US4004918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating waste produced during stainless steel making
Assignee: Japan Metals and Chemical Co Ltd
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Filing: 1975-06-12
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Granted: 1977-01-25
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Expires: 1995-06-12
Abstract
Abstract A method of treating waste produced during stainless steel making is disclosed. The method comprises the steps of kneading a sludge cake with a mixture of dust and scale to obtain a kneaded mass, adding an organic binder and eventually adding water with an inorganic binder to said kneaded mass, shaping said kneaded mass into a briquette, and heating said briquette at a low temperature. The briquette obtained can be used as a ferroalloy making raw material. Metal oxides contained in the briquette are reduced by a dry reduction refining added with a carbonaceous reducing agent and eventually with a flux to separate usable metals.
Inventors
- 👤 Hiroshi Fukuoka
- 👤 Teruhiko Kameyama
- 👤 Yuji Takahashi
- 👤 Kenji Nicho
- 👤 Tatsuo Misawa
- 👤 Tsuneyuki Inoue
- 👤 Kimiaki Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:04
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/02; C21; C21B; C21B11/00; C21B11/10; C21B13/00; C21B13/0006; C22B1/00; C22B1/14; C22B1/24; C22B1/242; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
A method of treating waste produced during stainless steel making and processing, comprising: forming a sludge cake containing 2-5 weight percent water by dehydrating slurry-like pickling sludge containing 30-70 weight percent water produced during pickling treatment in connection with a cold rolling step of stainless steel processing; kneading the sludge cake containing 2-15 weight percent water with a mixture of dust produced during stainless steel making and scale produced during a hot rolling step of stainless steel processing, thereby obtaining a kneaded mass; adding to said kneaded mass 1 to 5 weight percent of an organic binder and less than 5 weight percent of an inorganic binder, said weight percents being based upon the solid components of said kneaded mass; adjusting the water content while kneading to obtain a water content in the range of 8 to 20 weight percent of the total kneaded mass; shaping the kneaded mass under pressure into the form of a briquette; heating the briquette to reduce its water content; charging one or more briquettes, together with a carbonaceous reducing agent into an electric furnace for pyrometallurgically reduction refining to exact metal from such briquettes.
Claim 2
Independent Claim
190 words
A method of treating waste produced during stainless steel making and processing, comprising: forming a sludge cake containing 2-5 weight percent water by dehydrating slurry-like pickling sludge containing 30-70 weight percent water produced during pickling treatment in connection with a cold rolling step of stainless steel processing; kneading the sludge cake containing 2-15 weight percent water with a mixture of dust produced during stainless steel making and scale produced during a hot rolling step of stainless steel processing, thereby obtaining a kneaded mass; adding to said kneaded mass 1 to 5 weight percent of an organic binder and less than 5 weight percent of an inorganic binder, said weight percents being based upon the solid components of said kneaded mass; adjusting the water content while kneading to obtain a water content in the range of 8 to 20 weight percent of the total kneaded mass; shaping the kneaded mass under pressure into the form of a briquette; heating the briquette to reduce its water content; charging one or more briquettes, together with a carbonaceous reducing agent into an electric furnace for pyrometallurgically reduction refining to exact metal from such briquettes.
Claim 3
Dependent Claim
60 words
A method of treating waste produced during stainless steel making and processing as claimed in claim 1, wherein said briquette is charged together with a carbonaceous reducing agent and with a flux into the electric furnace in which refining is effected to extract a metal component from said briquette to reuse said metal component as a steel making raw material.
Claim 4
Dependent Claim
33 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said organic binder comprises a pulp waste liquid, molasses, tar emulsion, or carboxymethyl cellulose.
Claim 5
Dependent Claim
26 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said inorganic binder comprises bentonite or pozzuolan.
Claim 6
Dependent Claim
36 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said kneaded mass is shaped under a pressure of 1,000 to 4,000 Kg/cm 2 into said briquette.
Claim 7
Dependent Claim
41 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said briquette after heating contains less than 5 wt.% of water and has a squeezing strength on the order of 50 Kg/unit.
Claim 8
Dependent Claim
27 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said carbonaceous reducing agent comprises charcoal or coke.
Claim 9
Dependent Claim
26 words
A method of treating waste produced during a stainless steel making and processing as claimed in claim 1, wherein said flux comprises silica or caustic lime.
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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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |