Patent US2784393A successfully refreshed from Google Patents.
US3961032A
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Method for cleaning gases and vapors
Assignee: Hoogovens Ijmuiden BV
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Filing: 1974-12-11
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Granted: 1976-06-01
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Expires: 1994-12-11
Abstract
Abstract A method for preventing the formation of boiler scale from after treating gases produced in steel-making by adding to the wash water through which the gases pass a solution containing from 0.5 to 2% by weight HCl and from 100 to 150 grams Fe + + ions per liter. The rate of addition of the solution being such that H + and Fe + + ions are supplied to the water in constant amounts per unit time.
Inventors
- 👤 Jacobus Cornelis Vermeulen
- 👤 Eric Jan Stuart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:48
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/28; C21C5/38; B; B01; B01D; B01D53/00; B01D53/34; C21B; C21B5/00; C21B5/008; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y10; Y10S; Y10S75/00; Y10S75/961
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
80 words
Method of continuous treatment of CaO-carrying gas or vapour produced in steel-making by washing the gas or vapour with water, wherein the washing water is acidified by addition of a solution which contains from 0.5 to 2% by weight HCl and from 100 to 150 g. Fe + + ions per liter, the rate of addition of the solution being such that H + and Fe + + ions are supplied to the water in constant amounts per unit time.
Claim 2
Dependent Claim
80 words
Method of continuous treatment of CaO-carrying gas or vapour produced in steel-making by washing the gas or vapour with water, wherein the washing water is acidified by addition of a solution which contains from 0.5 to 2% by weight HCl and from 100 to 150 g. Fe + + ions per liter, the rate of addition of the solution being such that H + and Fe + + ions are supplied to the water in constant amounts per unit time.
Claim 3
Dependent Claim
48 words
Method according to claim 1 wherein the said amounts of H + and Fe + + supplied per unit time are selected in dependence upon the time-averaged rate of supply to the water of OH - ions derived from the Ca(OH) 2 which is dissolved in the water.
Claim 4
Dependent Claim
18 words
Method according to claim 1 wherein the said solution contains from 0.5 to 1% by weight free HCl.
Claim 5
Dependent Claim
27 words
Method according to claim 1 wherein the said solution is, or is derived from, pickling acid which has been used for pickling hot-rolled steel strip with HCl.
Claim 6
Dependent Claim
25 words
Method according to claim 1 wherein the iron oxide sludge resulting from the washing is dried and supplied directly or indirectly to a reduction furnace.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-01 | 1979-12-01 | 1980-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-01 | 1983-12-01 | 1984-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-01 | 1987-12-01 | 1988-06-01 | $7700.00 | Window Closed / Lapsed |