Rice hull ash compositions
AssigneeMolly Maguire, Inc.
InventorsJohn D. Goodwin, Forrest W. Mulkey, III
Life of this patent
Estimating the term…
Abstract
Disclosed is a lightweight silicate aggregate produced by the steps of mixing together dry rice hull ash, an alkali metal hydroxide, boric acid, and water; heating the mixture to a temperature sufficient to initiate reaction; curing the composition at a temperature less than the boiling point of water until the reaction is complete; comminuting the cured product and heating the comminuted product to form the expanded aggregate. The expanded aggregate is useful as, inter alia, a sorbent, filler, energy insulator or filter.
Claims7
A rice hull ash composition comprising
- (a) from about 45% to about 70% by weight of substantially water free rice hull ash which contains no more than about 4% carbon;
- (b) from about 10% to about 25% of an alkali metal hydroxide;
- (c) from about 2% to about 4% boric acid;
- and
- (d) from about 10% to about 25% by weight of water.
A solidified rice hull ash prepared by heating
- a. from about 45% to about 70% by weight of substantially water free rice hull ash which contains no more than about 4% carbon;
- b. from about 10% to about 25% of an alkali metal hydroxide;
- c. from about 2% to about 4% boric acid;
- and
- d. from about 10% to about 25% by weight of water to a temperature of between about 70.degree. C. and about 98.degree. C. and maintaining the temperature in such range until the mixture forms a solid mass.
An expanded rice hull ash composition prepared by heating a mixture comprising
- a. from about 45% to about 70% by weight of substantially water free rice hull ash which contains no more than about 4% carbon;
- b. from about 10% to about 25% of an alkali metal hydroxide;
- c. from about 2% to about 4% boric acid;
- and
- d. from about 10% to about 25% by weight of water to a temperature of between about 70.degree. C. and about 98.degree. C. and maintaining the temperature in such range until the mixture becomes a solid mass, comminuting the solidified mass into discrete particles and expanding the discrete particles by rapid heating.
Dependencies are inferred from the claim text.