用废聚苯乙烯泡沫制PU带锈防腐漆

武汉市现代工业技术研究所开发成功一种利用废聚苯乙烯泡沫改性制成聚氨基甲酸酯（ＰＵ）带锈防腐漆技术。该项技术已在湖北宜昌投入工业化生产,解决了大量难腐烂、难被生物降解的“白色污染”源。产品经国家法定部门检验,各项技术指标均高于普通防腐漆的国家标准。用此技术生产的ＰＵ防腐漆成本低廉,仅为普通防腐漆的１／３。该产品的主要特点：（１）单组分,干固快,漆膜光亮度好,抗冲击性强;（２）耐酸、碱和各种油等的性能良好;（３）可在有锈金属物件上直接涂刷,从而起到底面合一的效果。该产品可广泛用于化工、石油、冶金、轻…     

生活垃圾分类背景下对广州市废玻璃回收利用的思考

废玻璃是一种载能节能、低碳环保、可重复利用和再生利用的再生资源,广州市通过补贴政策、两网融合等手段,促进废玻璃回收利用,随着生活垃圾分类纵深推进,为了进一步提高废玻璃回收利用,从废玻璃回收利用现状入手,对比了北京、上海生活垃圾中废弃玻璃的占比情况,针对目前存在问题,提出废玻璃回收利用分析与建议.     

聚氯乙烯生产中副产高沸物的综合利用

介绍了以ＰＶＣ生产中副产的高沸物精制后作溶剂,降解后的废聚苯乙烯泡沫塑料的作主料,制造塑化防腐漆的工艺流程,产品性能及经济效益。     

一种对废线路板非金属组分预处理并回收利用的方法

<正>专利申请号:CN201810762394公开号:CN109092847A申请日:2018.07.11公开日:2018.12.28申请人:中山大学本发明公开了一种对废线路板非金属组分预处理并回收利用的方法,该方法首先通过拆解、初步破碎、分选等物理预处理法从废印刷线路板中分离出以环氧树脂和玻璃纤维     

废合金刀头中锡的回收利用工艺研究

探讨了废合金刀头中锡的回收利用工艺。使用三氯化铁和盐酸的混合液溶解刀头,以还原铁粉置换出铜后,添加1倍量的三氯化铁氧化Sn^(2+),使用5%的氢氧化钠以6 mL/min的速度调节溶液pH值为1.10,可较好地沉淀出锡。回收所得锡泥可供锡产业链相关厂家作为原料使用。     

废聚酯用品回收技术获成功

日本帝人公司研制成功从废聚酯用品回收高纯度对苯二甲酸二甲酯(DMT)和乙二醇(EG)的化学回收技术。 该技术可回收利用与其他材料混合的制成品或使用了添加剂、加工剂的制成品,得到的产品与未用过的DMT、EG产品纯度相同。 据报道,该公司目前正在改造其德山事业所的旧DMT设备,以建成年生产能力为3万吨的回收专用设备。预计这些设备可在2002年度投产。 帝人公司称,它目前主要以聚对苯二甲酸乙二醇酯)PET)瓶为回收对象,并将继续考虑利用聚酯纤维、聚酯薄膜等,公司用该技术回收的DMT等将全部自用消化。 据介绍,这项技术是将使用后的聚酯瓶粉碎、洗净,经解聚工序分离工序后,进入酯交换和重结晶工序、DMT分离工序及精制工序,精制后的DMT再经反应,得到高纯度对苯二甲酸(PTA),再生DMT纯度达99.99%,与未曾用过的纯品质量相同。 (汪硕)     

表面活性剂溶液法回收废白土中油脂的研究

用表面活性剂溶液法回收废白土中油脂,油脂回收率可达96%.讨论了表面活性剂的选择、作用原理、工艺条件的设计以及提取温度、提取时间与油脂回收率和油脂质量的关系.     

北京市居民PET饮料瓶的消费及回收行为研究

2010年,中国成为世界上PET饮料瓶使用量最大的国家,但中国目前缺乏正规、完整的废PET饮料瓶回收系统,导致了严重的社会与环境问题.因此,采用街头访问的方式,对北京市PET饮料瓶的回收情况展开调研.结果显示,消费后的废PET饮料瓶,44％被消费者存放在家里以卖钱,56％被消费者直接扔进垃圾桶.通过拾荒者、流动回收人员等回收者的回收行为,北京几乎所有的废PET饮料瓶都得到了回收,其中90％是由非正规的回收者回收的.回收后的废PET饮料瓶绝大部分都被小型的、非正规的、没有环境污染防治设施的小工厂使用.     

氨基磺酸溶液浸出废锂离子电池负极活性材料中的锂

随着锂离子电池的广泛应用,产生了大量废锂离子电池,其负极活性材料中积累了高品位的锂。锂作为一种稀有金属,对其进行回收利用很有意义。选取了无毒、稳定性好的氨基磺酸作为浸出剂,浸取废锂离子电池负极活性材料中的锂,考察了预处理方式对负极活性材料成分和结构的影响以及浸出条件对锂浸出率的影响。结果表明:600℃下煅烧4 h,可完全去除附着在负极活性材料表面的有机物;在氨基磺酸浓度0.75 mol/L、固液比5 g/L、浸出温度40℃、浸出时间45 min的最佳浸出条件下,负极活性材料中锂浸出率达97.2%。     

废聚乙烯的综合利用

废聚乙烯的回收利用是近年来环境污染控制的一个重要课题.作为废旧塑料的主要组成成份的废聚乙烯,人们已对其回收利用展开了大量的研究,并取得了很大的进步.从三大方面讨论了废聚乙烯的综合利用问题,同时,讨论了很多最新技术,并对每一方法的优缺点作出分析,对其应用前景作出了预测.     

Influence of Carbonyl Fe on Degradation of Epoxy in Ozone Environment

Carbonyl iron/epoxy coatings are widely used in military as a radar absorbing coating (RAC). The behaviors of RACs under working environments are very important, especially in the new environments such as ozone appeared with widening of the application fields. The effects of ozone degradation on pure epoxy cured with anhydride and the influence of carbonyl Fe on the degradation of epoxy are studied. The results indicate that if the peak at 1,510 cm⁻¹ was used as the inner standard, the intensity of absorption peaks at 1,738, 1,247 and 1,182 cm⁻¹ increases with exposure time for pure epoxy resin, while for the carbonyl iron/epoxy coatings, the three peaks changes insignificantly with the exposure time. The results indicates the oxidation process begins at the hydroxyl and methyl groups, and finally ozonide and carbonyl are formed on the surface for pure epoxy, and epoxy is eroded gradually in depth by ozone. Carbonyl iron could hinder the meeting of ozone with epoxy with dilution or hindrance effect and could protect epoxy resin from ozone and thus delay the deterioration of the coating performance.     

阳离子交换树脂生产中废酸的回收利用及树脂质量控制

采用 酸套洗工艺代替传统的加水稀释洗涤工艺，成功地解决了阳离子交换树脂生产中废酸的回收利用问题，研究了采用新洗涤工艺后树脂变红的机理和防止对策，结果表明，树脂发红帅微生物的参与而引起的。采以完善洗涤 灭菌措施可防止树脂 ，从而确保了稀酸套洗工艺的顺利实施。     

Biosorption of copper from aqueous solutions utilizing agricultural wastes

The purpose of this study was to determine the copper (Cu) biosorption capacities of several agricultural wastes from aqueous solutions. Samples of agricultural wastes were tested unaltered and after hydrochloric acid (HCl) treatment. Additional parameters tested include sample dose, contact time, particle size, mixing temperature, and the concentrations and pH of the Cu solutions. Desorption studies were performed to determine if the removed Cu could be recovered. In addition, tests were conducted to determine if the agricultural waste samples (AWS) could be reused for additional Cu biosorption cycles. The results of this study demonstrate a wide range of Cu biosorption proficiencies ranging from 0% to 100% removal. The parameters that resulted in higher Cu removal include higher pH and lower Cu solution concentration. Desorption results showed a 58% to 86% Cu recovery rate. Three of the five reused AWS were effective at removing Cu during subsequent trials. Therefore, these AWS types can be reused for additional Cu biosorption cycles. Hence, it is possible that using those AWS for metal treatment could reduce hazardous waste disposal inefficiencies and costs by avoiding disposing of spent AWS following each Cu biosorption cycle.     

