Abstract: The present invention relates to a heat exchange element for use in the direct process. The heat exchange element comprises a heat exchange element with a wear resistant coating on the surface of at least a portion of its surface. The wear resistant coating forms strong bonds to the heat exchange element and has a hardness greater than 50 Rockwell C. Such a coating can survive the physical and chemical environment present in the direct process.

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.