Improvements in or relating to the Treatment of Silver Ores Containing Zinc, and Gold Ores Containing Zinc.
Year: 1892

page_text: Date of Application, 26th Apr., 1892
Complete Specification Left 20th Feb. 1893-Accepted. 15th Apr.. 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Treatment of Silver Ores
Containing Zinc, and Gold Ores Containing Zinc.
I, HENRY ARTHUR PENROSE, of Gloucester Place, Swansea, in the County of
Glamorganshire, Wales, Assayer, &c. do hereby declare the nature of this invention
to be as follows :-
Hitherto there has been great difficulty in profitably smelting ores of silver
containing large quantities of zinc.
I have found that if silver ores, and gold ores, which contain compounds of zinc
be mixed with a suitable proportion of anthracite or any similar form of carbon,
crushed or broken down to the proper size and the mixture be heated in a rever-
beratory or other suitable furnace having an iron bottom removable or otherwise,
the zinc compound or compounds undergo such a change that the silver ores or
gold ores which have been subjected to this roasting can afterwards be smelted
with a comparatively small loss of silver by the ordinary methods in use for
smelting.
Dated this Twenty-third day of April 1892.
COMPLETE SPECIFICATION.
Improvements in or relating to the Treatment of Silver Ores
Containing Zinc, and Gold Ores Containing Zinc.
I, HENRY ARTHUR PENROSE of Gloucester Place Swansea in the County of
Glamorganshire, Wales, Assayer do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
I break the ore into small pieces or grind it into a coarse powder and well mix it
with coarsely powdered carbon in some suitable form preferably as anthracite in
suitable proportions. In practice I have found one part by weight of anthracite
with four parts by weight of ore containing about 25% of zinc give excellent
results but for various ores containing other proportions of zinc, arsenic or other
volatile substances these proportions may be modified. I then put the mixture of
broken or crushed ore and anthracite (or other suitable form of carbon) into a
reverberatory or other convenient form of furnace having an iron bed or bottom,
and calcine the mixture commencing with a low temperature, a "black heat," and
gradually raise the temperature to bright redness, stirring the mixture in the
furnace all the time or at very frequent intervals. The calcination will usually
take about twelve hours with ore containing about 25% of zinc, the size of the
charge depending upon the size of the furnace used, but the time taken may vary
somewhat according to the proportions of zinc, arsenic or other volatile substances
present, and the size of the charge. When the roasting is complete the charge is
withdrawn from the calcining furnace, and the ore may be afterwards smelted or
otherwise treated by any known method for the extraction of silver or gold and
zinc or all or any of these metals that may be present therein.
The object of this treatment is to prevent the usual loss of silver which occurs
when ores of silver and of gold containing more or less large percentages of zinc
are calcined preparatory to the extraction of the precious metals.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
The calcining of silver ore or gold ores containing zinc with the addition thereto
of anthracite or other suitable form of carbon in a suitable furnace substantially as 5
herein before described.
Dated this Sixteenth day of February 1893.