IMPROVEMENTS IN LIBERATING OR PRODUCING POTASH OR SODA, OR BOTH (AS THE CASE MAY BE), FROM NATURAL ALCALIPEROUS SILICATES, THE RESIDUUM OF THE PROCESS BEING AVAILABLE AS A MATERIAL FOR MANURE, PUZZOLANO, OR HYDRAULIC CEMENT
Year: 1857

page_text: LETTERS PATENT to. Frederick Oldfield Ward, of 12, Cork, Street,
Burlington Gardens, London, for the Invention of "IMPROVEMENTS IN
LIBERATING OR PRODUCING POTASH OR SODA, OR BOTH (AS THE CASE MAY
BE), FROM NATURAL ALCALIPEROUS SILICATES, THE RESIDUUM OF THE PROCESS
BEING AVAILABLE AS A MATERIAL FOR MANURE, PUZZOLANO, OR HYDRAULIC
CEMENT." Partly a communication from Frederick Wynants, a Belgian,
residing in Brussels.
Sealed the 9th March 1858, and dated the 30th December 1857.
PROVISIONAL SPECIFICATION left by the said Frederick Oldfield Ward
at the Office of the Commissioners of Patents, with his Petition, on the
80th December 1857.
I, FREDERICK OLDFIELD WARD, of 12, Cork Street, Burlington Gardens,
London, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN LIBERATING OR PRODUCING POTASH OR SODA, OB BOTH (AS THE CASE MAY BE),
FROM NATURAL ALCALIFEROUS SILICATES, THE RESIDUUM OF THE PROCESS BEING
AVAILABLE AS A MATERIAL FOR MANURE, PUZZOLANO, OR HYDRAULIC CEMENT," to
be as follows:-
This Invention has for its principal object the liberation of potash from
potash felspar (orthoclose) and from the more alcaliferous of the felspathic
rocks; it is also applicable to liberate soda from soda felspar (albite), potash
and soda from pummice and lava, and generally to liberate the alcaline bases
of such natural alcaliferous silicates as may prove rich enough to pay the
costs of the treatment.

page_text: The principal novelty of the Invention consists in the employment of
fluoride of calcium (fluorspar) to aid in effecting the above objects.
The fluoride of calcium is employed in conjunction with an earthy material
capable of decomposing alcaline silicates and fluosilicates, and for this purpose
lime, or its carbonate, or a mixture of the two, is preferred. This is believed
to be a novel combination. The mode of operating is very simple. The
natural silicate to be treated, the fluoride of calcium, and the earthy material
are pulverised and mixed in due proportion, the earthy material being in
excess of the silicate, and this again in excess of the fluoride of calcium. The
mixture is fritted at a proper heat, préferably in a reverberatory furnace, care
being taken to stir it during the process, and part of the earthy material being
in some cases stirred in gradually during the process. The frit thus obtained
yields caustic potash or soda, or both, in greater or less abundance (according
to the nature and richness of the natural silicate treated), when lixiviated,
boiled, digested, macerated, or otherwise suitably treated with water, to dissolve
out its soluble contents. The alcaline solution thus obtained from the frit
may either be used directly in the arts, or its alcaline contents may be
separated in the solid form, either as caustic alcali, or as carbonate, or other
salt at choice by the usual means. The frit as it comes from the furnace is an
alcaline fertiliser of very superior quality, and the residuum left after treatment
of the frit by water still retains considerable fertilising properties. This
residuum, when lightly calcined, makes an excellent puzzolano material, it
may also be employed with advantage in the manufacture of hydraulic cement.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Oldfield Ward in the Great Seal Patent Office on
the 30th June 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
OLDFIELD WARD, of 12, Cork Street, Burlington Gardens, London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of December, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Frederick Oldfield Ward, Her special licence, that I, the said Frederick
Oldfield Ward, and my executors, administrators, and assigns, or such others
as I, the said Frederick Oldfield Ward, or my executors, administrators, and

