﻿98 RICHMOND. 



The calculations for the production of 1 ton (2,000 pounds) of soda 

 pulp are based on the use of caustic soda made from imported soda ash 

 and native lime. They are as follows : 



7,560 liters (2,000 gallons) of caustic liquor of a specific gravity of 1.06 

 (8° Baume, 5.25 per cent of caustic soda) contains approximately 400 kilograms 

 (880 pounds) of alkali, which in turn requires for its manufacture: 



300 kilos (660 pounds) lime, at 0.22 cent per kilo (0.5 cent 



per pound ) _ $3.30 



534 kilos (1,176 pounds) soda ash, at 0.4 cent per kilo (1 cent 



per pound) 11.76 



15.06 

 75 per cent of soda ash recovered as such, 400 kilos (882 



pounds), at 0.4 cent per kilo (1 cent per pound) 8.82 



6.24 



While the above estimates are but rough approximations, they are 

 to be considered as fairly conservative and they • serve to indicate the 

 cost of the crude chemicals actually consumed in the production of one 

 ton of sulphite and soda pulp respectively. It will be noted that 

 estimates for the sulphite liquor call for a consumption of 8,399 liters 

 (2,222 gallons) for 2 cords of chips. In our sulphite digestions we were 

 able to cover 4.54 kilos (10 pounds) of well-packed chips, previously 

 steamed, with 18.90 liters (5 gallons) of liquor; this is equivalent to the 

 above volume for 2 cords of the wood. However, in practice 9,450 liters 

 (2,500 gallons) of liquor are usually employed. The sulphite liquor in 

 the estimate and the one which was found to produce the best results in 

 our experiments had the following composition: 



Per cent. 

 Total sulphurous acid 3.5 



Sulphurous acid combined, bisulphite of calcium 2.28 



Sulphurous acid free (in excess of the amount necessary to 



form calcium bisulphite 1.22 



Lime 1.00 



In Germany, all acid in excess of that which is necessary to form the 

 monosulphite of calcium (CaS0 3 ) is termed free acid; hence according to 

 the German system of nomenclature, the above liquor would contain : 



Per cent. 



Combined acid 1.14 



Free or available acid 2.36 



Total acid 3.50 



