Method for making silicon-containing products
AssigneeSi Options, LLC
InventorsNorman D. Hinman, Charles S. Wyman
Life of this patent
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Abstract
A method for producing carbon-silica products from silica-containing plant matter such as rice hulls or straw by leaching with sulfuric acid to remove non-silica minerals and metal while adjusting the mole ratio of fixed carbon to silica in the resultant product. The carbon and silica are intimately mixed on a micron or submicron scale and are characterized by high purity and reactivity, small particle size, high porosity, and contain volatile carbon that can be used as a source of energy for the production of silicon-containing products from the carbon-silica products. High purity silicon-containing products made from the carbon-silica products of the invention are also disclosed.
Claims105
A method for making carbon-silica products comprising the steps of:
- providing plant matter comprising at least about 3 weight percent of silica, non-silica minerals and metals;
- contacting the plant matter with an aqueous solution of sulfuric acid having an acid concentration ranging from about 0.01 weight percent to about 30 weight percent to produce a mixture of plant matter and acid solution;
- reacting the mixture at a temperature ranging from about 10° C. to about 250° C. for a reaction period ranging from about six seconds to about 48 hours, thereby leaching minerals out of the plant matter to produce a carbon-silica product having an adjusted mole ratio of fixed carbon to silica of at least about 1.0:1;
- and
- thereafter removing the acid solution from the carbon-silica product.
Dependencies are inferred from the claim text.