REFRACTORY GOLD ORES OF QUEENSLAND. 
259 
A mine near Cania (Gladstone district) shipped a few years ago 
several tons of a heavy complex ore, containing arseno-pvrites, copper 
pyrites, and some zincblendo assaying about 7 oz. of gold per ton. 
A further parcel of 5 tons 10 cwt., which likewise came from the 
Gladstone district, consisted of arseno- and copper pyrites, and assayed 
3 *4 oz. per ton. 
The only parcel consisting of a few tons of auriferous copper 
pyrites which has come under the writer’s notice was produced in the 
Rockhampton district , and assayed 4T5 oz. of gold per ton. 
From the Kilkivan district about 14 y tons of an iron arson o- 
pyrite have lately been treated, which assayed 3*45 oz. of gold per ton. 
The only district represented by auriferous antimonial sulphide is 
Cooktown, from whence a few tons containing 53T per cent, antimony 
sulphide, and assaying 3*65 oz. of gold per ton, have been shipped a 
few years ago. 
At Mount Shamrock a rich massive mineral ore, containing metallic 
bismuth and the selenides and tellurides of bismuth, is being mined. 
B.— CONCENTRATES WITH 80 PER CENT. AND MORE OF 
SULPHURETS. 
It must be pointed out here that very little progress lias been 
made in Queensland towards producing clean concentrates from 
tailings ; and the reason for this apparent failure is probably found in 
tlie Queensland system of gold-milling itself, as well as in an often 
wrongly applied economy. In most of the Queensland mills the 
roughly concentrated tailings are still being ’worked in grinding pans; 
and though it must he admitted that under favourable conditions a 
fair extraction of the gold contents may be effected, it is equally 
certain that, wherever chlorination and smelting works are in easy 
reach, it will be far more economical to adopt a perfect concentra- 
tion of the tailings at once, so as to produce clean hut also richer 
concentrates. 
The Queensland Under Secretary for Mines, in his well-tabulated 
Annual Eeport for 1S93, gives the number of crushing mills as fol- 
lows : — 
In operation ... ... ... ... ... 114 
Idle 51 
Total number of stamps ... ... ... 1,864 
This would allow us the low average of stamps for each mill, 
which for that particular year can only he shown having crushed 
208 T V tons per stamp per year, or T °^-ton per stamp per day. In 
arriving at these figures 389,000 tons have been calculated as being 
reduced by stamps, while 64,923 tons (approximately) have been 
crushed in a dry state by means of rollers, principally at Mount 
Morgan and Ravenswood. 
As the average crushing capacity of the Queensland mills maybe 
taken as l T y tons per stamp per day, it will be seen that not one-half 
of the crushing capacity of the Queensland goldfields has been usefully 
employed during that year. 
No doubt such a state of affairs is due partly to the unpro- 
ductiveness of some of the mines, partly to the prevailing desire of 
each individual mining company to possess its own mill. It surely 
stands to reason that a smaller number of mills or a consolidation of 