Leaching studies for tin recovery from waste e-scrap

Printed circuit boards (PCBs) are the most essential components of all electrical and electronic equipments, which contain noteworthy quantity of metals, some of which are toxic to life and all of which are valuable resources. Therefore, recycling of PCBs is necessary for the safe disposal/utilization of these metals. Present paper is a part of developing Indo-Korean recycling technique consists of organic swelling pre-treatment technique for the liberation of thin layer of metallic sheet and the treatment of epoxy resin to remove/recover toxic soldering material. To optimize the parameters required for recovery of tin from waste PCBs, initially the bench scale studies were carried out using fresh solder (containing 52.6% Sn and 47.3% Pb) varying the acid concentration, temperature, mixing time and pulp density. The experimental data indicate that 95.79% of tin was leached out from solder material using 5.5M HCl at fixed pulp density 50g/L and temperature 90°C in mixing time 165min. Kinetic studies followed the chemical reaction controlled dense constant size cylindrical particles with activation energy of 117.68kJ/mol. However, 97.79% of tin was found to be leached out from solder materials of liberated swelled epoxy resin using 4.5M HCl at 90°C, mixing time 60min and pulp density 50g/L. From the leach liquor of solder materials of epoxy resin, the precipitate of sodium stannate as value added product was obtained at pH 1.9. The Pb from the leach residue was removed by using 0.1M nitric acid at 90°C in mixing time 45min and pulp density 10g/L. The metal free epoxy resin could be disposed-of safely/used as filling material without affecting the environment.     

Recovery of materials from waste printed circuit boards by vacuum pyrolysis and vacuum centrifugal separation

In this research, a two-step process consisting of vacuum pyrolysis and vacuum centrifugal separation was employed to treat waste printed circuit boards (WPCBs). Firstly, WPCBs were pyrolysed under vacuum condition at 600 °C for 30 min in a lab-scale reactor. Then, the obtained pyrolysis residue was heated under vacuum until the solder was melted, and then the molten solder was separated from the pyrolysis residue by the centrifugal force. The results of vacuum pyrolysis showed that the type-A of WPCBs (the base plates of which was made from cellulose paper reinforced phenolic resin) pyrolysed to form an average of 67.97 wt.% residue, 27.73 wt.% oil, and 4.30 wt.% gas; and pyrolysis of the type-B of WPCBs (the base plates of which was made from glass fiber reinforced epoxy resin) led to an average mass balance of 72.20 wt.% residue, 21.45 wt.% oil, and 6.35 wt.% gas. The results of vacuum centrifugal separation showed that the separation of solder was complete when the pyrolysis residue was heated at 400 °C, and the rotating drum was rotated at 1200 rpm for 10 min. The pyrolysis oil and gas can be used as fuel or chemical feedstock after treatment. The pyrolysis residue after solder separation contained various metals, glass fibers and other inorganic materials, which could be recycled for further processing. The recovered solder can be reused directly and it can also be a good resource of lead and tin for refining.     

Recycling of carbon fiber-reinforced plastic using supercritical and subcritical fluids

The recycling of waste plastics is important for the prevention of the exhaustion of fossil resources. In this paper, recycling techniques of carbon fiber-reinforced plastic (CFRP) using supercritical and subcritical fluids were reviewed. The matrix resin of CFRP such as epoxy resin or resol resin was decomposed by supercritical and subcritical fluids, and the carbon fiber without thermal damage was recovered from CFRP. Mainly, water or alcohol was used as decomposition medium.     

