METHOD FOR RECOVERING ZINC FROM IRON MAKING DUST

• Main Authors: TOYAMA SHUNICHI, TATEYAMA RIKUO
• Format: Patent
• Language: English
• Published: 19.06.1987
• 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 recover zinc from making dust at a high removal rate by subjecting zinc-contg. dust to a leaching treatment in a hydrochloric acid soln. to classify the dust to a zinc rich phase and zinc lean phase and extracting and separating zinc from the zinc rich phase. CONSTITUTION:The zinc-contg. iron making dust is stirred for a specified period at <=0.5pH in the hydrochloric acid soln. and is classified to the zinc rich phase in which the zinc is segregated and (<100mu) and the zinc lean phase (>100mu) in which the zinc concn. is low by a classifier. The zinc rich phase is added to a hydrochloric acid of about 10-30% concn. to a mixing ratio of about 1 (solid): 9-19 (liquid) and is extracted for about one hour at about 40 deg.C temp. A solid-liquid sepn. is executed after the extraction. The separated zinc-contg. aq. soln. is neutralized to about 8.5-10.5pH and the zinc is recovered in the form of precipitate. The solid content separated from the zinc-contg. aq. soln. and the zinc lean phase are subjected to a neutralizing treatment and are reused as an iron source. The zinc is thereby efficiently recovered from the iron making dust and the residue after the zinc extraction is made usable as a iron source for a blast furnace.