Abstract: A process for calcining a filter cake in a directly heated rotary kiln wherein part of the filter cake is separated from the entire mass of filter cake, the separated portion is predried and recombined with the remainder portion and the combined predried and remainder portion is calcined. The filter cake can be inorganic solids such as oxides of titanium, chromium (III), zinc and iron.

Abstract: An organopolysiloxane of the formula ##STR1## in which x=0 to 500,y=5 to 500,z=5 to 500,R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 independently of one another, represent a saturated and/or unsaturated, optionally also branched alkyl radical having 1 to 4 C atoms, and/or an aryl radical having 6 to 9 C atoms, which may also be optionally alkyl-substituted,R.sub.7 represents an alkyl radical having 6 to 18 C atoms,and in which in each case at least 3% of the radicals bonded to Si are R.sub.7 and H. They are reactive with substrates and thus wash-resistant.

Abstract: A modified hydrophobic colored or magnetic pigment or filler comprising a hydrophobic pigment or filler containing from 0.05 to 10% by weight, based on the weight of the pigment or filler, of an organopolysiloxane corresponding to the formula ##STR1## wherein x=0 to 500,y=5 to 500,z=5 to 500,R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 denote, independently of one another, a saturated and/or unsaturated, unbranched or branched alkyl group haviang 1 to 4 carbon atoms and/or an aryl group having 6 to 9 carbon atoms, said aryl group being unsubstituted or alkyl substituted,R.sup.7 is a straight chained or branched alkyl group having 6 to 18 carbon atoms and R.sup.7 and H each amount to at least 3% of the number of groups attached to Si.