颗粒产生额外的运动加速度。选用≤0.125、0.125~0.250、0.250~0.500mm废弃电路板颗粒进行两因素三水平分选实验,结果表明,采用顶流式变径液固流化床分选系统可实现≤0.500mm废弃电路板中金属成分的有效富集,金属回收率最大达到了93.23%。     

废弃电路板双列直插式封装的集成电路芯片回收的经济性分析

废弃电路板电子元件拆除后回收具有较大的利润空间.回收的双列直插式封装(DIP)电子元件多数都保留正常的使用功能,经过适当的处理,检测合格后可以继续使用.提出了基于回收策略的废弃电路板DIP的集成电路(IC)芯片回收工艺,建立了回收经济性评估模型,并对2种回收的IC芯片进行经济性定量评价.     

液-固流化床回收印刷线路板中金属的研究

根据废弃印刷线路板中材料密度不同，采用水介质流化床对印刷线路板粉末中的金属进行回收，对0.25～0.177、0.177～0.104、0.104～0.074和-0.074 mm 4个粒级范围内的物料进行分选试验。试验结果表明，在上述4个粒级范围内，随介质流速的增大，金属回收率降低；金属回收率η与实际操作速度（ua）和颗粒终端沉降速度（ut）的比值φ（ua/ut）存在一定线性关系，分析模拟了η与φ之间的相关性方程，外推试验的结果证明了相关性方程的可靠性；在合适的操作条件下，各粒级范围内金属的回收率分别为95.02%、90.07%、87.5%和92.68%。     

风量对高频气力分选机分选效率及金属分布规律的影响——以废弃印刷电路板粉末为例

以金属高富集粒级0.5～0.125 mm的废弃电路板为分选物料,通过ICP-AES测定分选产品,研究了风量对高频气力分选机分选效率及金属分布规律的影响.结果表明,风量变化对分选效率及金属分布规律影响显著,当风量为200m3/h时分选效率达到最大值78.23％,铜品位为86.745％,相比原料中铜品位13.96％,富集约6.2倍.随着风量的变化,金属的分布呈现规律性变化:密度比铜大或与铜相差不多的金属颗粒(铅、铂和锌等),其变化规律与铜相似,回收率在85％左右变化；密度比铜小很多的金属颗粒(铝、镁等),由于其密度与分选物料中的非金属非常接近,在分选过程中会随非金属带人轻产物中去,从而造成重产物中铝和镁品位最低,甚至低于其在原料中的品位.所以若要分离富集铝和镁,须对分选后的物料进行二次分选.     

化学溶胀法分离废弃线路板中金属与基板

废弃线路板的粉碎和所含金属组分的高效解离是后续分选回收的前提条件。本研究分别使用乙二胺等10种溶剂浸泡废弃线路板，比较对线路板中铜箔与基板间剥离强度的影响，从而筛选出4种有代表性的溶剂，即溶剂D、溶剂F、丙酮和水, 比较废弃线路板经化学溶胀后的单体解离度和获得一定粒径分布的颗粒所需的破碎时间。研究结果表明，化学溶胀后破碎能大幅提高金属的单体解离度，浸泡效果的优良排序为：溶剂D>溶剂F>丙酮>水；浸泡时间越长，浸泡温度越高，对剥离强度的降低越有利；使用溶剂D在150℃、3 h或140℃、5 h的工艺下浸泡废弃线路板，可以使铜箔与基板自动脱落。研究结果为后续的分选提供了便利的条件。     

基于机械物理法的废旧电路板回收经济性分析

废旧电路板的有效回收对保护环境、实现资源的优化配置和社会可持续发展具有十分重要的意义。通过分析废旧电路板的回收方法,给出了机械物理法中3种典型回收方案的工艺流程,建立了其回收经济性评价模型,量化评估回收成本与收益。结合一个具体的回收实例,运用经济性评价模型对其回收成本与收益进行具体分析,验证了评价模型的可靠性,实现了回收方案的优选。最后,对提高废旧电路板回收经济性提出一些建议。     

废印刷电路板的静电分选实验研究

金属与非金属材料的分离是回收利用废印刷电路板的关键环节。对废印刷电路板物料的静电分选进行了实验研究。实验以电压、辊筒转速、电晕电极与辊筒之间的距离、静电极位置、电晕电极位置、电晕电极数量等为考察因素,研究各因素对电选效果的影响规律。结果表明,影响金属与非金属材料分离的主要因素是电压、辊筒转速和电晕电极与辊筒之间的距离,对于-0.9 0.45mm的破碎物料,当电压为24kV,辊筒转速为15Hz(54.6r/min),电晕电极与辊筒之间的距离为5.2cm时,得到最大静电分选综合效率67.37%。     

