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US 5,002,696 AGranted
Expanded mineral particles and apparatus and method of production
AssigneeGrefco, Inc.
InventorWilliam R. White
Life of this patent
Estimating the term…
Abstract
A non-porous, substantially hollow, expanded mineral product, such as expanded perlite, is produced by uniformly and indirectly heating ore for about 1 to 30 seconds in an expansion chamber maintained at about 1400.degree. F.-2100.degree. F. to produce uncoated particles which exhibit superior short term and long term density stability characterics in liquid systems, and which may subsequently be coated to provide enhanced density stability characteristics.
Claims26
An expanded mineral product comprising:
- mineral particles made from the group consisting of perlite, pumice, pumicite, pitchstone, obsidian and volcanic ash and which have been expanded to a greater volume then the volume of the particles prior to expansion,
- said expanded mineral product particles being uncoated, having a substantially smooth, non-porous surface and a nominal density less than about 2.0 gram/cc. as measured by air comparison pycnometer, and
- said particles having the property that when mixed with an emulsion or liquid which is chemically inert to said particles and which has a viscosity in the range of about 25,000 to 100,000 centipoise and at about 2% by weight of said particles to said liquid to form a mixture, said mixture is subjected to a vacuum of about 25" Hg for 10 minutes and then released, the density change of said liquid is less than 10%.
An expanded mineral product comprising:
- mineral particles made from the group consisting of perlite, pumice, pumicite, pitchstone, obsidian and volcanic ash and which have been expanded to a greater volume than the volume of the particles prior to expansion,
- said particles being uncoated, having a substantially smooth, non-porous surface and a nominal density less than 2.0 gram/cc as measured by air comparison pycnometer, and
- said particles having the property that when mixed with a liquid which is chemically inert to said particles and having a viscosity between 25,000 and 100,000 centipoise and at about 2% by weight of said liquid to form a mixture and said mixture is held at a temperature of 120.degree. F. for one month,
- results in a mixture density change of less than 10%.
1 more element
Dependencies are inferred from the claim text.