42 



HATCH : THE KOLAR GOLD-FIELD. 



In the other mines where sorting is carried on, e.g., Champion 

 Reef, Ooregum, Nundydroog and Balaghat, the ore is picked over 

 on floors situated in the immediate vicinity of the mills. 



In connection with the new mill now being erected at the Cham- 

 pion Reef Mine, it is proposed to locate sorting floors and rock- 

 breakers between the mill and the New Vertical shaft, where the 

 bulk of the ore will be hoisted. Two circular sorting tables will be 

 used, each having a diameter of 25 feet, with the waste-bin in the 

 centre. The sorted ore will be delivered to two Blake-Marsden rock- 

 breakers (see PI. 6). A similar arrangement is in contemplation at 

 the Ooregum Mine. The amount of waste sorted out at two of the 

 leading mines during a year's work is as follows :— 



Name of Mine. 



Ore hoisted. 



Quantity 



delivered at 



the mill. 



Waste 



rock sorted 



out. 



Percentage 



of waste 



sorted. 





Tons. 



Tons. 



Tons. 



Per cent. 



Mysore . . 



ioo,973 



93.757 



7,216 



7 



Ooregum 



71,486 



64,107 



7*379 



10 



At the Champion Reef Mine about 10 per cent, of waste is 

 rejected. 



Since in most of the mines the vein is in many places made up 

 of small seams of quartz intermixed with country rock, the whole of 

 which has to be broken down in stoping, it is evident that by the 

 adoption of efficient sorting appliances to eliminate the waste rock 

 the grade of the ore sent to the mill could be raised, or, in other 

 words, a larger quantity of gold could be recovered for the same 

 expenditure of money. Sorting after breaking as well as before 

 would probably be found profitable on account of the close admixture 

 of pay-ore with valueless country rock. 



