| 摘要 |
Classifying mineral material comprises: (a) providing at least one mineral material e.g. talc; (b) providing at least one additive for classifying, having (i) glycerol, (ii) glycerol with one/more of agents e.g. ethylene, or (iii) one/more poly-glycerols; (c) contacting, in one or more times, the material of step (a) with the additive in dry grinding and/or dry mixing step; (d) carrying out at least one classification of the material in a gaseous environment to obtain at least two different fractions of particles; and (e) optionally repeating the steps (c) and/or (d). Process for classifying mineral material, comprises (a) providing at least one mineral material comprising dolomite, talc, titanium dioxide, alumina, kaolin, and/or calcium carbonate; (b) providing at least one additive for classifying comprising (i) consisting of glycerol, in aqueous or pure form, (ii) consisting of glycerol with one or more of agents such as ethylene, glycol, mono-propylene glycol, triethylene glycol, an inorganic acid or salt of inorganic acid, formic acid or citric acid or a salt of formic acid or citric acid, organic polyacid or a salt of organic polyacid, alkanolamine, polyethyleneimine, polyalkylene glycol polymer having molecular weight of 200-20000 g/mole, preferably 600-6000 g/mole, a carbohydrate having a root mean square radius of gyration equal to or less than the modal radius of the mineral material, one or more poly-glycerols, where the agents are in aqueous or pure form, or (iii) comprising one or more poly-glycerols in the absence of glycerol; (c) contacting, in one or more times, the mineral material of step (a) with the additive for classification of step (b) in one or more dry grinding and/or dry mixing step; (d) carrying out at least one step of classification of the mineral material obtained from step (c) in a gaseous environment, to obtain at least two different fractions of particles of average particle sizes; and (e) optionally repeating the steps (c) and/or (d) all or part of the classified mineral material after step (d). An independent claim is included for a product obtained by the process. |
