Improvements in or relating to the Recovery of Precious Metals from their Ores.
Year: 1894

page_text: Date of Application, 24th Sept., 1894
Complete Specification Left, 13th July, 1895-Accepted, 17th Aug., 1895
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Recovery of Precious Metals
from their Ores.
I, HENRY LIVINGSTONE SULMAN, of 60 Gracechurch Street, in the City of
London, Analytical Chemist, do hereby declare the nature of this invention to be
as follows:-
This invention relates to the treatment of solutions containing precious metals,
more especially what are known as cyanide solutions, and the invention relates
particularly to the combination in the one process of two separate treatments;
first, the treatment of the ores with cyanide so as to produce the cyanide solution,
and secondly, the treatment of that solution with zinc in an extremely fine state of
division, for the purpose of precipitating from the solution the precious metals
contained therein.
In obtaining the solutions I may adopt any of the well known processes such as
percolating the ground ore or allowing it to stand in contact with dilute solution of
cyanide of potassium. The solution being obtained I then apply in any convenient
manner the finely divided zinc as for example by sieving it in, throwing in the
powder or introducing it as a suspension in water. The zine has the effect of
throwing down the precious metals contained in the solution.
I have tried various means of reducing the zinc to the necessary state of fineness
and I find the best is where it is obtained by condensation from the metallic
vapours given off in the distillation of zinc say for example the product from the
flues and settling chambers.
Dated this 24th day of September 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
Improvements in or relating to the Recovery of Precious Metals
from their Ores.
I, HENRY LIVINGSTONE SULMAN of 60 Gracechurch Street, in the City of
London, Analytical Chemist, 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 relates to the treatment of solutions containing precious metals,
more especially what are known as cyanide solutions, and the invention relates
particularly to the combination in the one process of two separate treatments;
first, the treatment of the ores with cyanide so as to produce the cyanide solution,
and secondly, the treatment of that solution with zinc in an extremely fine state of
division, for the purpose of precipitating from the solution the precious metals
contained therein.
In obtaining the solutions I may adopt any of the well-known processes such as
percolating the ground ore or allowing it to stand in contact with dilute solution of

page_text: cyanide of potassium. The solution being obtained I then apply in any convenient
manner the finely divided zinc as for example by sieving it in, throwing in the
powder or introducing it as a suspension in water. The zinc has the effect of
throwing down the precious metals contained in the solution.
I have tried various means of reducing the zinc to the necessary state of fineness
and I find the best is where it is obtained by condensation from the metallic
vapours given off in the distillation of zinc say for example the product from the
flues and settling chambers, technically known as zinc dust or fume.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is ;-
1. In the treatment of ores for the recovery of precious metals therefrom the
combination with a cyanide solution of zinc in the form of dust or fume.
2. The extraction of the precious metal from the ore by a cyanide solution and
the subsequent precipitation by zinc dust or fume.
Dated this 12th day of July 1895.
HENRY LIVINGSTONE SULMAN.
Boult & Wade,
Agents for the Applicant.