US3870535A
Expired / Lapsed
US
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Method of treating coal mining refuse
Assignee: CONVERSION SYSTEMS OF PENNSYLVANIA Inc
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Filing: 1973-12-26
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Granted: 1975-03-11
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Expires: 1993-12-26
Abstract
Abstract Sulfuric acid-containing coal mining refuse is reacted in the presence of moisture with lime, and preferably also with a pozzolanically active material such as fly ash, whereby the existing sulfuric acid is neutralized with lime and further reacted with lime and pozzolan to produce a non-polluting cementitious material, which is self-hardening at atmospheric pressure. This material may be used as structural fill or as a road base material. Alternatively, piles of such refuse may be treated so that a self-hardening mixture is formed either totally or on the surface thereof, thereby preventing further water percolation therethrough and resultant subsurface water contamination.
Inventors
- 👤 Leonard John Minnick
- 👤 Charles L Smith
- 👤 William C Webster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:44
CPC Classifications
C; C04; C04B; C04B7/00; C04B7/24; Y; Y02; Y02P; Y02P40/00; Y02P40/10; Y10; Y10S; Y10S106/00; Y10S106/01; Y10S106/90
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
51 words
METHOF OF TREATING SULFURIC ACID-CONTAINING COAL MINING REFUSED COMPRISING INTIMATELY ADMIXING SAID REFUSE, IN THE PRESENCE OF WATER, WITH LIME. THE AMOUNT OF LIME EXCEEDING THAT STOICHIOMETRICALLY NECESSARY TO NEUTRALIZE SAID SULFURIC ACID CONTENT OF SAID REFUSE, AND PERMITTING SAID ADMIXTURE TO HARDEN, AT ATMOSPHERIC PRESSURE, FOR AT LEAST SEVERAL DAYS.
Claim 2
Dependent Claim
51 words
METHOF OF TREATING SULFURIC ACID-CONTAINING COAL MINING REFUSED COMPRISING INTIMATELY ADMIXING SAID REFUSE, IN THE PRESENCE OF WATER, WITH LIME. THE AMOUNT OF LIME EXCEEDING THAT STOICHIOMETRICALLY NECESSARY TO NEUTRALIZE SAID SULFURIC ACID CONTENT OF SAID REFUSE, AND PERMITTING SAID ADMIXTURE TO HARDEN, AT ATMOSPHERIC PRESSURE, FOR AT LEAST SEVERAL DAYS.
Claim 3
Dependent Claim
51 words
Method of treating sulfuric acid-containing coal mining refuse comprising intimately admixing said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said refuse, and permitting said admixture to harden, at atmospheric pressure, for at least several days.
Claim 4
Dependent Claim
51 words
Method of treating sulfuric acid-containing coal mining refuse comprising intimately admixing said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said refuse, and permitting said admixture to harden, at atmospheric pressure, for at least several days.
Claim 5
Dependent Claim
25 words
Method of treating mining refuse, as recited in claim 1, wherein pozzolanically active particulate material is concurrently intimately admixed with said refuse and hydrated lime.
Claim 6
Dependent Claim
18 words
Method of treating mining refuse, as recited in claim 2, wherein said pozzolanically active material is fly ash.
Claim 7
Dependent Claim
23 words
Method of treating mining refuse, as recited in claim 3, wherein water comprises 5 - 15% by weight of the total reaction mixture.
Claim 8
Dependent Claim
38 words
Method of treating mining refuse, as recited in claim 3, wherein said lime comprises an amount exceeding the amount necessary stoichiometrically to neutralize the sulfuric acid content by 1 - 6% by weight of the total reaction mixture.
Claim 9
Dependent Claim
25 words
Method of treating mining refuse, as recited in claim 3, wherein said fly ash comprises 4 - 12% by weight of the total reaction mixture.
Claim 10
Dependent Claim
20 words
Method of treating mining refuse, as recited in claim 3, wherein said refuse is first mechanically reduced in particle size.
Claim 11
Dependent Claim
50 words
Method of treating mining refuse, as recited in claim 1, wherein water comprises 5 - 15% by weight of the total reaction mixture and line comprises an amount exceeding the amount necessary stoichiometrically to neutralize the sulfuric acid content by 1 - 6% by weight of the total reaction mixture.
Claim 12
Dependent Claim
29 words
Method of treating mining refuse, as in claim 6, wherein said pozzolanically active material is fly ash which comprises 4 - 12% by weight of the total reaction mixture.
Claim 13
Dependent Claim
82 words
Method of treating a surface portion of a mass of sulfuric acid-containing coal mining refuse, comprising intimately admixing said surface portion of said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said surface portion of said refuse, wherein said admixture also includes fly ash and 5 - 15%, by weight, water and permitting said admixture to cure autogenously under ambient, atmospheric pressure for at least several days.
Claim 14
Dependent Claim
82 words
Method of treating a surface portion of a mass of sulfuric acid-containing coal mining refuse, comprising intimately admixing said surface portion of said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said surface portion of said refuse, wherein said admixture also includes fly ash and 5 - 15%, by weight, water and permitting said admixture to cure autogenously under ambient, atmospheric pressure for at least several days.
Claim 15
Dependent Claim
64 words
Method of treating sulfuric acid-containing coal mining refuse comprising intimately admixing said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said refuse, emplacing said admixture over the surface of a site open to the atmosphere and permitting the thus emplaced admixture to cure autogenously for at least several days.
Claim 16
Dependent Claim
64 words
Method of treating sulfuric acid-containing coal mining refuse comprising intimately admixing said refuse, in the presence of water, with lime, the amount of lime exceeding that stoichiometrically necessary to neutralize said sulfuric acid content of said refuse, emplacing said admixture over the surface of a site open to the atmosphere and permitting the thus emplaced admixture to cure autogenously for at least several days.
Claim 17
Dependent Claim
23 words
Method, as recited in claim 11, wherein the water content of said reaction mixture is that which provides maximum density in said mixture.
Claim 18
Dependent Claim
23 words
Method, as recited in claim 8, wherein the water content of said reaction mixture is that which provides maximum density in said mixture.
Claim 19
Dependent Claim
23 words
Method, as recited in claim 9, wherein the water content of said Reaction mixture is that which provides maximum density in said mixture.
Claim 20
Dependent Claim
8 words
Product produced by the process of claim 12.
Claim 21
Dependent Claim
8 words
Product produced by the process of claim 13.
References Cited (Backward Citations)
US2241604A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |