GB874686A - Process of protecting coal against deterioration - Google Patents

Abstract

Aqueous alkyd resin emulsions containing 1%-25% resin solids are used to coat lumps of coal or other solid fuel (see Group XII). Any alkyd resin emulsifiable in water may be used but p preferably there is employed an oil-in-water emulsion of a glyceride oil modified alkyd resin and an alkyd resin prepared from the adduct of a 2-4 carbon alkylene oxide with a polyhydric alcohol having at least 5 carbon atoms and at least 4 hydroxyl groups, a dibasic aliphatic acid and an unsaturated monobasic aliphatic acid. The two resin components are prepared separately and blended while warm, the mixture being poured into water and dispersed therein with e.g. alkaline dispersing agents such as the nitrogenous bases. The emulsion may initially be prepared with from 5%-60% of resin solids and preferably with 40%-50%. In one example each of the two following formulations is heated for about 2 hours at between 240 DEG and 250 DEG C. until the acid number is from 16 to 20 and then cooled to 150 DEG C. Formulation A: 148 parts by weight phthalic anhydride; 220 parts by weight distilled tall oil; 28 parts by weight ethylene glycol; 82 parts by weight pentaerythritol; Formulation B : 5 parts by weight fumaric acid; 33 parts by weight linseed oil fatty acids; 14 parts by weight gum rosin; 63 parts by weight condensate of 1 mol sorbitol with 30 mols ethylene oxide. Formulation B is added to Formulation A, mixed for 30 minutes and cooled to 130 DEG C. before being added over a 1 hour period to a 2% aqueous solution of morpholine at 95 DEG C. with agitation. This emulsion may be mixed with an equal amount of an emulsified petroleum hydrocarbon resin. Cobalt tallate may be added as a drier to either the original or mixed emulsion. In a further example 102 parts of a resin obtained from 148 parts by weight phthalic anhydride, 280 parts by weight linseed oil fatty acids and 95 parts by weight glycerine are emulsified in 122 parts by weight of water which contains 1 part by weight saponified rosin, 1 part sodium di-(methylamyl) sulfosuccinate and 4 parts by weight of the condensate of octyl phenol with ethylene oxide. This resin may also be emulsified in an aqueous solution containing 7,7% casein, 4,6% ammonia (28% NH4,OH) and 1,6% triethanolamine or in an aqueous solution containing 4% oleic acid and 4% morpholine. Alternatively the resin may first be dissolved in mineral spirits and emulsified in water containing di-(methylamyl) sulfosuccinate, saponified rosin and the condensate of 1 mol refined tall oil fatty acids with 15 mols of ethylene oxide. In the initial preparation of the resin a mixture of soya-oil fatty acids and tung oil may replace the linseed oil fatty acids. A resin prepared from litharge, soya bean oil, pentaerythritol and phthalic anhydride may also be emulsified by first being dissolved in mineral spirits and these added to water containing di-(methylamyl) sulfosuccinate and the saponified rosin and condensate referred to above.ALSO:Coal, peat and other solid fuels such as lignite, charcoal and briquettes are given a protective coating by spraying or dipping lumps of the fuel with or in an emulsion of an alkyd resin in water at the rate of from 1-50 pounds of resin solids per ton of fuel and drying the emulsion. Driers such as cobalt tallates or naphthenates may be incor+ porated in the emulsions and the fuels may be wetted before the treatment and the water used to wet the fuels may contain a wetting agent such as sodium dioctylsulfosuccinate and related compounds. When the emulsion is applied by spraying an emulsion containing between 2 and 25% resin solids is preferably used but when the fuel is dipped in the emulsion, the emulsion preferably contains 1 to 15% resin solids. Any alkyd resin emulsifiable in water may be used but preferably there is employed an oil-in-water emulsion of a glyceride oil modified alkyd resin and an alkyd resin prepared from the adduct of a 2 to 4 carbon alkylene oxide with a polyhydric alcohol having at least 5 carbon atoms and at least 4 hydroxyl groups, a dibasic aliphatic acid and an unsaturated monobasic aliphatic acid (see Group IV(a)).