Abstract: The invention relates to a method for preparing durable titanium dioxide particles. The preparation process includes an aqueous grinding step, which comprising providing an aqueous slurry or dispersion comprising titanium dioxide particles, aluminum containing compound and phosphorous containing compound into grinding equipment. The slurry or dispersion is subjected to an aqueous grinding process, and subsequently titanium dioxide particles having a core of titanium dioxide and a pre-coating layer thereon is obtained, said pre-coating layer containing aluminum and phosphorous containing compounds. The invention further covers the resulting titanium dioxide particles and uses thereof.

Abstract: A method for producing a low-structure magnesium silicate SLR product useful to lower the strike through of low brightness paper products comprises adding a raw mineral source of soluble magnesium ions and sulfuric acid in a proportion and under conditions effective to form a slurry comprising soluble magnesium sulfate and a silica leach residue (SLR), and adding to the slurry a solution of an alkali metal silicate in a molar equivalent proportion of MgO:SiO.sub.2 of 1:2.0-4.0 under conditions effective to precipitate the magnesium ions and form a product comprising a low-structure magnesium silicate and SLR having a proportion of SiO.sub.2 MgO:SLR of 50-75%:5-12%:10-50% by weight of the product.A low-structure magnesium silicate SLR filler comprises 50 to 75 wt % SiO.sub.2, 5 to 12 wt % MgO, 10 to 50 wt % SLR, 0 to 6 wt % Fe.sub.2 O.sub.3, and 0 to 7 wt % Al.sub.2 O.sub.3, wherein the proportion MgO:SiO.sub.2 is 1:2.0-4.0.A paper product comprises at least an amount of the filler of the invention.

Abstract: A method for producing a low-structure magnesium silicate SLR product useful to lower the strike through of low brightness paper products comprises adding a raw mineral source of soluble magnesium ions and sulfuric acid in a proportion and under conditions effective to form a slurry comprising soluble magnesium sulfate and a silica leach residue (SLR), and adding to the slurry a solution of an alkali metal silicate in a molar equivalent proportion of MgO:SiO.sub.2 of 1:2.0-4.0 under conditions effective to precipitate the magnesium ions and form a product comprising a low-structure magnesium silicate and SLR having a proportion of SiO.sub.2 :MgO:SLR of 50-75%:5-12%:10-50% by weight of the product.A low-structure magnesium silicate SLR filler comprises 50 to 75 wt % SiO.sub.2, 5 to 12 wt % MgO, 10 to 50 wt % SLR, 0 to 6 wt % Fe.sub.2 O.sub.3, and 0 to 7 wt % Al.sub.2 O.sub.3, wherein the proportion MgO:SiO.sub.2 is 1:2.0-4.0.A paper product comprises at least an amount of the filler of the invention.

Abstract: Low structure magnesium silicate pigment is useful as a low cost, low brightness filler for newsprint. The magnesium silicate is prepared by dissolving a serpentine mineral in sulfuric acid and reacting the resulting solution with an alkali metal silicate to precipitate a magnesium silicate pigment.