This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 Excerpt: ...system the waste lime sludge of the sulphate cellulose mills is employed. Schwalbe states that the neutralisation sludge obtained, after the process, contains sufficient calcium sulphite to effect a saving of 40 per cent, of the sulphur required for boiling wood. The volume of liquor to be treated amounts to 10,000 ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 Excerpt: ...system the waste lime sludge of the sulphate cellulose mills is employed. Schwalbe states that the neutralisation sludge obtained, after the process, contains sufficient calcium sulphite to effect a saving of 40 per cent, of the sulphur required for boiling wood. The volume of liquor to be treated amounts to 10,000 litres for every 100 tons of cellulose and the dry precipitate obtained on neutralising amounts to 15 tons. The liquid, after being neutralised, is cooled, aerated, then fermented for 72 hours at a temperature of 75 C, by means of yeast, and afterwards distilled. The alcohol obtained contains considerable proportions of methyl alcohol, aldehydes, furfural and acetone. It may be noted that this process, while interesting as showing the possibility of obtaining useful products from the waste liquor, does not deal with the serious problem of the prevention of pollution of streams by the discharge of the waste liquor. The direct recovery of the original sulphur has not yet been evolved as a satisfactory process. Evaporation and combustion of the concentrated lye means a large loss of sulphur, and a method for the regeneration of the latter from organic sulphur compounds has yet to be discovered. Obviously this is the correct solution of a difficult problem, W.P. K as it might avoid the formation of a large quantity of by-products which find no useful application in papermaking or any industrial operations. Washing and Finishing.--The pulp discharged from the digestor is thoroughly washed with water for the removal of the spent liquor, and then subjected to a careful screening in order to remove incompletely digested pieces of wood and any dirt which may be present. This is effected by screens of various kinds, all based upon the same principle, thoug...
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