Dispersible silica particulates

Solid, homogeneous, spherical precipitated silica beads having a mean particle size of at least 80 microns, a BET specific surface area ranging from 140 to 200 m.sup.2 /g, a CTAB specific surface area ranging from 140 to 200 m.sup.2 /g, total pore volume of at least 2.5 cm.sup.3 /g and a pore size distribution such that the pore volume provided by pores ranging from 175 to 275 .ANG. in diameter constitutes at least 50% of the pore volume provided by the pores having diameters no greater than 400.ANG..

A precipitated silica shaped article, having a BET specific surface area ranging from 140 to 200 m.sup.2 /g, a CTAB specific surface area ranging from 140 to 200 m.sup.2 /g, a DOP oil absorption ranging from 150 to 350 ml/100 g, a pore size distribution such that the pore volume provided by pores ranging from 175 to 275 .ANG. in diameter constitutes at least 60% of the pore volume provided by the pores having diameters no greater than 400 .ANG. and exhibiting a degree of attrition of less than 20%.

Precipitated silica particulates prepared by reacting a silicate with an acid agent, comprising (i) introducing such acid agent into a liquid reaction medium which comprises at least a portion of the silicate required for complete reaction and an electrolyte, to adjust the pH of said reaction medium to a value of at least 7, the concentration of silica in said reaction medium being less than 100 g/l anal that of the electrolyte being less than 17 g/l, (ii) next introducing additional acid agent and any remaining required silicate into said reaction medium to produce a suspension of precipitated silica particulates having a dry solids content of no greater than 24 % by weight, and (iii) recovering and drying said precipitated silica particulates.