Improvements in the Process for the Volatilization of Galena into White Compounds of Lead, and of Zinc into White Compounds of Zinc, the Making of Litharge, and the Smelting of Metals from their Ores or Slags.
Year: 1895

page_text: Date of Application, 25th July, 1895
Complete Specification Left, 24th Apr., 1896-Accepted, 25th July, 1896
PROVISIONAL SPECIFICATION.
Improvements in the Process for the Volatilization of Galena into
White Compounds of Lead, and of Zinc into White Compounds
of Zinc, the Making of Litharge, and the Smelting of Metals
from their Ores or Slags.
I, ANDREW CHARLES JOSEPH CHARLIER, of 107 Breadalbane Terrace, Hill
Street, Glasgow, in the County of Lanark, North Britain, Chemist, do hereby
declare the nature of this invention to be as follows :—
:
This invention relates to improvements in the volatilization of galena into white
compounds of lead the making of litharge and the smelting of metals from their
ores or slags. Many patents have been taken out from time to time for the
volatilising of galena or sulphide of lead into white compounds of lead to be used
as pigments, also the manufacture of oxide of lead from pig lead, also the
conversion of zinc ores into similar white pigments, and finally the smelting of
metals from their ores or from slags and residues containing metal. The great
expense of fuel and upkeep of furnaces and complete condensation of products
and labour has, however, prevented previous processes from being universally
adopted.
I am now able to overcome all these difficulties by using gaseous fuel such as
ordinary coal gas previously compressed up to a pressure of say 60 lbs., and
working in conjunction with an air blast heated up to the required temperature,
according to the metal I propose to work. The process is intended to apply more
particularly to the volatilization of lead and zinc compounds but with slight
modifications in the furnace it can be used also for making litharge from pig-lead
and also the smelting of metals from their ores and slags.
The furnace when working with lead may be of non water jacketed either up to
the top or at least 4 or 3 feet fiom the bottom, but in working zinc or other metals
an ordinary fireclay furnace is sufficient. The furnace at the bottom may have a
moveable or other sloping side for one half of the diameter and the other half may
be basin shaped so as to catch any melted metal and ends outside the walls of the
furnace so that as this fills up it can be extracted from the furnace without
sto ping the operation, suitable provision being made for the removal of the slag
and cleaning of the furnace. The great difference between this and all other
processes is that as a rule no solid fuel is used whatever, but when necessary
may have a small layer of hard carbon such as is formed in gas retorts when
carbonising coal.
I
The gas jet together with the heated air is forced under pressure into the
furnace when the ore is to be volatilized, which may be made to strike just at the
top of the sloping bottom. The furnace is made as air-tight as possible, only
sufficient air being introduced to produce complete combustion and this when
necessary is introduced by means of tuyeres supplied with either cold or heated air.
In working with lead or zinc the ore is sprinkled through the top of the furnace by
any of the well-known methods and falling through the heated furnace into the
flame is at once volatilized and passed off to the condenser. Any of the ore being
reduced into metal falls into the basin at the bottom of the furnace which will
contain also the silver present in the ore.
By this process 1 not only save the expense of coke as fuel and consequent

page_text: labour of re-charging, but also I prevent the forming of any large quantity of slag
and the process is therefore worked with practically no waste. Furthermore, the
condensing of the lead or zinc fume is now accomplished at a greatly less cost, for
previously some means had to be adopted of drawing the fume away from the
furnace by means of fans or steam meldrums and forcing it through the condensers
in order to collect it and prevent it escaping into the atmosphere. By putting the
gas into the furnace under pressure I can create a pressure which will drive the
fume without the need of any outside agent into the condensers. Although I
claim this I do not bar myself from still using some other agent such as steam or
fans if the particular metal I am working should so require it. I simply claim to
collect my fume in any of the well-known methods and that it can be done in the
manner above described far more economically than heretofore.
When I require to make litharge from pig-lead I keep my basin always full of
melted lead with the flame playing over it. I also if necessary use a small jet of
steam to play on the top of the melted lead which not only keeps the oxidation but
blows the litharge to the side of the basin and which can then be collected in the
ordinary way by the man in charge.
When treating rough ores, slags or residues for the extraction of the metals
contained therein I fill up my furnace with them and then heat up the furnace with
the gas under pressure in combination with the heated air, the metal is recovered
in the bottom of the furnace,-suitable provision being made for the removal of the
residues from the furnace after the metal has been extracted either by means of a
door or other outlet placed in a convenient part of the furnace.
Having the gas etc., under perfect control any heat can be obtained sufficient to
melt almost any metal, whilst if in any case the heat is too high it can be at once
reduced which is impossible when ordinary fuel such as coal or coke is used.
My invention therefore consists particularly in the use of gas under pressure in
conjunction with heated air for the conversion of galena into white compounds of
lead by volatilisation, likewise the same from zinc ores into white compounds of
zinc also the extraction of all kinds of metals, lead, zinc, iron, antimony &c.,
either from their ores, slags, or residues to be done in a certain manner as before
explained.
Dated this 24th day of July 1895.
JOHNSONS,
115 St. Vincent Street, Glasgow.
COMPLETE SPECIFICATION.
Improvements in the Process for the Volatilization of Galena into
White Compounds of Lead, and of Zinc into White Compounds
of Zinc, the Making of Litharge, and the Smelting of Metals
from their Ores or Slags.
I, ANDREW CHARLES JOSEPH CHARLIER, of 107 Breadalbane Terrace, Hill
Street, Glasgow, in the County of Lanark, North Britain, 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 improvements in the volatilization of galena into white
compounds of lead: the making of litharge and the smelting of metals such as
lead, zinc, iron, antimony & the like, from their ores or slags. Many patents have
been taken out from time to time for the volatilizing of galena or sulphide of lead
into white compounds of lead to be used as pigments, also the manufacture of oxide
of lead from pig lead, also the conversion of zinc ores into similar white pigments,

