Advanced Fluorite Regeneration Technology to Recover Spent Fluoride Chemicals Drained from Semiconductor Manufacturing Process (Special Issue on Scientific ULSI Manufacturing Technology)

概要

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A regeneration technology of fluorite (CaF_2) from spent HF and Buffered HF (BHF) has been investigated. The mechanism of "direct conversion" of granular calcite (CaCO_3) into granular fluorite has revealed and several special phenomena are first found to be efficient. An advanced system has been developed. This system regenerates granular fluorite by conversion of granular calcite filled in a column. High purity and low water fluorite is recovered as a substitute for natural fluorspar (CaF_2). The fluorine concentration in the processed effluent is minimized to a level of 5 ppm. The separation of the HF processing line and BHF processing line equipped ammonia stripper is an important to system design because ammonia generated from BHF significantly retards the conversion efficiency from CaCO_3 to CaF_2. The new system reforming the conventional slaked lime processing solves long-pending problem, resulting in a very compact system with a very small amount of product.
社団法人電子情報通信学会の論文
1996-03-25