Improved Method of Treating Galvanizers' Flux Skimmings to Recover Ammonia and Facilitate the Extraction of the Zinc, with Apparatus for Use therein.
Year: 1895

page_text: Date of Application, 21st Mar., 1895
Complete Specification Left, 30 h Nov., 1895-Accepted, 11th Jan., 1896
PROVISIONAL SPECIFICATION.
Improved Method of Treating Galvanizers' Flux Skimmings to
Recover Ammonia and Facilitate the Extraction of the Zinc,
with Apparatus for Use therein.
We, CHARLES GEORGE TOWNSEND BENNETT, and EDWARD HENRY
SHORTMAN, of Pelsall, Staffordshire, Manufacturers, and BENJAMIN BRACEY, of
Avondale Road, St. Georges, Bristol, Engineer, do hereby declare the nature of
this invention to be as follows:-
This invention consists of the hereindescribed improved method of treating
galvanizer's flux skimmings to recover ammonia and facilitate the extraction of
the zinc with apparatus for use therein. Heretofore in the process of smelting
galvanizer's flux skimmings to recover the ammonia and zinc the presence of
ammonia has created difficulty with the manufacturer and further has resulted in
a loss of both zinc and ammonia. By our invention we are able to recover the
ammonia and to facilitate the extraction of the zinc.
In carrying out our invention the galvanizer's flux skimmings are pulverised as
thoroughly as possible by some suitable machine. The pulverised skimmings are
then mixed in a separator with milk of lime and sufficient hot water to keep the
mixture fluid until the separation of the ammonia is complete. The solution should
be kept agitated and boiling until all the ammonia is extracted and it is then run
into settling tanks and allowed to settle until all the water can be run off quite
clear, after which the remaining sediment may be placed upon metallic plates over
flues to dry or be otherwise sufficiently dried when it will be in such form that the
zinc may be extracted by ordinary well known methods.
The separator which we employ for the process stated above may be a horizontal
wrought iron boiler provided with a dome and a pipe of sufficient diameter and
height to prevent the carrying over of lime to the condenser and the separator
should contain an agitator. The separator is or may be erected in brickwork at a
height of about five feet more or less above the firebars of the furnace in order to
secure uniform heat around the separator.
The ammonia upon leaving the separator as stated above is conducted by a large
iron or other suitable pipe to a condenser of any suitable form which should be
fixed sufficiently high to deliver into a store tank, the bottom of the said store
tank being high enough to deliver into a distilling machine for distilling the
ammonia.
Dated this 20th day of March 1905.
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.

page_text: Improved Method of Treating Galvanizers' Flux Skimmings to
Recover Ammonia and Facilitate the Extraction of the Zinc,
with Apparatus for Use therein.
We, CHARLES GEORGE TOWNSEND BENNETT, and EDWARD HENRY
SHORTMAN, of Pelsall, Staffordshire, Manufacturers, and BENJAMIN BRACEY,
late of Avondale Road, St. Georges, Bristol, now residing at Pelsall, aforesaid,
Engineer, do hereby declare the nature of this invention and in what 'inanner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This invention consists of the hereindescribed improved method of treating
galvanizer's flux skimmings to recover ammonia and facilitate the extraction of
the zinc with apparatus for use therein. Heretofore in the process of smelting
galvanizer's flux skimmings to recover the zinc, the presence of ammonia has
created difficulty with the manufacturer and further has resulted in a loss of some
of the zinc and the whole of the ammonia. By our invention we are able to recover
the ammonia and to facilitate the extraction of the zinc.
In carrying out our invention the galvanizer's flux skimmings are pulverized as
thoroughly as possible by some suitable machine. The pulverized skimmings are
then mixed in a separator with milk of lime containing sufficient hot water to keep
the mixture fluid until the separation of the ammonia is complete. During this
process the solution should be kept agitated and boiling until all the ammonia is
extracted and it is then run into settling tanks and allowed to settle until all the
water can be run off quite clear, after which the remaining sediment may be placed
upon metallic plates over flues to dry or be otherwise sufficiently dried when it
will be in such form that the zinc may be extracted by ordinary well known
methods.
a
The proportion of the milk of lime which we use with the pulverized galvanizer's
flux skimmings depends upon the quality of the lime and the particular sample
of skimmings to be acted upon, but it will be understood that sufficient milk of
lime has to be used as will neutralize the acid in the said skimmings.
The separator which we employ for the process stated above may be a horizontal
wrought iron boiler provided with a dome and a pipe of sufficient diameter and height
to prevent the carrying over of lime to the condenser. This pipe serves as a
purifier. The separator should contain an agitator. The separator is or may be
erected in brickwork at a height of about five feet more or less above the firebars
of the furnace in order to secure uniform heat around the separator.
The ammonia upon leaving the separator as stated above is conducted by a large
iron or other suitable pipe to a condenser of any suitable form which should be
fixed sufficiently high to deliver into a store tank, from which the liquid may be
used as required.
The accompanying drawing illustrates in sectional elevation an apparatus suitable
for the practical carrying out of this invention. A is the separator which is a
wrought iron boiler, circular in cross section, and made with flat ends with a man-
hole B through which the separator is charged with the pulverized galvanizer's flux
skimmings, the milk of lime required being first run in the separator by the tap C.
The separator is fitted with an agitator consisting of flat iron bars d¹ bolted to
arms d² which are fixed to a square shaft d³, passing through the centre of the
boiler, which shaft can revolve in suitable bearings a a² and at one end d passes
through the gland as and stuffing box a'. Rotary motion is communicated to the
separator shaft d³ d by any convenient means. The furnace grate (not shewn on
the drawing) for heating the separator A is situated somewhere about say five

