48 The ratio and Cazo Process. 



General Expenses. 



Salaries, - 



Rent, - 



Repairs and miscellaneous, 



Total cost of working per ton 



Cost of grinding one ton of ore, 



Cost per ton of working 10 quintals in 30 arrastras, 



" " " Patio working, - ' 



" " " settlers and distilling, 



" " " salaries, rent, repairs, &c, 



0.713 





0.274 • 





0.384 





11.371 





_ 



- $0,570 





3.112 





- 3.380 





0.565 





- 1.371 



$8,998 



This estimate takes no account of the mercury lost, estimating 

 this at about $7.00. This would make a cost of $16.00, a much 

 lower figure than that given by other authorities. Mr. Chism 

 gives as the cost of working a $60 ore in ten ton tortas as fol- 

 lows:* 



Cost per Ton of 2,000 lbs. 

 Breaking per ton, f - - - $1.53 



Grinding, ------ 1 40 



Scraping arrastra to get out the gold amalgam, - - .13 



Carriage of slimes from arrastra to patio, - .60 



Mules hired, - - - 1.73 



Labor, including driving and tending mules, spading and washing 



torta, ----- 1.80 



Salt at 6 Mexican dollars per carga of 98.3 litres, - - - 2.80 



Sulphate of copper at SO. 25 (Mex.) per pound, - - 1.33 



Charcoal for retorting and assaying at $0.37 \ (Mex.) per arroba, - .33 



Quicksilver at $0.62^ (Mex.) per lb., '- - - 4.68 



Salaries, general expenses, including keeping and feeding of mules, 6.66 

 Repairs, ------ 2.33 



Concentration of sulphurets, - - - - - 2.26 



Total, - $27.58 



The expense of working with tortas of this size is much greater 

 than if the pile were more than twice as large. When the tortas 

 were of 19 tons and all the machines were driven by water 

 power, the expense was as follows: 



* Trans. Am. Inst. Min. Eng., Vol. 11. 



f Breaking a ton of large ore costs $2.66, but as the smalls are also 

 worked the average cost is as stated. 



