A Decennial Recokd 147 



magazine sheet. This has been done witliout undue cost or sacrifice 

 in yields. 



One of the questions which is very frequently the subject of 

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

 vantages of diffusers and pans. This problem, 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 

 always been of great importance, and any means which 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 suljDhate process offers a 

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

 that valuable j^roducts 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 wliich, however, are offset liy 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. While the conditions 

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

 inconceivable tliat by intensive study a solution for this problem can 

 be found. 



Woods which are pulped by 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, 

 Tliis 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 wliere a successful 

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

 necessary to experiment witli ne^v deposits is practically prohibitive 

 unless the investigations can be first carried out upon a laboratory 



