摘要
开发酸性氯化体系中微量金的高效富集分离关键技术,对贵金属行业的快速健康发展具有重要意义。本文甄选大孔弱碱性D303阴离子交换树脂,常温下考察了多种因素对酸性氯化体系中微量金吸附的影响;筛选酸性硫脲作为解析剂,研究了常温下解析液pH和解析时间对饱和树脂金解吸效果的影响,并进行了动态解析实验,对该过程的吸附模型和热力学进行了深入研究。结果表明:采用D303树脂常温下吸附酸性氯化体系中的微量金时,其在10 min内可以达到动态吸附平衡,较高的氯离子浓度会抑制树脂对金的吸附,在盐酸浓度为1mol/L、常温吸附10 min的优化条件下,金的吸附率在99.9%以上,饱和容量为120.0 mg/g;吸附过程符合准二级动力学方程,速率常数为6.51×10^(-4)g/(mg·min),等温吸附符合Langmuir模型,理论饱和容量为129.9 mg/g;298 K时吸附反应的△G为-7.84 kJ/mol,吸附反应能够自发进行。优选硫脲作为解吸剂时,金的静态解吸率可达93.8%;动态解吸体积为1倍床体积(BV)时,解吸后液中金的浓度达到峰值17.59 g/L,解吸体积为3 BV时金的总解吸率可达91%。
Developing key technologies for efficiently enrichment and separation of trace gold in acid chlorination system is of great significance to the rapid and healthy development of precious metal industry.Macroporous weakly basic D303 anion exchange resin was selected to adsorb trace gold from acid chlorination solution,the influences of various factors on the adsorption of trace gold were investigated.Selected acidic thiourea as eluent,the effects of pH and time on the desorption behaviors of saturation resin at room temperature were systematically investigated,and dynamic desorption was conducted based on the preceding results.The adsorption kinetics,thermodynamics,and isothermal models of the adsorption were discussed.The results show that D303 resin adsorb gold from acid chlorination system can achieve dynamic equilibrium within 10 min,and chloride of high concentration inhibites the adsorption process of gold.The optimized conditions for this process are as folloew:HCl of 1mol/L,time of 10 min and room temperature.Under these conditions,the gold adsorption ratio can reach more than 99.9%,and the saturation capacity is 120.0 mg/g.The adsorption process conforms to the pseudo-second-order kinetic equation,and the adsorption rate constant is 6.51×10^(−4)g/(mg∙min);the isothermal adsorption conforms to Langmuir model,the theoretical saturation capacity of gold is 129.9 mg/g,ΔG is−7.84 kJ/mol at 298 K.When thiourea is selected as the eluent,the static desorption rate of gold can reach 93.8%,the peak concentration of gold can reach 17.59 g/L at one bed volume,and the total desorption rate can reach 91%at three bed volumes.
作者
孙渊君
邓雨晴
马玉天
何世伟
陈大林
张福元
SUN Yuan-jun;DENG Yu-qing;MA Yu-tian;HE Shi-wei;CHEN Da-lin;ZHANG Fu-yuan(State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization,Jinchang 737100,China;School of Metallurgical Engineering,Anhui University of Technology,Ma’anshan 243032,China)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2023年第9期3033-3042,共10页
The Chinese Journal of Nonferrous Metals
基金
国家重点实验室开放基金资助项目(GZSYS-KF-2020-008)
国家自然科学基金资助项目(51904005)。
关键词
酸性氯化体系
金
树脂
吸附
解吸
acid chlorination system
gold
resin
adsorption
desorption
