IMPROVEMENTS IN THE MANUFACTURE OF COPPERAS, APPLICABLE TO THEBLE TO THE PURIFICATION OF ILLUMINATING GAS AND TO OTHER PURPOSES
Year: 1868

page_text: LETTERS PATENT to Peter Spence, of Newton Heath, Manchester, in
the County of Lancaster, Manufacturing Chemist, for the Invention
of "IMPROVEMENTS IN THE MANUFACTURE OF COPPERAS, APPLICABLE TO THE
Sealed the 23rd March 1869, and dated the 26th September 1868.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the
Office of the Commissioners of Patents, with his Petition, on the
26th September 1868.
I, PETER SPENCE, of Newton Heath, in the County of Lancaster,
Manufacturing Chemist, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF COPPERAS, APPLICABLE TO THE
PURIFICATION OF ILLUMINATING GAS AND TO OTHER PURPOSES," to be as
follows:-
My Invention consists in the production of copperas from compounds
of iron in a proto state by treatment with sulphuric acid. The substance
I prefer is the slag of puddling furnaces, commonly called tap cinder,

page_text: or the slag which results from regulus during the process of smelting
copper ores, but other proto compounds in a native state or arising from
manufactures may be employed, of the former of which I give as
examples the Cleveland and black band iron stones. These substances
having been ground are treated in an ordinary manner with sulphuric
acid in a suitable vessel, and the result is copperas in a dry powdery
condition, applicable to the purification of gas from ammonia or to other
ordinary manufacturing purposes in which copperas is required. If it
be desired to produce the usual copperas of commerce it may be
obtained by dissolving the dry powdery mass in an ordinary manner,
and then crystallizing it as usually practised in such processes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Peter Spence in the Great Seal Patent Office on
the 25th March 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PETER
SPENCE, of Newton Heath, Manchester, in the County of Lancaster,
Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of September, in the
year of our Lord One thousand eight hundred and sixty-eight, and in the
thirty-second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Peter Spence, Her special license that I,
the said Peter Spence, my executors, administrators, and assigns, or
such others as I, the said Peter Spence, 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 MANUFACTURE OF
COPPERAS, APPLICABLE TO THE PURIFICATION OF ILLUMINATING GAS AND TO OTHER
PURPOSES," upon the condition, amongst others, that I, the said Peter
Spence, 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

page_text: months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Peter Spence, 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 :-
In carrying out my Invention for improvements in the manufacture
of copperas applicable to the purification of gas and other purposes I
take iron ores that contain a large amount of proloxide of iron, and
I prefer that they should contain not less than 25 to 30 per cent. of
iron in the state of proloxide. The iron ores suitable for my purpose
include the clay ironstones, the Cleveland volitic iron ores, the Lin-
colnshire ores, and others, provided they have not been weathered and so
converted into peroxides of iron, and any other orcs in which the iron is
chiefly in the condition of proloxide, prolosilicate, or prolocarbonate. I
also use the slags from the ore furnace of the copper smelter, which con-
tain a large quantity of protosilicate of iron, and other slags of similar
composition. These ores and slags I grind to powder, and I find that
the powder is fine enough when passed through a sieve of twenty meshes
to the lineal inch. I now take, say, 200 lbs. of this powder, and having
ascertained its proportion of iron in the state of protoxide, I calculate the
quantity of acid required to combine with all the iron contained as
named. The powder is put into a shallow basin in the floor of the
house, and when the acid to be used is sulphuric acid of the ordinary
chamber strength of 120 degrees of Twaddle's hydrometer, or 1.6 specific
gravity, then before adding the acid I give an ordinary bucketful of
water and mix it with the powder in the basin, if the ore contains from
50 to 55 per cent. of iron in the state of protoxide. I now add an equal
weight or 200 lbs. of the acid of 1.6 specific gravity, and more or less
according to the proportion of protoxide of iron in the powder; the
workman now stirs the mixture with an iron rake or shovel, bringing
up the powder from the bottom of the basin into the liquid; in a few
minutes it heats and becomes semi-liquid, then boils and almost instantly
becomes a pasty mass, it is then thrown out, and when cool becomes
perfectly dry. Instead of mixing water with the powder before adding
the acid I find it profitable to use from four to six bucketfuls, or, say, 8
to 12 gallons of the mother liquor of the alum manufacture, which
contains sulphate of iron, alum, and free sulphuric acid, and I find that

page_text: when the alum mother liquor so used is of the specifice gravity of 1.3,
then whatever weight of it I so use I can deduct half of such weight
from the acid to be subsequently added; or I can use instead of water
or alum mother liquor the liquor produced in ordinary copperas, making
as it runs from the copperas bed where iron pyrites is allowed to
decompose by atmospheric action, and when using this liquor I can
deduct one-third of its weight from the quantity of acid to be subsequently
added to the powder on which I am operating, and I find that in each
of these cases the required action takes place, and the product is equally
dry and fit for the purposes to which I apply it. The substance produced,
as described, and which I have named dry copperas, may be used for
nearly all the purposes for which crystalised green copperas or prolo-
sulphate of iron is now used, the solution obtained from the dried powder
by hot water being nearly identical with a solution of green copperas,
and fitted for similar uses. The special purpose for which I have found
the dry copperas extremely suitable is the purification of illuminating
gas from compounds of ammonia, and subsequently from sulphuretted
hydrogen, and for both these purposes it can be used in the ordinary
dry lime purifyers. Crystalised copperas mixed with sawdust and other-
wise has long been used for separating ammonia compounds from
illuminating gas, but great complaints have arisen of its allowing
ammonia to pass, the crystalised form not being mechanically well
adapted for the retention of these compounds. The dry copperas as
made by my Invention. I find from its granular form will not allow any
of the ammonia to pass until all the sulphate of iron in the dry copperas
is decomposed; its open grained condition and comparative freedom
from water of crystalisation also prevent its becoming clammy, and so
causing obstruction to the passing of the gas. After passing illumi-
nating gas through the dry copperas till all the acid is combined with
ammonia and the iron is precipitated, I find that though no longer
capable of abstracting ammonia it is now specially adapted for the
decomposition and separation of sulphuretted hydrogen, all that is
required being that the material have air passed through it alternately
with the gas, as is well known, or that it be thrown out of the
purifiers and be allowed to lie for a few hours to oxidise the iron, when
it is again fitted for use, and I find that it is more easily oxidised than
the greater portion of the natural oxides of iron now used for purifying
illuminating gas from sulphuretted hydrogen. A similar compound
which I also name dry copperas, but restricted in its use to the purifi-

page_text: cation of illuminating gas from ammonia and sulphuretted hydrogen,
as described, I make by substituting the muriatic acid of commerce for
sulphuric acid, and in making this article I use no water or liquor. To
200 lbs. of the powder containing 50 to 55 per cent. of protoxide of
iron I take 400 lbs. of the muriatic or hydrochloric acid of commerce
and proceed to mix in a similar manner. The action is the same, and
when the pasty substance obtained is mixed with sawdust or other
drying body it is thereby converted into a dry granular mass fitted for
purification of gas, as described, and I so use it when preferred.
Having thus described and ascertained the nature of my said Inven-
tion and the manner in which the same is to be performed, I desire it
to be understood that I claim as secured to me under the above in
part recited Letters Patent, the use of the substance which I have
named dry copperas, made substantially as described for the purposes
above set forth.
In witness whereof, I, the said Peter Spence, have hereunto set my
hand and seal, this Twenty-fourth day of March, in the year of
our Lord One thousand eight hundred and sixty-nine.
PETER SPENCE. (L.S.)