Improvements in the Extraction of Copper from Copper Ores.
Year: 1888

page_text: Date of Application, 15th Sept., 1888
Complete Specification Left, 11th June, 1889-Accepted, 13th July, 1889
PROVISIONAL SPECIFICATION.
Improvements in the Extraction of Copper from Copper Ores.
I, HENRY DOETSCH, of Huelva, in the Kingdom of Spain, Merchant, do hereby
declare the nature of this invention to be as follows:-
This Invention consists in the preparation of persalts of iron by dissolving
natural iron oxides (such as ochre &c.) in sulphuric or hydrochloric acid using the
persalts of iron thus obtained for the extraction of copper from copper pyrites and
other copper ores.
The iron oxides are ground to a fine powder and mixed with the equivalent
quantities of the mineral acids mentioned, preferably strong sulphuric acid. The
mixture of sulphuric acid and iron oxide is heated to a temperature of 100° to
150° Fahr. in inverse proportion to the strength of the acid when suddenly a
reaction sets in converting the iron oxide into soluble persulphate of iron.
Copper pyrites or other copper ores are treated with a solution of the persulphate
of iron thus obtained, whereby the reaction between the persalts of iron and sulphide
or oxide of copper renders the copper soluble.
Th: 15th J...
nhan 1000.
CARPMAEL & Co.,
A cents.
COMPLETE SPECIFICATION.
Improvements in the Extraction of Copper from Copper Ores.
I, HENRY DOETSCH, of Huelva, in the Kingdom of Spain, Merchant, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:
This Invention consists in the preparation of persalts of iron by dissolving natural
iron oxides (such as ochre &c.) in sulphuric or bydrochloric acid using the persalts
of iron thus obtained for the extraction of copper from copper pyrites and other
copper ores.
The iron oxides are ground to a fine powder and mixed with the equivalent
quantities of the mineral acids mentioned, preferably strong sulphuric acid. The
mixture of sulphuric acid and iron oxide is heated to a temperature of 100°
to 150° Fahr. in inverse proportion to the strength of the acid when suddenly a
reaction sets in converting the iron oxide into soluble persulphate of iron.
Copper pyrites or other copper ores are treated with a solution of the persulphate
of iron thus obtained, whereby the reaction between the persalts of iron and sulphide
or oxide of copper renders the copper soluble.
The way in which I prefer to operate is as follows:-I take finely crushed ochre
and form a conical heap of it containing two or three tons. I also take an equivalent
quantity of commercial sulphuric acid (oil of vitriol) and I mix with it sufficient
water to raise the temperature to say 150 degrees or I warm the acid in a steam heated
lead coil. I form a cavity in the centre of the heap of ochre and I pour in the acid.
Then with iron rakes I mix the materials together. Action soon commences and the
whole becomes a dry white mass.
The persulphate salt thus obtained I dissolve in water making a solution containing
one per cent. of the salt or thereabout. With this solution I treat the copper ore.
The raw ore is laid in heaps of great extent and the heaps are from time to time
watered with the solution. The copper in the ore is thus rendered soluble and the
77

page_text: liquor draining from the heaps is in the well known manner treated with metallic
iron whereby the copper is obtained in a metallic state.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare. that what
I claim is
The preparation of persalts of iron and the use of the same in the extraction of
copper from copper ores in the manner substantially as herein described.
Dated this 11th day of June 1889.
CARPMAEL & Co.,
Agents for the Applicant.