Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

Patent · Tue Feb 15 00:00:00 EST 1994

OSTI ID:5163943

Zaromb, S; Lawson, D B

A process for recovering zinc-rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered by distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10 C, separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream. 1 figure.

• DOE Contract Number: W-31109-ENG-38
• Assignee: PTO; EDB-94-063819
• Patent Number(s): US 5286465; A
• Application Number: PPN: US 7-905330
• OSTI ID: 5163943
• Resource Relation: Patent File Date: 29 Jun 1992
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
DUSTS
MATERIALS RECOVERY
IRON
METAL INDUSTRY
WASTE MANAGEMENT
ZINC
DISSOLUTION
ELEMENTS
INDUSTRY
MANAGEMENT
METALS
PROCESSING
TRANSITION ELEMENTS
WASTE PROCESSING
320305* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Industrial Waste Management