AN IMPROVED PROCESS FOR THE UTILIZATION OF GALVANIZER'S FLUX OR SKIMMINGS, AND OBTAINING AMMONIA AND ZINC PRODUCTS THEREFROM
Year: 1883

page_text: LETTERS PATENT to Thomas Kenyou of Eccles in the County of Lancaster
for an Invention of "AN IMPROVED PROCESS FOR THE UTILIZATION OF
GALVANIZER'S FLUX OR SKIMMINGS, AND OBTAINING AMMONIA AND ZINC
PRODUCTS THEREFROM.”
PROVISIONAL SPECIFICATION left by the said Thomas Kenyon at the
Office of the Commissioners of Patents on the 16th August 1883.
THOMAS KENYON of Eccles in the County of Lancaster AN IMPROVED PROCESS
FOR THE UTILIZATION OF GALVANIZER'S FLUX OR SKIMMINGS AND OBTAINING
AMMONIA AND ZINC PRODUCTS THEREFROM
This invention relates more particularly to the better working of the liquors
obtained in the ordinary treatment of the waste galvanizer's flux or skimmings by
lixiviation with water in vats. As this washing is well understood and often
carried on, no description of it need be given here further than to say that the flux
or skimmings by the washing process is converted into an insoluble portion, and
a soluble portion or liquor which alone is treated in the improved method herein-
after described.
The improved process is based on the fact that by means of an alkali, an alkaline
earth or a Carbonate of such alkali or alkaline earth, a separation of the zinc and
Ammonia contained in the flux liquor may be made, and each substance brought
into a form useful and readily saleable.
In carrying out my improved process I take liquor obtained from lixiviation of
the galvanizer's flux or skimmings as above mentioned, consisting mainly of
chloride of zinc and chloride of ammonium in watery solution and add thereto
sufficient of an alkaline base to combine with the chlorine contained in such liquor
as chloride of lime, leaving the zinc as oxide. The alkalies and alkaline earthis,
Potash, Soda, Lithia, Lime, Baryta, Strontia, and Magnesia or a mixture of any two
or more of them or their several Carbonates may all be used for this purpose, but

