摘要
废电路板中的金主要以薄层形式镀覆在基板表面或接口上,其含金量超过1%,是一种重要的二次资源。目前对废电路板中金的回收,大多采用破碎分选-湿法冶金的方法,存在流程长、污染环境等缺点,因此丞需开发一种高效环保的新工艺。本文基于高锰酸钾(KMnO_(4))-过氧化氢(H_(2)O_(2))-甘氨酸(C_(2)H_(5)NO_(2))体系对废电路板中的基板进行氧化,以使含金针脚(PCGs)剥离,从而达到富集回收的目的;探讨了高锰酸钾浓度、过氧化氢质量分数、甘氨酸浓度对PCGs回收率的影响,结果表明,在KMnO_(4)浓度为0.6 mol/L、H_(2)O_(2)质量分数为17.4%、C_(2)H_(5)NO_(2)浓度为0.1 mol/L、温度为80℃、反应时间为60 min的条件下,PCGs的回收率为99.95%。对PCGs富集回收的机理分析可知,PCGs的富集回收率取决于H_(2)O_(2)的分解速率。在优化条件下,建立了该体系中H_(2)O_(2)的分解反应模型:R_(PCGS)=[H_(2)O_(2)]_(0)×e^(-0.3238)×[KMnO_(4)]_(0)^(t),该模型从理论上解释了PCGs富集回收的过程。本研究提出的方法避免了破碎和化学浸出等过程,提高了金的回收效率,降低了成本和环境污染风险。
The gold in the waste circuit board is mainly coated on the substrate surface or interface in the form of thin layer,with the gold content of over 1%,which is an important secondary resource.At present,the recovery of gold in waste circuit board mostly adopts the method of crushing and separation-hydrometallurgy,which has the shortcomings of long process and environmental pollution,so it is urgent to develop a new process of efficient and environmental protection.In this paper,potassium permanganate(KMnO_(4))-hydrogen peroxide(H_(2)O_(2))-glycine(C_(2)H_(5)NO_(2))system was used to oxidize the substrate of the waste circuit board in order to peel off the gold-containing pin(PCGs),so as to achieve the purpose of enrichment and recovery.The effects of potassium permanganate concentration,hydrogen peroxide mass fraction and glycine concentration on PCGs recovery were investigated.The results showed that under the conditions of KMnO_(4)concentration of 0.6 mol/L,H_(2)O_(2)mass fraction of 17.4%,C_(2)H_(5)NO_(2)concentration of 0.1 mol/L,temperature of 80℃,and reaction time of 60 min,the highest recovery rate of PCGs could reach 99.95%.The mechanism analysis of PCG enrichment and recovery showed that the enrichment and recovery rate of PCGs depends on the decomposition rate of H_(2)O_(2).Under optimized conditions,the decomposition reaction model of H_(2)O_(2)in the system was established:R_(PCGS)=[H_(2)O_(2)]0×e^(-0.3238)×[KMnO_(4)]_(0)^(t),This model theoretically explains the process of PCGs enrichment and recovery.The method proposed in this study avoids processes such as fragmentation and chemical leaching,improves the efficiency of gold recovery,and reduces costs and environmental pollution risks.
作者
鲁妍
贺子镇
王建波
LU Yan;HE Zizhen;WANG Jianbo(School of Environment and Resource,Southwest University of Science and Technology,Mianyang Sichuan 621010,China;Key Laboratory of Solid Waste Treatment and Resource Recycle,Ministry of Education,Mianyang Sichuan 621010,China;Sichuan Province Non-metal Mineral Powder Modification and High Quality Utilization Technology Engineering Laboratory,Mianyang Sichuan 621010,China)
出处
《化工矿物与加工》
CAS
2024年第9期64-70,共7页
Industrial Minerals & Processing
基金
国家自然科学基金项目(52000152)。
关键词
金针脚
高锰酸钾
过氧化氢
甘氨酸
分解反应模型
络合反应
回收率
golden needle foot
potassium permanganate
hydrogen peroxide
glycine
decomposition reaction model
complexation reaction
recovery rate
