IMPROVEMENTS IN THE PREPARATION OF SULPHATE OF MAGNESIA APPLICABLE TO THE TREATMENT OF THE CRUDE POTASH SALTS OF STASSFURT, AND THE REFUSE FROM THE MANUFACTURE OF CHLORIDE OF POTASSIUM
Year: 1867

page_text: LETTERS PATENT to Charles Albisser, of 11, Mincing Lane, in the City of
London, for the Invention of "IMPROVEMENTS IN THE PREPARATION OF
SULPHATE OF MAGNESIA APPLICABLE TO THE TREATMENT OF THE CRUDE POTASH
SALTS OF STASSFURT, AND THE REFUSE FROM THE MANUFACTURE OF CHLORIDE
OF POTASSIUM."-A communication from abroad by Julius Vorster
and Hermann Grüneberg, residing at Cologne, in the Kingdom of
Prussia.
Sealed the 6th March 1868, and dated the 29th November 1867.
PROVISIONAL SPECIFICATION left by the said Charles Albisser at the
Office of the Commissioners of Patents, with his Petition, on the 29th
November 1867.
I, CHARLES ALBISSER, of 11, Mincing Lane, in the City of London, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE PREPARA-
TION OF SULPHATE OF MAGNESIA, APPLICABLE TO THE TREATMENT OF THE CRUDE
POTASH SALTS OF STASSPURT, AND THE REFUSE FROM THE MANUFACTURE OF CHLORIDE
OF POTASSIUM," to be as follows:-
The Stassfurt Abraum salts, and also the refuse salts of the muriate of
potash manufactory, contain muriates of potash, of soda, of magnesia, anhydrit
clay, and sulpbate of magnesia in varying proportions. The sulphate of
magnesia is contained therein in chemical combination with one equivalent
of water (MgO, SO, × HO), and is called as such kieserit, which is
insoluble in cold water in its natural state. To obtain it in a pure form fit.

page_text: for use for manufacturing purposes I put the above mentioned crude and
refuse salts containing kieserit into flat fine sieves; those sieves are hung in
tubs filled with water, and in consequence the mass in the sieves is submitted
to the action of water. From the different substances contained in the crude
salts only the soluble parts, as muriate of potash, common salt, muriate of
soda, and muriate of magnesia dissolve and become a liquor, whilst the kieserit,
which is about 16 per cent. of the mass, goes through the sieve in the form of
a fine crystalline powder, and collects itself on the bottom of the tub like
starch flour. As the different salts contained with the kieserit in the crude
salts and refuse salts as above mentioned dissolve, and the insoluble parts of
the salts and refuse salts, viz., the anhydrit and clay remain for the most
part on the sieve I obtain on the bottom of the tub the kieserit in a nearly
pure form. The kiescrit thus obtained hardens itself very soon, a part of it
combining itself with water, and cementing the powder together. After
having drawn the salt liquor from the tub the kicserit is broken out from the
bottom, and submitted to a strong calcination. Or the kieserit can also be
parted from above-mentioned impurities without the application of sieves by
simple solution in water, and then cleansing the kieserit from impurities. I
prefer however the above specified process. After calcination I grind the
kieserit pieces very fine, and so obtain a material readily soluble in water, and
much richer in sulphate of magnesia than the ordinary commercial Epsom
salts. When it is stirred well in water it heats itself vehemently, and dissolves
very easily, combining itself with 7 equivalents of water. The solution can
be crystallized if desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Albisser in the Great Seal Patent Office on the
29th May 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
ALBISSER, of 11, Mincing Lane, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by. Her Letters
Patent, bearing date the Twenty-ninth day of November, in the year of our
Lord One thousand eight hundred and sixty-seven, in the thirty-first year of
Iler reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Albisser, Her special licence that I, the said Charles Albisser,
my executors, administrators, and assigns, or such others as I, the said
Charles Albisser, my executors, administrators, and assigns, should at any

