煤中伴生矿物的摩擦荷电特性

根据煤粉中煤和伴生矿物的摩擦荷电特性来设计摩擦荷电系统,使煤和伴生矿物充分异性荷电,是强化煤粉摩擦荷电过程、提高分选效率的关键。以石英、高岭土、方解石这3种煤粉中的主要伴生矿物作为研究对象,利用铜管中气力输送过程使颗粒摩擦荷电,并使用法拉第筒和静电计测量铜管出口颗粒的荷电量,研究了气速、给料速度、管道长度对其摩擦荷电特性的影响。结果表明,石英、高岭土、方解石与铜管摩擦均带负电;各伴生矿物的荷质比均随气速增大而增大,随给料速度增大而减小,随管道长度增加而增加;相同实验条件下,方解石与铜管摩擦后荷质比最大,高岭土荷质比次之,石英荷质比最小,功函数大小为方解石>高岭土>石英>铜。基于连续碰撞荷电机理,同时考虑气速、给料速度、管道长度的影响,建立了稀相气力输送过程颗粒摩擦荷电模型。3种伴生矿物颗粒荷质比的模型计算值与实验值的相关系数均大于0.95,平均相对偏差均小于10%。实验结果表明模型具有较高的预测精度,可以为摩擦荷电系统的设计提供指导。     

基于翅片式摩擦桶的车用聚合物粒子荷电及静电分离探索

对摩擦桶式荷电器中车用聚合物粒子的荷电情况进行了初步探究，基于法拉第桶测定了聚丙烯（PP）、聚氨酯（PU）、聚酰胺（PA）、聚乙烯（PE）、聚氯乙烯（PVC）和丙烯腈?丁二烯?苯乙烯（ABS）6种车用聚合物粒子在摩擦桶式荷电器下的摩擦荷电序列，并以ABS和PA为例，验证了其在不同摩擦桶式荷电器转速（n）和荷电时间（t）下的荷电规律，确定了ABS和 PA的最佳静电分选参数。结果表明，聚合物粒子荷电量（Q）与n和t呈正比关系；各车用聚合物粒子的摩擦荷电序列为（-）PE→ABS→PVC→PU→聚甲基丙烯酸甲酯（PMMA）→PP→PA（+）；ABS和PA的最优分选参数为n=20 r/min、t=1 min，此时两者分离纯度分别达到94.18 %和99.86 %，回收率分别为88.4 %和75.3 %，总回收率为90.15 %。     

微细粒煤摩擦电选的研究现状

介绍了微细粒煤摩擦电选的技术原理、研究现状和实际分选效果及现阶段存在的问题     

废旧塑料分选技术

废旧塑料的回收包括 3个阶段 :收集、分选、加工或再生等步骤。只有清洁的废旧塑料才能生产高质量的产品 ,这需要有效的塑料分选方法。评述了光选、电选、风力分选、密度分选、浮选等废旧塑料分选技术 ,指出浮选在废旧塑料分选方面具备独特优势     

煤粉电晕荷电特性的单因素实验研究与分析

自行设计煤粉荷电与荷电量测量实验装置,采用线-筒型电极结构及直流正电晕方式荷电,荷电量的测量采用法拉第筒法.实验煤种选取无烟煤和高硫烟煤.通过对荷电电压(15 kV～27 kV)、粒径(63 μm～237 μm)、流速(0.80 m/s～3.21 m/s)、给粉浓度(2.23 kg/m3～22.53 kg/m3)和煤种等主要影响因素与颗粒荷质比之间关系的实验研究,得到煤粉电晕荷电的规律性,为进一步深入探究煤粉荷电本质提供了有价值的参考依据.     

荷电膜技术在酸碱盐废水处理中的应用研究进展

随着工业化进程的加快,工业废水对水环境带来的污染愈加严重,正在危及人们赖以生存的家园。由于荷电膜在酸碱盐废水处理展现出的独特优势,已成为膜领域的研究热点之一。本文阐述了荷电膜技术在酸碱盐废水处理的应用进展,分析了目前存在的关键问题,并对未来荷电膜技术研究重点进行展望。     

