Use of formulations containing glycerol as a dry grinding aid agent of mineral matter

Abstract

The invention consists in the use, as a dry grinding aid agent of a mineral matter chosen from among the dolomites, talc, titanium dioxide, alumina, kaolin and calcium carbonate, the function of which is to reduce the specific grinding energy and to increase the grinding capacity, of formulations containing glycerol.

1 - A dry grinding aid agent comprising:
 (i) glycerol, in an aqueous or pure form, or   (ii) glycerol with one or more of the following agents: ethylene glycol, monopropylene glycol, triethylene glycol, an inorganic acid or an inorganic acid salt, formic or citric acid or a formic or citric acid salt, an organic polyacid or an organic polyacid salt, an alcanolamine, a poly(ethylene imine), a polyalkylene glycol polymer of molecular mass by weight of between 200 g/mole and 20,000 g/mole, preferentially between 600 g/mole and 6,000 g/mole, a carbohydrate having a root mean square of the radius of gyration equal to or less than the modal radius of the mineral matter, one or more polyglycerols, where the said agent or agents are in the aqueous or pure form, or   (iii) one or more polyglycerols in aqueous or pure form.   
     
     
         2 - The dry grinding aid agent according to  claim 1 , wherein the Gardner colour index of the dry grinding aid agent has a value of less than 3 measured according to the Gardner DIN 1804630/ASTM D 1544 68 method, expressed in a scale from 1 (colourless) to 20 (very dark brown). 
     
     
         3 - The dry grinding aid agent according to  claim 1 , consisting of glycerol in a pure form. 
     
     
         4 - The dry grinding aid agent according to  claim 1 , consisting of glycerol in an aqueous form. 
     
     
         5 - The dry grinding aid agent according to  claim 4 , consisting of 25% to 95%, by weight of glycerol relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         6 - The dry grinding aid agent according to  claim 1 , consisting of glycerol with one or more of said agents, in an aqueous or pure form. 
     
     
         7 - The dry grinding aid agent according to  claim 6 , wherein said agent is an inorganic acid and said inorganic acid is a phosphoric acid. 
     
     
         8 - The dry grinding aid agent according to  claim 6 , wherein said agent is an inorganic salt and said inorganic salt is a mono-, di- or tri-alkaline salt. 
     
     
         9 - The dry grinding aid agent according to  claim 6 , wherein said agent is a salt of formic or citric acid and said salt of formic or citric acid is a mono-, di- or tri-alkaline salt. 
     
     
         10 - The dry grinding aid agent according to  claim 6 , wherein said agent is an organic polyacid and said organic polyacid has the formula COOH—(CH 2 ) n —COON, in which n is an integer having a value of between 0 and 7, inclusive, or is a mono- or di-alkaline salt of the organic polyacid of formula COOH—(CH 2 )n-COOH, in which n is equal to an integer having a value of between 0 and 7 inclusive, or is a polymeric organic polyacid of one or more of the following monomers, in the acid form, or in the form which is partially or fully neutralised with one or more cations of Group I or II of the Periodic Table of the Elements, acrylic, methacrylic, maleic or itaconic, or is an oxalic acid, a pimelic acid or an adipic acid. 
     
     
         11 - dry grinding aid agent according to  claim 6 , wherein said agent is alcanolamine and said alcanolamine is selected from the group consisting of 2-amino-2-methyl-1-propanol, 2-amino-2-ethyl-1,3-propanediol, tri-ethanolamine, N-butyldiethanolamine and tri-iso-propanolamine, which are optionally neutralised by a formic or citric acid salt, or of an organic polyacid salt. 
     
     
         12 - The dry grinding aid agent according to  claim 6 , wherein said agent is a polyalkylene glycol polymer and said polyalkylene glycol polymer is a polyethylene glycol, a polypropylene glycol, or an ethylene-propylene glycol copolymer, in random or block form. 
     
     
         13 - The dry grinding aid agent according to  claim 6 , wherein said agent is a carbohydrate having a root mean square of the radius of gyration of the said carbohydrate equal to or less than the modal radius of the mineral matter, and said carbohydrate having a root mean square of the radius of gyration of the said carbohydrate equal to or less than the modal radius of the mineral matter is glucose, fructose, sucrose, starch or cellulose. 
     
     
         14 - The dry grinding aid agent according to  claim 6 , wherein said agent is at least one polyglycerol, and the polyglycerol is selected from the group consisting of di-glycerol, tri-glycerol, tetra-glycerol, penta-glycerol, hexa-glycerol, hepta-glycerol, octa-glycerol, nona-glycerol and deca-glycerol and mixtures thereof. 
     
     
         15 - The dry grinding aid agent according to  claim 6 , consisting of 20% to 95% by weight of glycerol, 1% to 50% by weight of the said agent and 0% to 65% by weight of water, relative to their total weight, where the sum of the percentages by weight of glycerol, of the said agent and of water are, in each case, equal to 100%. 
     
     
         16 - The dry grinding aid agent according to  claim 1 , consisting of one or more polyglycerols in a pure form. 
     