page_text: feet more or less below the bottom of the separator. The separator may be set.
like a steam boiler. As the ammonia leaves the separator A it passes up the
large iron pipe E serving as a purifier which by preference contains small hard
cinders e or other suitable material, supported by a perforated bottom plate e¹,.
through which the ammonia gas percolates leaving any particles of lime or other
matter behind and preventing them from being carried over to the condenser F.
The gases leave the large outlet pipe or purifier E by the pipe 9 and pass up.
through the small enclosed tank k and pipe h to the condenser which is a square
wooden tank F fitted with a coil of pipes i through which the moist gases pass,
this tank F being supplied with cold water so that the gas in the pipes becomes.
condensed into a solution of ammonia before it reaches the exit j from which it can
be run into a store bank. The small tank k into which the gas flows by the pipe g
before it enters the pipe is provided so that any gases condensed may be caught.
in this tank and return through the down pipe to the separator A, thus allowing
only the moist ammonia gas to pass through the pipe / to the condenser.
water supply tap and pipe by which water can be supplied from the condenser
tank F into the top of the pipe E so as to cleanse the cinders or like material e
N is a brick tank into.
therein, the water running through into the separator A.
which the charge can be run from the separator A by the tap O after the ammonia.
has been extracted and in which tank N the charge will rapidly settle down so that.
the water can be run off or otherwise removed and then the remaining material.
removed and placed upon driers to be dried for the smelting of the zinc.
m is a
It will be evident that instead of employing the cinders or like material e² in the
purifier pipe E, and which enable us to make this pipe E comparatively short as
shewn, we may dispense entirely with the cinders or like material e and make.
the pipe much higher so as thereby to prevent any lime or other material other
than ammonia gas passing into the condenser.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In treating galvanizer's flux skimmings to recover the ammonia and facilitate
the extraction of the zinc, mixing the pulverized flux skimmings with milk of lime
in a heated vessel or separator to free the ammonia therefrom, substantially as.
hereinbefore described.
2. In treating galvanizer's flux skimmings to recover the ammonia and facilitate
the extraction of the zine, mixing the pulverized flux skimmings with milk of lime
in a closed heated vessel or separator and condensing the ammonia gases arising.
therefrom, substantially as herein before described.
3. The method of treating galvanizer's flux skimmings to recover the ammonia
and facilitate the extraction of the zinc, consisting in mixing the pulverized flux
skimmings with milk of lime in a closed heated vessel or separator, condensing the
ammonia gases arising therefrom, running off the residue from the separator, and
finally drying the said residue, substantially as herein before described.
4. The method of treating galvanizer's flux skimmings to recover the ammonia.
and facilitate the extraction of the zinc, consisting in mixing the pulverized flux
skimmings with milk of lime and water in a closed heated vessel or separator,.
condensing the ammonia gases arising therefrom, running off the residue from the
separator into settling tanks, removing the liquid portion from the settling tanks,
and finally drying the residue, substantially as herein before described.
5. In an apparatus for treating galvanizer's flux skimmings to recover the
ammonia and facilitate the extraction of the zinc, the combination of a closed.
boiler or separator containing an agitator, a large outlet pipe or purifier, leading
from the top of the same, and a condenser connected by pipes to said purifier, the
whole so arranged that the pulverized flux skimmings and milk of lime are heated
and agitated in the separator and the gases arising therefrom pass through the

page_text: said outlet pipe or purifier into the condenser and are condensed and form a solution
of ammonia, substantially as hereinbefore described.
6. In an apparatus for treating galvanizer's flux skimmings to recover the
ammonia and facilitate the extraction of the zinc as claimed by the fifth claiming
clause hereof, the combination with the said separator of settling tanks and means
for running the residue from the separator after the ammonia has been extracted,
substantially as hereinbefore described.
7. The combination and arrangement of parts constituting the apparatus
herein before described and illustrated by the accompanying drawing for the
i purpose set forth.
Dated this 29th day of November 1895.
CHARLES BOSWORTH KETLEY,
Agent for the Applicants.