Im- PROVEMENTS IN TREATING PYRITES, AND IN OBTAINING SULPHATE OF SODA PROVISIONAL SPECIFICATION
Year: 1871

page_text: LETTERS PATENT to Emil Königs, Manufacturing Chemist, of
Westhofen, in Westphalia, but at present residing at Maryhill, in
the County of Lanark, North Britain, for the Invention of "Im-
PROVEMENTS IN TREATING PYRITES, AND IN OBTAINING SULPHATE OF SODA
PROVISIONAL SPECIFICATION left by the said Emil Königs at the
Office of the Commissioners of Patents, with his Petition, on the
30th March 1871.
I, EMIL KÖNIGS, Manufacturing Chemist, of Westhofen, in West-
phalia, but at present residing at Maryhill, in the County of Lanark,
North Britain, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN TREATING PYRITES, AND IN OBTAINING SULPHATE OF SODA
AND OTHER PRODUCTS," to be as follows, that is to say :-
This Invention has for one of its objects the obtaining of sulphate of
soda in a more direct, simple, and economical manner than hitherto,
and also comprises the obtainment of other products arising from the
same general process.

page_text: The Invention consists in taking raw pyrites, common salt, and oxide
of iron, in the form, by preference, of burnt iron pyrites, all in coarse
powder, forming them into bricks with the aid of a little water, and,
after drying them heating or igniting these bricks in a reverberatory
or other suitable, furnace, care being taken to arrange the bricks in the
furnace, so that gases and steam may have free access between and
amongst them. Heat generated by means of ordinary fuel is at first
applied, but the application is discontinued after the chemical reaction
is once started; when the flue leading to the chimney is closed, the
ash-pit door partly closed, and another flue is opened to lead the vapors
or fumes to any suitable condenser. Steam is then led into the furnace
and decomposes the chloride of iron formed in the reaction, yielding
hydrochloric acid which passes to the condenser.
If the heat is regulated so as to be comparatively moderate, the bricks
will after the operation contain sulphate of soda, salts of iron, and an
insoluble compound of iron, which last on being burned yields red oxide
of iron or iron minium, suitable as a coloring matter for paint.
With a stronger heat, assisted if necessary by a coke fire, the iron
salts will be decomposed by the action of the steam, hydrochloric acid
being driven off, leaving an insoluble oxide of iron and a tolerably pure
sulphate of soda which can be dissolved out.
When the pyrites employed contains copper, this metal may be
separated from the solution formed after the heating operation by
precipitating it by means of iron or by other known means.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Emil Königs in the Great Seal Patent Office
on the 29th September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMIL
KÖNIGS, Manufacturing Chemist, of Westhofen, in Westphalia, but
at present residing at Maryhill, in the County of Lanark, North Britain, 3
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of March, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-

page_text: fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Emil Königs, Her special licence
that I, the said Emil Königs, my executors, administrators, and assigns,
or such others as I, the said Emil Königs, 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, excrcise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN TREATING PYRITES,
AND IN OBTAINING SULPHATE OF SODA AND OTHER PRODUCTS," upon the
condition (amongst others) that I, the said Emil Königs, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, 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 Scal
Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Emil Königs, 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 in writing, that is to say :—
My said Invention has for one of its objects the obtaining of sulphate
of soda in a more direct, simple, and economical manner than hitherto,
and also comprises the obtainment of other products arising from the
same general process.
In practising my said Invention according to one modification I take
raw pyrites, chloride of sodium (common salt), and oxide of iron; this
last by preference in the form of burnt iron pyrites, all in coarse powder,
and in the proportions of about 15 parts by weight of pyrites, containing
48 per centum of sulphur, 30 parts burnt pyrites, and 20 parts chloride
of sodium.
The proportions are to be modified according to the per-centage of
sulphur in the pyrites. Sulphide of iron and oxide of iron may be
substituted for the pyrites, and burnt pyrites or partially burnt pyrites
may be used instead of the mixture of burnt and unburnt pyrites. Where
considerations of economy do not prevent it chloride of potassium may
be substituted for the chloride of sodium. It is not essential to adhere
precisely to the proportions stated, as where pyrites is cheap a larger

