MANUFACTURE OF CARBIDE OF CALCIUM. 137 



showecl that 5,000 to 6,000 tons of saleable carbide could be made at 

 a cost of under £8 per ton for an initial expenditure of about .£25,000. 

 Expenditure included step down, transformer, switch gear, furnace, 

 grinding plant, <kc. 



Output. 

 The Electro Chemist for 1901 gave tlie production of carbide per 

 electrical horse-power day as : — 



7'4: lb. in a continuous furnace. 

 lO'O lb. in intermittent furnace. 

 10'2 lb. in Gin and Lelense furnace. 

 9'5 to 10"7 lb. in Deutsche G. and S. Anstalt furnace. 

 A test by C. F. Curtis at the Union Carbide Company plant at 

 Niagara Falls gave 9 '85 lb. 



Now, 7' 4 lb. per day is equal to 1 ton per year of 300 working 

 days ; it will be perceived, therefore, that, allowing for all manufactur- 

 ing risks, a production of 1 ton of saleable carbide per electrical 

 horse-power year is a certainty. With good management and first 

 quality lime and coke, there should be a production of 1^ ton when 

 tlie factory has got into working order. 



Materials. 



As the anthracite in Australia contains a good deal of ash, it 

 cannot be used for making carbide. Fortunately, however, a number 

 of coke ovens have been built lately in New South Wales, and a good 

 supply could be depended upon at a price not exceeding, say, 20s. per 

 ton delivered. 



It may be mentioned that several of the largest carbide works in 

 Europe depend on England for their supply of carbon : Thus the Alby 

 carbide works in Sweden use South Welsh anthracite at 21s. a ton 

 delivered, and the Meraker Works, sixty miles east of Trondheim, 

 buy English gas coke at 25s. a ton delivered. 



Regarding the lime there, large quantities are available within 

 easy reach of Cairns, and local coal for burning it could be obtained 

 at 15s. a ton. 



Professor P. A. Guye's Estimate of Cost per Ton of Carbide, 



without Packing. 



Frs. 



1,000 kilos of lime at 15 frs. per ton ... ... ... 15 



700 kilos of retort coke at 25 frs. per ton 17'50 



20 kilos of electrodes at 35 frs. per 100 kilos ... 7 

 Electric power (1 kilo year) at 50 frs., giving 2'1 



tons 23-80 



Small expenses, wages (8 frs.), mechanical power for ac- 



cessoiy work, transports, grinding (30 frs.) ... 38 



General expenses ... ... ... ... ... 22 



Depreciation at 8 per cent, on the plant, 75 frs. ... 6 



Interest on the capital at 5 percent, on 100 frs. invested 5 



13430 



Or £5 6s. 5d. per ton. 



