Mr. J. Napier on Copper Smelting. 271 



Our remarks apply particularly to fusing-furnaces. There 

 are other furnaces for calcination where a lower heat is required, 

 and where currents of air are admitted to the chamber otherwise 

 than through the fire, producing actions and reactions within 

 the chamber differing from those in the fusing-furuace, which 

 will be noticed when describing the process of calcination ; but 

 the fuel and the principles of fij-ing are the same, except that 

 the weakest free burning coal may be used. For refining the 

 metals generally, the best coal alone is used, and that known to 

 contain no sulphur. 



A fusing-furuace in constant work and of the ordinary size, 

 consumes about three tons of fuel in twenty-four hours, but the 

 consumption of fuel varies with the size of the furnaces j a fair 

 average may be given at two tons of coal for five tons of stuff 

 melted. 



Patent fuel, which is culm or small coal mixed with pitch or 

 tar and made into a cake by pressure, then baked at a high heat, 

 has been tried, but does not compete either in price or quality 

 \Tith coal in this country j but not being subject to deteriora- 

 tion in a ship's hold, it is found to come into competition with 

 coal exported from this country. 



Many trials have been made both at home and abroad with 

 a mixture of coal and wood, but they have not proved favour- 

 able to its use. Coal and wood, and patent fuel and wood, 

 have been extensively tried abroad against coal alone and patent 

 fuel alone, in their effective powers for fusing in reverberatory 

 furnaces, but both coal and patent fuel alone are far superior to 

 any of them mixed with wood ; of course the oeconomy of one 

 over the other is a question depending upon the locality and the 

 price of each of the materials ; we speak only of their effects in 

 smelting by reverberatoi-y furnaces. In smelting copper by 

 blast or cupola furnaces, such fuels as anthracite, charcoal, 

 ice, which cannot be used for the reverberatory furnace, are best. 

 Cop])or smelting has been carried ou in Australia these few years 

 by blast furnaces, using for fuel a mixture of coal and charcoal. 

 In Austria, Hungaiy, and several other parts of the Continent, 

 all the copper is made by means of blast-furnaces, the fuel being 

 charcoal : these operations, and the kind of furnaces used, will 

 be considered in their proper place. 



In some jiarts smelting operations are carried on by means of 

 peat-charcoal ; a fuel, we think, well suited for this purpose 

 when accom])ani(;d by l)last. With such a field as Ireland, with 

 plenty of copper ore and peat within herself, the operations of 

 Hmelting could be done easily and profitably. Irish ores are 

 well fitted to be treated by the blast, and they give a superior 

 quality of copper. 



[To be continued.] 