page_text: proportion of it may be used, and will serve to supply a portion of the
heat and so save fuel; whilst where it is costly the proportion of it
may be reduced to what is barely necessary to decompose all the chloride
of sodium without loss of sulphurous acid. The mixture is, with the
aid of a little water, formed into bricks or blocks of any convenient
shape, but by preference of a thickness of about two inches; and after
being dried these bricks are heated or ignited in a reverberatory or other
suitable furnace, care being taken to arrange them in the furnace, so
that gases and steam may have free access between and among them.
Heat obtained by ordinary fuel is at first applied, either directly or by
means of air heated to the requisito degree, but the application of licat
when direct, and not by means of air, is discontinued after the chemical
reaction is once started, and then the flue leading to the chimney is
closed, and the fuel withdrawn from the fire grates; steam is at the
same time led into the furnace, and the vapors or fumes are led by
passages or flues to condensers of the kind usually employed for
condensing hydrochloric acid. The condensing towers will not require
to be supplied with as much water as usual since the steam will furnish
a nearly sufficient quantity. When applying heat directly the ash-pit
door is left partly open after the withdrawal of the fuel, so as to admit
along with the steam as much air as is requisite for oxidation, and when
heating with hot air the supply of air is diminished as soon as the bricks
become hot enough and the chemical reaction is started, being adjusted
as nearly as possible to what is required along with the steam for the
chemical action in the furnace.
If the heat is regulated so as to be comparatively moderate, the bricks
after crushing and lixiviation, which last should be assisted by agitation,
will yield sulphate of soda, residual oxide of iron, salts of iron, and an
insoluble compound of iron, the last named being diffused in a state
of fine slime through the agitated solution of sulphate of soda. The
solution is kept standing in tanks in a heated state until the slime
subsides; and this slime is separated, dried, and calcined, preferably in
the form of bricks, and if previously well washed will yield iron minium
of good quality, suitable as a coloring matter for paint. The solution
of sulphato of soda obtained from the moderately burnt bricks is
concentrated and crystalised, and the mother liquor may be used for
lixiviating fresh quantities or for moistening the materials when making
them into bricks. The crystals thus obtained will contain some iron and

page_text: perhaps other impurities, depending on the composition of the pyrites
employed; they are therefor to be dissolved with the aid of heat; the
solution purified by adding hydrate of calcium, filtered, and again
crystalised to obtain pure sulphate of soda.
If the first solution contains copper, which will be the case when
cuprcous pyrites has been employed, this metal is precipitated from the
solution by means of iron, or otherwise, the solution being kept hot to
prevent crystalisation.
When a strong heat has been applied to the bricks, and which should
be assisted if necessary by firing with coke towards the end of the
process, particularly if the air admitted has been cold, all the iron salts
will have been decomposed by the action of the steam, hydrochloric acid
being driven off, and an insoluble oxide of iron left with scarcely any
slime, whilst the sulphate of soda will be comparatively pure. The
bricks are roughly crushed and the salts are dissolved out with warm
water or with warm dilute solutions derived from previous operations.
This process may be conducted as in dealing with calcined alum schist
or with black ash, provided it is done rapidly and continuously so as to
avoid crystalisation in the mass of materials. The sulphate of soda
obtained from the solution by evaporating, salting out, and calcining may
be used at once for making soda in the black ash furnace. If the
pyrites contains any copper it will be found in the solution, and may be
precipitated by iron aided with a little acid, and after the removal
of the copper any zinc, and the iron dissolved whilst precipitating ;
the copper or otherwise may be precipitated by hydrate of calcium.
The supernatant solution may then be filtered and the sulphate of soda
crystalised out of it. The hydrochloric acid obtained in the process has
about the strength and color of crude commercial acid if the steam has
not been in excess.
Having thus particularly described my said Invention, and the manner
of performing the same, I have to state that what I believe to be novel
and original, and claim as secured to me by the herein-before in part
recited Letters Patent is, -
1. The heating and treating with air and steam, bricks or blocks
composed of pyrites, burnt pyrites, and chloride of sodium, or the
equivalents herein-before referred to, to obtain sulphate of soda or of
potash and other products, as herein-before described.

page_text: 2. The modes herein-before described of heating mixtures of sulphides
and chlorides, made into bricks or blocks, whereby the admixture of
carbonic acid or coal smoke with the hydrochloric acid is avoided.
3. The obtaining of iron minium suitable as a coloring matter for
paint from the materials employed in making sulphate of soda, as herein-
before described.
In witness whereof, I, the said Emil Königs, have hereunto set
my hand and scal, this Twenty-eighth day of September, in the
year of our Lord One thousand eight hundred and seventy-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
EMIL KONIGS. (L.S.)