An Improved Process and Apparatus for the Manufacture of Zinc Oxides, Sulphates, and Sulphides from Zinc Ashes, Zinc Blende, Carbonate of Zinc, and other Ores of a Complex Nature, such as Ores containing Lead, Zinc, Silver, Copper, Manganese, Iron, or other Metals in combination.
Year: 1894

page_text: Date of Application, 9th June, 1894
Complete Specification Left, 9th Mar., 1895-Accepted, 24th May, 1895
PROVISIONAL SPECIFICATION.
An Improved Process and Apparatus for the Manufacture of Zinc
Oxides, Sulphates, and Sulphides from Zinc Ashes, Zinc Blende,
Carbonate of Zinc, and other Ores of a Complex Nature, such as
Ores containing Lead, Zinc, Silver, Copper, Manganese, Iron, or
other Metals in combination.
I, ATKINSON CROSSLEY, of Beili Glas, Cwmavon, near Pontypool, in the
County of Monmouth, Manufacturing Chemist, do hereby declare the nature of
this invention to be as follows:-
My present invention relates to an improved process of, and apparatus for, the
manufacture of zinc oxides, sulphates, and sulphides, from zinc ashes, zinc blende,
carbonate of zinc, and other ores of a complex nature, such as ores containing lead,
zinc, silver, copper, manganese, iron, or other metals in combination.
Ores of the nature described are ordinarily exceedingly difficult to treat
successfully, and my invention has for its object a novel method or process of
treatment by which the required result can be obtained successfully, easily, and
economically.
In order to put my invention in operation, I first take the sulphides of these
metallic ores described, and I roast them for the purpose of converting those that
are convertible, to their oxides and sulphates, in a roasting furnace which is so
constructed as to be self-feeding and self-delivering as hereinafter described, and
the gases are then conducted from such furnace by suitable tunnels or flues into
acid chambers of the kind usually used for the purpose of manufacturing sulphuric
acid. The ores are then ready for treatment by the following process.-Ores,
however, such as calamine, zinc ashes, skimmings from galvanisers' works, and the
like, do not require such preliminary roasting, but can be treated direct.
According to the proportion of metal contained in each or any of the before-
mentioned ores or waste products so much acid, preferably sulphuric acid, is then
added as is necessary to dissolve the same, and is heated with the ores at
concentrated strength in a cast iron steam-jacketted pan, in order to convert any
lead therein contained to an insoluble lead sulphate, (assuming sulphuric acid to
have been used), and is then diluted with water to such a degree as is found most
suitable, whereby the zinc, iron, manganese, iron, and copper, if any, are converte.l
into soluble sulphates. The clear liquor is afterwards filtered off, leaving the
residual ore of lead, and silver or gold if any be present, in such a condition as to
be dealt with in the ordinary way of smelting, as usually adopted with ores of a
nou-complex order or condition.
The clear acid sulphate liquor is then treated with sodic sulphide, or sulphuretted
hydrogen, or any alkaline sulphide, which at once precipitates the copper as copper
sulphide, the liquor is then again filtered from its precipitate, and is again treated
with an alkali, (ammonia by preference), until neutral, when a stream of chlorine
gas (or suitable chlorine compound) is passed into it, until all the manganese and
iron is sufficiently oxidised to form manganic dioxide and ferric oxide, when it
is thrown down by a slight excess of ammonia. When it has been sufficiently
treated by this process, a further excess of ammonia is added to bring into a state
of solution all the zinc oxide, the liquor is again filtered from its solution, and the

page_text: ammonia is then distilled off, or rendered neutral by the addition of a suitable acid,
and recovered that is to say the free ammonia, not being a sulphate. The zinc
oxide is then thrown down, and the 'liquor is again filtered from precipitate, and is
then treated by any of the well-known methods to recover the ammonia, which
may be used over again in the said manufacture.
The zinc oxide is then taken, and well washed from all traces of alkaline
sulphates, dried, and it is then put into a muffle furnace, and heated for such a time,
and at such heat as is necessary to give it the required density and body for use as
a pigment for various purposes in the arts.