荷电膜的研究及其应用

讨论了荷电膜的分离机理，综述了L—S相转化法、复合法等几种制备方法，介绍了荷电膜在饮用水净化、生化制药和电泳喷涂等方面的应用。     

荷电高分子分离膜研究进展

本文对压力驱动膜过程中所用到的荷电高分子分离膜的分离机理、制备方法、表征手段以及影响荷电膜分离性能的因素进行了综述。     

细微颗粒物荷电收集处理的实验与模拟计算研究

本文介绍了一个颗粒荷电段与颗粒收集段耦合的静电除尘器,并对其开展细微颗粒物荷电收集处理的实验与模拟计算研究。该颗粒荷电段包含四个或八个电晕针,由负高压直流电供电;颗粒收集段设计为平行板对板结构,板与高压直流电源和地线交替连接。由颗粒发生装置产生细微颗粒物,验证该装置在不同的几何构型、环境和操作参数下的颗粒去除效率。实验与模拟结果表明,于粒径小于几十纳米的颗粒,存在部分荷电模式;于较大颗粒,颗粒荷电段和收集段的参数都对去除效率有显著影响。     

电晕放电喷雾荷电特性

静电喷雾广泛应用于工业各个领域,如静电喷涂、静电雾化燃烧、静电雾化除尘等,其应用效果与喷雾荷电特性密切相关。为获得更佳荷电效果,本文探究了电晕荷电过程中感应电流对液滴真实荷电电流的影响,通过改变荷电电压、电极间距、电极环直径及液体流量等,实验研究了各因素变化对喷雾荷质比、电荷衰减及液滴粒径的影响。结果表明：相比于感应荷电,电晕荷电过程不稳定但能获得更佳的荷电效果,液滴荷质比随荷电电压的增加而先减小后增大,随电极环直径的增加而先增大后减小,随电极间距的增大而增大,电极环直径80mm,电极间距40mm能获得最佳荷电效果;荷电液滴带电量会随输运距离增加而泄漏衰减,相同距离下液滴通过电晕放电带有电荷后衰减更快;液滴带电后能够降低液体表面张力,随着液滴荷电量的增加,雾化液滴粒径有所降低。     

Triboelectrostatic separation of pvc materials from mixed plastics for waste plastic recycling

This study covers the triboelectrostatic separation of Polyvinylchloride (PVC) materials from mixed plastics such as polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polystyrene (PS). The PVC material generates hazardous hydrogen chloride gas resulting from the combustion in the incinerators. The laboratory scale triboelectrostatic separation system consists of a fluidized-bed tribocharger, a separation chamber, a collection chamber and a controller. Negative and positive surface charges can be imparted to the PVC and PET particles, respectively, due to the difference of triboelectric charging series between the particles in the fluidized-bed tribocharger. They can be separated by passing through an external electric field. A highly concentrated PVC (91.9%) can be recovered with a yield of about 96.1% from the mixture of PVC and PET materials in a single stage of processing. For the removal of PVC from the two-component mixed plastics such as PVC/PET, PVC/PP, PVC/PE or PVC/PS, separation results show the recovery of 96–99% with the pure extract content in excess of 90%. The triboelectrostatic separation system using the fluidized-bed tribocharger shows the potential to be an effective method for removing PVC from mixed plastics for waste plastic recycling.     

Basic study on separate charge of coal and waste plastics in coke oven chamber

Nippon Steel Corporation started to operate a waste plastic recycling process using coke ovens at Nagoya and Kimitsu Works in 2000 and at Yawata and Muroran Works in 2002. Now the total capacity is 120,000 tons per year and the recycling process is operating smoothly. In this process, coals and added plastics are carbonized and changed into coke, tar, oil and coke oven gas in a coke oven chamber. At present, upper limit of the addition rate of waste plastics to blended coals is 1% so that the plastic addition does not affect coke strength. However, the amount of waste plastics in Japan is as much as about 10 million tons per year and there is a real need for increasing the amount of waste plastics treated by the waste plastic recycling process using coke ovens. We investigated a method of increasing the addition rate of waste plastics without affecting coke strength by charging coal and plastic separately in a coke oven chamber. In the case of the same plastic addition rate, charging the plastic in the bottom or the top part of the coke oven chamber can decrease the deterioration of coke strength compared with charging a homogeneous mixture of coal and plastic. Charging the plastic in the bottom decreases the coke strength to a greater extent than charging the plastic in the top. This is because the decomposition of the plastic charged in the bottom decreases the bulk density of the upper coal layer. The results suggest that charging the coal and waste plastics separately increases the amount of waste plastics treated in the waste plastic recycling process using coke ovens. In order to commercialize this method, further studies are necessary concerning the charging method, device and the effect of this method on the coke oven operation.     

