REFRACTORY GOLD ORES OF QUEEN" S LAND . 257 
6.— THE REFRACTORY GOLD ORES OF QUEENSLAND.— THEIR 
SOURCES AND TREATMENT. 
By E. A. WEINBERG , M.E. 
The term “refractory gold ores,” as used in this paper, is 
intended to designate those ores which will not yield their gold, or 
only a small portion of it, to the ordinary treatment by amalgamation 
on copper plates. 
Their occurrence is a general one, as every goldfield in Queensland 
is producing more or less refractory ore, either massive, or distributed 
through the quartz, as auriferous iron, arseno- and copper pyrites, as 
auriferous sulphide of lead, bismuth, antimony, and zinc, and finally 
as telluride. 
No exact data are available to show in what quantities these ores 
have been mined, or in what proportion they have been present in the 
original crushing material, as it is only during the last five or six 
years that anything like a systematic treatment has been initiated to 
deal with them in a rational manner. Even to-day the Queensland 
system of gold-milling may give rise to more or less adverse criticism 
from the standpoint of modern American or South African gold- 
milling practices, particularly so in regard to the treatment of tailings 
carrying payable quantities of gold enclosed by pyrites and other base 
metal sulphides. 
In the course of this paper the writer will endeavour to point out 
where and how the present system may possibly be improved upon. 
For convenience’ sake, the following classification has been 
adopted : — 
A. Refractory gold ores, massive , ca»rying 10 jjer cent, and 
over of pyrites or other sulphides. 
JB. Concentrates of pyrites and other base metal sulphides, 
with 80 per cent, and more of mineral. 
C. Tailings, either as such or roughly concentrated with a few 
per cent, of sulphurets up to 40 per cent. 
D. Comparatively rich ores, with none or very little sulphurets, 
which, though really free gold ores, will not yield their 
gold in a fair percentage to ordinary amalgamation, 
JE. Argentiferous ores and exceptional ores. 
A.— MASSIVE AURIFEROUS SULPHIDE ORES WITH 40 PER CENT 
AND MORE OF PYRITES, &c. 
Wherever these ores occur in quantities, the first attention should 
be directed to ascertaining if any coarse gold is present. Should 
repeated panning tests have proved the absence of coarse gold, the 
value of the ore is then determined by assay, in order to obtain a 
guidance in regard to subsequent treatment. In most cases which 
have come under my special notice during a six years’ acquaintance 
with Queensland ores, it will recommend itself to separate the heavily 
mineralised portion from the bulk of the crushing stuff by simple hand 
picking, and to deal with, it separately. 
Frequently these ores have, besides the gold, a further commercial 
value, owing to the presence of either payable quantities of lead or 
copper. 
R 