Sulphides of zinc are made by a similar process, except that after the iron and
manganese are got rid of as described, the liquor is again made acid and sulphuretted
hydrogen passed through the same, and the zinc thrown down as a precipitate of
zinc sulphide, which is washed, and dried; and is then ready for use.
Zinc sulphate can also be made by this process of purification, and is crystallised
from.the acid liquor instead of being precipitated.
upper
The furnace or heating apparatus which I prefer to use as above described,
consists of metal or other tubes inclined to revolve at an angle and made to revolve
slowly so that the material can be fed in at the upper end of one. of the tubes or
cylinders, and slowly descends to the lower end, from which it passes into the.
end of a similar revolving tube or cylinder below, inclined at an opposite angle,
down which it passes to a discharge opening, or to the upper end of a third cylinder
or tube, inclined in the same direction as the first one, and so on through as many
tubes as are necessary to complete the process.
The revolving tubes are supported in suitable bearings, and are set in revolution
by wheels or other equivalent mechanism driven by any convenient power.
The revolving tubes are arranged in a furnace by which they are heated, and
I prefer to surround them with fixed casings of refractory material, at a short
distance from 'the outer surface, by which the action of the heat is rendered very
uniform and effective.
The gases from the ores are conducted away 'from the ends of the tubes through
suitable flues or tunnels to acid chambers as already described.
.Dated this 9th day of June 1894.
EDWARDS & Co.,
65 and '66, Chancery Lane, London, Agents for the Applicant.
COMPLETE SPECIFICATION..
An Improved Process and Apparatus for the Manufacture of Zinc
Oxides, Sulphates, and Sulphides from Zinc Ashes; Zinc Blende,
Carbonate of Zinc, and other Ores of a Complex Nature, such as
Ores containing Lead, Zinc, Silver; Copper; Manganese, Iron; or
other Metals in combination.
I, ATKINSON CROSSLEY; of Beli Glas, 'Cwnavon, near Pontypool, in the
County of Monmouth, Manufacturing 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; that is to say :-
My present invention relates to an improved process of, and apparatus for, the
manufacture of zinc oxides, sulphates, and sulphides, from zine ashes, zinc blende,
carbonate of zinc, and other ores of a complex nature, such as ores containing lead,
zinc, silver, copper, manganese, iron, or other metals in combination..
Ores of the nature described are ordinarily exceedingly difficult to treat
successfully; and 'my invention has for its object. a novel method or process of

page_text: treatment by which the required. result can be obtained successfully, easily, and
economically.
In order to put iny invention in operation, I first take the sulphides of the metallic
ores described, and I roast them for the purpose of converting those that are
convertible, to their oxides and sulphates, in a roasting furnace which is so
constructed as to be self-feeding and self-delivering as hereinafter described, and
the gases are then conducted from such furnace by suitable tunnels or flues into
acid chambers of the kind usually used for the purpose of manufacturing sulphuric
acid. The ores are then ready for treatment by the following process.-Ores,
however, such as calamine, zinc ashes, skimmings from galvanisers' works, and the
like, do not require such preliminary roasting, but can be treated direct.
According to the proportion of metal contained in each or any of the before
mentioned ores or waste products, so much acid, preferably sulphuric acid, is then
added as is necessary to dissolve the same, and is heated with the ores at a
concentrated strength in a cast iron or other suitable steam-jacketted pan, in order
to convert any lead therein contained to an insoluble lead sulphate (it being
assumed in this description that sulphuric acid is the acid used) and is then diluted
with water to such a degree as is found most suitable, whereby the. zinc, iron,
manganese, and copper, if any, are converted into soluble sulphates. The clear
liquor is afterwards filtered off, leaving the residual ore of lead, and silver or gold
if any be present,-in such a condition as to be easily dealt with in the ordinary
way of smelting, as usually adopted with ores of a non-complex order or condition.
The clear acid sulphate liquor is then treated with sodic sulphide, or sulphuretted
hydrogen, or any alkaline sulphide which at once precipitates the copper as copper
sulphide.