page_text: time agree with, and no others, from time to time and at all times there-
after 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 "IMPROVE-
MENTS IN THE PREPARATION OF SULPHATE OF MAGNESIA, APPLICABLE TO THE TREAT-
MENT OF THE CRUDE POTASH SALTS OF STASSFURT, AND THE REFUSE FROM THE
MANUFACTURE OF CHLORIDE OF POTASSIUM," a communication to me from abroad.
by Julius Vorster and Hermann Grüneberg, persons resident at Cologne, in
the Kingdom of Prussia, upon the condition (amongst others) that I, the said:
Charles Albisser, 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 Seal Patent. Office within six calendar months next and.
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Albisser, do hereby declare
the nature of the said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
The Stassfurt Abraum salts and the refuse salts of the muriate of potash.
manufactory contain muriates of potash, of soda, of magnesia, anbydrato.
clay, sulphate of magnesia in varying proportions. The sulphate of magnesia
is contained therein in chemical combination with one equivalent water-
(MgO SO. +HO), and is called as such kieserit, which is insoluble in
cold water in its natural state.
A Patent dated the 23rd day of September last was granted to Augustus
Ziegele for the manufacture of Epsom salts from these crude salts. The
kieserit which the crude salts contain may however be separated and manu-
factured into a form in which it is commercially useful without hydrating the
sulphate of magnesia so as to bring it to the state in which it is commonly
known as Epsom salts. The preparation of such sulphate of magnesia from
crudo salts containing kieserit is the object of the present Invention. To
obtain it in a pure form the above-mentioned crude and refuse salts con-
taining kieserit are put into flat fine sieves, these sieves are hung in tubs.
filled with water, and in consequence the water is in contact with the mass
in the sieves. From the different materials contained in the salts only
the soluble parts, as muriate of potash, common salt (muriate of soda),
and muriate of magnesia dissolve. The kieserit of which there is about
16% in the mass however goes through the sieve in form of fine crystal

page_text: powder, and collects at the bottom of the tub like starch flour. As the
soluble salts contained with the kieserit in the above-mentioned crude salts and
refuse salts dissolve, and the insoluble parts of the crude salts and refuse
salts, viz., the anhydrit and clay remain for their principal part in the sieve,
I obtain on the bottom of the tub the kieserit in a nearly pure form. The
kieserit thus obtained hardens very soon, a part of it combining itself
chemically with water, and in crystallizing cements the powder together. After
having drawn off the salt liquor from the tub the kieserit is broken out from
the bottom. The washing process may be otherwise conducted to separate
the kieserit from the soluble and insoluble impurities, but the use of sieves in
the manner described is preferred. The purified kieserit so obtained is dried
by strong calcination. By this calcination the kiescrit pieces are transformed
into a state about equal to burnt limestone; the material is ground very fine,
and in this form it may be sent into the market. It may be used for the
purposes for which crystallized Epsom salts are ordinarily employed, and
frequently its use is more advantageous as it contains a considerably higher
per-centage of sulphate of magnesia than crystallized Epsom salts, and the
cost of crystallization is saved. When it is required for use it is stirred well
in water, it heats itself vehemently and dissolves very easily. By this
operation it combines itself with 7 equivalents water and can therefore be
crystallized.
The manufacture of crystallized Epsom salts from this calcined material is
very simple.
It is sufficient to hydrate the calcined kieserit by treating the
same with cold or hot water, then to clear the liquor if necessary, and to
evaporate the same, and crystallize in the ordinary way. The principal point
is to obtain a complete hydration of the calcined material, which is obtained
by treating again and again with water the parts of the calcined material
which are not transformed by the first hydration.
In witness whereof, I, the said Charles Abisser, have hereunto set my
hand and seal, this Twentieth day of March, in the year of our Lord
One thousand eight hundred and sixty-eight.
CHARLES ALBISSER. (L.S.)