Production of silicon carbide
AssigneeGraphite Sales, Inc.
InventorsWalter H. Carlson, Gerald B. Zander, George C. Hanna, Kevin L. Burmeister
Life of this patent
Estimating the term…
Abstract
A process for the manufacture of silicon carbide crystals and whiskers comprises reacting at a temperature between 1,400.degree. C. and 2,100.degree. C. and in the presence of an inert gas, a material including as essential ingredients carbon, alumina, iron oxide, potassium oxide, and silica in an amount to provide a carbon to silicon ratio of from about 0.84:1 to about 2.17:1.
Claims19
A process for the production of silicon carbide crystals and whiskers comprising reacting at a temperature of between about 1,400.degree. C. to about 2,100.degree. C. and in the presence of an inert gas, a mined material of nature referred to herein as Black Diamond having as essential ingredients, carbon, silica, aluminum, iron oxide, potassium oxide, volatiles and moisture wherein a typical composition based on weight, comprises about 3% moisture, about 33% carbon, about 8% volatiles, and about 56% ash, said ash including, based on the weight of the ash, about 76.8% silica, about 12.9% alumina, about 4.6% iron oxide, and about 2.4 potassium oxide, and said typical composition providing a carbon to silicon ratio of about 1.57:1.
A process for making silicon carbide in crystal and whisker forms in yields greater than about 75% based on the conversion to silicon carbide of the total weight amount of silica and carbon in the reactants comprising the steps of:
- selecting as one of the reactants a mined material of nature referred to herein as Black Diamond containing as essential ingredients carbon, silica, alumina, iron oxide and potassium oxide;
- adding to said one of the reactants, as required, additional reactants selected from the group of carbon, silica and silicon carbide in amounts sufficient to provide a carbon to silicon ratio of about 0.84 to 1.57 based on the total weights of the reactants;
- and,
- reacting said material of nature and said additional reactants in an inert environment at a temperature of around 1800.degree. C. to 2100.degree. C.
Dependencies are inferred from the claim text.