【作者】 董阳； 韦平； 胡源； 卓锦德； 赖世燿；

【Author】 DONG Y;WEI P;HU Y;JOW J;LAI S;National Institute of Clean-and-low-carbon Energy (NICE),Future Science and Technology City;School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University;State Key Laboratory of Fire Science, University of Science and Technology of China;

【机构】 北京低碳清洁能源研究所功能材料研发中心； 化学与化学工程学院,上海交通大学； 火灾科学国家重点实验室,中国科学技术大学；

【摘要】 由于经济的快速增长和对能源的需求,中国已成为世界上最大的燃煤发电国,粉煤灰的排放量逐年上升,在2010年已达到4.8亿吨,其利用率达68%。目前我国粉煤灰的利用有约41%用于水泥和混凝土,19%用于建材,26%用于墙体,5%用于道路,5%用于农业,和4%用于矿物提取及回填。粉煤灰利用多在附加值较低的领域,主要的原因是粉煤灰量大而且成分差异性大。因此,粉煤灰的利用常受到运输半径和当地建筑市场及季节的影响,很难充分利用,特别是中西部偏远地区燃煤电厂的粉煤灰。北京低碳清洁能源研究所功能材料中心,目前采用材料科学的方法处理不同的粉煤灰,并开发出先进、创新的材料和产品技术来提高其附加价值,希望能有效和充分利用每个燃煤电厂的粉煤灰。该中心的粉煤灰团队已经开发了多项核心材料技术,用于不同领域的高价值应用,包括防火和阻燃的应用。虽然防火和阻燃应用未必能完全消化那些待处理的粉煤灰,但也演示了粉煤灰在高价值应用的可能性。已有文献报道粉煤灰可用来提高有机聚合物的阻燃效果,例如在聚碳酸酯、聚氯乙烯、环氧树脂、环氧树脂和聚丙烯混合料,或在硬质聚氨酯泡沫体材中与聚磷酸铵和季戊四醇的协同阻燃效果。但到目前为止,市面上仍没有粉煤灰基的阻燃剂。从阻燃的机制看来,粉煤灰是可以用来部分取代高分子降低其可燃性,但由于其化学惰性的特性,很难做到膨胀阻隔或气相阻燃的效果。单独使用粉煤灰当阻燃剂,很难在氧指数或UL-94阻燃测试中达到很好的阻燃效果,例如在聚烯烃中顶多达到UL-94 HB等级。利用先进、领先的分离技术和特殊工艺分离出的微纳米粉煤灰圆珠,在现有的阻燃材料里可适当的添加是不会影响其阻燃效果,但可降低成本并改善加工性。本文章主要报告以微纳米粉煤灰圆珠为原料,经过特殊工艺处理,开发出2种新型绿色、低碳、环保阻燃剂,磷氮硅阻燃剂和磷硅阻燃剂,分别在聚烯烃和硬质聚氨酯泡沫体系与现有的阻燃剂做阻燃对比。这2种新型阻燃剂使用粉煤灰超过30%重量,是绿色环保型产品,可满足国家免增值税的激励政策。文中介绍的三种新型粉煤灰基产品,微纳米圆珠、磷氮硅阻燃剂、和磷硅阻燃剂,的颜色为灰色或浅灰色。对此颜色不是问题的产品,建议通过产品配方的优化方式,在各个应用中平衡所需的产品性能,加工性能和成本的要求,来发挥其最大的循环经济效益。更多还原

【Abstract】 Due to the rapid economic growth and energy demand, China has become the world’s largest coal-fired power producer. Fly ash production is increased year after year, and in 2010 has reached 480 million tons with its utilization up to 68%. Currently, it has 41% fly ash used for cement and concrete, 19% for building materials, 26% for walls, 5% for roads, 5% for agriculture, and 4% for mineral extraction and backfilling. The main fly ash use is in low value applications. The key reasons are large fly ash volume and significant differences in fly ash compositions. Therefore, fly ash utilization is often limited by the transportation radius and affected by the local construction market and seasons, especially those coal-fired power plants located in the Mid-West remote areas. Performance materials center at National Institute of Clean-and-low-carbon Energy(NICE) has taken materials-science approaches and developed advanced, innovative material and product technologies to greatly enhance its added value, hoping to achieve full utilization and maximum value of fly ash from each coal-fired power plant. Several core technologies have been developed for fire protection and flame retardant applications as ones of our high-value applications. Both applications might not be able to digest all the left fly ash, but demonstrate the possibility of using fly ash in the high-value applications.In literature the use of fly ash has been reported to improve flame retardance in several polymers, such as polycarbonate, polyvinyl chloride, epoxy resins, epoxy and polypropylene blends, or rigid polyurethane foam synergistic with ammonium polyphosphate and pentaerythritol. But so far, no fly ash-based flame retardant is available in the marketplace. Based on flame retardant mechanism, fly ash can be used to dilute the polymeric fuel, but is difficult to achieve intumescent or gas phase flame retardancy due to its chemically inert nature. When fly ash is used alone as flame retardant, it is difficult to achieve good flame retardance in terms of limited oxygen index or UL-94 vertical flame tests. For example, it can at most achieve the UL-94 HB rating in polyolefin. Micro-nano fly ash spheres are produced by the advanced, leading-edge separation technology and can be added into the existing flame retardant compound at the appropriate loading level to reduce cost and improve processability without affecting its flame retardancy. This paper compares flame retardancy of 2 new green, low-carbon, environmentally friendly flame retardants, phosphorus-nitrogen-silicate flame retardant and phosphorus-silicate flame retardant based on micro-nano flyash spheres, with existing flame retardants in polyolefin and rigid polyurethane foam, respectively. These products, containing fly ash more than 30% by weight, are the green products which can meet the Chinese VAT-free incentives. The color of these new fly ash-based products, micro-nano fly ash sphere, phosphorus-nitrogen-silicate flame retardant, and phosphorus-silicate flame retardant, is gray or light gray. For any products having no issue for this color, it is recommended to balance properties, processing, and cost requirements for various applications through formulation optimization to maximize its recycled economic utilization effectiveness.更多还原