PRETREATMENT OF ALUMINUM RESIDUAL ASH

• Main Authors: MATSUURA HIROYUKI, YAMAUCHI YOSHIRO, YAMASHITA INEO, MATSUI KAZUHIRO
• Format: Patent
• Language: English
• Published: 05.04.1994
• Edition: 5
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; FERROUS OR NON-FERROUS ALLOYS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PURPOSE:To eliminate the generation of gaseous ammonia at the time of reutilizing the residual ash as the ceramic material and soil conditioner and to efficiently utilize the ash as resources by heating the ash at a specified temp. in an oxidizing atmosphere. CONSTITUTION:The residual ash generated in the aluminum melting process is heated to 700-1400 deg.C in an oxidizing atmosphere to decompose the aluminum nitride in the ash to aluminum oxide. As a result, the aluminum nitride is allowed to react with water with relatively simple equipment and process, and the aluminum nitride is decomposed without generating harmful ammonia. The reaction rate is lowered at the temp. of <700 deg.C, and it takes much longer time for the reaction. Conversely, at >1400 deg.C, more energy is required, and it is unfavorable from the viewpoint of chemical equilibrium.