US3572500A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Beneficiation of diatomaceous earth
Assignee: Cities Service Co
•
Filing: 1968-06-18
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Granted: 1971-03-30
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Expires: 1988-06-18
Abstract
Abstract Diatomaceous earth can be purified of sand and clay and reduced to a smaller particle size by wet attritioning raw diatomaceous earth to reduce the diatomite particle size, hydraulically classifying the wet attritioned material to remove sand and quartz, dispersing clay and centrifugally classifying to remove said clay. Wet attritioning can be done in the presence of a clay dispersant and centrifugal classification can be done before or after the quartz and sand are removed.
Inventors
- 👤 Anastasios P Kouloheris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:00
CPC Classifications
B; B03; B03B; B03B9/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
104 words
A method of beneficiating raw diatomaceous earth containing appreciable quantities of clay which comprises: a. wet attritioning the raw diatomaceous earth to reduce the diatomite particle size to from about 5 to about 44 microns; b. hydraulically centrifugally classifying the product of step (a) to a +325 mesh fraction and a -325 mesh fraction and discarding the +325 mesh fraction; c. mixing the -325 mesh fraction with a clay dispersant to disperse clay particles; and d. centrifugally classifying the mixture obtained in step (c) into a +2 and a -2 micron fraction and recovering the +2 micron fraction characterized by a high diatomite content.
Claim 2
Independent Claim
104 words
A method of beneficiating raw diatomaceous earth containing appreciable quantities of clay which comprises: a. wet attritioning the raw diatomaceous earth to reduce the diatomite particle size to from about 5 to about 44 microns; b. hydraulically centrifugally classifying the product of step (a) to a +325 mesh fraction and a -325 mesh fraction and discarding the +325 mesh fraction; c. mixing the -325 mesh fraction with a clay dispersant to disperse clay particles; and d. centrifugally classifying the mixture obtained in step (c) into a +2 and a -2 micron fraction and recovering the +2 micron fraction characterized by a high diatomite content.
Claim 3
Dependent Claim
37 words
A method according to claim 1 in which the amount of clay dispersant employed is within the range of from about 1 to about 14 pounds of dispersant per ton of raw diatomaceous earth material being treated.
Claim 4
Dependent Claim
38 words
A method according to claim 1 in which the clay dispersant is employed in an amount in the range of from about 2 to about 4 pounds of dispersant per ton of raw diatomaceous earth material being treated.
Claim 5
Dependent Claim
34 words
A method according to claim 1 in which the wet attritioning is conducted in presence of from about 0.25 to about 3.5 pounds of clay dispersant per ton of raw diatomaceous earth being treated.
Claim 6
Dependent Claim
16 words
A method according to claim 1 in which said hydraulic classification comprises a two-stage hydrocyclone classification.
Claim 7
Dependent Claim
41 words
A method according to claim 1 in which the clay content of the raw diatomaceous earth being treated is in the range of from about 5 percent to about 10 percent by weight and the +2 micron fraction recovered is calcined.
Claim 8
Independent Claim
121 words
A method of beneficiating diatomaceous earth containing appreciable quantities of clay and silt containing quartz which comprises: a. wet attritioning the raw diatomaceous earth in the presence of a clay dispersant to reduce the diatomite particle size to from about 5 to about 40 microns; b. removing clay by centrifugally classifying the product of step (a) into a +2 and a -2 micron fraction, discarding the -2 micron fraction which is rich in clay and recovering the +2 micron fraction; c. hydraulically centrifugally classifying said +2 micron fraction into a +325 and a -325 mesh fracTion and recovering the - 325 mesh fraction; and d. treating the -325 mesh fraction to further remove impurities and recovering the beneficiated diatomaceous earth product.
Claim 9
Independent Claim
121 words
A method of beneficiating diatomaceous earth containing appreciable quantities of clay and silt containing quartz which comprises: a. wet attritioning the raw diatomaceous earth in the presence of a clay dispersant to reduce the diatomite particle size to from about 5 to about 40 microns; b. removing clay by centrifugally classifying the product of step (a) into a +2 and a -2 micron fraction, discarding the -2 micron fraction which is rich in clay and recovering the +2 micron fraction; c. hydraulically centrifugally classifying said +2 micron fraction into a +325 and a -325 mesh fracTion and recovering the - 325 mesh fraction; and d. treating the -325 mesh fraction to further remove impurities and recovering the beneficiated diatomaceous earth product.
Claim 10
Dependent Claim
32 words
A method according to claim 7 in which the amount of clay dispersant employed is from about 1 to about 14 pounds per ton of raw diatomaceous earth solid material being treated.
Claim 11
Dependent Claim
32 words
A method according to claim 7 in which the amount of clay dispersant employed is from about 2 to about 4 pounds per ton of raw diatomaceous earth solid material being treated.
Claim 12
Dependent Claim
47 words
A method according to claim 7 in which the - 325 mesh fraction treated in step (d) is elutriated to separate silt from the diatomite particles, the underflow from the elutriation operation being discarded, the overflow therefrom comprising a dilute slurry of diatomite particles, which is recovered.
Claim 13
Dependent Claim
47 words
A method according to claim 7 in which the - 325 mesh fraction which is treated is subjected to a froth flotation operation with a cationic reagent to float silt and clay particles from said fraction, the - 325 mesh underflow containing the diatomite fraction being recovered.
Claim 14
Dependent Claim
35 words
A method according to claim 11 in which the - 325 mesh underflow fraction is thickened and filtered to produce a concentrated filter cake, containing from about 60 to about 70 percent by weight solids.
Claim 15
Dependent Claim
46 words
A method according to claim 12 in which a flocculant is employed in an amount of from about 0.2 to about 0.5 pounds of flocculant per ton of solids in said - 325 mesh underflow slurry to facilitate settling of the solids in said thickening operation.
Claim 16
Dependent Claim
19 words
A method according to claim 12 in which the - 325 mesh underflow fraction is bleached prior to filtration.
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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) | 1974-03-29 | 1974-09-28 | 1975-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-29 | 1978-09-28 | 1979-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-29 | 1982-09-28 | 1983-03-30 | $7700.00 | Window Closed / Lapsed |