page_text: 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 andt
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 LIBERATING OR PRODUCING POTASH OR SODA,. OR
BOTH (AS THE CASE MAY BE), FROM NATURAL ALCALIPEROUS SILICATES, THE
RESIDUUM OF THE PROCESS BEING AVAILABLE AS A MATERIAL FOR MANURE, PUZZO-
LANO, AND HYDRAULIC CEMENT," partly my own Invention, partly communi-
cated by Frederick Wynants, a Belgian, residing in Brussels, upon the
condition (amongst others) that I, the said Frederick Oldfield Ward, or 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 per-
formed, 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.
i
NOW KNOW YE, that I, the said Frederick Oldfield Ward, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:-
This Invention has for its principal object the liberation of potash from
potash felspar (orthoclase) and from the more alcaliferous of the felspathic
rocks; it is also applicable to liberate soda from soda felspar (albite), potash
and soda from pummice and lava, and generally to liberate the alcaline bases
of such natural alcaliferous silicates as may prove rich enough to pay the
costs of the treatment.
The principal novelty of the Invention consists in the employment of fluoride
of calcium (fluorspar) to aid in effecting the above objects.
The fluoride of calcium is employed in conjunction with an earthy material
capable of decomposing alcaline silicates and fluosilicates, and for this
purpose lime or its carbonate, or a mixture of the two, is preferred. This is
believed to be a novel combination. The mode of operating is very simple.
The natural silicate to be treated, the fluoride of calcium, and the earthy
material are pulverised and mixed in due proportion, the earthy material
being in excess of the silicate, and this again in excess of the fluoride of
calcium. The mixture is fritted at a proper heat, preferably in a rever-
batory furnace, care being taken to stir it during the process. The frit
thus obtained yields caustic potash. or soda, or both, in greater or less
abundance (according to the nature and richness of the natural alcaliferous

page_text: silicitate treated) when lixiviated, boiled, digested, macerated, or otherwise
suitably treated with water to dissolve out its soluble contents. The alcaline
solution thus obtained from the frit, may either be used directly in the
arts, or its alcaline contents may be separated in the solid form, either as
caustic alcali, or as carbonate or other salt, at choice by the usual means.
The frit as it comes from the furnace, is an alcaline fertilizer of very superior
quality; and the residuum left after the treatment of the frit by water still
retains considerable fertilizing properties. This residuum, when lightly calcined,
makes an excellent puzzolano material, and may also be employed with
advantage in the manufacture of hydraulic cement.
And in order that the nature of this Invention, and the best means of per-
forming it with which I am acquainted may be fully made known and declared,
I would observe, with reference to the choice of an earthy material or materials
capable of decomposing alcaline silicates and fluosilicates by the mode of
operating described, that carbonate of lime is on the whole to be preferred, the
ordinary or the magnesian carbonate of lime being selected according to local
and other circumstances.
In determining the proportions of earthy material to be added to any given
silicate or mixture of silicates to be treated, regard is to be had to their
composition, and so much earthy material should be supplied that each
equivalent of alumina and each equivalent of silica in the mass treated may be
provided with three equivalents or thereabouts of earthy base, including as well
the proportion of earthy base contained in the alcaliferous mass treated as the
proportion furnished by the earthy material added. In some cases the quality
of the residuum of the operation may be improved as a cement material by the
admixture of a proportion of aluminiferous material, preferably of clay rich in
alumina. Such addition is particularly useful when the material treated is
poor in alumina or is of a quartzy nature; as much clay may be added as will
bring up the proportion of alumina in the residuum to about half as much by
weight as the proportion of silica therein. In some cases the clay may be
added, together with the earthy material, before fritting the mass, so that the
whole
may be fritted together. In other cases the clay may be added to the
insoluble residuum left after the treatment of the frit by water.
In all cases
the clay should be well and uniformly mixed with the other ingredients so as
to make a homogeneous product. And whenever clay is used care should be
taken to add earthy material, also in the proportion already mentioned as
answering best, that is to say, such proportion as that the whole of the silica and
aluminȧ present, including the silica and alumina contained in the clay, may be
supplied with enough earthy base to render them tribasic or thereabouts.

page_text: The proportion of fluoride of calcium employed may vary considerably, but
seven or eight parts by weight in each hundred parts of the mixed mass
answer very well, and this proportion is recommended for ordinary cases..
The material should be finely ground and intimately and uniformly mixed
by the usual means, then exposed, preferably in a reverbatory furnace, to such
heat moderated by the fluoride employed, and ranging usually from red to
bright red, as will cause the ingredients to partially fuse and agglutinate, or, as
it is termed, frit together sufficiently to bring about their chemical reaction on
each other, an effect which may be promoted by stirring them, and is usually
accomplished in from half an hour to an hour's time. The firing should,
however, still be continued, though the temperature may usually be reduced
with advantage until all or nearly all the carbonic acid present is driven off,
as well as any water that may be present. This may easily be ascertained by
trying from time to time whether a portion of the frit will or will not effervesce
with sulphuric or hydrochloric acid.
The marking character of the calcined product or frit thus obtained, and
that by which it is distinguished from the products of former fritting processes
for the liberation of alcali from natural alcaliferous silicates, consists in its
containing along with alcali a proportion of fluorine. The treatment by water,
as herein indicated, of such product or frit, so characterised, in order to extract
therefrom the alcaline matter, is believed to be novel.
The method of aqueous extraction recommended in preference is the mode
well known and commonly practised by chemical manufacturers as methodical
lixiviation in boiling water, a system too well understood to need detailed
description here. It may suffice to observe, that by this system the water is
made to pass in succession over less and less exhausted portions of the calcined
product or frit, so as to become richer in alcali as it proceeds, till it finally
washes a quite fresh portion of the frit, and flows away as nearly saturated as
may be. The extraction of the alcali from the frit by means of water may
advantageously be continued to the point at which, if longer persisted in, the
water would begin to dissolve sensible quantities of lime. This may be readily
determined by testing the ley for lime at intervals in the usual way, prefer-
ably with neutral oxalate of potash.
The crude alcaline ley thus obtained is pure enough to answer for many of
the purposes for which an alcaline ley is required. It may be readily freed by
subsidence or filtration from any insoluble earthy matter which it may hold in
suspension; and if, as often happens, it is colored by dissolved mangamic acid
or by peroxyde of iron, these impurities may be readily doxydised and thrown
down by the addition of a little organic matter. The ley, when evaporated to

