US4049397A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of granulated abrasives from fused or sintered refractory inorganic hard substances having a high grain toughness
Assignee: Dynamit Nobel AG
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Filing: 1975-04-16
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Granted: 1977-09-20
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Expires: 1995-04-16
Abstract
Abstract A process for the manufacture of granular abrasives having improved grain toughness from refractory, inorganic hard substances which comprises crushing a lump or block of said refractory inorganic substance, thereafter subjecting the resultant grains to a grind sorting process such that substantially only the porous grains, grains containing flaws or coarsely crystalline grains are comminuted and separating them in the ground condition from the balance of the material.
Inventors
- 👤 Gerd-Edzard Bockstiegel
- 👤 Manfred Neidhardt
- 👤 Gerhard Rehfeld
- 👤 Werner Umlauf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:11
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/14; C09K3/1409
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
151 words
A process for preparing an abrasive composition which consists essentially of crushing an alumina block or lump having an alumina content of 40-100% by weight and a zirconium content of 0-60% by weight to obtain a crushed mass; subjecting said mass to a grain shaping treatment by blasting the crushed material in an apparatus having at least one baffle plate; ball milling the crushed mass employing a grinding medium of balls whose diameter is between 3 and 8 cm. while revolving the ball mill at a rate of between 8 and 40 rpm, the weight of the milling medium being between 1.0 and 4.0 that of the weight of the crushed mass while carrying out the ball milling for a period of between 0.5 and 4.0 hours and thereafter separating particles from the so ball milled composition which have a particle size of 8-24 mesh from the balance of the material.
Claim 2
Dependent Claim
151 words
A process for preparing an abrasive composition which consists essentially of crushing an alumina block or lump having an alumina content of 40-100% by weight and a zirconium content of 0-60% by weight to obtain a crushed mass; subjecting said mass to a grain shaping treatment by blasting the crushed material in an apparatus having at least one baffle plate; ball milling the crushed mass employing a grinding medium of balls whose diameter is between 3 and 8 cm. while revolving the ball mill at a rate of between 8 and 40 rpm, the weight of the milling medium being between 1.0 and 4.0 that of the weight of the crushed mass while carrying out the ball milling for a period of between 0.5 and 4.0 hours and thereafter separating particles from the so ball milled composition which have a particle size of 8-24 mesh from the balance of the material.
Claim 3
Dependent Claim
25 words
A process according to claim 1 wherein the ball milling is carried out in a ball mill having a diameter between 80 and 200 cm.
Claim 4
Dependent Claim
29 words
A process according to claim 1 wherein the crushed mass which is subjected to ball milling contains porous granular material, granular material containing flaws or coarsely crystalline granular material.
Claim 5
Dependent Claim
27 words
A process according to claim 1 wherein the ball milling is carried out until all of the grains therein have a crystal-like size smaller than 70 microns.
Claim 6
Dependent Claim
20 words
A process according to claim 1 wherein said ball milling is performed using bodies which are of regular geometrical shape.
Claim 7
Dependent Claim
13 words
A process according to claim 5 wherein said bodies are spherical in shape.
Claim 8
Dependent Claim
18 words
A process according to claim 1 wherein said inorganic substance is formed by melting aluminum oxide or bauxite.
Claim 9
Dependent Claim
23 words
A process according to claim 1 wherein said inorganic substance is formed by melting aluminum oxide and/or bauxite and zirconium oxide and/or baddeleyite.
Claim 10
Dependent Claim
22 words
A process according to claim 8 wherein said inorganic substance contains zirconium oxide in an amount of 10 to 60 weight percent.
Claim 11
Dependent Claim
17 words
A process according to claim 9 wherein the zirconium oxide content is 20 to 45 weight percent.
References Cited (Backward Citations)
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US3437468A
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US3607162A
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US3679383A
Cited
US3491491A
Cited
US3891408A
Cited
US3881282A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |