| 摘要 |
1466284 Reducing the strength of ice DOW CHEMICAL CO 11 July 1974 [19 July 1973] 30763/74 Headings C5X and C5G The strength of ice is reduced by dissolving in water on the surface of particulate solids prior to freezing a composition comprising (A) a water-soluble polyhydroxy compound or monoalkyl ether thereof and (B) a watersoluble organic nonvolatile compound or polymeric material having at least one hydrophilic group, compound (B) being different from compound (A), and the composition being applied to the solids in an amount of at least 0À125 weight per cent of (A) plus (B) based on the surface moisture on the solids. Suitable compounds (A) are the polyhydroxyalkanes, e.g. ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerine and sugar and the monoalkyl ethers, e.g. the monobutyl ether of ethylene glycol. Suitable compounds (B) are pimaric acid, urea, glycolic acid, tetrasodium salt of ethylene diamine tetracetic acid, sodium acetate and acetic acid. Suitable polymeric materials (B) are polyacrylamide, polyvinyl pyrrolidone, polyethylene imine, polyacrylates, polyamide copolymers and natural gums, e.g. guar gum. The polyacrylamide may be at least 10% hydrolysed. The invention may be applied to coal so that, when frozen, the resulting mass is physically weak and not difficult to break apart before loading or unloading operations. In the examples, bulk coal and filter cake coal are treated. |