Or, the clear acid sulphate liquor may be treated by the addition of metallic zinc,
or by electrolytic action (for instance, by immersing in it copper and zinc plates
electrically connected) in which case the copper is precipitated in a spongy
metallic form.
The liquor is then again filtered from its precipitate, and is again treated with
an alkali, (ammonia by preference) until neutral, when a stream of chlorine gas (or
suitable chlorine compound) is passed into it, until all the manganese and iron are
sufficiently oxidized to form manganic oxide and ferric oxide, when they are thrown
down by a slight excess of ammonia. When the liquor has been sufficiently
treated by this process, a further excess of ammonia is added to bring into a state
of solution all the zinc oxide, the liquor is again filtered from its solution, and the
ammonia is then distilled off, or rendered neutral by the addition of a. suitable acid
and recovered (that is to say the free ammonia, not being a sulphate). The zinc
oxide is then thrown down, and the liquor is again filtered from precipitate, and is
then treated by any of the well-known methods to recover the ammonia, which
may be used over again in the said manufacture.
The zinc oxide is then taken and well washed from all traces of alkaline
sulphates, dried, and it is then put into a muffle furnace, and heated for such a time,
and at such a heat, as is necessary to give it the required density and body for use
as a pigment for various purposes in the arts.
Sulphides of zinc are made by a similar process, except that after the iron and
manganese are got rid of as described, the liquor is again made acid and sulpharetted
hydrogen passed through it, and the zinc thrown down as a precipitate of zinc
sulphide, which is washed, and dried, and is then ready for use.
Zinc sulphate can also be made by this process of purification, and is crystallized
from the acid liquor instead of being precipitated.
The furnace or heating apparatus which I prefer to use as above described is of
the kind described and illustrated in the Specification of Letters Patent
dated A.D. 1891, and numbered 12,813, and dated A.D. 1894, and numbered 2618.
The gases from the ores are conducted away from the furnace through suitable
flues or tunnels to acid chambers as already described.

page_text: I. do not confine myself to the precise details of my improved process and
apparatus, which may be varied more or less to suit different circumstances, but
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 :-
:
1. The improved process herein described, consisting in taking the metallic ores
to be treated (first roasted if necessary), then adding to them an acid and heating
it with the ores, to convert any lead present to an insoluble salt, then diluting with
water, and converting the zinc, iron, manganese, and copper, if any, to soluble salts,
then filtering off the clear liquor; leaving the residual ore of lead, and silver or
gold if any be present, to be dealt with by ordinary smelting processes, all
substantially in the manner and for the purposes described.
2. In combination with the process claimed in Claim 1, the process of treating
the clear acid liquor filtered off as therein described, with sodic sulphide,
sulphuretted hydrogen, or alkaline sulphide, and precipitating the copper present
as copper sulphide, then filtering the liquor from the precipitate, and treating it
with an alkali until neutral, then passing chlorine into it until all manganese and
iron ore present are sufficiently oxidized to form manganic and ferric oxides, which
are then thrown down by a slight excess of alkali, (then adding a further excess of
alkali when ammonia is the alkali used to bring the zinc oxide into solution),
filtering the liquor, and recovering the alkali, then again filtering the liquor from
the precipitated zinc oxide, which is washed, dried, and heated in a furnace to
render it fit for use as a pigment, substantially as described.
3. For the purpose of making sulphides, instead of oxides, of zinc; in the
process claimed in Claim 2, after the manganese and iron are got rid of as described,
making the liquor again acid, then passing sulphuretted hydrogen through it, and
then washing and drying the precipitate of zinc sulphide which is thrown down,
substantially as described.
4. For the purpose of obtaining zinc sulphate, in the process claimed in Claim 2,
crystallizing the zinc sulphate from the acid liquor (instead of precipitation)
substantially as described.
5. In the process described and claimed in Claim 1, the method of treating the
clear liquor to recover the copper, by the addition of metallic zinc, substantially as
described.
the
6. In the process described and claimed in Claim 1, the method of recovering
copper from the clear liquor by electrolytic action, substantially as described.
Dated this 9th day of March 1895.
EDWARDS & Co.,
65 and 66, Chancery Lane, London, Agents for the Applicant.