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Title: Production of aluminum-silicon alloy and ferrosilicon and commercial purity aluminum by the direct reduction process. Third interim technical (quarterly) report for the period March 1, 1978--May 31, 1978

Technical Report ·
DOI:https://doi.org/10.2172/6550590· OSTI ID:6550590

A complete mass and energy balance for real ores was calculated for the carbothermic reduction step. Corrected thermal data for estimated compounds resulted in 70/sup 0/C reduction of the predicted third-stage temperature. Bauxite, clay and coke mixes were agglomerated on a commercial briquetter. A correlation was obtained between compressive strength and calcination temperature plus rate of calcination of extrusions made from ores and coke. Evaluations of coal in place of coke in the burden was initiated. Evaluations of calcined briquettes and extrusions under reaction conditions resulted in the agglomerates retaining shape and solid phase at temperatures up to 1800/sup 0/C. Runs were made at various concentrations of Fe/sub 2/O/sub 3/ in the burden. Metallic product yields were improved and final-stage temperature was lowered to 1950/sup 0/C. Two improved methods were developed for preparing reduction product samples. Second stage kinetics runs were made to determine the effects of heating rate and temperature. A computer program was formulated for mathematical modeling of carbothermic reduction kinetics. Refractories were tested at reaction conditions and rated; several carbides were the most promising candidates. Safe, efficient operation of water cooled O/sub 2/ tuyeres was attained in crucible type, self-heated reactors. Metal was produced for the first time in an O/sub 2/ heated reactor. Preliminary design for the continuous vertical shaft reactor was completed. A conceptual large scale pilot reactor was designed. A high temperature bench scale crystallizer was designed. Experiments were continued on crystallization of Al--Si alloys containing critical impurities. Liquidus temperatures were determined for Al--Si--Fe and Al--Si--Ti charges. A preliminary design of the pilot crystallizer was completed. Design was continued on crystallizer auxiliaries.

Research Organization:
Aluminum Co. of America, Alcoa Center, PA. Alcoa Labs.
DOE Contract Number:
EC-77-C-01-5089
OSTI ID:
6550590
Report Number(s):
CONS-5089-3
Country of Publication:
United States
Language:
English