page_text: for very obvious reasons I give preference to Lime in the form known as Milk or
Cream of lime.
The liquor used may be strong or weak. I prefer it moderately strong as the
after treatment dilutes it.
I am particularly careful to add lime, only in sufficient quantity to decompose
the zinc salt contained in the liquor, leaving the ammonia salt undecomposed.
I am aware that this liquor has been utilized before this time by adding an alkaline
base (preferably lime) in sufficient quantity to combine with all the chlorine
contained in the liquor. The ammonia being thus liberated has been driven away
by distillation by the application of heat, and received in acids to form salts of
Ammonia, but my process substitutes crystallization for distillation and effects a
saving of acid.
At the same time I do not debar myself from taking liquor produced in my
process as above and by adding a further excess of lime or other alkalino hase
working the same by the continuous process of distillation for making ammoniacal
salts.
The liquor and milk of lime may be mixed cold, in any suitable vessel; in this
case much agitation is necessary and ammonia may be lost; therefore I prefer
mixing in a closed vessel fitted with inlet and outlet pipes for admission and exit
of liquor and lime, also with a perforated pipe for adinission of steam into the
mixture. Such a vessel being provided I introduce a quantity of liquor produced
from flux, or skimmings as before mentioned, and put in enough milk of lime to
decompose-the-zinc-salts, leaving-the-ammonia-salt intact-as-mentioned--before-
The two fluids may be pumped in or allowed to flow by their own gravity. A very
simple chemical test and calculation will shew the amount of lime liquor required
for any known amount of flux liquor in the decomposing vessel.
"I next close all openings into this vessel and turn on steam through the perforated
pipe, when the re-action is completed, the exit cock is opened, and the mixture runs
off into a settling tank provided for its reception; where it is allowed to remain at
rest until settled.
In this settling tank will now be found a clear solution of chloride of Calcium,
and chloride of ammonium, and a precipitate or mud of oxido of zinc containing
some chloride. The clear liquid being run off is evaporated in the ordinary way
and gives, after such evaporation followed by the necessary cooling, crystals of good
anarketable muriate of ammonia. The zinc mud remaining in the settling tank is
rich and reasonably pure, and may be utilized in many ways, which it is needless
here to specify.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Kenyou in the Patent Office on the 15th February 1884.
THOMAS KENYON of Eccles in the County of Lancaster AN IMPROVED PROCESS
FOR THE UTILIZATION OF GALVANIZER'S FLUX OR SKIMMINGS, AND OBTAINING
AMMONIA AND ZINC PRODUCTS THEREFROM
This invention relates more particularly to the better working of the liquors
obtained in the ordinary treatment of the galvanizers waste flux or skimmings by
lixiviation with water in vats, and as this process is well known no description of
it need be given except to say that the flux is separated into an insoluble part, and
a soluble part called liquor. My invention is applied to the liquor though I can
use the original flux but I prefer to treat the liquor. In carrying out my process
I take liquor as above mentioned and ascertain by the ordinary chemical test its
proportion of chlorine and ammonia I then to a certain weight of the liquor, add
sufficient milk of lime to combine with a portion of the chlorine leaving the
remainder of the chlorine united with ammonia or chloride of ammonium.
every seventeen parts of anhydrous ammonia in the liquor I must leave
35.5 parts of chlorine untouched but all the rest of the chlorine may be combined
with lime and will require for every 35.5 parts, 28 parts of pure anhydrous lime in
the form of a thick milk. I prefer a strong liquor for this treatment as the addition
of milk of lime, and after proceedings dilute it.
For
This operation may be performed in an open vessel in the cold, but as heat and
pressure accelerate and improve the process I introduce the solutions mixed in
proportions as above either together or separately into a closed vessel. or still
containing a perforated iron pipe below the level of the liquor. such pipe being
connected with a steam boiler under ordinary working pressure. This vessel or
still is also fitted with pipes for the introduction and withdrawal of the liquid
contents.
Steam is now introduced and pressure applied until the decomposition is
complete, all opening into the still being closed excepting the steam entrance
By fixing in this still a small pipe and cock which may be opened or closed
at pleasure, a rough test may be applied to ascertain whether sufficient lime has
been used.
The rule is to add milk of lime until after a thorough mixture; a sample of
steam allowed to escape from this pipe smells faintly of Ammonia, When the
reaction is completed the exit cock is opened, and the mixture runs off into a
settling tank provided for its reception, where it is allowed to remain at rest until
settled.
In this settling tank will now be found a clear solution of cloride of calcium and
chloride of ammonium and a precipitate or mud of oxide of zinc containing some
chloride.
The clear liquid being run off is evaporated in the ordinary way and gives after
such evaporation followed by the necessary cooling, crystals of good marketable
muriate of ammonia.
The zinc mud remaining in the settling tank is rich and reasonably pure and
may be utilized in many ways, which it is needless here to specify.
Í do not confine myself to the use of lime in this process as Potash, Soda, baryta,
strontia, or magnesia may be used, or their carbonates, but for obvious reasons limo
is the best and I prefer it.
I am aware that galvanizers flux, or flux liquor has been decomposed by means
of lime before, which has however been used in excess, thus necessitating a distil-
lation or furnacing to drive off the Ammonia. I use contrary to this a deficiency

page_text: of lime and do away with this distillation or furuacing and work by means of
crystallization. I also utilize the muriatic acid contained in the flux.
Having now described the nature and object of my said Invention and in what
manner the same is to be performed I wish it to be understood that I do not claim
as my invention the total decomposition of the flux liquor by an alkali, alkaline
earth or carbonate of such alkali or alkaline earth, because such decomposition
(combined with solution of the ammonia as gas and in combination with acids) has
been carried on previously, but I claim as a working process
The partial decomposition of flux liquor by means of an insufficient quantity of
alkali, alkaline earth or carbonate of alkali, and the subsequent recovery of muriate
of ammonia from the same by evaporation and crystallization substantially in the
manner and for the purposes bereinbefore set forth.
-
In witness whereof I the said Thomas Kenyon have hereunto set my hand and
seal this Fourteenth day of February in the year of our Lord one thousand eight
hundred and eighty four