CRANE. | 7 Concentration. 329 
15. Harz jig (five sieves), 10 to 12 mesh to the inch; yields, first, discharge 
blende to 17, hutch galena to 16; second, discharge blende to 17, 
hutch blende to 17; third, discharge blende to 17, hutch blende to 
17; fourth, discharge blende to 17, hutch blende to 17; fifth, dis- 
charge blende to 17, hutch blende to 17, waste to 21. 
16. Galena to bin. 
17. Blende to bin. 
18. Spitz kasten; yields spigot to 13, discharge to 14. 
19. Spitz kasten; yields spigot to 14, discharge to 20. 
20. Settling pond; water to 22. 
21. Dump. 
22. Mill-water pond. 
Class II. 
An outline of the system of concentration of lead and zinc 
ores as employed in the Commercial mill on the Apple Jack 
ground, in the Galena portion of the district, will serve to 
illustrate the second class. This mill is a two-story or ‘‘ gray- 
ity’’ mill, which is a radical departure from the usual plan 
of mill construction. Here two rougher jigs occupy the 
second floor, while the cleaners are placed on the first floor. 
The idea of the arrangement is to prevent reelevating a large 
amount of the material treated; yet it either requires two 
jig men, one for each floor, or means that one must be pass- 
ing between the two floors. The former arrangement is ex- 
pensive, while the latter is, to say the least, hard on the jig 
man. 
Ore hoisted to 1. 
Crusher room; ore to 2. 
. Grizzly, 14 inch spaces; yields oversize to 3, undersize to 4. 
Blake crusher, reducing to ? inch; ore to 5. 
Rolls No. 2; ore by elevator to 6. 
Rolls No. 1; ore by elevator to 6. 
Trommel, 2-inch holes; yields oversize to 7, undersize to 8. 
Rolls No. 3; ore by elevator to 6. 
Two Harz jigs (six sieves) 4-inch spaces; yields, first, discharge ga- 
lena to 18, hutch to 10; second, discharge middlings to 9, hutch to 
10; third, discharge middlings to 9, hutch to 10; fourth, discharge 
middlings to 9, hutch to 7; fifth, discharge middlings to 9, hutch 
to 10; sixth, discharge middlings to 9, hutch to 10, tailings to 15. 
9. Rolls No. 4; ore by elevator to 6. 
10. Two Harz jigs (five sieves), 5 mesh to inch; yields, first, discharge 
blende to 14, hutch galena to 13; second, discharge blende to 14; 
hutch blende to 14; third, discharge blende to 14, hutch blende to 
to 14; fourth, discharge blende to 14, hutch blende to 14; fifth, 
discharge product to 11, hutch product to 11, tailings to 15. 
11. Spitz kasten; yields spigots, 1st, 2d, 3d, and 4th, to 12. 
GO SS) SIN Le 29 i be 
