GB953778A - Production of non-dusting coal products - Google Patents

Abstract

Three examples are given of aqueous dispersions of polymers or copolymers that form tacky films in the region of 0 DEG C., on coal surfaces. In the first, (all parts by weight) 190 parts butyl acrylate and 10 parts vinyl isobutyl ether are emulsified in a solution of 8 parts of a sulphonated condensation product derived from 1 mole sperm oil alcohol and 15 moles ethylene oxide, in 200 parts water. 0.4 part potassium persulphate is added and the mixture polymerized. In the second, 180 parts ethylhexyl acrylate and 20 parts "Lorol" acrylate ("Lorol" is a trade name applied to mixtures of aliphatic alcohols obtained by high pressure hydrogenation of coconut oil) are emulsified in a solution of 7 parts of the sulphonated condensation product derived from 1 mole iso octyl phenol and 20 moles ethylene oxide in 200 parts water, 0.4 part potassium persulphate being added before polymerizing. In the third, 100 parts vinyl propionate and 100 parts vinyl octanoate are emulsified in an aqueous solution containing 8 parts of the sulphonated condensation product derived from 1 mole stearyl alcohol and 10 moles ethylene oxide, potassium persulphate being added and polymerization being carried out as above. Specification 842,672 is referred to.ALSO:Coal and coal products are made dustless or non-dusting by spraying them with an electrolyte-resistant, i.e. non-coagulating, aqueous dispersion of a polymer or copolymer that forms on the surface of the coal a coating that will remain soft and tacky at temperatures down to 0 DEG C. Polymers and copolymers made by the methods described in Specification 842,672 may be used, preferably those using oxyethylated and sulphonated alkyl phenols or fatty alcohols as dispersing agents. Glycols may be added for anti-freezing purposes. Polymers and copolymers mentioned are: acrylates of alcohols having at least four carbon atoms, e.g. straight-chained or branched butyl, hexyl, octyl, decyl, stearyl acrylate and corresponding methacrylates; vinyl esters of fatty acids having at least three carbon atoms, e.g. vinyl propionate, laurate, stearate; vinyl ethers of alcohols having up to eight carbon atoms, or butadiene or isoprene. Three specific examples are described giving parts by weight.ALSO:Coal and coal products are made dustless or non-dusting by spraying them with an electrolyte-resistant, i.e. non-coagulating, aqueous dispersion of a polymer or copolymer that forms on the surface of the coal a coating that will remain soft and tacky at temperatures down to 0 DEG C. Polymers and copolymers made by the methods described in Specification 842,672 may be used, preferably those using oxyethylated and sulphonated alkyl phenols or fatty alcohols as dispersing agents. Glycols may be added for anti-freezing purposes. Polymers and copolymers mentioned are: acrylates of alcohols having at least four carbon atoms, e.g. straightchained or branched butyl, hexyl, octyl, decyl, stearyl acrylate and corresponding methacrylates; vinyl esters of fatty acids having at least three carbon atoms, e.g. vinyl propionate, laurate, stearate, vinyl ethers of alcohols having up to eight carbon atoms, or butadiene or isoprene. Three specific examples are described giving parts by weight.