Improvements in the Treatment of Auriferous and Argentiferous Materials and in Apparatus therefor.
Year: 1889

page_text: Date of Application, 7th June, 1889-Accepted, 13th July, 1889
CDROITUSULON
42
Improvements in the Treatment of Auriferous and Argentiferous
Materials and in Apparatus therefor.
We ALFRED ANDREW LOCKWOOD of Paeroa near Auckland in the Colony of New
Zealand and HERBERT CHAPPEL of Sydney in the Colony of New South Wales Estate
Agent 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:
This invention has reference to the treatment of Auriferous and Argentiferous
Rocks Stones Earth sand &c. in order to eliminate all arsenic, sulphur base metals
or like substances therefrom so that the precious metals may be easily amalgamated
or otherwise extracted from the residue.
These improvements in the treatment of auriferous and argentiferous materials
consist, first, in the special method or process of roasting the gold or silver bearing
rocks, stones; earth, sand &c. in a divided form in closed or air-tight retorts furnaces
cupolas ovens or heated chambers and injecting into and amongst the roasting
material either steam superheated steam or carburetted hydrogen, and, secondly, in
the particular combination and arrangement of apparatus in which we prefer to carry
out such method or process.
In practice we use retorts or ovens similar to those used in the manufacture of gas
and we have them similarly arranged in a set or "bench." In the front of each retort
and outside of the same is an iron mouth or cap with an airtight door. To this
cap is also joined a discharge pipe for the fumes from the roasting materials and
through it passes a small pipe which extends all along the bottom of the retort and
is perforated throughout its length. Where sulphur is likely to be driven from the
materials under treatment the iron caps and other metal parts would be preferably
lined with fireclay to prevent the sulphur attacking the metal. The gold or silver
bearing material being preferably broken to small gauge, say, one quarter inch
gauge, is placed in the retorts and roasted. Through the perforations in the small
pipe extending along the retort as may be desired steam superheated steam or
carburetted hydrogen is injected into and among it which causes all sulphur arsenic
and all base metals to be carried off through the discharge pipe and to be conveyed to
condensing chambers or vessels. After the roasting is completed the contents of the
retorts are conveyed to grinding and amalgamating pans into which they are fed
while hot and are therein further treated as well understood.
But in order that our invention may be clearly understood reference will now be
made to the drawings herewith in which Figure 1 is a front view of our improved
apparatus, Figure 2 is a section of the same on line a a Figure 1, and Figure 3 is a
section on line 6 6 Figure 2-A are the closed ovens or retorts made of fire clay and
set in brickwork as well understood in the setting of gas retorts-B is the furnace
and C the flue to chimney-D is main to condensing chambers or tanks―E is steam
pipe from a boiler or a super-heater-A¹ are iron caps-A2 doors-A³ discharge
pipes B are fire bars--B2 fire door-D₁ is junction to steam pipe D2 and D³ stop
valves or cocks-E are perforated pipes in the retorts-E² are stop cocks-In
operation the ore or other material broken if necessary to a small gauge is placed in
the retorts A and the doors A³ closed so as to make an airtight chamber-The fire in
furnace B being kept going the material is soon heated and while it is roasting steam
or superheated steam is injected into the retorts by opening cocks E-The steam thus
injected forms carburetted hydrogen in the retorts and thus decomposes said
material causing the volatilized baser metals sulphur, arsenic &c. to pass off by
pipes A³ to flue D and into the condensing chambers or tanks-Should the material
under treatment be of such a nature as to require it the steam is previous to its

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introduction to the retorts passed through a heated chamber filled with wood dust
carbon or such suitable material-- Sometimes the uppermost retort is used for the
generation of the carburetted hydrogen; it is filled with carbon or wood dust or coal
or such like and the steam caused to pass through it by the manipulation of cocks D'
and D or again sometimes sufficient carbon or wood ashes might be added to each
of the charges of the retorts to generate in each retort sufficient carburetted
hydrogen for the purpose required-Of course the roasting depends upon the heat
of the furnace and must be judged by experience gained in the treatment of the
various kinds and descriptions of materials they being sufficiently roasted when it is
considered that all sulphur arsenic and the base metals are driven off and it is
advantageous during the roasting to open the door A² of each retort (being careful to
shut off the supply of steam) and to move or rake the charge about When roasting
is completed the material is discharged by raking into trucks underneath which
convey it to grinding and amalgamating machines where it is treated while still hot.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
First The special method or process involved in the roasting of such auriferous
and argentiferous materials in closed or airtight retorts furnaces cupolas ovens or
heated chambers and during such roasting injecting or introducing into and amongst
the material steam or superheated steam or carburetted hydrogen or either or all or
two of them commingled substantially as herein described and explained.
Second-The particular combination and arrangement with retorts having discharge
pipes and a main to condensing chambers of pipes with perforated extensions along
said retorts and with the necessary cocks or valves substantially as herein described
and explained and as illustrated in the drawings.
Dated this First day of April One thousand eight hundred and eighty nine