OTHER WHEN IN CONJUNCTION, AND IN OBTAINING USEFUL PRODUCTS THEREFROM
Year: 1854

page_text: OTHER WHEN IN CONJUNCTION, AND IN OBTAINING USEFUL PRODUCTS THEREFROM."
PROVISIONAL SPECIFICATION left by the said James Higgin at the
Office of the Commissioners of Patents, with his Petition, on the 4th
April 1854.
I, JAMES HIGGIN, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MODE OR METHOD OF SEPARATING METALS FROM EACH OTHER
WHEN IN CONJUNCTION, AND IN OBTAINING USEPUL PRODUCTS THEREFROM," to be as
follows:-
I propose to obtain from the refuse clippings of tin plate the metal, tin, or
any of its salts, and after having so freed the iron from the tin or the greatest
portion of it, to render the same more fit for certain purposes. The method by
which I effect this object is to act on the tin plate with acid liquids or vapours,
in such a manner that only a small portion of the iron is dissolved, whilst the
tin is removed in solution, and from this solution the tin is either thrown down
[Price 8d.]

page_text: as metal by zinc; or an oxide of tin is obtained by means of an alkali, from
which oxide I then prepare any of the salts of tin, in the manner well known
by any practical chemist. I prefer muriatic acid, either alone or in com-
bination with other substances, for removing the tin, but do not confine myself
to that acid, as other acids will answer the same purpose, but perhaps not
so effectually.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Higgin in the Great Seal Patent Office on the 4th
October 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. JAMES
HIGGIN, of the City of Manchester, in the County of Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Royal
Letters Patent, bearing date the Fourth day of April, in the year of our Lord
One thousand eight hundred and fifty-four, in the seventeenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Higgin, Her special licence that I, the said James Higgin,
my executors, administrators, and assigns, or such others as I, the said James
Higgin, my executors, administrators, and assigns, should at any time agree
with, and no others. from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE MODE OR
METHOD OF SEPARATING METALS FROM EACH OTHER WHEN IN CONJUNCTION, AND IN
OBTAINING PRODUCTS THEREFROM." upon the condition (amongst others) that I,
the said James Higgin, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Royal Letters Patent.
NOW KNOW YE, that I, the said James Iliggin, do hereby declare the
nature of my said 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):-
My Invention consists in utilising the refuse pieces of tin plate from various
manufactures where tin plate is used. This substance consists of thin plates

page_text: of iron covered with tin, either pure or mixed with small quantities of other
metals, and I propose to separate the external coating and leave the iron in a
fit state to be worked up again for various useful purposes, at the same time
economising the tin taken off, by making therefrom metallic tin, or varions
salts or preparations of tin.
My method is to steep the scrap of tin in an acid or acid mixture, whereby
a solution of the tin ensues, and my process is as follows:-Into a large
cistern, which may be of wood, lead, stone, or other suitable metal or material
(but I prefer stone when convenient). I throw the scrap tin, pressing it down as
much as possible until the cistern is full. I then run into the cistern muriatic
acid, diluted with two parts of water, until the tin is covered, by which hydrogen
gas is disengaged and the tin is dissolved. When all the tin appears to be
taken off the scrap, I run off the liquor by means of a tap at the bottom of
the cistern, and then pump water on the scrap until it is covered. and after-
wards draw off the wash water into a separate vessel; I then empty the cistern
of the stripped scrap and fill it again with a fresh quantity, and then pump on
it the acid liquor drawn off the previous charge. I thus continue this process
until the acid is saturated, and will dissolve no more. I subject the liquor to
the treatment hereafier described, and make use of the wash water to dilute a
fresh quantity of acid. The stripped scrap, consisting of iron only, is available
for reworking into bar iron or other suitable purposes. As, however, in this
process a considerable quantity of iron is lost by solution. I have discovered
that by a suitable addition of some oxidising agent the tin is removed sooner,
and the iron scarcely acted upon. The substances 1 have found most advania-
geous are, nitrate of soda, bi-chromate of potash, peroxide of manganese, and
per salts of iron, but those mixtures which produce chlorine are preferable.
I prefer a mixture of muriatic acid and nitrate of soda, because the chlorine
is only liberated as wanted, and it has the property of forming a salt of
ammonia by the action of the scrap, and muriatic acid on the nitrate of soda,
which ammonia can be easily collected at a further stage of the process. The
proportions I have found most efficient are, 16 cwt. of muriatic acid at 36°
Twaddell's hydrometer, 14 cwt. nitrate of soda of commerce, and 320 gallons
of water, which mixture is used as above described. The solution of the
metals containing tin and iron with small quantities of other metals is now
run off into a cistern, where powdered chalk is added until effervescence no
longer ensues. The liquor is then left to settle, the clear liquor then drawn
off, and the precipitate washed with water until it is free from muriate of
lime. It is then filtered to a paste, and consists principally of protoxide of tin,

page_text: The
some peroxide of tin, mixed with small quantities of other oxides.
powder when dried may be smelted in the ordinary manner to obtain metallic
tin, or dissolved in boiling caustic soda to make stannate of soda, which it
does by decomposing partly into metallic tin, or it may be dissolved in muriatic
acid and a salt of tin crystallised therefrom; or in cases where a salt of zinc
can be turned to a profitable use, pieces of zinc may be added to the solution
of metals as it leaves the tin scrap, when metallic tin will be precipitated and
zinc dissolved instead.
Another part of my Invention relates to cases where chlorine gas can be
cheaply made, and is as follows:-Into a pipe or other suitable vessel filled
with scrap tin I pass chlorine gas previously dried, by passing it over trays
filled with dry chloride of calcium. The tin is rapidly removed as bi-chloride
of tin, which is condensed in water at the other end of the vessel; a glass
plate is left in the side of the vessel, through which it can be seen when the
tin is all removed, at which time the connection is broken, and the chlorine
passed through another vessel with scrap, the stripped scrap being removed
from the vessel. By having two or more vessels suitably connected with the
chlorine still, a proper quantity of scrap can be stripped without loss of
chlorine. It is found better to heat the chlorine gently, by passing it through
heated stoneware pipes before it goes over the chloride of calcium, so as to
volatilize the bi-chloride of tin more perfectly. In this process some per-
chloride of iron is formed, which condenses at the further end of the pipes.
and can be easily removed by washing from the scrap.
The last portion of my Invention consists in obtaining ammonia or the
salts of ammonia from the liquor drawn off the precipitated oxide of tin.
This liquor, which contains muriate of ammonia. is put into a still, and some
hydrate of lime added, a fire is lighted. and the ammonia drawn over and
condensed in the usual manner.
Having thus fully described the nature and particulars of my said Invention.
I desire it to be distinctly understood that I do not confine myself to the
precise details herein set forth. as such may be varied or modified without
departing from the principle thereof; but I claim as my Invention, and
which, to the best of my knowledge and belief, has not been hitherto used within
this realm,-
Firstly, the use of acids. either alone or mixed with an oxidizing substance,
for the separation of metallic tin or preparations of it from scrap tin plate.
Secondly, the use of chlorine gas or a liquor containing chlorine, for the
same purpose.
!

page_text: Thirdly, the separation of ammonia as a bye-product in the process of
separating tin from scrap tin plate.
In witness whereof, I, the said James Higgin, have hereunto set my
hand and seal, this Third day of October, One thousand eight hun-
dred and fifty-four.
Signed, sealed, and delivered by the within-
named James Higgin in the presence of
E. J. HUGHES,
Patent Agent,
Manchester.
JAMES HIGGIN. (L.S.)