A process for the synthesis of organohalosilane monomers, comprising the steps of: forming a slurry of cyclone fines, ultra fines and/or spent contact mass, which are silicon-containing solid residues generated during a fluidized-bed Direct Synthesis of organohalosilanes, in a thermally stable solvent selected from the group consisting of linear or branched paraffins, naphthenes, alkylated benzenes, dialkylated benzenes, aromatic ethers, polyaromatic hydrocarbons, hydrochloric acid and mixtures thereof; and reacting the agitated slurry with at least one organohalide of the formula R 1 X and optionally organohalosilane and/or hydrogen halide in the presence of an additive selected from the group consisting of dialkylpolyethers, podands, secondary amines, terpenes, diterpenes, triterpenes, nitrohydrocarbons, nitriles, hexamethyldisiloxane, trimethylsilyl-endblocked polydimethylsiloxanes having a viscosity of from 5 to 100 cSt, and mixtures thereof, for a reaction time and at a temperature and pressure sufficient to produce organohalosilane monomers having the formulae R 1 SiHX 2, R 1 2 SiHX, R 1 3 SiX, R 1 SiX 3, and R 1 2 SiX 2 or mixtures thereof; wherein R 1 is an aromatic group, a saturated or unsaturated aliphatic group, alkaryl group, or cycloaliphatic hydrocarbyl group; wherein X is a halogen; and wherein the term alkyl designates a straight, branched or cyclic alkyl group; and recovering said organohalosilane monomers from said solvent. forming a slurry of cyclone fines, ultra fines and/or spent contact mass, which are silicon-containing solid residues generated during a fluidized-bed Direct Synthesis of organohalosilanes, in a thermally stable solvent selected from the group consisting of linear or branched paraffins, naphthenes, alkylated benzenes, dialkylated benzenes, aromatic ethers, polyaromatic hydrocarbons, hydrochloric acid and mixtures thereof; and reacting the agitated slurry with at least one organohalide of the formula R 1 X and optionally organohalosilane and/or hydrogen halide in the presence of an additive selected from the group consisting of dialkylpolyethers, podands, secondary amines, terpenes, diterpenes, triterpenes, nitrohydrocarbons, nitriles, hexamethyldisiloxane, trimethylsilyl-endblocked polydimethylsiloxanes having a viscosity of from 5 to 100 cSt, and mixtures thereof, for a reaction time and at a temperature and pressure sufficient to produce organohalosilane monomers having the formulae R 1 SiHX 2, R 1 2 SiHX, R 1 3 SiX, R 1 SiX 3, and R 1 2 SiX 2 or mixtures thereof; wherein R 1 is an aromatic group, a saturated or unsaturated aliphatic group, alkaryl group, or cycloaliphatic hydrocarbyl group; wherein X is a halogen; and wherein the term alkyl designates a straight, branched or cyclic alkyl group; and reacting the agitated slurry with at least one organohalide of the formula R 1 X and optionally organohalosilane and/or hydrogen halide in the presence of an additive selected from the group consisting of dialkylpolyethers, podands, secondary amines, terpenes, diterpenes, triterpenes, nitrohydrocarbons, nitriles, hexamethyldisiloxane, trimethylsilyl-endblocked polydimethylsiloxanes having a viscosity of from 5 to 100 cSt, and mixtures thereof, for a reaction time and at a temperature and pressure sufficient to produce organohalosilane monomers having the formulae R 1 SiHX 2, R 1 2 SiHX, R 1 3 SiX, R 1 SiX 3, and R 1 2 SiX 2 or mixtures thereof; wherein R 1 is an aromatic group, a saturated or unsaturated aliphatic group, alkaryl group, or cycloaliphatic hydrocarbyl group; wherein X is a halogen; and wherein the term alkyl designates a straight, branched or cyclic alkyl group; and recovering said organohalosilane monomers from said solvent.