| abstract |
The invention provides a process for producing surface-modified particulate fine solids F with high surface area, in which in a process step (A) a portion of unmodified fine solids F1 is mixed with organosilicon compound, forming an organosilicon compound-containing offgas, in a process step (B) the mixture of unmodified fine solids F1 is reacted with organosilicon compound, forming surface-modified fine solids F and optionally an organosilicon compound-containing offgas, in a process step (C) the surface-modified fine solids F are freed of adsorbed by-products and unreacted organosilicon compound, which is obtained as offgas, in a process step (D) a further portion of unmodified fine solids F1 is metered into the offgas obtained in process steps (A), (C) and optionally (B), the solids F1 being mixed with organosilicon compound present in the offgas, and in a process step (E) the mixture obtained in process step (D) is fed in process step (A) into the portion of unmodified fine solids F1 and organosilicon compound. |