季铵化对阳离子捕收剂N,N-十二烷基二乙醇胺性能的影响研究

Effect of Quaternization on Properties of Cationic Collector N,N-dodecyl Diethanolamine

为了系统地研究季铵化对含羟基叔胺类捕收剂性能的影响,以N,N-十二烷基二乙醇胺(BHDA)和N,N-双(2-羟乙基)-N-甲基十二烷基氯化铵(BHMDC)作为研究对象,基于构型特性和性质分析,并采用浮选试验、动电位分析、生物降解性和水生生物毒性检测,对比研究了两种含羟基捕收剂的性能差异。构型特性和性质分析可知,季铵化可以增加捕收剂极性基团尺寸,提高药剂选择性,同时使药剂易与水混溶,pH值的适用范围更广,性能也更稳定。浮选试验结果表明,2种捕收剂对石英的捕收能力均较好,BHMDC对赤铁矿的捕收能力弱于BHDA;相比于BHDA,季铵化后的BHMDC为捕收剂进行人工混合矿浮选获得的铁精矿指标更好,具有更好的选择性;BHMDC用量为20 mg/L时,可获得品位为63.08%、回收率66.02%的铁精矿。动电位分析可知,与BHMDC作用后,石英和赤铁矿表面动电位变化的差值更大,其对石英和赤铁矿吸附性能的差异更显著,呈现出更好的选择性。生物降解性和水生生物毒性研究表明,相比于BHDA,BHMDC的生物降解性和水生生物毒性均显著降低,说明季铵化会降低含羟基阳离子捕收剂的生物降解性和生物毒性。因此,季铵化反应有助于提高含羟基叔胺类捕收剂的浮选性能,改善捕收剂的生物毒性。研究结果对于高效环保型季铵盐类捕收剂的设计、研发和应用具有借鉴和指导意义。

In order to study the effect of quaternization on the performance of hydroxyl tertiary amine collectors,N,Ndodecyl diethanolamine(BHDA)and N,N-bis(2-hydroxyethyl)-N-methyl dodecyl ammonium chloride(BHMDC)were taken as the research objects,the performance differences of two hydroxyl collectors were compared through flotation tests,dynamic potential analysis,biodegradability and aquatic toxicity test,combined with configuration characteristics and property analyses.The analyses of the configuration characteristics and properties show that quaternization could increase the size of polar groups of collectors and their selectivity,make them miscible with water to have a wider range of pH value and more stable performance.The flotation test results show that the collecting capacities of two collectors for quartz were good,and the collecting capacity of BHMDC for hematite was worse than that of BHDA.Compared with BHDA,the iron concentrate obtained by BHMDC had a better index and better selectivity.When the dosage of BHMDC was 20 mg/L,the iron concentrate with the grade of 63.08%and recovery of 66.02%could be obtained.The results of dynamic potential tests show that the difference between the dynamic potential changes of hematite and quartz treated with BHMDC was larger,showing better selectivity.Biodegradation characteristics and aquatic toxicity studies show that compared with BHDA,the biodegradability and the aquatic toxicity of BHMDC were significantly reduced,indicating that the quaternization would reduce the biodegradability and the toxicity of hydroxylamine cationic surfactants.Therefore,the quaternization reaction was helpful to improve the flotation performance of hydroxyl tertiary amine collectors and their biological toxicity.It is of great guide significance and reference for the design,the research and development,and the application of high-efficiency and environmental friendly quaternary ammonium salt collectors.