Improvements in the Treatment of Waste Pickle from Galvanizing Works and other such like Acid Liquors, and in the Apparatus employed therefor.
Year: 1889

page_text: Date of Application, 29th Oct., 1889
Complete Specification Left, 23rd July, 1890-Accepted, 23rd Aug., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Waste Pickle from Galvanizing
Works and other such like Acid Liquors, and in the Apparatus
employed therefor.
I THOMAS TURNER of 217 Ladywood Road Birmingham in the County of Warwick
Lecturer on Metallurgy do hereby declare the nature of my said invention to be as
follows:-
My invention has for its object improvements in the treatment of waste pickle from
galvanizing works, and other such like acid liquors and in the apparatus employed
therefor so that such liquors may be more fully utilized than heretofore. For this
purpose I apply heat to the liquors in the manner and in the apparatus hereafter to be
explained while air and steam or either air or steam is at the same time introduced
into the said apparatus.
In carrying out my invention I use a reverberatory furnace made of fire brick set in
a mixture of tar and fire clay mortar. The furnace is built with a low arch and a
solid bottom is constructed of bricks set in tar and fire clay. The furnace is fitted
with working openings and with a pipe or pipes passing through the upper part of the
furnace for carrying away the regenerated acid. The waste liquor which may have
been previously concentrated if desired is introduced from above through a suitable
pipe or pipes passing through the roof or sides of the furnace and being distributed to
the pipe or pipes by means of suitable troughs or pipes, with taps or other arrange-
ments outside the furnace to allow the attendant to regulate the amount of acid in any
part of the furnace, but these details may be considerably varied.
The hottest part of the furnace or apparatus is at a low red heat. This heat may
be produced by any fuel or in any suitable manner such as by the use of gas or waste
heat, but I have found the waste coke from galvanizing pots either alone or in mixture
with fresh coke to be a very suitable fuel.
Though I prefer that my furnace should be a self contained reverberatory furnace
with its own combustion chamber it will be quite evident that a separate chamber
vessel may be used with similar effect and the heat conducted to it in any desired
manner.
Hitherto an insuperable difficulty has been met with in the effort to obtain a furnace
capable of resisting the action of an acid liquid containing a large quantity of salt
or salts in solution. This I overcome as follows. I make the bottom of the furnace
in the shape of a very shallow basin, and have the upper courses of brickwork set as
carefully as possible so as to avoid leakage during the first working of the furnace.
I also prefer to insert an impervious layer such as a joint of sulphur or other material
a few courses above the ground line of the furnace. But I do not depend upon these
materials to render the furnace impervious to liquid except during the first working
of the furnace. In starting the furnace the temperature is raised to about a low red
beat before any waste liquor is introduced. The liquor is then run in slowly and
gradually becomes concentrated.
This very concentrated liquor gradually permeates the brickwork or other material
used for the furnace bottom and cements it into a hard solid impervious mass.
Thus the deposit from the liquor itself forms for itself an impervious working
bottom when a foundation for the same is formed either as before described or in a
similar manner or with other material.
In the subsequent working of the furnace care is taken to run in the waste liquor
only as fast as it is evaporated, and only a shallow layer of concentrated liquor is
allowed to remain in the furnace. A layer or cake of more or less basic chloride of
iron is thus produced and completely protects the furnace bottom. When a sufficient

page_text: thickness of this crust has been formed the supply of acid may be stopped for a time
so as to raise the temperature of the furnace somewhat so as to dry the chloride of iron
and allow of its more ready removal from the furnace bottom. The cake is then
broken up and heated either in the hotter end of the same, or another furnace, to a
temperature not exceeding a dull red heat. The chloride of iron in contact with air,
and the acid water vapours present in the furnace is decomposed yielding oxide of
iron and hydrochloric acid. Care must be taken to conduct the roasting in such a
manner as to prevent the passing over of brown fumes of ferric chloride.
The oxide of iron may be used for such purposes as its special freedom from injurious
impurities render it suitable. The hydrochloric acid is condensed in the usual way
with pipes tanks or towers.
GEORGE BARKER,
77,. Colmore Row, Birmingham, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Waste Pickle from Galvanizing
Works and other such like Acid Liquors, and in the Apparatus
employed therefor.
I, THOMAS TURNER of 217 Ladywood Road, Birmingham, in the County of Warwick,
Lecturer on Metallurgy do hereby declare the nature of iny said invention, and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
My invention has for its object ;-improvements in the treatment of waste pickle
from galvanizing works, and other such like acid liquors and in the apparatus employed
therefor; so that such liquors may be more fully utilized than heretofore. For this
purpose, I apply heat to the liquors in the manner, and in the apparatus hereinafter to
be explained while air and steain, or either air or steam, is at the same time introduced
into the said apparatus.
In carrying out my invention I use a reverberatory furnace made of fire-brick set
in a mixture of tar and fire clay mortar or other acid resisting mortar or cement. The
furnace is built with a low arch which may be more or less raised at the hot end of
the furnace and a solid bottom is constructed of bricks set in tar and fire clay or other
acid resisting cementing material. The furnace is fitted with working openings and
with a pipe or pipes passing through the upper parts of the furnace for carrying away
the regenerated acid. The waste liquor which may have been previously concentrated
by the waste heat from the furnace itself, or other means, if desired, is introduced
from above through a suitable pipe or pipes passing through the roof or sides of the
furnace, and being distributed to the pipe or pipes by means of suitable troughs or
pipes with taps or other arrangements outside the furnace to allow the attendant to
regulate the amount of acid in any part of the furnace; but these details may be con-
siderably varied. The hottest part of the furnace or apparatus is at a low red heat.
This beat may be produced by any fuel or in any suitable manner, such as by the use
of gas or waste heat, but I have found the waste coke from the galvanizing pots,
either alone or in mixture with fresh, to be a very suitable fuel. Though I prefer
that my furnace should be a self contained, reverberatory furnace with its own com-
bustion chamber, it will be quite evident that a separate chamber or vessel may be
used with similar effect and the heat conducted to it in any desired manner..
Hitherto an insuperable difficulty has been met with in the effort to obtain a furnace
capable of resisting the action of an acid liquid containing a large quantity of salt or
salts in solution. This I overcome as follows:-I make the bottom of the evaporating
part of the furnace in the shape of a very shallow basin and have the upper courses of
brickwork set as carefully as possible so as to avoid leakage during the first working
of the furnace. I also prefer to insert an impervious layer, such as a joint of sulphur,
puddle, asphalt, acid resisting cement, concrete or other impervious material a few
courses above the ground line of the furnace.

