IMPROVEMENTS IN THE TREATMENT OF CERTAIN COMPLEX METALLIC ORES OR SOLUTIONS
Year: 1884

page_text: I, GEORGE ISAAC JAMES WELLS, of Arundel Avenue, Sefton Park, Liverpool,
in the County of Lancaster, Manufacturing Chemist, do hereby.declare the nature
of my said invention for "IMPROVEMENTS IN THE TREATMENT OF CERTAIN COMPLEX
METALLIC ORES OR SOLUTIONS" to be as follows:-
The ores to which my invention specially relates are those containing several of
the better known metals especially silver, copper, lead, zinc or iron together with
one or more metaloids or metals as sulphur selenium, arsenic or antimony, and the
object of the invention is to separate each metal from the others by a species of
fractional precipitation.
By digesting the unroasted ore (reduced to a fine state of division) in hot
hydrochloric acid in vessels which I prefer to be constructed of stone, the lead is
converted into chloride, which becomes soluble in certain menstrua. The crude.
plumbic solution is then partially neutralized with lime or carbonate of lime (the
calcium chloride produced augmenting the solvent power of the liquor,) well boiled,
run off whilst hot through a suitable filter.
The filter media being peat as described in the English Patent No 2386, May 10th
1883. If the hydrochloric acid obtainable, contains much sulphuric acid 1 prefer
to filter the hydrochloric acid solution without neutralizing with lime, adding strong
solution of sodium or magnesium chlorides to the residue, after the acid solution is
run off, well boil, filter, afterwards washing with boiling water and passing this
through the same filter whether containing the calcium or sodium or magnesium
chlorides. The filtrates are allowed to cool in the tank, where the greater part of
the chloride of lead deposits in crystals. The clear liquor is run off into another
tank. The remaining lead in solution is precipitated by the addition of a sulphide.
The complex solution obtained from the drainage of alkali waste being suitable for
the purpose. The residue left in the stone vessels is taken out washed dried and
calcined.
The calcined ore is now treated with hydrochloric acid of suitable strength and
quantity (according to the composition of the ore) which dissolves out the copper,
silver, zinc and iron. This operation is repeated if necessary to extract the metals
more perfectly. The silver is now thrown down by the well known process with
soluble iodide and the supernatant liquors perfectly neutralized with chalk or
limestone dust...

page_text: The metals, copper, any lead present, the zinc and iron may be precipitated and
separated from each other by the successive additions of carefully measured
quantities of the soluble sulphide. When it is desired to obtain zinc oxide instead
of zinc sulphide, the process is varied as follows: Previous to the neutralization of
the solutions obtained by treatment of the calcined ore with hydrochloric acid there
is added sufficient bleaching powder or any cheap oxidising agent to convert any
ferrous iron present into the ferric state-The neutralization by limestone dust or
chalk is then completed, and sufficient quantity added to completely separate from
the solution, the oxide of iron and alumina. After the separation of these by
means of a filter press, the clear liquor obtained is treated with the drainage of
alkali waste or soluble sulphide in sufficient quantity or quantities to precipitate
the copper and any lead present together or successively. After the deposition of
these the clear liquor is treated with milk of lime in a boiling state in quantity
sufficient to throw down the whole of the zinc as oxide. This process is especially
applicable when the complex ores are rich in lead, but for ores poor in lead I prefer
to modify the process as follows:
First carefully calcine the ore then digest with hot hydrochloric acid, chloride of
sodium, water, successively, filtering the resulting liquors (containing all the metals
together) into a cooling tank where the greater part of the lead is deposited as
chloride, the clear liquor is run off into another tank where the silver is precipitated
by the well known iodide process. The clear liquor from this is carefully neutralized
and the copper, lead, zinc and iron may be separately precipitated as before
described.
When it is desired to obtain the zinc as oxide instead of sulphide, the process is
varied as follows: After the precipitation of the silver as iodide, the clear liquor is
neutralized and oxidised so as to convert any ferrous salt into ferric state. The
clear liquor filtered from the ferric oxide and alumina is treated with soluble
sulphide in sufficient quantities to remove first the copper and afterwards the lead.
The zinc may be precipitated as oxide.
The successive precipitation of copper, lead, zinc and iron by the sulphide
solution is very perfect each of the sulphides being obtained in a state of great
purity. The separation of silver is also very complete by this re-agent, and it falls
out after the copper is removed and before the lead is attacked, but the compara-
tively great value of silver as compared with the other metals renders it inexpedient
to risk any loss of this metal by a process which carelessly worked might lead to
unsatisfactory results. I do not therefore recommend the sulphide reaction for the
extraction of this metal under ordinary circumstances.
1
TAI
1004

