Improvements in the Production of Sulphide of Zinc and Chloride of Ammonium.
Year: 1886

page_text: Date of Application, 9th Dec., 1886.
Complete Left, 9th Sept., 1887
Complete Accepted, 11th Oct., 1887.
Improvements in the Production of Sulphide of Zinc and Chloride
of Ammonium.
I HARTLEY KENYON of No. 7, Barrett Street, Manchester, in the County of Lancaster,
Manufacturing Chemist, do hereby declare the nature of this Invention to be as
follows:-
-
In the galvanising of iron, zinc waste, usually containing or accompanying zinc,
iron, lead, manganese, chlorine and ammonia is produced. The operation for removal
of the iron and manganese is usually attended with difficulty. I take such waste and
therewith saturate hydrochloric acid or I disintegrate the waste, wash it with water
and with the waters resulting from previous washings, in order to remove the soluble
salts. The washed matters may then be drained and dried and be employed to saturate
hydrochloric acid. In either case I add sulphuric acid in quantity sufficient to com-
bine with the lead. The resultant is filtered, whereby carbon, silica, sulphate of lead
and perhaps glycerine and other matters are eliminated. The liquor passing the filters
is charged into an agitator and is therein treated with ammonia to take up the zinc
and precipitate the iron and manganese. In my process I require chloride of zinc and
this I obtain by dissolving in hydrochloric acid zinc, zinc skimmings or dross or
suitable matters containing zinc, iron, manganese and lead if present being eliminated.
I charge a second agitator with the liquor resulting from the operations in the first
named agitator and I treat such liquor with sulphide of hydrogen until the zinc has
become precipitated and the ammonia has become saturated with sulphide of hydrogen.
Into the resultant liquor I pass the chloride of zinc until the zinc is precipitated in
the form of sulphide leaving chloride of ammonium in solution. I prefer to obtain
the said sulphide of hydrogen from soda-makers waste in the following manner.
use a "bone pan
" which for convenience may have its bottom divided into passages
covered by perforated grids. The pan may have sloping sides and roof and be pro-
vided with barrow openings. I charge the soda waste into such pan and pass steam
which may be superheated into the said passages. The steam by contact with the
waste is decomposed oxygen remaining in combination in the pan and sulphide of
hydrogen passing off into the agitator. I charge the aforesaid chloride of ammonium
I

page_text: into a furnace having one bed above another and provided with steam heating
chambers. The chloride is charged on to the upper bed and is passed through or over
by means of a rake or by suitable means. A lower chamber is supplied with hydro-
carbons and hot air to raidiate heat to the upper and lower beds. The heat in the
bottom furnace or chamber is maintained below the burning point of sulphur. The
sulphide of zinc is charged into this part and is carried forward by means of a rake
or by suitable means. The chloride of ammonium is driven into one of two side
chambers. To facilitate the sublimation of the chloride of ammonium superheated
steam may be employed.
Dated this 8th day of December 1086

page_text: COMPLETE SPECIFICATION.
Improvements in the Production of Sulphide of Zinc and Chloride
of Ammonium.
I HARTLEY KENYON of No. 7 Barrett Street, Manchester, in the County of Lancaster,
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:-
In the galvanising of iron zinc waste usually containing or accompanying zinc iron
lead chlorine manganese and ammonia is produced. The removal of the iron and
manganese in the ordinary manner is attended with difficulty. The principal objects
of my invention are to facilitate the elimination of the iron and manganese and to
obtain ammonium chloride from the resultant. I obtain the precipitation of the iron
and manganese as oxides by agitating the dissolved matters so as to bring the iron
and manganese into intimate contact with the air. I prepare a saturated solution of
the waste by means of hydrochloric acid or I disintegrate the waste and wash it with
water or with the liquors resulting from previous washing operations in order to
remove the soluble salts such for example as the chlorides of zinc and ammonia or
the double chloride of zinc and ammonia. The washed matters are then drained and
if preferred are dried, and may be employed to saturate hydrochloric acid the resultant
solution being available for use in the obtainment of a further quantity of zinc
chloride. To the hydrochloric acid solution of the waste or to the liquor resulting
from the washing of the waste as aforesaid I add sulphuric acid in sufficient quantity
to precipitate the lead if it is considered to be advisable to remove this metal
separately. The liquor is then filtered to remove matters held in suspension such for
example as carbon silica and sulphate of lead. The liquor passing through the filters
is then treated with ammonia to take up the zinc and is agitated to oxidise the iron
and manganese. For this part of the process I may use any suitable agitator which
will agitate the solution in contact with air as for example a revolving shaft furnished
with arms or beaters which are only partly immersed may be used or jets of air under
pressure may be discharged into the solution. During this treatment the iron and
manganese combine with oxygen and are precipitated. I now charge a second agitator
with the supernatant liquor from the first agitator and treat the liquor with hydrogen
sulphide until the zinc has become precipitated as sulphide and the ammonia has
become saturated with hydrogen sulphide. I may obtain the hydrogen sulphide from
soda makers waste which I charge into a suitable pan or chamber and pass superheated
steam into the said waste. The steam is decomposed oxygen remaining in combination
in the pan and hydrogen sulphide passing into the agitator. I do not however confine
myself to any particular method of producing the said gas. I prepare a solution of
zinc chloride by dissolving in hydrochloric acid zinc skimmings or dross or other
suitable matters containing zinc and I pass this solution into the sulphide of ammonia
liquor in or obtained from the second agitator until the zinc is precipitated in the form
of sulphide leaving ammonium chloride in solution. I charge the supernatant solution

page_text: into a furnace wherein the solution is evaporated until the ammonium chloride is
sublimed. I convey the sublimed chloride into a suitable chamber or into chambers in
which the chloride is deposited. To facilitate the sublimation I may pass steam into
and through the furnace the steam carrying forward the chloride into a suitable cooler
or condenser. I may vary the process by charging the furnace with the associated
chloride and sulphide without separation the chloride being sublimed and the sulphide
left behind in the furnace.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is :-
(1) The complete process for the recovery of sulphide of zinc and chloride of
ammonium from galvanisers waste substantially as set forth.
(2) In the treatment of such waste for the obtainment of sulphide of zinc and
chloride of ammonium the precipitation of iron and manganese from the solutions of such
waste by agitating the solutions so as to convert the said metals into oxides substantially
as set forth.
(3) The recovery of chloride of ammonium from solutions derived from the said
waste and containing the chloride by sublimation substantially as set forth.
Dated this 8th day of September 1887
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.