Chemistry of inorganic compounds – Treating mixture to obtain metal containing compound – Group vib metal
Patent
1990-09-19
1992-12-15
Morris, Theodore
Chemistry of inorganic compounds
Treating mixture to obtain metal containing compound
Group vib metal
423 54, 423 53, 423 57, 423127, 423132, 423DIG2, C22B 300, C01G 3700
Patent
active
051715473
ABSTRACT:
The present invention is directed to a method for treating a sludge containing substantial amounts of chromium, aluminum, calcium, iron, and phosphorous. The method comprises forming a slurry of the sludge; reacting the slurry with an acid to dissolve substantially all the aluminum and chromium and provide a solids residue comprising mostly calcium sulfate; separating the chromium/aluminum-containing solution from the solids residue; raising the pH of the chromium/aluminum solution to precipitate chromium as chromium hydroxide; and separating the chromium hydroxide from the remaining aluminum-containing solution. The chromium hydroxide is then enriched with an alkali or earth alkali compound and calcined in an oxidizing atmosphere to convert the chromium to a chromate. The calcine is leached in an aqueous medium at a controlled pH to yield a high concentration, high purity chromate solution suitable for producing metallic chromium or a variety of chromium chemicals.
REFERENCES:
patent: 4207295 (1980-06-01), Kagetsu et al.
patent: 4668483 (1987-05-01), Ladd et al.
patent: 4798708 (1989-01-01), Ladd et al.
patent: 4954168 (1990-09-01), Crnojevich et al.
Case Andrew B.
Crnojevich Ranko
Rando Felix D.
Sweeney John D.
AMAX, Inc.
Morris Theodore
Squillante Edward
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