Investigation on the Recovery of Rinsing Wastewater from Lead Frame Cyanide Species with the Method of Ion exchange Resin

• Main Authors: Huang-Chou Huang, 黃煌洲
• Other Authors: Sheng-Lung Lin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/f884bv

碩士 === 朝陽科技大學 === 環境工程與管理系碩士班 === 92 === With the prosperous development of industries, the utilizations of water resources have reached a limitation. The shortage of water resources would seriously affect the progress of economic. It has become a main goal to found an available industrial wastewater recovery technique and to practically be applied by industries. The recycling of industrial wastewater would reduce the cost of water utilization and benefit the sustainable administration of Taiwan’s water resource. This study focused on the wastewater, which was treated with coagulation/sedimentation processes and then discharged to receiving water system, from one electrical metal surface treatment factory. The wastewater quantity is over 1,000 tons per day from the electroplating units of semiconductor Lead Frame processes. Cyanide species rinse water was selected to assess the feasibility of recovery with the method of ion exchange after investigating the qualities and quantities of entire wastewater. Available resins were sifted first, then seek the operation parameters, best combinations of resin types and running data were conclusively identified. The results of this studies could be applied into the factories for the purposes of recycling/ reuse of cyanide species rinse water and reducing the supplement quantity of clean water. The results showed that best adsorption efficiencies of silver and copper were obtained while adopting strong base anion resin (DCN1) with 12 space velocity (S.V) per hour from the recovery experiments of lead frame cyanide species rinse water. The regeneration efficiency of salt-base regenerating reagent was over 98% under 2 S.V. Activated carbon+ decyanide complex resin+ purified resin were best combination for the recovery of cyanide rinse water. Silver cyanide rinse water with its high economic profit was evaluated as the main target to install a commercial scale recovery equipment. Practical running demonstrated that 100 tons pure water per day were recycled and repeatedly used in the process. The recycling efficiency of pure water was more than 65%, and the regeneration efficiency of resin was over 85%. The silver content was more than 2 grams per liter in the rinse water of recycling/regeneration processes, and the silver can be recovered with electrolysis method. This study showed that the recovery/recycling of cyanide species rinse water were effective and valuable silver was recovered when operating with not only the lab scale but also the commercial scale. From the standpoints of environmental protection and sustainable development, we expect the results of this research to be referred and applied in relative clean fabrication industries.