溴系阻燃剂的溶解性能及分离回收研究

Research on recycling and solubility of brominated flame ratardants contianed in waste electronic plastic

针对废旧电子塑料再生利用带来的环境污染和健康风险,测定了不同温度下十溴联苯醚（DBDPO）、十溴二苯乙烷（DBDPE）在柠檬烯溶剂中的饱和溶解度,并利用固-液平衡模型对数据进行了关联。根据两种溴系阻燃剂（BFRs）的溶解度差异,结合现有废旧电子塑料的溶剂法再生工艺,建立了分离DBDPO、同时回收利用DBDPE及三氧化二锑（Sb_2O_3）的新工艺。结果表明,DBDPE的热过滤分离温度不宜高于60℃,DBDPO的冷冻分离温度范围为0-5℃。冷冻分离后的塑料溶液在40℃、3 000 r/min的搅拌速度下,用2倍塑料溶液体积的正丙醇沉淀回收聚苯乙烯塑料,所得再生塑料的PBDEs浓度被降低到0.075%,DBDPE、Sb2O3的回收率分别达到了85.91%和95.75%。

In order to reduce the pollution and health risks from the BFRs contained in waste electronic plastic. The solubilities of DBDPO and DBDPE coexistence in limonene were measured,solubility data was correlated with solid-liquid equilibrium model,it was found that polynomial equation was suitable to fit the experimental results. According to the difference in solubility of two BFRs,an new process that can remove DBDPO and recycle DBDPE as well as antimony trioxide was developped based on existing solvent process. The results showed that temperature of seprating DBDPE and Sb2O3 should not be higher than60 ℃,and the suitable temperature range of seprating DBDPO through freezing crystallization is from 0 -5 ℃. After separating DBDPO crystal,10% of plastic solution is precipitated under 2 ∶ 1（ volume ratio of n-propanol to solution）,40 ℃ and 2 000 r / min,concentration of PBDEs residues in recycled plastic is reduced to 0. 075%,85. 91% of DBDPE and 95. 75% of Sb2O3 were respectively recycled through this process.