Patent US4039625A successfully refreshed from Google Patents.
US4039625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beneficiation of olivine foundry sand by differential attrition grinding
Assignee: United States Department of the Interior
•
Filing: 1976-12-10
•
Granted: 1977-08-02
•
Expires: 1996-12-10
Abstract
Abstract A high quality olivine foundry sand is produced from olivine-containing rock by wet differential attrition grinding followed by a size separation to remove finely-divided gangue materials. The olivine sand product displays rounded grains, has a low impurity content and produces castings having superior surface quality.
Inventors
- 👤 Edward G. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:57
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/20; C01B33/22
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A process for the recovery of olivine sand from olivine-containing rock which comprises: subjecting said rock to wet differential attrition grinding at an intensity and for a time sufficient to round individual olivine sand grains and to finely comminute the non-olivine gangue minerals contained in said rock; separating said olivine sand grains from the finely comminuted non-olivine gangue minerals, and recovering an olivine sand product suitable for use as a foundry sand.
Claim 2
Dependent Claim
72 words
A process for the recovery of olivine sand from olivine-containing rock which comprises: subjecting said rock to wet differential attrition grinding at an intensity and for a time sufficient to round individual olivine sand grains and to finely comminute the non-olivine gangue minerals contained in said rock; separating said olivine sand grains from the finely comminuted non-olivine gangue minerals, and recovering an olivine sand product suitable for use as a foundry sand.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said rock is crushed to about minus 20 mesh prior to attrition grinding.
Claim 4
Dependent Claim
17 words
The process of claim 2 wherein olivine sand grains are separated from gangue materials by hydraulic classification.
Claim 5
Dependent Claim
16 words
The process of claim 2 wherein olivine sand grains are separated from gangue materials by screening.
Claim 6
Dependent Claim
11 words
The process of claim 2 wherein said olivine-containing rock is dunite.
Claim 7
Dependent Claim
30 words
The process of claim 2 wherein said separated olivine sand grains are subjected to a second wet differential attrition grinding and are thereafter again separated from finely comminuted gangue minerals.
Claim 8
Dependent Claim
27 words
The process of claim 2 wherein said olivine sand product has a grain size larger than about 200 mesh and displays a LOI of less than 1.35%.
Claim 9
Dependent Claim
24 words
The process of claim 2 wherein the solids concentration is maintained within the range of 30% to 50% during said wet differential attrition grinding.
Claim 10
Dependent Claim
19 words
The process of claim 2 wherein the grinding time is in the range of 5 minutes to 1 hour.
Claim 11
Dependent Claim
11 words
An olivine foundry sand produced by the process of claim 1.
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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |