Development of Simple Treatment Process of Etching Waste Liquor of Print Circuit Board Using Pseudo Liquid Membranes

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 11555207
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: 反応・分離工学
• Research Institution: KYOTO UNIVERSITY
• Principal Investigator: TANIGAKI Masataka Kyoto University, International Innovation Center, Professor, 国際融合創造センタ, 教授 (30027148)
• Co-Investigator(Kenkyū-buntansha): KURUMADA Ken-ichi Kyoto University, School of Engineering, Instructor, 工学部, 助教授 (80273473) ; SHIROISHI Akihiro Toyama University, Professor, 地域共同研究センタ, 教授
• Project Period (FY): 1999 – 2001
• Keywords: Waste Etching Liquor / Treatment Process / Electro-Static Pseudo Liquid Membrane / Bulk Liquid Membrane / Dispersion Behavior of Droplets / Mass Transfer

Research Abstract

This work was carried out with the aim of developing a simple treatment method of recovering copper metal and enabling the recycle use of acid from the etching waste liquor of print circuit board.
In the first year (Report 1), (1)the systematic selection of extractant which can extract copper from the high concentration waste liquor of acid, (2)experimental work of Electric Pseudo Liquid Membrane (ESPLIM) and (3)Bulk Liquid Membrane (BLM) was carried out. The partial recovery of copper and the recycle use of acid were found possible. However, the multi stage operation was necessary for ESPLIM. In the case of BLM, the improvement of the mass transfer rate was necessary.
In the second year (report 2), experimental work with mainly (3)Bulk Liquid Membrane (BLM) was continued with a newly-developed extractant. Forced circulation of the organic phase was introduced to promote the exchange of the oil drops in the stirred tank and the above bulk organic layer. This enabled the rapid exchange of the organic phases and the effective mass transfer rate. However, (4)the feasibility study of the etching waste liquor revealed that the extraction of a large amount of acid together with copper is a serious problem. New extractant which extract metal only is required.
Because of the unfortunate results so far, (5)behavior of droplets in the electric field and the estimation of mass transfer rate was chosen as a new aim of the present work. The model which successfully explains the observed dispersion and the movement of the droplets made it possible to estimate the overall-extraction ability of ESPLIM operation.