Abstract: Chemical grade silicon metalloid having improved performance in the direct process for making organohalosilanes is selected by (A) measuring the temperature of each batch of silicon metalloid during both the refining and the casting of the silicon metalloid; (B) measuring the elemental impurity levels in each batch of the silicon metalloid after refining of the silicon metalloid; (C) predicting the properties of the slag phase produced during refining of the silicon metalloid based on equilibrium calculations using the elemental impurity levels and the measured temperatures of each batch of silicon metalloid; and (D) selecting a chemical grade silicon metalloid for use in the direct process for making organohalosilanes based upon the predicted slag properties; such that the slag density, the viscosity, and the melting point of the slag, are within acceptable and predetermined ranges for each individual batch.

Abstract: Chemical grade silicon metalloid having improved performance in the direct process for making organohalosilanes is selected by (A) measuring the temperature of each batch of silicon metalloid during both the refing and the casting of the silicon metalloid; (B) measuring the elemental impurity levels in each batch of the silicon metalloid after refining of the silicon metalloid; (C) predicting the properties of the slag phase produced during refining of the silicon metalloid, based on equilibrium calculations, using the elemental impurity levels and the measured temperatures of each batch of silicon metalloid; and (D) selecting a chemical grade silicon metalloid for use in the direct process for making organohalsilanes, based upon the predicted slag properties; such that the slag density, the viscosity, and the melting point of the slag, are within acceptable and predetermined ranges for each individual batch.

Abstract: A process for the use of water granulated silicon in the preparation of alkylhalosilanes. The process comprises contacting an alkyl halide described by formula RX, with a particulate water granulated silicon containing greater than 0.5 to about 5.0 weight percent iron, in the presence of a catalyst composition comprising copper, at a temperature within a range of about 250.degree. C. to 350.degree. C. where R is selected from the group consisting of alkyls comprising one to about four carbon atoms and X is a halogen.