IMPROVEMENTS IN PROCESSES AND APPARATUS FOR OBTAINING USEFUL PRODUCTS IN THE TREATMENT OF GALVANIZERS FLUX AND OTHER MATTERS
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Hartley Kenyon at the Office of the
Commissioners of Patents on the 2nd December 1882.
HARTLEY KENYON of Altrincham in the County of Chester, Manufacturing
Chemist, "IMPROVEMENTS IN PROCESSES AND APPARATUS FOR OBTAINING USEFUL
PRODUCTS IN THE TREATMENT OF GALVANIZERS FLUX AND OTHER MATTERS
"
My Invention has for its principal object to utilise galvanizers flux and thereby
to obtain zinc paint and other useful products. I employ two retorts or ovens
which may be built back to back each being-say for example about fifty feet long
and having a heated floor declining from the mouth or inlet towards a finishing
bed and an arched crown. The floors are supported by long pillars which divide
the space below into flues. In some or in all of these pillars I form conduits for
the heating of air and in some I fix steam pipes for superheating steam. I convey
superheated steam and air into a gas-producer and burn the gas below the floors of
the retorts. The gas is introduced at the back end and flows to the front and
returns to the back where it flows upwards into a flue formed between the crown
and a short inner arch which covers the finishing bed. Air is introduced to
support combustion and to furnish oxygen. The gases flow over the bed towards
the front end. I prefer to use Harly coal or other coal rich in nitrogen in the gas
production. I may use coke or other suitable fuel in place of gas in the beating
of the retorts. I take a portion of galvanized flux lixiviate it removing a portion
of the chlorides. A portion of the vat liquor may be concentrated to obtain zinc
and ammoniacal salts. The vat liquor and mother liquor I use in my processes.
I feed flux on to the floor of a retort which I will term number one and work the
said flux down towards the finishing bed. The gases passing from the lower flues
are mingled with heated air and pass over the floor Chlorides of zinc, ammonia
and iron being liberated. The gases and vapours are conducted into the first of a
series of absorbers which may be boiler shells or cylindrical iron shells. In each
absorber a shaft carrying agitators is fitted to revolve to throw up spray and to
bring the vapours into contact with the charges in the absorbers. I charge the
first absorber with milk of ordinary lime or of magnesium lime. The greater part
of the free ammonia passes off with the hot vapours from the first absorber into

page_text: The
a second absorber into which the liquid or semi-liquid matters from the first
absorber are also conveyed. In this absorber I nearly saturate the lime or
magnesium lime with vat liquor or mother liquor obtained as aforesaid
vapours are passed over into the third absorber which is charged with vat or
mother liquor. The ammonia combines with chlorine and the zinc and iron are
precipitated as oxides. Any excess of ammonia in the liquor from this absorber I
fix by adding thereto a further quantity of vat liquor and a little sulphide of
ammonium The semi-liquid or pasty matters from the second absorber are run
or fed on to the floor of number two retort which by preference is also charged
with spent flux and with the precipitated zinc and iron from the second and
third absorbers. The gases and vapours from this retort are led into the first or
the third absorber. In the number one retort oxide of zinc is left and in the
number two retort oxide of zinc and chloride of calcium or of magnesium are left.
These products are obtained from the residues by ordinary or suitable operations.
To maintain the required flow of gases and vapours through the apparatus I use
an exhausting, ejecting or pumping apparatus. In place of the lime I may use
caustic aminonia, sulphide of ammonium, sulphide of calcium, sulphide of sodium
or caustic soda. Instead of returning the products of combustion over the floor of
the retort I may convey hot unburnt gas from the producer over the floor carrying
over the gas into the absorber subsequently utilising the gas as fuel. In some
cases to obtain ammoniacal salts I pa-s gas from the producer into the retort which
is charged with galvanizers flux, chloride of iron, chloride of manganese or sulphate
of iron the gas being conveyed from the retort into the bottom of a large chamber
and passed out at the top to be consumed or stored. In another process I wash
the said gas with sprays of solutions of any of the last named salts and condense
the vapour to obtain ammoniacal salts.