废旧家用电器塑料资源化利用及发展趋势

塑料是家用电器中广泛使用的原材料,如何高效高值地回收利用废旧家用电器塑料是至关重要的问题。各种塑料依据其性能优势在家电产品中得到广泛应用,并呈现轻量、健康和环保的发展趋势。通过对我国废塑料再生行业的政策和标准进行梳理和分析,综述了废塑料回收利用现状。最后,提出了发展建议：在生产者责任延伸制度的推动下,废旧家用电器塑料行业可采用智能化高效分选设备与复合处理工艺提升资源化利用价值;开展再生塑料行业的相关标准化工作;构建与完善再生材料的应用市场;加强生态设计提升原生塑料的可再生利用性。     

废旧塑料的回收与利用

综述了利用区块链技术进行废旧塑料的回收.使用区块链技术建立的塑料银行可以激励人们自发地回收废旧塑料.废旧塑料的回收流程大多是线下的,监管困难,使用区块链技术可以使用户在区块链上查询全流程的回收数据,便于监管.在废旧塑料的分选和利用方面,介绍了聚乙烯和聚丙烯的分选,聚对苯二甲酸乙二酯与聚氯乙烯混合固体塑料的分选.废旧塑料...     

Time-resolved,pulsed laser sensitized acoustic technology: Application to on-line sorting of waste plastics

In industrial recycling of waste plastics the on-line sorting of different kinds of consumer plastics often represents the key to the successful commercial operation. The principle and a limited feasibility study of a novel wavelength independent photoacoustic sensor applied to this problem are presented. This wavelength independent sensor offers the advantages of low cost, portability, and is not limited by the surface modifications such a color, printed labels, etc. in the commercial products. © 1994 John Wiley & Sons, Inc.     

废塑料脱氯技术现状及产业化进展

废塑料化学回收再利用已成为研究热点,但在含氯废塑料化学回收过程中,氯化物对生产装置有强腐蚀性,同时污染环境、降低产品质量。通过对我国现行关于含氯量的相关排放标准的解析,脱氯技术的发展是完善废塑料化学回收工艺的重要途径。详细介绍了国内外各脱氯技术（分选技术、机械技术、溶剂脱氯技术和分步热分解技术、吸附技术和催化技术）的特点、反应机理及产业化应用情况,分析比较了各技术的优缺点,提出了组合脱氯技术以加快推进含氯废塑料化学回收工艺的发展。     

Materielles Recycling thermoplastischer Kunststoffabfälle

Material Recycling of Plastics Waste. The recycling of plastics waste comprises of two main steps, viz. waste preparation and melt processing. Depending on the quality of the waste input and the desired product, the various recycling processes differ considerably in these two steps. For mixed and contaminated plastics wastes, processes are available which, with minimum preparation, process the melt into thick-walled products. Better defined plastics wastes on the other hand are treated with greater investment in preparation and are generally processed with extrusion into granules for normal plastic processes. Preparation includes shredding, washing and drying, sorting, and agglomeration.     

固体废弃塑料挤注压一体化设备的研发

提出挤注压一体化技术,采用新型肘杆直压复合式二次合模机构,利用二次压缩成型工艺解决了废弃塑料熔融料含气量大、流动性差等特性引起的注塑问题,提高了注塑制品的成型精度及质量;同时,利用连接装置完成“连续”挤出与“间歇”注塑压缩工作方式之间的协调与自动衔接,实现了固体废弃塑料到制品的直接转换。固体废弃塑料挤注压一体化设备的应用,在降低处理成本的同时极大地提高了固体废弃塑料回收再利用比例,实现了固体废弃塑料的高效处理与高值化再利用。     

废玻璃的回收和再利用

随着玻璃材料的使用越来越广泛,同时也产生了许多玻璃废弃物,形成大量的废玻璃制品,造成资源浪费,导致对环境负担和污染。废玻璃因为分量重、有棱角和颜色杂乱等特点,收集、运输都很困难,回收加工成本高。通过对废玻璃的回收工艺、分选方法和再利用途径的论述分析,提出了废玻璃的综合利用途径。     

Triboelectrification of particulate flows on surfaces: Part II — Mechanisms and models

Triboelectric charge accumulation both poses problems and offers opportunities for dry particulate processing. It generates hazards in many industrial systems, but is exploited in several important applications, including electrophotographic toner charging and triboelectric separation. However, the charging of continuous particulate flows on solid surfaces is poorly understood, and design of devices to optimise triboelectric behaviour is often qualitative or based on trial and error. This study attempts to identify the main charging mechanisms for a continuous particulate flow on a flat surface. The proposed charging models incorporate contact time, velocity and mode of contact. A model incorporating contact area effects arising from sliding and rolling contact is consistent with experimental data, as long as a charge limit is imposed on bouncing particles. A mechanism for this charge limit, involving separation discharge, is proposed. The effect of delocalised image charge on the system is estimated and found to be negligible. Some general design principles are proposed for triboelectric optimisation of particle processing devices.