日本炼铁中废塑料的循环利用技术

JFE钢公司于1996年10月开始在京浜厂1号高炉对产业废靼料进行处理．是日本最早开始进行高炉喷吹废期料的钢铁公司。从2000年4月开始，与《包装容器再生利用法》实施同时，日本高炉开始喷吹普通废塑料。高炉喷吹废塑料的工艺是．先把收集的废塑料进行破碎分解，分成薄膜类塑料和固形类塑料。后用破碎机破碎到适合高炉喷吹的粒度。薄膜类废塑料破碎处理后．利用比重差法的离心分离装置分离出聚氯乙烯．通过制粒工序进行制粒。将两个系统加工的废塑料颗粒装入贮料仓。然后再送入喷吹罐。喷吹时再从喷吹罐与喷吹气体一起喷入高炉风口回旋区。废塑料在高炉风口回旋区内会急剧燃烧气化．并在炉内作为还原气体被有效利用。     

高炉中喷吹废塑料的可行性研究（Ⅰ）：——废塑料与煤粉的燃烧特性对比研究

为了研究向高炉中喷吹废塑料的可行性,对几种常见废塑料与高炉喷吹用煤粉的燃烧特性进行了对比研究。结果表明：废塑料具有良好的燃烧性能;废塑料的开始燃烧温度和激烈燃烧温度都比煤粉低,燃烧时间较煤粉短,燃烧速度快,燃烧灰尽少,因此更有利于高炉喷吹。     

高炉喷吹废塑料与喷吹煤粉比较分析

从工艺流程、原料化处理工艺及在高炉中能量利用三方面对高炉喷吹煤粉和废塑料进行比较分析可以看出,高炉喷吹废塑料和高炉喷吹煤粉一样可以作为高炉辅助喷吹燃料技术,高炉喷吹废塑料不仅为高炉炼铁提供了燃料,更能解决废塑料造成的环境污染问题,是兼顾社会效益、环境效益和生产效益的综合利用技术。     

高炉喷吹技术进展

介绍了高炉喷吹煤粉、高炉喷吹喷焦粉、高炉喷吹焦炉煤气以及高炉喷吹废塑料四种较为常见的高炉喷吹技术。     

煤和塑料混熔喷吹技术研究

概述了国外高炉喷吹废塑料技术现状和国内研究进展,提出了煤与废塑料混熔高炉喷吹新工艺.对不同比例的废塑料与煤粉混合,在200 ℃的混熔温度下制成样品进行燃烧特性试验.结果表明:混熔样品具有良好的燃烧性能,开始燃烧温度和激烈燃烧温度都比煤粉低,塑料的存在对煤有提前燃烧作用,废塑料混熔比例在25%时燃烧时间较煤粉短,燃烧速度快;废塑料与煤混熔对高炉喷吹技术,理论上是可行的.     

高炉喷吹废塑料技术及应用前景

从废塑料喷吹后的燃烧分析、对高炉冶炼的影响、能量的利用等多方面分析了废塑料应用于高炉喷吹的可行性。并分析了国外高炉喷吹废塑料的实践与进展。分析表明：高炉喷吹废塑料的技术既为废塑料的综合利用和治理“白色污染”开辟了一条很好的途径,也为冶金企业节约能源提供了一种新的手段。     

废塑料应用于高炉喷吹的技术现状及展望

通过对国外高炉喷吹废塑料的实践分析，探讨了我国高炉喷吹废塑料的可行性，以及高炉喷吹废塑料技术为治理“白色污染”，节约能源及增加企业效益，提供了一个良好的途径。     

废弃聚氯乙烯热解脱氯的研究

高炉喷吹废塑料是20世纪90年代初由德国提出的处理废塑料的最佳方法，在国外高炉喷吹废塑料的实践中，含氯废塑料的处理一直是个难题，作对含氯废塑料的热解法脱氯进行了实验室基础研究。结果表明：在隔绝空气或用氮气保护的条件下，以一恒定的温度加热，氯脱除率超过90%，处理后的含氯废塑料可以直接喷入高炉。     