Nylon recovery from carpet waste through pyrolysis under the presence of zinc oxide and the roll-milling treatment

Recycling of carpet waste is not extensively carried out because of its complex combination of materials. A representative type of carpet consists of three layers: nylon fibers, adhesives, and backing materials made of poly(vinyl chloride), PVC. Thermal treatment of carpet waste, thus, leads to the emission of hazardous chlorinated compounds. In the present work, we have employed the one-directional thermal treatment of the backing materials under the presence of zinc oxide, which promotes the thermal degradation of PVC. Nylon fibers could be effectively recovered by the consequent milling treatment from the brittle backing materials. The influence of process parameters, such as pyrolysis temperature and reaction time, on the separation efficiency is discussed.     

Removing cadmium from aqueous solutions utilizing agricultural wastes

The purpose of this study was to determine the cadmium (Cd) biosorption capacities of several agricultural wastes from aqueous solutions. Samples were tested unaltered and after hydrochloric acid treatment. Additional parameters tested include sample dose, contact time, particle size, mixing temperature, and the concentrations and pH of the Cd solutions. Desorption studies were performed to determine if the removed Cd could be recovered. In addition, tests were conducted to determine if the agricultural waste samples (AWS) could be reused for additional Cd biosorption cycles. The results of this study demonstrate a wide range of Cd biosorption proficiencies ranging from 33 to 100% removal. The parameters that resulted in higher Cd removal include higher sample dose, higher pH, and lower Cd solution concentration. Desorption results showed a 36–56% Cd recovery rate. Reused AWS were effective at removing Cd during subsequent trials. Therefore, all AWS types tested in this study can be reused for additional Cd biosorption cycles. Hence, it is possible that using AWS for metal treatment could reduce hazardous waste disposal inefficiencies and costs by avoiding disposing of spent AWS following each Cd biosorption cycle.     

The separation of waste printed circuit board by dissolving bromine epoxy resin using organic solvent

Separation of waste printed circuit boards (WPCBs) has been a bottleneck in WPCBs resource processing. In this study, the separation of WPCBs was performed using dimethyl sulfoxide (DMSO) as a solvent. Various parameters, which included solid to liquid ratio, temperature, WPCB sizes, and time, were studied to understand the separation of WPCBs by dissolving bromine epoxy resin using DMSO. Experimental results showed that the concentration of dissolving the bromine epoxy resin increased with increasing various parameters. The optimum condition of complete separation of WPCBs was solid to liquid ratio of 1:7 and WPCB sizes of 16 mm² at 145 °C for 60 min. The used DMSO was vapored under the decompression, which obtained the regenerated DMSO and dissolved bromine epoxy resin. This clean and non-polluting technology offers a new way to separate valuable materials from WPCBs and prevent the environmental pollution of waste printed circuit boards effectively.     

Utilizing agricultural wastes to remove hexavalent chromium from aqueous solutions

The purpose of this study was to determine the hexavalent chromium (Cr^VI) biosorption capacities of several agricultural wastes from aqueous solutions. Samples were tested unaltered and after hydrochloric acid (HCl) treatment. Additional parameters tested include sample dose, contact time, particle size, mixing temperature, and the concentrations and pH of the Cr^VI solutions. Desorption studies were performed to determine if the removed Cr^VI could be recovered. In addition, tests were conducted to determine if the agricultural waste samples (AWS) could be reused for additional Cr^VI biosorption cycles. The results of this study demonstrate a wide range of Cr^VI biosorption proficiencies ranging from 13 to 98 percent removal. The parameters that resulted in higher Cr^VI removal include HCl treatment, higher sample dose, lower Cr^VI solution concentration, and lower mixing temperature. Desorption results showed an 8 to 25 percent Cr^VI recovery rate. Reused AWS were effective at removing Cr^VI during subsequent trials. Therefore, all AWS can be reused for additional Cr^VI biosorption cycles. Hence, these could reduce hazardous waste disposal inefficiencies and costs by avoiding disposing of spent AWS following each Cr^VI biosorption cycle.