page_text: COMPLETE SPECIFICATION.
I, GEORGE ISAAC JAMES WELLS, Arundel Avenue, Sefton Park, Liverpool,
Lancashire, do hereby declare the nature of my said invention for "IMPROVEMENTS
IN THE TREATMENT OF CERTAIN COMPLEX METALLIC ORES OR SOLUTIONS," and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
By digesting the unroasted ore (reduced to a fine state of division) in bot
hydrochloric acid in vessels which I prefer to be constructed of stone, the lead is
converted into chloride, which becomes soluble in certain menstrua. The crude
plumbic solution is then partially neutralized with lime or carbonate of lime (the
calcium chloride produced augmenting the solvent power of the liquor) well boiled,
run off whilst hot through a suitable filter.
The filter media being peat as described in the English Patent No 2386, May 10th
1883, If the hydrochloric acid obtainable contains much sulphuric acid, I prefer
to filter the hydrochloric acid solution without neutralizing with lime, adding
strong solution of sodium or magnesium chlorides to the residue, after the acid
solution is run off, well boil, filter, afterwards washing with boiling water and
passing through the same filter whether containing the calcium or sodium or
magnesium chlorides. The filtrates are allowed to cool in the tank where the
greater part of the chloride of lead deposits in crystals. The clear liquor is run off
into another tank. The remaining lead in solution is precipitated by the addition
of a sulphide. The complex solution obtained from the drainage of alkali waste
being suitable for the purpose. The residue left in the stone vessels is taken out
washed, dried and calcined.
The calcined ore is now treated with hydrochloric acid of quantity (according to
the composition of the ore) which dissolves out the copper, silver, zinc, and iron.
This operation is repeated if necessary to extract the metals more perfectly The
silver is now thrown down by the well known process with soluble iodide and the
supernatant liquors perfectly neutralized with chalk or limestone dust.
The metals, copper, any lead present, the zinc and iron may be precipitated and
separated from each other. by the successive additions of carefully measured
quantities of the soluble sulphide. When it is desired to obtain zinc oxide instead
of zinc sulphide, the process is varied as follows: Previous to the neutralization of
the solutions obtained by treatment of the calcined ore with hydrochloric acid there
is added sufficient bleaching powder or any cheap oxidising agent to convert any
ferrous iron present into the ferric state. The neutralization by limestone dust or
chalk is then completed, and sufficient quantity added to completely separate from
the solution, the oxide of iron and alumina. After the separation of these by
means of a filter press, the clear liquor obtained is treated with the drainage of
alkali waste or soluble sulphide in sufficient quantity or quantities to precipitate
the copper and any lead present together or successively. After the deposition of
these, the clear liquor is treated with milk of lime in a boiling state, in quantity
sufficient to throw down the whole of the zinc as oxide. This process is especially

page_text: applicable when the complex ores are rich in lead, but for ores poor in lead I prefer
to modify the process as follows.
First carefully calcine the ore, then digest successively with hot hydrochlorio
acid solution of chloride of sodium, calcium, or magnesium, and water filtering the
resulting liquors (containing all the metals together) into a cooling tank where the
greater part of the lead is deposited as chloride, the clear liquor is run off into
another tank where the silver is precipitated by the well known iodide process.
The clear liquor from this is carefully neutralized and the copper, lead, zinc, and
iron may be separately precipitated as before described.
When it is desired to obtain the zine as oxide instead of sulphide the process is
varied as follows: After the precipitation of the silver as iodide, the clear liquor
is neutralized and oxidised so as to convert any ferrous salt into ferric state. Tho
clear liquor filtered from the ferric oxide and alumina is treated with soluble
sulphide in sufficient quantities to remove first the copper and afterwards the lead.
The zinc may be precipitated as oxide.
The successive precipitation of copper, lead, zinc and iron by the sulphide
solution is very perfect each of the sulphides being obtained in a state of great
purity. The separation of silver is also very complete by this re-agent, and it falls
out after the copper is removed and before the lead is attacked, but the compara-
tively great value of silver as compared with the other metals renders it inexpedient
to risk any loss of this metal by a process which carelessly worked might lead to
unsatisfactory results I do not therefore recommend the sulphide reaction for the
extraction of this metal under ordinary circumstances.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I wish it to be
understood that I am well aware that sulphuretted hydrogen and alkaline sulphides
have been long used for the precipitation of metals from their solutions also that
from acid solutions of copper and nickel the copper can be precipitated by
sulphuretted hydrogen, whilst nickel remains in solution and may be precipitated
by the same re-agent afterwards from a neutral solution; also that alkaline
sulphides and even the very sulphide solution I specially prefer have been used in
separating groups of metals from their solutions and that in my Patent No 2386 of
1883 I myself claim separating the lead, copper, silver group from zinc by means
of alkaline sulphides and then separating zinc from iron by the same re-agent, and
I make no claim for these reactions in my present application, but I do not believe
that it was publicly known until the date of my present application that the same
re-agent could separate from a complex solution each individual metal successively
and that thus not merely groups, but individual metals could be isolated successively
the one from the other I declare therefore that what I claim is
The fractional precipitation, and individual separation successively of the metals
contained in complex metallic solutions, by means of decomposable sulphide added
in such successive portions as shall be necessary to separate from their solutions,
and from each other, the before mentioned metals in their order, beginning with
copper and ending with iron substantially as described.