真空蒸馏回收镍镉电池中镉金属工艺优化模型研究

利用正交试验的方法对真空蒸馏回收镍镉电池进行工艺研究。通过分析温度、压力、蒸馏时间、打孔数目4个因素对镉金属回收比重的影响,确定了真空蒸馏回收镍镉电池中镉金属的最佳试验条件为温度950℃,压力133Pa,蒸馏12h,打孔4个。并在此基础上建立模型对镉金属回收量进行估算,为镍镉电池回收的中试试验奠定了基础。     

真空蒸馏回收镍镉电池中镉金属工艺优化模型研究

利用正交试验的方法对真空蒸馏回收镍镉电池进行工艺研究。通过分析温度、压力、蒸馏时间、打孔数目4个因素对镉金属回收比重的影响，确定了真空蒸馏回收镍镉电池中镉金属的最佳试验条件为温度950℃，压力133Pa，蒸馏12h，打孔4个。并在此基础上建立模型对镉金属回收量进行估算，为镍镉电池回收的中试试验奠定了基础。     

Development of hybrid processes for the removal of volatile organic compounds,plasticizer, and pharmaceutically active compound using sewage sludge,waste scrap tires,and wood chips as sorbents and microbial immobilization matrices

Environmental Science and Pollution Research - This study evaluated the reutilization of waste materials (scrap tires, sewage sludge, and wood chips) to remove volatile organic compounds (VOCs)...     

磷石膏再生利用途径的综合评价

依据层次分析法原理,用经济、环境和资源化3个影响因素建立磷石膏资源化途径优选的递阶层次结构模型。以山东某化工厂生产磷酸产生的磷石膏为研究案例,从磷石膏组成成分与含量分析的角度出发,结合磷石膏各资源化途径的独特要求,探讨磷石膏资源化特性与资源化途径的密切关系,拟合出磷石膏的各种资源化特性,作为结构模型中的资源化因子。然后分别对模型中的3个影响因素进行定性和半定量化处理,最终实现磷石膏资源化途径优选的决策评价,为政府部门和环境管理者提供决策参考。     

A novel application of concentrated solar thermal energy in foundries

Scrap preheating in foundries is a technology that saves melting energy, leading to economic and environmental benefits. The proposed method in this paper utilizes solar thermal energy for preheating scrap, effected through a parabolic trough concentrator that focuses sunlight onto a receiver which carries the metallic scrap. Scraps of various thicknesses were placed on the receiver to study the heat absorption by them. Experimental results revealed the pattern with which heat is gained by the scrap, the efficiency of the process and how it is affected as the scrap gains heat. The inferences from them gave practical guidelines on handling scraps for best possible energy savings. Based on the experiments conducted, preheat of up to 160 °C and a maximum efficiency of 70 % and a minimum efficiency of 40 % could be achieved across the time elapsed and heat gained by the scrap. Calculations show that this technology has the potential to save around 8 % of the energy consumption in foundries. Cumulative benefits are very encouraging: 180.45 million kWh of energy savings and 203,905 t of carbon emissions cut per year across the globe. This research reveals immense scope for this technology to be adopted by foundries throughout the world.     

真空碳热还原法无害化处理废弃阴极射线管锥玻璃的研究

危险电子废物阴极射线管(cathode ray tube,CRT)是当前我国电子垃圾处理处置中首要必须解决的难题,其关键在于含铅锥玻璃的处珲处置.本研究探讨了真空碳热还原法从CRT锥玻璃中分离并回收有害重会属铅的同时同收钾和钠的规律.结果表明,铅、钾和钠的回收率随温度的升高、压力的降低、碳加入量的增加及保持时间的延长而增大;当温度为1 000℃、系统压力为10 Pa时,加入10%的碳粉并保持4 h,铅回收率接近100%,钠和钾的回收率分别为65.04%和50.55%.该方法为废弃阴极射线管玻璃的无害化和资源化提供了理论依据和实验数据.     

报废电子器件处理技术进展

报废电子器件的数量急剧增长，加强其回收利用研究已经得到广泛重视。对报废电子器件的资源情况、回收技术，尤其是以环境保护-资源综合回收为目的的物理分离技术及其应用进行了评述，指出便于回收的电子器件的设计是未来发展的趋势。     

纤维素废弃物水热处理制H2的研究进展

水热处理为纤维素废弃物资源化应用开辟了一条新的途径，文中就水热处理技术的特点、水热条件下纤维素的降解过程进行了介绍，并着重综述了纤维素废弃物水热制H2方面的研究进展，同时对纤维素及其废弃物的水热处理和资源化研究前景进行了展望。     

纤维素废弃物水热处理制H2的研究进展

水热处理为纤维素废弃物资源化应用开辟了一条新的途径,文中就水热处理技术的特点、水热条件下纤维素的降解过程进行了介绍,并着重综述了纤维素废弃物水热制H2方面的研究进展,同时对纤维素及其废弃物的水热处理和资源化研究前景进行了展望.     

