US4150975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing metallic chromium
Assignee: Tosoh Corp
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Filing: 1978-07-06
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Granted: 1979-04-24
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Expires: 1998-07-06
Abstract
Abstract Disclosed is a process for producing metallic chromium from a chromium- and iron-containing ore. First, the chromium- and iron-containing ore is subjected to carbon reduction to obtain a ferro-chrome; secondly, the ferro-chrome is treated with a chlorinating agent, such as aqueous hydrochloric acid, to obtain an aqueous solution containing chromium chloride and ferrous chloride; thirdly, the ferrous ion present in the aqueous chlorinated solution is oxidized into a ferric ion; fourthly, the aqueous ferric ion-containing solution is contacted with an extractant to extract the ferric ion therefrom; fifthly, the extraction residue, i.e. an aqueous chromium chloride solution, or powdered chromium chloride obtained therefrom, is treated in an oxidizing atmosphere maintained at 500 DEG -1,400 DEG C. by an oxidizing flame where the chromium chloride is roasted to be thereby converted to chromic oxide, and; finally, the chromic oxide is reduced into metallic chromium, preferably by a carbon reduction procedure carried out in two stages.
Inventors
- 👤 Hiroshi Miyake
- 👤 Satoru Tenma
- 👤 Nobuyoshi Sato
- 👤 Akira Honda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:27
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/30; C22B34/32; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
136 words
A process for producing metallic chromium which comprises the steps of: reducing a chromium- and iron-containing ore in the presence of a carbonaceous material to obtain a ferro-chrome; treating the ferro-chrome with a chlorinating agent to obtain an aqueous solution containing chromium chloride and ferrous chloride; oxidizing the ferrous ion present in the aqueous solution containing chromium chloride and ferrous chloride, into the ferric ion; contacting the aqueous ferric ion-containing solution with an extractant to extract the ferric ion therefrom; treating the chromium chloride of the aqueous solution, from which the ferric ion has been extracted, in an oxidizing atmosphere maintained at a temperature of from 500° to 1,400° C. by an oxidizing flame where the chromium chloride is roasted to be thereby converted to chromium oxide, and; then, reducing the chromium oxide into metallic chromium.
Claim 2
Dependent Claim
136 words
A process for producing metallic chromium which comprises the steps of: reducing a chromium- and iron-containing ore in the presence of a carbonaceous material to obtain a ferro-chrome; treating the ferro-chrome with a chlorinating agent to obtain an aqueous solution containing chromium chloride and ferrous chloride; oxidizing the ferrous ion present in the aqueous solution containing chromium chloride and ferrous chloride, into the ferric ion; contacting the aqueous ferric ion-containing solution with an extractant to extract the ferric ion therefrom; treating the chromium chloride of the aqueous solution, from which the ferric ion has been extracted, in an oxidizing atmosphere maintained at a temperature of from 500° to 1,400° C. by an oxidizing flame where the chromium chloride is roasted to be thereby converted to chromium oxide, and; then, reducing the chromium oxide into metallic chromium.
Claim 3
Dependent Claim
83 words
A process according to claim 1 wherein the reduction of the chromium oxide into metallic chromium is effected by the steps of: reducing the chromium oxide in the presence of a carbonaceous material to an extent such that the reduced product contains 1 to 10% by weight of oxygen and 1 to 10% by weight of carbon, based on the weight of the reduced product, and; then, further reducing said reduced product at a pressure of 0.1 to 760 torrs into metallic chromium.
Claim 4
Dependent Claim
46 words
A process according to claim 2 wherein said first reduction step is carried out to an extent such that the reduced product contains 1 to 6% by weight of oxygen and 1 to 5% by weight of carbon, based on the weight of the reduced product.
Claim 5
Dependent Claim
22 words
A process according to claim 1 wherein the reduction of the chromium oxide into metallic chromium is effected by a Thermit process.
Claim 6
Dependent Claim
56 words
A process according to claim 1 wherein the aqueous solution of the chlorinating agent is aqueous hydrochloric acid having at least one N concentration and the amount thereof is such that the resultant aqueous solution contains 50 to 200 g/l of chromium, 10 to 100 g/l of iron and 0.2N to 12N of free hydrochloric acid.
Claim 7
Dependent Claim
43 words
A process according to claim 1 wherein said oxidation of the ferrous ion to the ferric ion is carried out by introducing into the ferrous ion-containing aqueous solution at least one substance selected from the group consisting of gaseous chlorine and chromic anhydride.
Claim 8
Dependent Claim
79 words
A process according to claim 1 wherein said extractant used for the extraction of the ferric ion is a solution of 5 to 50% by weight of an extracting agent in diluent; said extracting agent being at least one compound selected from the group consisting of organic phosphates and other phosphorus-containing compounds, primary, secondary and tertiary amines and quaternary ammonium salts, and said diluent being at least one compound selected from the group consisting of hydrocarbons and chlorinated hydrocarbons.
Claim 9
Dependent Claim
52 words
A process according to claim 1 wherein the aqueous solution, which has been contacted with the extractant to extract the ferric ion therefrom, is further contacted with a tertiary amine extractant to extract impurity metal ingredients other than iron, prior to the step of roasting the chromium chloride of the aqueous solution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |