1298 



Canadian Forestry Journal, September, 1917 



some industries a filter mass of sul- 

 phite pulp has been successfully used 

 in place of cotton fibre. 



Waste Liquors 



Waste sulphite liquor is one of the 

 most frequently quoted industrial 

 wastes, as millions of gallons are 

 turned into the rivers every day 

 carrying half of the original pulpwood 

 substance together with most of the 

 lime and sulphur used. Recovery 

 of by-products is difficult and costly 

 but it is safe to say that Canada will 

 begin to practice recovery in the near 

 future. In Europe and the United 

 States evaporated liquor is used quite 

 extensively as a binder for briquetting 

 fuel and as core binder in foundry 

 work. The tannin-like substances are 

 separated and incorporated with true 

 tannins in preparing sole leather. 

 Sweden has taken the lead in re- 

 covery of ethyl (grain) alcohol and 

 produced in 1916 over one-half milhon 

 Imperial gallons of 95 per cent 

 alcohol for industrial purposes, motor 

 fuel and potable spirits. It is re- 

 ported that Germany has estabhshed 

 this process in fourteen sulphite 

 plants in order to conserve potatoes 

 which are the usual source of alcohol 

 in that country. Waste sulphite 

 Hquor contains about 1.5 per cent 

 of fermentable sugars which are pro- 

 duced from the wood during the 

 cooking process and these sugars are 

 fermented to alcohol by yeast. The 

 direct recovery of sugars and other 

 organic matter makes available a 

 fairly good cattle food. Recent pro- 

 cesses aim at the precipitation of the 

 lignin content for use as fuel and a 

 number of new plants are going up in 

 Norway. A^linor processes are the 

 recovery of destructive distillation 

 products, fertilizer and mordants for 

 dyeing. There is also the possibihty 

 of recovering sulphur compounds 

 which however do not originate in 

 the wood. 



Twine From Paper 



The sulphate process used 13.1 per 

 cent of the Canadian pulpwood con- 

 sumption in 1915. This process is a 

 development of recent years and pro- 

 duces a remarkably strong flexible 

 fibre by the combined action of 



caustic soda and sodium sulphide on 

 the softwood chips. The value of 

 kraft ptilp is most noticeable in the 

 brown, strong, thin wrapping papers 

 which are now so widely used. A 

 variety of ingenious uses for this pulp 

 have been worked out in Europe and 

 elsewhere. Paper twine is made by 

 cutting kraft paper into narrow strips 

 and spinning into a coarse strand now 

 largely used for wrapping parcels and 

 for binder twine. The threads may 

 be assembled to produce first-class 

 rope. By weaving there is obtained 

 bagging material to replace burlap, 

 carpets and matting, coarse cloth for 

 upholstering furniture or even for 

 wearing apparel, and also belting 

 which is now used in Europe. By 

 wrapping layers of kraft paper on a 

 core and impregnating with tar binder 

 conduits are made which can be turn- 

 ed and threaded; these are especially 

 useful for underground electrical con- 

 duits and acid-resisting water pipes. 

 Kraft pulp is also used for making 

 imitation leather for suitcases, as 

 well as counters and heels for boots 

 and shoes. 



In Europe the sulphate process is 

 sometimes modified to give more fully 

 cooked sulphate pulp which can be 

 bleached and used for higher-grade 

 papers such as book and writing. 



Oils From Waste 



The spent liquor is always eva- 

 porated, incinerated and causticized 

 for the recovery of alkalise which are 

 used again for cooking. One Cana- 

 dian mill is now recovering so-called 

 "resin oil" w^hich separates from the 

 spent liquor. Turpentine and small 

 quantities of other light oils may be 

 recovered from resinous woods by 

 distilling with steam during the cook- 

 ing operation and resin soap separates 

 from the spent liquor on cooling. 

 This applies particularly to manu- 

 facture of kraft pulp from longleaf 

 pine in the Southern States. Methods 

 have been proposed for the produc- 

 tion of methyl alcohol, acetone, acetic 

 acid, higher oils by the destructive 

 distillation of the evaporated liquor 

 with simultaneous recovery of alkali 

 and perhaps oxalic acid from the 

 residue. 