日本炼铁中废塑料作为高炉原料的技术

JFE钢公司于1996年10月开始在京浜厂1号高炉对产业废塑料进行处理，是日本最早开始进行高炉喷吹废塑料的钢铁公司。从2000年4月开始，与《包装容器再生利用法》实施同时，日本高炉开始喷吹普通废塑料。高炉喷吹废塑料的工艺是，先把收集的废塑料进行破碎分解，分成薄膜类塑料和固形类塑料。     

废塑料与煤粉的热解特性对比及动力学研究

 采用热重分析法(TGA)研究了城市固体垃圾中的4种常见废弃塑料——废弃聚乙烯农膜(PE)、废弃聚苯乙烯泡沫塑料(PS)、废弃聚丙烯编织袋(PP)、丢弃的聚对苯二甲酸乙二醇酯饮料瓶(PET)和高炉喷吹用煤粉的热解特性,并计算出它们各自的热解动力学参数。结果表明：废塑料和煤粉的热裂解都属于一级反应,但是煤粉裂解温度远高于废塑料,而裂解量却远小于废塑料,在高炉高温条件下,废塑料将具有比煤粉更好的燃烧特性。     

高 炉 渣 干 法 粒 化 技 术 的 分 析

 对比了高炉渣干法粒化与干熄焦技术的特点,发现高炉渣的理化性能与焦炭差距很大,因此高炉渣的干法粒化不能采用干熄焦路线。根据高炉渣的用途,干法粒化路线可分为回收热能、生成水泥原料等技术路线。单独回收热能技术,可不考虑高炉渣的玻璃化;仅考虑作为水泥原料,则可不考虑回收热能,因此技术难度降低,便于工业化。高炉渣作为水泥原料同时回收热能技术路线,理论上经济效益最高,但是技术难度很大。     

冷结球团生产工艺改进与应用

新兴 铸管集团公司上泉铁矿冷球厂在铁精粉冷结球团生产中,将以往的粘结 入干精粉,然后搅拌均交再压球的方法,改进为干精 均匀撒开,喷入粘结剂,稍经拌合连续压球的新工艺,使压球机产率提高了三分之一,粘结剂吨球用量由１３０ｋｇ降为９０ｋｇ,经济效益显著提高,值得推广应用。     

Conversion of injected waste plastics in blast furnace

Operation of several blast furnaces proved that waste plastic (WP) injection makes recycling of industrial and municipal organic wastes and coke saving possible. However, the extent and reaction kinetics of plastic conversion are hardly explored yet. Therefore, a comprehensive study on WP characteristics and conversion behaviour under simulated raceway, bird's nest and shaft conditions, as well as on its interaction with coke, has been undertaken. Numerous analytical, laboratory and pilot facilities have been used. It has shown that despite favourable chemistry, it is hardly possible to reach a high conversion degree of plastics under the raceway conditions. Consumption of unburned residues in coke bed and in shaft is possible. The effect of this phenomenon on coke reactivity has to be considered as well.     

Disposal of Waste Plastics With Traditional Coking Process

A new technology for treating waste plastics （WP） by traditional coking process was introduced. With a thermo-balance and a 10 g atmospheric fixed bed reactor, the thermo-gravimetric behavior and product were studied during co-coking of WP with blended coal. And then, using a coke-oven with capacity of 200 kg, the characteristics of products were assessed. The results showed that there is an overlapping temperature range （200-550℃ ） of decomposition between WP and blended coal, and the pyrolysis synergism index η and synergism strength β proposed could evaluate the synergism between them. 1% of added WP results in the maximum synergism in all series experiments. The increase of added WP decreases the synergism. Tar yield in co-coking is increased with the decrease of water yield for synergism. Moreover, it was also found that the quality indexes of coke, such as M10, M40, CRI and CSR, are degraded with the increase of WP until 4%, though the quality of tar and gas is optimized for WP addition.     

