高降解性月桂酰基丙基氧化胺的合成及浮选性能研究

Synthesis of Highly Degradable N,N-imethylaminopropyl Dodecyl Amide Oxide and Its Application as Collector in Reverse Flotation of Hematite

常见的胺类阳离子捕收剂具有较高的毒性,而且降解性能差,不仅对人们生产生活带来了严重的影响,而且污染环境,阻碍了胺类捕收剂在工业上的安全应用。采用常见的胺类表面活性剂——月桂酰基丙基叔胺为原料,合成一种新型的低毒高降解性胺类表面活性剂——月桂酰基丙基氧化胺(LAO),并将其首次作为捕收剂用于赤铁矿与石英的浮选分离试验。分别采用石英、赤铁矿单矿物浮选和人工混合矿浮选试验,考察LAO的浮选特性。单矿物浮选试验结果表明,LAO作为捕收剂对石英具有良好的捕收能力,在pH=6.0∼8.0之间石英的回收率可达95.0%以上,且赤铁矿回收率低于10.0%。人工混合矿浮选试验表明,LAO对石英和赤铁矿具有良好的选择性,LAO用量15.0 mg/L,淀粉用量6.0 mg/L,矿浆pH值为5.98的条件下,LAO对赤铁矿和石英的分离效率可达88.86%,远高于常见阳离子捕收剂十二胺。生物降解和毒理试验结果表明,相比于高毒性难降解的胺类捕收剂十二胺,LAO毒性低,属于低毒有机化合物,其生物降解性能也优于DDA。在此基础上,探讨LAO生物降解机理,为低毒高降解性胺类阳离子捕收剂的设计及其在工业上的应用提供指导。

Traditional amine collectors have effect on the human life and industrial production and bring some environment pollution due to their high toxicity and low biodegradability,which also hinders their safe application on industry.In this study,we use common surfactant of N,N-Dimethyl-N-dodecanoyl-1,3-diaminopropane(DMDDP)to synthesis highly degradable N,N-Dimethylaminopropyldodecylamide oxide(LAO),then employ that as a collector in reverse flotation processing of Hematite.Then we performed the single mineral flotation and artificially mixed mineral flotation to explore the flotation characteristics of LAO.The results of the single mineral flotation confirmed LAO has excellent collecting ability and the recovery of quartz could larger than 95.0%when pH=6.0∼8.0,while the recovery of hematite was less than 10.0%.Based on the artificially mixed mineral flotation,the separating efficiency of LAO was calculated as 88.86%under the best flotation conditions that the usages of LAO and inhibitor are respectively,15.0 mg/L and 6 mg/L,which is much better than DDA.Additionally,the results of biodegradation test and pervious toxicity test illustrate LAO that is a low toxicity organic compound has lower toxicity as and higher biodegradability than traditional DDA collector.The biodegradation mechanism of LAO is explored based on the experimental data with the goal of providing the design guidance and industrial application of amine collectors with low toxicity and high biodegradability.