Method of producing silica sols with controllable broad size distribution and minimum particle size

Colloidal silica having a controllable broad particle size distribution and a controllable minimum particle size is disclosed and claimed. Particles below a predetermined size are excluded from the product colloidal silica of the invention. A method for continuously producing the desired colloidal composition is disclosed comprising the steps of providing preformed silica particles having a surface area which controls the particle size of the colloidal silica product, adding a feed silica comprising an alkaline solution and silicate at a feed rate which is less than a nucleation rate.