我国医疗废物资源化可行性探讨

疫情以来,医疗废物的规范化管理越来越受到重视.目前我国的医疗废物普遍采用焚烧和高温蒸汽处理等处置方式,经过无害化处置后的医疗废物具有极高的回收利用价值.我国医疗废物管理存在对医疗废物危害性的重视不足、医院医疗废物管理体系不完善、医疗废物没有得到科学的资源化利用、监管部门分工不明确等问题.通过分析医疗废物资源化的必要性,...     

Some Problems of Recycling Industrial Materials

The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system. The classification of industrial materials from the viewpoint of large-scale recycling was stated. Recycling of materials, on three different levels, was introduced in the industrial system. The metal flow diagram in the life cycle of products, in the case of no materials recycled, materials partially recycled, and materials completely recycled, was given. The natural resource conservation and the waste emission reduction were analyzed under the condition of materials completely recycled. The expressions for the relation between resource efficiency and material recycling rate, and the relation between eco-efficiency and material recycling rate were derived, and the curves describing the relationship between them were protracted. The diagram of iron flow in the life cycle of iron and steel products in China, in 2001, was given, and the iron resource efficiency, material recycling rate, and iron eco-efficiency were analyzed. The variation of iron resource efficiency with the material recycling rate was analyzed for two different production ratios.     

Near-net-shape forming of Al-Al3Ni functionally graded material over eutectic melting temperature

A possibility to make near-net-shape functionally graded material (FGM) products has been examined. The FGM billets having a graded volume fraction of Al₃Ni in thickness direction were machined from an Al-Al₃Ni FGM thick-walled tube manufactured by a vacuum centrifugal method. Billets, which were set in the container for the backward extruding, were heated to 650 °C to 680 °C, at which temperature the FGM becomes a mixture of molten aluminum eutectic and solid intermetallics. Then, billets were extruded successfully to FGM cups by a semisolid forming, except at 650 °C. Residual bulky Al₃Ni particles are found at higher temperature. Thus, an optimum operation temperature is found to be around 660 °C, because bulky Al₃Ni particles transform to fine spheroidal or fibrous shape after the forming. The volume fraction of intermetallics at the bottom region of the cup was condensed more than 60 vol pct in a proper billet setting.     

Fatal acute pulmonary oedema after inhalation of fumes from polytetrafluoroethylene (PTFE)

The cases of three patients with acute pulmonary oedema caused by inhalation of fumes from heated polytetrafluoroethylene (PTFE) in a plastic factory are described. One patient died from profound hypoxaemia and shock shortly after admission, and the other two patients survived after medical treatment. This is the first report of fatal pulmonary oedema in a worker exposed to PTFE heated in a plastic extruding operation. From this observation, it appears that inhalation exposure to pyrolytic products from polytetrafluoroethylene can cause fatal respiratory complications. Special precautions are warranted in this kind of operation to prevent workers from being exposed to these substances.     

冶金余热高效综合利用技术

介绍了冶金企业各工序余热资源高效综合利用技术,包括烧结余热及干熄焦余热高效利用、高炉炉顶煤气余压发电及饱和蒸汽发电技术等,建议大力发展余热回收系统集成系统及冶金渣有压热闷技术,扩大余热利用和余热资源范围。     

LD7铝合金废屑直接再生新工艺

利用粉碎—清洗—干燥—压实—热挤压的工艺过程,对LD7铝合金废屑进行了直接再生成材的研究。结果表明,较高的挤压温度和适当的挤压比可保证颗粒间良好的焊合及坯料中气体的排除;采用常温压实制坯方法,可大大降低再生材中的气体含量。用这种再生工艺制成的铝材其性能已达到了LD7原生材的国家标准。将这种工艺用于工业性试验,也得到了满意的结果。