     
         17 - The dry grinding aid agent according to  claim 16 , wherein said polyglycerol or polyglycerols are selected from the group consisting of di-glycerol, tri-glycerol, tetra-glycerol, penta-glycerol, hexa-glycerol, hepta-glycerol, octa-glycerol, nona-glycerol and deca-glycerol and mixtures thereof. 
     
     
         18 - The dry grinding aid agent according to  claim 1 , consisting of one or more polyglycerols in an aqueous form. 
     
     
         19 - The dry grinding aid agent according to  claim 18 , consisting of 25% to 95% by weight of polyglycerols relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         20 - The dry grinding aid agent according to  claim 18 , wherein said polyglycerol or polyglycerols are selected from the group consisting of di-glycerol, tri-glycerol, tetra-glycerol, penta-glycerol, hexa-glycerol, hepta-glycerol, octa-glycerol, nona-glycerol and deca-glycerol and mixtures thereof. 
     
     
         21 - The dry grinding aid agent according to  claim 4 , consisting of 45% to 90%, by weight of glycerol relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         22 - The dry grinding aid agent according to  claim 4 , consisting of 75% to 85%, by weight of glycerol relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         23 - The dry grinding aid agent according to  claim 6 , wherein said agent is an inorganic salt and said inorganic salt is a salt of a cation of Group I or II of the Periodic Table of the Elements. 
     
     
         24 - The dry grinding aid agent according to  claim 6 , wherein said agent is a salt of formic or citric acid and said salt of formic or citric acid is a salt of a cation of Group I or II of the Periodic Table of the Elements. 
     
     
         25 - The dry grinding aid agent according to  claim 6 , wherein said agent is at least one polyglycerol, and the polyglycerol is a di-glycerol or a tri-glycerol. 
     
     
         26 - The dry grinding aid agent according to  claim 6 , consisting of 30% to 90% by weight of glycerol, 10% to 45% by weight of the said agent and 0% to 60% by weight of water, relative to their total weight, where the sum of the percentages by weight of glycerol, of the said agent and of water are, in each case, equal to 100%. 
     
     
         27 - The dry grinding aid agent according to  claim 6 , consisting of 35% to 75% by weight of glycerol, 30% to 40% by weight of the said agent and 5% to 50% by weight of water, relative to their total weight, where the sum of the percentages by weight of glycerol, of the said agent and of water are, in each case, equal to 100% 
     
     
         28 - The dry grinding aid agent according to  claim 18 , consisting of 45% to 90% by weight of polyglycerols relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         29 - The dry grinding aid agent according to  claim 18 , consisting of 75% to 85% by weight of polyglycerols relative to the total weight of the dry grinding aid agent, the remainder consisting of water. 
     
     
         30 - A process of dry grinding mineral matter, comprising
 dry grinding a mineral matter in the presence of a dry grinding aid agent, wherein said dry grinding agent comprises:   (i) glycerol, in an aqueous or pure form, or   (ii) glycerol with one or more of the following agents: ethylene glycol, monopropylene glycol, triethylene glycol, an inorganic acid or an inorganic acid salt, formic or citric acid or a formic or citric acid salt, an organic polyacid or an organic polyacid salt, an alcanolamine, a poly(ethylene imine), a polyalkylene glycol polymer of molecular mass by weight of between 200 g/mole and 20,000 g/mole, preferentially between 600 g/mole and 6,000 g/mole, a carbohydrate having a root mean square of the radius of gyration equal to or less than the modal radius of the mineral matter, one or more polyglycerols, where the said agent or agents are in the aqueous or pure form, or   (iii) one or more polyglycerols in aqueous or pure form, and   the mineral matter is selected from the group consisting of a dolomite, talc, titanium dioxide, alumina, kaolin and calcium carbonate.   
     
     
         31 - The process of dry grinding mineral matter according to  claim 30 , wherein said dry grinding agent comprises 100 to 5,000 ppm, of glycerol or polyglycerol, relative to the dry weight of the said mineral matter. 
     
     
         32 - The process of dry grinding mineral matter according to  claim 30 , wherein said dry grinding agent comprises between 0.1 and 1 mg, total dry equivalent, of said glycerol or said polyglycerol and every possible agent for each m 2  of mineral matter. 
     
     
         33 - The process of dry grinding mineral matter according to  claim 30 , wherein said mineral matter is ground to an average diameter, measured by a Sedigraph™ 5100, of between 0.5 and 10 μm 
     
     
         34 - The process of dry grinding mineral matter according to  claim 30 , wherein said mineral matter is ground to average diameter, measured by a Sedigraph™ 5100, of between 1 μm and 5 μm. 
     
     
         35 - The process of dry grinding mineral matter according to  claim 30 , wherein said mineral matter is ground until a percentage by weight of particles having a diameter of less than 2 μm, measured by a Sedigraph™ 5100, of between 20% and 90% is obtained. 
     
     
         36 - The process of dry grinding mineral matter according to  claim 30 , wherein said mineral matter is a natural calcium carbonate.