﻿PHILIPPINE FIBERS. 97 



actual practice — was followed, but repeated trials on wood in various 

 states of subdivision conclusively showed that it was possible to produce 

 an equivalent yield with a considerably weaker liquor in the same 

 time, by doubling the number of chips per given weight. While there 

 undoubtedly is a minimum limit beyond which wood could not safely be 

 divided without impairing the length and strength of the fibers, that 

 limit is by no means reached in present practice. Even the passing of 

 the green, chipped wood under heavy crushing rollers, a procedure 

 worked in some sulphite mills, is a very efficient means of mechanical 

 disintegration. 



The method of preparing wood for sulphite digestion and the im- 

 provements in the operation itself have resulted in a great saving of the 

 time required for the digestions. It was usual, when the process was 

 first applied, to boil the pulp for twenty hours or more, but now fourteen 

 to sixteen hours, dependent upon the kind of wood and the quality of the 

 pulp desired, is the more common practice. 



Much has been written regarding the relative cost of the two processes 

 of manufacture under discussion. Many factors enter into a calculation 

 of the comparative cost of producing soda and sulphite cellulose. How- 

 ever, the problem is an important one in the event of the introduction of 

 the industry in a new country and therefore it deserves some considera- 

 tion. Leaving out the initial expense of installation, which is un- 

 doubtedly greater for a sulphite than for a soda plant, it is proposed 

 briefly to discuss the relative cost of producing a ton of sulphite and soda 

 pulp from white lauan or mayapis wood, the local market quotations on 

 the chemicals required alone being considered. 



Calculations for the production of 1 ton of sulphite pulp, based on 

 the use of a straight bisulphite of calcium liquor of 3.5 per cent total 

 sulphurous acid content and 1 per cent of lime, Japanese sulphur and 

 native lime being used, are as follows : 



Fifteen per cent of sulphur recovered; 2 cords of wood give 1 ton (2,000 pounds) 

 of pulp; 8,399.16 liters (2,222 gallons) of liquor contain 295.3 kilograms (650 

 pounds) sulphurous acid, or 155.4 kilograms (341.88 pounds) of sulphur." 



Sulphur is calculated at 2.75 cents per kilogram (1.25 cents 



per pound ) $4.27 



And 84.08 kilograms (185 pounds) lime, at 1.1 cents per 



kilogram (0.5 cent per pound) _ 92 



5.19 

 15 per cent of sulphur recovered — that is, 23.33 kilos (51i 



pounds) — at 2.75 cents per kilo (1.25 cents per pound) 64 



4.55 



"Ninety-five per cent of the sulphur burned being rendered available in the 

 form of sulphur dioxide. 

 54329 2 



