Patent ID: 8916121

Claim:
A process for the treatment of talc, the process comprising the steps of: (a) forming a suspension of a talc in a liquid phase, the liquid phase of the suspension comprising hexane, octane, or a mixture thereof, wherein the talc: (i) has a purity of 98 wt % or less and a specific surface area ranging from about 2 to about 12 m 2 /g, measured by the BET method according to ISO 9277 using nitrogen; (ii) has an initial weight median particle size (d 50 ), measured by laser diffraction/scattering particle size analysis according to the Malvern method, ranging from about 15 to about 40 μm; (iii) has a first brightness value B1 of 80% or less, measured according to ISO 2469; and (iv) includes impurities selected from the group consisting of iron sulphide, carbon, or any mixture thereof, and (b) increasing the specific surface area of the talc by about 100% to about 500% relative to the specific surface area of the talc provided in step (a) in the liquid phase to produce a treated talc, and decreasing the d 50 of the talc into the range of about 7 to about 30 μm, wherein the treated talc has a brightness value B2, measured according to ISO 2469, and B2 is greater than B1 by at least 0.3%.