Processing of carbon steel furnace dusts
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jan 21, 1992
Issued Date -
N/A
app pub date -
Apr 26, 1991
filing date -
Jun 18, 1990
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
In a process for the hydrometallurgical treatment of electric arc furnace dusts which includes an acetic acid leach, the acetic acid solution used to perform the leach is made strong enough to dissolve heavy metal residues in the dusts, the iron-containing residues of which are recycled to a steel producing furnace. Zinc and other heavy metals are precipitated from hot acetic acid solution as useful products by the use of hydrogen sulphide. Calcium is then precipitated from the acetic acid solution as a clean gypsum using a deficiency of sulphuric acid, thus avoiding leaving sulphate ions in solution in sufficient concentration to interact with the dust and form sulphates in the iron containing residues when the acetic acid is recycled to the leaching step.
First Claim
Other Claims data not available