654 



GEOLOGY AND MINING INDUSTRY OF LEADYILLE. 



constitute the slag, containing about ii per cent, of lead, or 15 pounds, and the loss in 

 fumes is equal to about four pounds of lead per charge. Each charge gives about 5.07 

 parts of slag for one [)art of bullion. The furnaces run about two hundred charges in 

 24 hours, yielding: Bullion, IG tons; slag, SO tons; and consuming: Eich ores, 63^ 

 tons ; fuel, 20 tons ; charges, 143 tons. 



Smelter D. 

 SmeUiny charr/cs made in August, 1880. 



Charge (ore and flux), 1,030 pounds. Smelting charge (ore, flux, and fuel). 1,190 pounds. 



In the preceding smelting charges the proportions are — 



Flux to ore 47 



Fuel to ore '22i 



Fuel to charge 1.5^ 



The composition of this smelting charge is a normal one. The composition of 

 the average smelting charge, calculated from the data given in Table IV, is the fol- 

 lowing: 



Ore. 700 pounds- 



Flux. 170.3 pounds. 



Fuel, 133.4 pounds 



Various ores 700 i Dolomite 41.65 ; Charcoal. 



I Hematite 48.65 ! Colie 



Old slags 80 



Charge (ore and flux), 870.3 pounds. Smelting charge (ore, flux, and fuel), 1,0 



In the average smelting charge the proportions are — 



i.7 pounds. 



Flux to ore 24^ 



Fuel to ore 19 



Fuel to charge \T^ 



The percentage of fuel is the smallest which has beeu yet observed, and this last 

 smelting charge would prove the most perfect if it were not for the important ele- 

 ment, time, which has been purposely neglected. The question will be discussed after 

 exhausting the composition of smelting charges of the various smelters, and it will 

 be seen whether it is advisable to aim at the lowest percentage of fuel in smelting 

 charges. 



Smklter e. 



Smelting charges made in Jtigiist, 1880. 



Charge (ore and flux). 330 pounds. Smelting charge (ore. flux and fuel), 433 pounds. 



