A Decennial Record 147 



magazine sheet. This has been done without undue cost or sacrifice 

 in yields. 



One of the questions which is very frequently the subject of 

 conversation when sulphate mill men get together is the relative ad- 

 vantages of diff users and pans. This 2:)roblem, however, can only be 

 successfully attacked upon the mill scale, and the same applies to a 

 study of the cause of corrosion of diffusers. 



The successful recovery of chemicals from the waste liquor has 

 ahvays been of great importance, and any means wliich can be devised 

 to raise the percentage of recovered chemicals would immediately be 

 reflected in a decreasing cost for manufacture. Here again but little 

 can be done upon a small scale. 



Paralleling the recovery of by-products from sulphite liquors, 

 distillation of those obtained in the soda or sulphate process offers a 

 means of more fully utilizing the present waste. It is definitely known 

 that valuable products exist in the black liquors, but their recovery 

 upon a commercial scale is not yet a complete success. 



Salt cake has been universally used in the sulphate process to 

 make up the chemical losses, but the use of niter cake offers certain 

 advantages which, however, are offset by a few serious drawbacks. 

 If opportunity could be given for a thorough investigation into the use 

 of niter cake, this problem might be solved. 



A constant source of trouble in the sulphate mill is found in the 

 refractory material used in lining the smelters. Wliile the conditions 

 existing in a sulphate smelter doubtless offer great difficulty, it is not 

 inconceivable that by intensive study a solution for this problem can 

 be found. 



AVoods which are pulped b}- the alkali process lend themselves 

 very readily to recovery of various products prior to pulping. So far, 

 however, tannin is the only product which is now recovered on a com- 

 mercial scale, but the high rosin and turpentine content of the southern 

 pines suggest that before long these materials will also be recovered. 

 This problem can be very successfully attacked upon a laboratory 

 scale and has already been too long delayed. 



There are but few quarries in this country where a successful 

 grade of stone for pulp grinders is found, and the cost of the work 

 necessary to experiment with new deposits is practically prohibitive 

 unless the investigations can be first carried out upon a laboratory 



