2AG FANNING AND EDDINGFIELD. 
this particular lot, and can not be expected necessarily to apply 
to other lots, and the design of a plant to treat such ore by cyani- 
dation should undoubtedly be arranged to permit amalgamation 
after tube-milling. Such a system would greatly decrease the 
time necessary for the high extraction and lead to a much lower 
consumption of cyanide. However, this would be counter- 
balanced somewhat by the extra cost and difficulties of amal- 
gamation. 
Cyanidation tests on lot No. 2.—A series of tests were then 
made upon lot 2 in order to confirm the results obtained in 
cyaniding samples of lot 1. In this new series of tests a 
sample was crushed through 60-mesh, amalgamated,.and the 
tailings cyanided. Another sample was crushed through 100- 
mesh, amalgamated, and the tailings cyanided. Still another 
sample was tube-milled for six hours and cyanided direct. 
TABLE XXVIII.—Cyanidation tests. Lot No. 2.* 
. mies > Ios tp S ee 
a |28 | 22/98 | os] ¢ |G | 8 | 88 
3. (58 2123 |e5|2/4./3 | 28 
“Sige | 28/82 Jec| 8 | 38/83] ss 
wP x ie} - =| = :| §s g °.8 me Se 
: Product. 2 On | HS oS (HSE! 2S) 8 | eel] uno}] am 
z 2] 28 |e8.| fa |5c2| ga] & | Bs] 28) Bae 
80 i Rad! 8 auul eel] gg | §7} 2 aoe| ¢ 
H 3 | & |288| x8 |#sa/8e| $|2 |S | as) & 
= eB |< |< a |< a Bla |e |S a 
G@ms.! Pesos. | Pesos.! P. ct. | Pesos. | P. ct.\ P. ct.| P. ct. Pounds '\Hours. 
b1 | Ore through 60- 
meshve= 5.43 160 | 109.60 | 67.40 | 38.5 | 28.90 | 57.0 | 78.4 | 0.29 | 3:1 7.8 48 
b2 Dowie essa 160 | 109.60 | 67.40 | 38.5 | 12.00 | 82.3 | 89.0 | 0.29) 3:1 8.0 96 
[| 
| 
3 | Ore through 100- | 
meshti-< 222522 270 | 110.80 | 64.50 | 41.6] 5.00 | 92.3 | 95.4 | 0.29) 3:1 5.4 48 
4 Done sae tee 270 | 110.80 | 64.50 | 41.6} 4.00 93.7 | 96.5 | 0.29 | 3:1 4.8 96 
4 In cyanidation the samples were agitated in a bottle using about 2 kilograms (5 pounds) 
of lime per ton of ore. 
b Extraction based on tailings assays. 
As shown by the tests of Table XXVIII, when the ore is put 
through 60-mesh, amalgamated, and cyanided, there is obtained 
an extraction of 73.4 per cent in forty-eight hours and 89 per 
cent in ninety-six hours. When the ore is put through 100-mesh, 
amalgamated, and cyanided, there is obtained an extraction of 
95.4 per cent in forty-eight hours and an extraction of 96.5 per 
cent in ninety-six hours. It is evident that additional fine 
grinding gives a much higher extraction in the same time. 
To obtain the comparison with cyanidation direct, not preceded 
by amalgamation, the tests shown in Table XXIX were made. 
