摘要
烃基黄原酸盐是有色金属硫化矿浮选中经常使用的有机浮选药剂,本文研究臭氧氧化浮选药剂丁基黄原酸钾(potassium n-butylxanthate,简称KBX)的反应速率常数.采用两种不同动力学模型对臭氧分子与KBX直接反应速率进行测定:①直接测定臭氧消耗对数模型,②竞争动力学模型.当[KBX]0≥10[O3]0,加入叔丁醇抑制.OH产生,在温度为(293±2)K,pH为2.0,3.0和4.0时,第一种模型测定的直接反应速率分别为153.0,163.2和169.7L·mol-.1s-1.竞争动力学法在pH为2.0,温度为(293±2)K时测定的直接反应速率为143.0L·mol-.1s-1.臭氧与KBX反应的表观反应速率常数kKBX随着pH增大而增大,当pH值由6.7增加到7.6时,表观反应速率常数由334.2L·mol-.1s-1提高到752.1L·mol-.1s-1.本文还进一步研究了pH和.OH抑制剂叔丁醇对KBX去除的影响,KBX的去除率随pH的升高而增大,随着叔丁醇加入的量增大去除率有所降低,这也说明臭氧氧化KBX是臭氧分子与.OH共同作用的结果.
Xanthates are organic flotation reagents used frequently in processing of non-ferrous metal sulfates. The oxidation rate constant for potassium n-butyl xanthate （KBX） with ozone was studied in this work. Two different kinetic models,i.e. the log-reduction of ozone with potassium n-butyl xanthate in excess and a competitive kinetic model,were applied in the determination of the rate constant. According to the first model,at pH 2.0,3.0 and 4.0,the rate constants were 153.0 L·mol-1·s-1,163.2 L·mol-1·s-1 and 169.7 L·mol-1·s-1 respectively,when ／[KBX／]0≥10／[O3／]0 and the well known scavenger of hydroxyl radicals tert-butanol was added to the solution. However,the competitive kinetic model gave an oxidation rate constant of 143 L·mol-1·s-1 at pH 2. The overall degradation rate constants of KBX with ozone increased with pH and varied form 334.2 L·mol-1·s-1 at pH 6.74 to 752.1 L·mol-1·s-1 at pH 7.56. The removal efficiency of KBX declined along with the increasing dose of the hydroxyl radical inhibitor tert-butanol,which suggested the ozone molecule cooperated with the hydroxyl radical to remove KBX in the oxidation process.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第3期511-517,共7页
Acta Scientiae Circumstantiae
基金
全国优秀博士学位论文作者专项资金资助项目(No.200549)
国家自然科学基金项目(No.50874032)~~
关键词
丁基黄原酸钾
臭氧化
直接反应速率
表观反应速率
potassium n-butyl xanthate
ozonation
direct rate oxidation
overall rate constant