page_text: dryness, yields abundance of crude hydrated alcali, containing a variable per-
centage of silica, usually about twenty-five per cent. by weight, but otherwise
of remarkable purity. To the glass manufacturer, and in many cases to the
soap manufacturer, the presence of the silica is not objectionable. But the
silica may be readily precipitated by passing a current of carbonic acid through
the ley, which, if then cleared of the silicious precipitate by subsidence or
filtration in the usual way, will yield carbonated alcali of remarkable purity.
If any salt other than than the carbonate be required, the corresponding acid
may be substituted for the carbonic acid.
The marking character of the insoluble residuum thus obtained, and that by
which it is distinguished from the insoluble residua of other processes for the
extraction of alcali from natural alcaliferous silicates, consists in its containing
a proportion of fluorine in combination. The application of residuum thus
characterised, obtained when extracting alcali from natural alcaliferous silicates,
to the manufacture of manure, hydraulic cement, and puzzolana, as herein
indicated, is believed to be novel. For application as manure such residuum
may be dried,. and used (as also may the frit itself) either alone or in admix-
ture with phosphatic and nitrogenous ingredients to form an artificial fertilising
compost, as is well understood. For conversion into hydraulic cement such
residuum may be recalcined to drive off water of hydration, and also in some
cases to expel carbonic acid, and the product of recalcination, if not already
fine enough, may be ground and sifted as in the manufacture of ordinary
cement. To convert the residuum into puzzolana, which only differs from
cement in its more argilaceous quality, a silicate of alumina, preferably burnt
clay may be added thereto, or the clay may be burnt therewith in such
quantity that the total amount of silica and alumina in the mixed product may
bear to the total amount of earthy base therein a ratio or proportion ranging
between seventy to thirty and ninety to ten, the mean being eighty to twenty
(by weight).
Having thus fully described the nature of this Invention, and the best means
which experiment has hitherto suggested for carrying it into effect, I would
observe that I am aware that it has been proposed to leat natural alcaliferous
silicates with lime, in order to liberate alcali therefrom; also, that it has been
proposed to employ phosphates, sulphates, and chlorides to facilitate the
liberation of alcali by fire from natural alcaliferous silicates. The exposure of
such silicates to the prolonged action of watery moisture, and to the prolonged
action of fermenting organic matter, are other methods which I am aware
have been proposed with a similar view. From those modes the present
Invention differs essentially; and as it may be substantially practised. without

page_text: adhering to the precise details of temperature, time, proportion, manipulation,
and the like, above indicated as preferable, I proceed, in conclusion, to define
it by the following claims:-
Firstly, I claim the mode of producing or liberating potash or soda, or both
(as the case may be), from natural alcaliferous silicates, substantially as herein-
before described.
Secondly, I claim the employment of fluoride of calcium in conjunction
with earthy material or mixture of earthy materials to act with the aid of heat
on natural alcaliferous silicates, so as to produce or liberate therefrom potash
or soda, or both (as the case may be), substantially as herein-before described.
Thirdly, I claim the extraction by water of the soluble alcaline contents of
calcined product or frit, obtained when liberating alcali from alcaliferous
silicates, and distinguished by the double character that it contains, both
alcaline matter and fluorine.
Lastly, I claim the application of insoluble residuum, obtained when libera-
ting alcali from alcaliferous silicates, and characterised by its containing as one
of its ingredients fluorine, in the manufacture of manure, of hydraulic cement,
or of puzzolana, at the operator's choice, substantially as herein-before
described.
In witness whereof, I, the said Frederick Oldfield Ward, have here-
unto set my hand and seal, this Thirtieth day of June, in the year of
our Lord One thousand eight hundred and fifty-eight.
FREDERICK OLDFIELD WARD. (L.S.)