| abstract |
Methods of making microfibrillated cellulose and grinding media, granular ceramic grinding media. The method comprises: microfibrillating a fibrous matrix comprising cellulose by milling in the presence of a particulate grinding medium, the particulate grinding medium being removed after the grinding is complete, the particulate grinding medium having a specific gravity of at least 3.5, the particulate ceramic grinding medium Formed by sintering a composition comprising at least one of zirconia ZrO 2 and alumina Al 2 O 3 , at the beginning of grinding, the particulate grinding media has (i) a surface roughness of at least 0.5 μm, or (ii) at least 0.10 The average coefficient of friction of, or both (i) and (ii), the particulate ceramic grinding media is roughened during grinding such that after grinding is complete, the surface roughness is greater than the surface roughness at the beginning of grinding, and/or the average friction The coefficient is greater than the average coefficient of friction at the beginning of grinding, the surface roughness increases by at least 5% during grinding, and/or the average coefficient of friction increases by at least 5% during grinding. |