The Dismantling of End-of-Life Vehicles in Estonia Before Putting into Effect the Directive 2000/53/EC (3 pp)

Background, Aims and Scope When joining the European Union on 1st May 2004, Estonia had to conform its legislation to the European Union legislation. In relation with that, also the treatment requirements on end-of-life vehicles proceeding from Directive 2000/53/EC of the European Parliament and of the Council of 18 September 2000 were established in Estonia for the first time. Since this area was not regulated with law beforehand, there was not any information available about it. The aim of the current survey was to ascertain the condition of scrap yards in mid 2004. In addition to that, also to identify the number of scrap yards operating in Estonia, to classify these by the number of dismantled vehicles and the potential environmental hazard, and to map the locations of car dismantling companies and evaluate their compliance with the valid requirements. Methods The companies that have been registered in the Commercial Registry under the activity code 503090-end-of-life vehicle dismantling were visited and visually reviewed. During the visits, the compliance of scrap yards with the existing requirements was evaluated and it was also attempted to identify how environmentally sound the dismantling technology of every scrap yard owner is. Results and Discussion Altogether, 63 scrap yards operated in Estonia by mid 2004. Twelve of them dismantled more than 100 vehicles, 13 of them 51-99 vehicles and 38 up to 50 vehicles a year. The total annual market capacity on dismantling of vehicles in Estonia is considered to be approx. 10,000 units. There are very few companies dealing only with car dismantling as the main business. Most scrap-yard owners also offer side services, e.g. haulage, car repair and maintenance. The dismantlers are interested in the selling of second-hand spare parts and scrap metal. Only one company out of 63 complied with all the requirements enacted by the relevant decision of the Estonian Minister of Environment. The rest of the scrap yards did not meet the requirements on the site on storage and treatment nor did they have the hazardous waste handling licence or the waste permit. Of the requirements established for the site for storage of end-of-life vehicles, 97% of the scrap yards were surrounded with a fence, 67% had a 24-hour guard, 45% had covered the areas with waterproof cover, but only 3% had an oil trap. Sites for treatment were in a somewhat better condition, these were mostly situated inside the buildings, where floors were covered with waterproof covers. Most of the dismantlers collected the waste oil and waste fluids into separate vessels, but there were a number of dismantlers who did not know of existence of polychlorinated biphenyls (PCB) in car air conditioning systems and the availability of mercury in sensors belonging in passenger safety systems. Proceeding from the general condition of the scrap yard, the rest of 62 scarp yards were distributed between two empirical parameters - 'rather environmentally hazardous' or 'rather not environmentally hazardous'. As a matter of fact, 17% of scrap yards turned out 'rather environmentally hazardous'. Conclusion Out of the scrap yards operating in Estonia, only one is compliant with the requirements set up by Directive 2000/53/EC. Another 62 appeared during the review to be sites of potential environmental pollution. In order to comply with environmental requirements and get the hazardous waste treatment license, the scrap yard owners have to invest into state-of-the-art dismantling and environment protection equipment. The main obstacle to reach the environmentally sound scrap-yard is the high investment cost and the black market for spare parts. Recommendation and Outlook As the correction of the market in end-of-life vehicle treatment started after the adoption of Directive 2000/53/EC, the environmental authorities have to look after the ongoing correction. It is because there is still a demand for cheap spare parts and it makes it attractive to dismantle the vehicles out of scrap-yards by licensees.     

铁屑粉煤灰组合处理含磷废水

实验研究了铁屑粉煤灰组合处理含磷废水的除磷效果.通过单因素实验,考查了铁屑粉煤灰质量比、反应时间、pH值和投加量对除磷效果的影响.实验结果表明,该法除磷的最优条件为铁屑和粉煤灰的质量比为2∶1,反应时间为20 min,pH值为6,投加量为20 g/L.在最优实验条件下磷的去除率达到了97.5％.对比了该法和粉煤灰吸附法与传统铁屑法的除磷效果.与单一粉煤灰吸附法和传统铁屑法除磷的结果相比较,铁屑粉煤灰组合除磷的方法具有明显优势.     

工业废铝渣制备聚合硫酸铝及其絮凝性能研究

以一家金属材料厂生产过程中产生的废铝渣作为研究对象,通过对溶解条件和聚合工艺的优化,制备了聚合硫酸铝。将制备的聚合硫酸铝分别用于模拟浊度水及高色度高浓度有机工业废水的处理,实验结果表明,利用工业废渣所制得的聚合硫酸铝具有较好的除浊、脱色、去除COD效果。此工艺不仅可回收利用废铝渣,又可省去废渣处置费用,为废铝渣的综合利用提供了实用技术。