separate port was provided the aforementioned feed kaolin the quantity of the silane was such as to provide a dosage of 2 2 of the dry equivalent weight of the feed clay the clay and treating solution remained in the turbulizer u00ae mixing zone for 30 seconds to 1 minute the product was taken directly from the turbulizer u00ae and analyzed the figure depicts the particle size distribution p s d of the product and of the feed clay showing that the fraction below 0 25 u03bcm e s d was reduced from about 47 to about 37 as a result of treatment with the aggregating agent when this aggregated product is used as a paper filler or as a paper coating pigment as in the formulations of examples 1 and 10 of u s pat no 4 935 062 improvements in the normalized light scatter for the filled sheets and in such properties as sheet gloss print gloss and opacity for the coated sheets can be obtained as compared to use of the unaggregated feed clay an aggregating solution of tetraethoxysilane teos was used to treat a feed clay as in example 1 above except that 3 00 of the teos aggregating agent was added based on the dry equivalent weight of feed clay the sub 0 25 u03bcm content was reduced from about 42 for the feed clay to about 28 for the aggregated product while the present invention has been particularly set forth in terms of specific embodiments thereof it will be understood in view of the present disclosure that numerous variations upon the invention are now enabled to.