page_text: This impervious joint, may also, if desired, be carried partly up the sides of the solid
bottom as shewn in the drawings, but should not be carried quite to the bed of the
furnace itself.
But I do not depend upon these above mentioned materials to render the furnace
impervious to liquid except during the first working of the furnace. In starting the
furnace, the temperature is raised to about a low red heat before any waste liquor is
introduced. The liquor is then run in slowly, and gradually becomes concentrated.
This very concentrated liquor gradually permeates the brickwork or other material
used for the furnace bottom and cements it into a hard, solid, impervious mass. Thus
the deposit from the liquor itself forms for itself an impervious working bottom when
a foundation for the same is formed either as before described or in a similar manner
or with other material. By carrying out the process as described a tight bottom can
be made of almost any material such as ashes, sand, pebbles, &c., &c., but the method
I have described I have found to produce the best results. In the subsequent working
of the furnace care is taken to run the waste liquor only as fast as it is decomposed
and only a shallow layer of concentrated liquor is allowed to remain in the furnace.
A layer or deposit of more or less basic chloride of iron is thus produced and com-
pletely protects the furnace bottom. When a sufficient thickness of this crust has
been formed, the supply of acid may be stopped for a time so as to raise the tempera-
ture of the furnace somewhat, so as to dry the chloride of iron and allow of its more
ready removal froin the furnace bottom or the chloride of iron may be removed by
suitable scrapers while in a thick or pasty condition and may be then either pushed
onto the hotter part of the furnace which is used for roasting or it may be drawn out
of the furnace when it almost instantly solidifies and may then be very conveniently
handled. The distribution of the liquor and handling of the precipitate may be
assisted by suitable mechanical contrivances if desired. The solid chloride of iron in
either form is then heated either in the hotter part of the same, or another furnace, to
a temperature not exceeding a dull red heat.
The chloride of iron in contact with air and the acid water vapours present in the
furnace is decomposed, yielding oxide of iron and hydrochloric acid; care must be
taken to conduct the roasting in such a manner as to prevent the passing over of
brown fumes of ferric-chloride. The formation of these brown fumes is to a great
extent, obviated by passing the gases from the roasting part of the furnace over the
evaporating portion, since the excess of steam in the latter part of the furnace at once
decomposes the ferric chloride which may pass over. This being shown in the
drawings. It will thus be seen that my process is quite distinct from evaporation and
roasting in the ordinary sense of these terms since these two operations are continuously
carried on side by side in the same furnace or vessel and when working in the usual
manner continuous, destructive, distillation takes place though I may occasionally for
special reasons conduct only evaporation or roasting in the furnace at one time. The
strength of the acid may be increased or decreased at will by conducting a larger or
smaller proportion of roasting in the furnace at a given time: usually however I
produce a strength suitable for reuse in galvanizing works.
The oxide of iron may be used for such purposes as its special freedom from injurious
impurities renders it suitable. The hydrochloric acid is condensed in the usual way,
with pipes, tanks and towers.
To enable others to more readily carry my invention into practical effect I have
appended hereunto a double sheet of drawings showing the furnace I have found to
answer best, though many alterations may be made therein without departing from
the principle of the invention.
Figure 1. is a side elevation of the furnace.
Figure 2. is a longitudinal sectional elevation of the furnace on line A. B.
Figure 3. is a sectional plan of the furnace on line C. D.
Figure 4. is a cross section on line E. F.
The furnace has a low arch H extending the whole length but it may be made
higher over the roasting floor; if desired. The arch is carried by strong side walls W
with iron stays w¹ and rods to hold them in their relative positions to each other. The

page_text: solid bottom J is made of fire brick set in tar and fire clay or other acid resisting
cementing material. The impervious layer, which may be of any convenient thickness
is shown by K which may be carried up at the sides as shewn . The ordinary
working openings R. enable the attendant to operate the furnace with facility and of
these there may be any number. The openings R' are into the combustion chamber
which is separated froin the roasting hearth by the bridge T. The pipe S carries
away the regenerated acid to be dealt with in the usual way by pipes, tanks and
towers. The waste liquid is conducted to the furnace through the pipe or pipes M by
the trough N and the quantity regulated by the tap n¹. The operation of the furnace
may be assisted by mechanical appliances for removing the chloride from the bottom
of the furnace to the roasting hearth j and for withdrawing the same.
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 improvements in the treatment of waste pickle from galvanizing works and
other such like acid liquors and in the apparatus employed therefor; substantially as
herein set forth and illustrated by the drawings.
Dated this 22nd day of July 1800
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent for the Applicant.