page_text: and finally the smelting of metals from their ores or from slags and residues
containing metal. The great expense of fuel and upkeep of furnaces and complete
condensation of products, and labour, has, however, prevented previous processes
from being universally adopted.
I am now able to overcome all these difficulties by using gaseous fuel such as
ordinary coal gas previously compressed up to a pressure of say 60 lbs., and
working in conjunction with an air blast heated up to the required temperature,
according to the metal I propose to work. The process is intended to apply more
particularly to the volatilization of lead and zinc compounds but with slight
modifications in the furnace it can be used also for making litharge from pig-lead
and also the smelting of metals from their ores and slags.
The furnace employed when working lead is eight feet high and four feet broad,
from the bottom to four feet from the top, in other words half of the furnace is
made of iron, water jacketed, through which water is made to run to keep it cool;
the upper part of the furnace is built of fire brick, and in the cover there is an
automatic feeder for sprinkling the lead regularly over the surface of the furnace,
the pipe conducting the lead fumes from the furnace into the condenser is also in
the top of the furnace.
The air pipe is lead round and round outside the upper part of the furnace so as
to heat the air before it enters the furnace in conjunction with the gas.
The principal construction about the furnace is the bottom, it has not an
ordinary flat bottom but is made partly sloping and partly saucer shaped the
sloping bottom extending only over half the area of the bottom, and ends in
a saucer shaped receptacle which completes the remaining portion of the bottom.
The gas and air are forced into the furnace just where the slope begins.
In charging the furnace for making white lead from lead ore, galena (otherwise
known as sulphide of lead) is used. After the furnace has been heated to the
proper temperature the feeder at the top is filled with galena, a small quantity of
the ore being continually sprinkled into the furnace and as it comes in contact with
the gas flame it volatilizes into sulphate of lead and passes off in a state of fume or
smoke and is collected in the condenser connected with the furnace. Any of the
ore which may not at once be volatilized falls down the slope into the saucer where
it eventually becomes reduced into metallic lead, the saucer also catches any silver
which may be in the ore and which will not volatilize with the lead.
The saucer shaped portion of the bottom extends a few inches outside the end of
the furnace so that when the receptacle becomes full of metal it can be removed
from the furnace without stopping the operation.
The sloping side is removable so that when required the interior of the furnace
can be cleaned.
Exactly the same process is adopted in working zinc ores.
In making litharge the feeder at the top of the furnace is not employed but the
furnace is filled with pig or scrap lead and the gas applied which melts the lead
and fills up the basin with molten lead. As soon as enough lead has been melted
the gas flame in combination with the heated air is played over the surface of the
molten lead. This at once oxidises the lead into litharge which forms at the top
and is blown to the end of the basin which extends outside the furnace when it is
removed by the man in charge.
A fresh surface of molten lead is exposed to the gas and air flame and so
continued until the whole of the lead has been formed into litharge, more pig lead
being added from time to time so as to keep the molten lead always level with the
top of the basin.
In treating or working antimony or iron ores or rough ores, slags and residues,
the furnace is identical in construction except that it can be made entirely of fire
bricks thus doing away with the iron water jacket; the furnace is charged with
ore, slags etc. after they are broken up and the highest heat possible to be obtained
by the air and gas is employed by which means any metals contained in the slags
ores, etc. are melted out and fall into the basin at the bottom of the furnace whilst

page_text: the earthy or non-metallic substances contained in the slags etc. float on the top of
the molten metal. The metal is removed from time to time from the basin
after the earthy matter has been removed from the top through the door of the
furnace employed for this purpose.
Having the gas etc., under perfect control any heat can be obtained sufficient to
melt almost any metal, whilst if in any case the heat is too high it can be
at once reduced which is impossible when ordinary fuel such as coal or coke
is used.
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 :-
The use of gas under pressure in conjunction with heated air for the conversion
of galena into white compounds of lead by volatilisation, likewise the same from
zinc ores into white compounds of zinc also the extraction of all kinds of metals,
lead, zinc, iron, antimony &c., either from their ores, slags or residues, in the
manner and with the furnaces as herewith described.
Dated this wond dow of A 1905
:
JOHNSONS,
115 St. Vincent Street, Glasgow, Applicant's Agents.
JOHNSONS,
115 St. Vincent Street, Glasgow, Applicant's Agents.