THE RUSSELL PROCESS IN AUSTRALIA. 315 
4-2 oz.; and from the bottom, 12:4 oz. silver per ton respectively. 
In another instance the ore on top assayed 7°6 oz. per ton, while 
that near the bottom assayed 12°4 oz. The leaching of shallow 
charges (about 2 feet deep), consisting solely of flue-dust, went on 
slowly, but effectually. 
In drying the precipitates the free sulphur generally caught fire 
and burned away ; the assays represent the precipitates so treated. 
They were sold in England on the following terms :-—-The 
copper (wet assay, less two units) was paid for at market C.B. 
rates ; the gold at £4 4s. per ounce fine, and the silver at the full 
market rate for the fine silver contents, less 1d. per ounce fine, for 
refining. Owing to the intermittent nature of the work the 
precipitates were pressed irregularly, and varied widely in value. 
The annexed Table IJ gives the assays of the various parcels, and 
explains itself. Owing to the great loss of solutions through 
leakage of the vats during the early stages of the work, before 
the nature of such large wooden tanks became understood by 
the workmen, no figures of the consumption of chemicals or 
of the actual extraction of silver can be given which would be at 
all reliable. Table I gives the result of each vat of ore treated. 
In the case of vats H and J, which represent work done under 
good condition all through, the clean-up gave an actual extraction 
in excess of the apparent extraction as calculated from the tailings 
assay of 0-5 per cent. 
The ore in vats A, B, C, K, and L contained more sulphurets 
than the others, and show plainly their presence in the low 
extraction by ordinary solution in the mill compared with that in 
the assay office. Vats A, B, C represent 100 tons of tailings from 
some raw-leaching experiments upon sulphide ore, made by the 
mining company which built the mill. These tailings contained 
a large quantity of blende and arsenopyrite. Mr. Simpson’s 
analyses represent only the new ore treated in vats D to M. 
The result of the treatment of the ore alone was a mean 
extraction of 84-05 per cent. of the silver in the roasted ore and 
of 78°37 per cent. of the silver contained in the ore before 
chloridising. 
Doubtless very much better results would have been obtained 
if the mill had been able to continue work long enough to enable 
us to profit by our experiences. 
In conclusion, the following opinions have been arrived at by 
the writer as the result of his experiments and experiences since 
he first became interested in hyposulphite lixiviation, and from 
studying the experiences of others :— 
(1) The Russell process is a good one under certain conditions 
and for certain ores, which latter are plainly indicated. 
It presents no difficulties of a serious nature, and its 
manipulations are easily learned by workmen. 
