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Improvements in the purification of 1, 1, 1-trichloro-2, 2-bis(4-chlorophenyl) ethane
Improvements in the purification of 1, 1, 1-trichloro-2, 2-bis(4-chlorophenyl) ethane
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机译:1,1,1,1-三氯-2,2-双(4-氯苯基)乙烷的提纯改进
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摘要
Dichlorodiphenyltrichloroethane - (1 : 1 : 1-trichloro - 2 : 2 - bis - (4 - chlorophenyl) ethane) is purified by subjecting it to centrifugal force of not less than 10 G. while heating to a temperature not exceeding the melting-point of the pure product by means of a hot fluid, so as to cause separation of liquid materials from the solid. Heating may be by various methods, with the material in any form containing impurities. In examples DDT flake of 66 per cent para-isomer is subjected to centrifugal force of 990 X gravity, while being heated with boiling water, to give a solid residue containing 92 per cent p-p1-isomer; granulated DDT is centrifuged with water up to 62 DEG C. after separating, with water up to 80 DEG C. and steam, to give a product of 95 per cent purity; fused DDT of 74 per cent para isomer, powdered, is centrifuged with water up to 70 DEG C. to give 88 per cent pure product; a hot solution of sodium sulphate or other salt may also be used for washing and the process may be performed continuously.
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