40 BULLETIN 80, U. S. DEPARTMENT OF AGRICULTURE. 



(11) Aspen may be successfully cooked with a minimum of from 

 20 to 25 pounds of caustic soda charged per 100 pounds of wood. 

 The amount of this chemical actually consumed in the production 

 of well-cooked bleaching pulps varies from 18 to 24 pounds per 100 

 pounds of wood. 



PRACTICAL VALUE OF RESULTS. 



The experiments discussed in this bulletin have shown in detail 

 the effects of certain cooking conditions on the yields and properties 

 of the resultant pulp, on the efficiency of the cooking chemicals, and 

 on various items affecting costs of production. From a study of 

 these results it should be possible for a mill operator so to regulate 

 the cooking process as to secure the largest possible yield of pulp of 

 the desired quality at a minimum cost for chemicals, fuel, labor, and 

 overhead charges hi so far as the operation is affected by the cooking 

 conditions considered. 



The clear, sound wood used in the experiments afforded yields of 

 good pulp from 10 to 25 per cent higher than the better run of the 

 yields reported by pulp mills. Moreover, some of these experimental 

 yields were obtained with shorter cooking periods and less chemicals 

 than are employed commercially. Although the laboratory results 

 may not be equaled in mill practice, the possibility of greatly 

 increased efficiency in the process of converting wood into soda pulp 

 is indicated. 



