THE MINING AND QUARRY INDUSTRY I906 35 



outlet of Lake Henderson. The tract lies without the limits of the 

 deposits that have been previously described. Though much of 

 the ore is mixed with rock there are large bodies of practically 

 solid magnetite of a quality not inferior to the Sanford ore. The 

 following is a record of one of the drill holes. 



Feet Inc hes 



Lean ore, consisting of disseminated magnetite with 



feldspar and pyroxene 19 •' 3 



Rich ore 30 6 



Rock and lean ore mixed 15 • • 



Rich ore 33 6 



Rock carrying some ore 11 r 



Lean ore 12 



Rock and lean ore 8 



Rich ore alternating with rock. 10 7 



Rock 5 



144 II 



The Cheney ore bed west of Lake Sanford and the several de- 

 posits between Lakes Sanford and Henderson are known to be 

 extensive. 



An interesting feature that has been brought out by recent ex- 

 perimentation with the ores is the possibility of reducing the titan- 

 ium by mill treatment. It has been established that in some cases 

 at least this element is not uniformly distributed in chemical com- 

 bination with the iron, as has been advanced by some writers. By 

 crushing the ore to fine size and passing over magnets, a process 

 like that used in the concentration of nontitaniferous magnetites, 

 it is found that a separation can be made into a strongly magnetic 

 portion and a residuum that is very weakly magnetic. The magnetic 

 material shows on analysis a smaller content of titanium than the 

 average of the ore used in the experiment, the content decreasing 

 with the fineness to which the ore has been crushed. The weakly 

 magnetic portion, which passes into the tailings, contains on the 

 other hand an increased proportion of this element. The experi- 

 ments seem to prove beyond all doubt that in such cases the ore 

 consists of a mechanical mixture of two minerals, one of which is 

 magnetite, with only a small amount of titanium, and the other a 

 titanium-bearing iron oxid that is probably ilmenite. With the 

 Sanford ore, it has been found that the titanium can be brought 

 down to a limit where the utilization of the concentrates in the blast 



