IMPROVEMENTS IN THE MANUFACTURE OF MINERAL GUM, AND IN ITS USE FOR STIFFENING ADHESIVE AND GLAZING PURPOSES
Year: 1877

page_text: LETTERS PATENT to John Thomas Way, of No. 9, Russel Road, Kensington,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF MINERAL GUM, AND IN ITS USE FOR STIFFENING ADHESIVE
AND GLAZING PURPOSES.”
Sealed the 24th April 1878, and dated the 2nd November 1877.
PROVISIONAL SPECIFICATION left by the said John Thomas Way at the
Office of the Commissioners of Patents on the 2nd November 1877.
JOHN THOMAS WAY, of No. 9, Russel Road, Kensington, in the County of
Middlesex. "IMPROVEMENTS IN THE MANUFACTURE OF MINERAL GUM AND IN ITS
USE FOR STIFFENING ADHESIVE AND GLAZING PURPOSES."
This Invention has for its object improvements in the manufacture and in the
use of phosphatic and aluminous compounds.
I have discovered a mineral gum having, when in solution, very similar properties
to gum arabic, and applicable as a cement and also for stiffening fabrics and other
materials, and as a substitute for glue, and also to impart a glaze or varnish to the
surface of paper, wood, and other materials.
For the purpose of preparing the mineral gum I treat phosphate of alumina with
acid, either sulphuric acid or phosphoric acid may be employed, and I saturate the
acid with the phosphate, making it dissolve as much of it as it will. The different
forms of native phosphate of alumina can be used in this process, but I have found
the mineral which is known as redonda phosphate, which also contains phosphate
of iron, very suitable, and I shall describe the method adopted with it.
To make a solution suitable to be used as gum I proceed as follows:-I take
redonda phosphate, containing, say, 37 per cent. of phosphoric acid, and grind and
furnace it, when the phosphoric acid will by loss of weight become about 47 per
Price AJI

page_text: cent. I then mix it with sulphuric acid in such proportion that there shall be
from 3 to 3 parts by weight of the furnaced phosphate for each part by weight
of oil of vitriol present in the acid; for instance, I take 10 parts by measure (which
is equal to 18 parts by weight) of oil of vitriol, which I dilute with 100 parts of
water; to this diluted acid I add 60 parts by weight of the ground and furnaced
redonda phosphate. I digest the materials with occasional stirring for a few hours.
I prefer to maintain the temperature at about 160° to 180° Fahrenheit, until I find
that a portion of the liquid taken between the finger and thumb becomes sticky in
drying. I then pass it through a filter of calico, linen, or flannel, and obtain a clear
liquor of a gummy or adhesive nature. I concentrate this liquor, if necessary, by
evaporation; for this purpose I apply a temperature, not exceeding 170° or 180°
Fahrenheit; but to avoid the necessity of evaporation I usually employ an acid
less diluted (say, 1 part by measure of oil of vitriol to 7 or 8-parts of water), and
filter the liquid by pressure in a Needham's filter press or otherwise. By continued
evaporation I obtain the material in a dry condition; resembling gum arabic, and
soluble in cold water.
In dissolving redonda phosphate in solution of phosphoric acid for the production
of an adhesive material I use the phoshphate in much the same proportion as in
the case of sulphuric acid, that is to say, 3, to 31 parts, by weight to each part of
real phosphoric acid contained in the solution of phosphoric acid; but in this, as
in the case of sulphuric acid, the rule is to employ as much phosphate as the acid
can dissolve; or in other words, the phosphate should be in slight excess of the
solvent power of the acid.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Thomas Way in the Great Seal Patent Office on the 2nd
May 1878.
JOHN THOMAS WAY, of No. 9, Russell Road, Kensington, in the County of.
Middlesex. "IMPROVEMENTS IN THE MANUFACTURE OF MINERAL GUM, AND IN ITS
USE FOR STIFFENING ADHESIVE AND GLAZING PURPOSES."
This Invention has for its object improvements in the manufacture of mineral
gum, and in its use for stiffening adhesive and glazing purposes.
I have discovered a mineral gum having, when in solution, very similar properties
to gum arabic, and applicable as a cement, and also for stiffening fabrics and other
materials, and as a substitute for glue, and also to impart a glaze or varnish to the
surface of paper, wood, and other materials.
For the purpose of preparing the mineral gum I treat phosphate of alumina with
acid, either sulphuric acid or phosphoric acid may be employed, and I saturate the
acid with the phosphate, making it dissolve as much of it as it will. The different
forms of native phosphate of alumina can be used in this process, but I have found
the mineral which is known as redonda phosphate, which also contains phosphate
of iron, very suitable, and I shall describe the method adopted with it.
Although the strongest (that is, the most adhesive) gum is produced by treating
the native phosphate of alumina by oil of vitriol diluted with only 7 or 8 parts of
water, it is found practically very difficult to filter such a product from the mass of
undissolved oxide of iron, &c., even by the aid of pressure as with Needham's press.
I generally therefore find it desirable where a clear product is to be made to
proceed as follows:-In a wooden vessel lined with lead, four feet square by two
feet deep, 370 to 380 lbs. of ground and furnaced redonda phosphate (containing,
say, 47 per cent. of phosphoric acid) is moistened with 15 gallons of water; to this
is added 10 gallons of chamber acid of 120° Twaddell (1.600 specific gravity),
diluted with 35 gallons of water. Chamber acid of this gravity contains about 70
per cent. of oil of vitriol, consequently the above 10 gallons will be equal to about
6 gallons, or 112 lbs. by weight, of oil of vitriol. The diluted acid is run in slowly
upon the moistened phosphate, the materials being meanwhile well stirred by a
wooden stirrer to prevent caking; open steam of about 30 lbs. pressure is now
introduced by a leaden pipe, and the whole is boiled with constant stirring for two
or three hours, until the gravity as the hot liquor is reduced by condensation of the
steam to about 60° Twaddell, 1.300 specific gravity. The heat is now discontinued,
and heavier insoluble matters allowed to settle for half an hour, when the liquor,
still hot, can be readily filtered by a Needham's press. At this gravity, however,
the gum is not sufficiently strong for many purposes. It is concentrated in a
shallow leaden pan (say, 10 feet by 5, by 6 inches deep) set in brickwork on a bed
of fire-slabs, with a furnace at one end and flues running under the whole bed of
the pan, the fire requires to be regulated so that the temperature of the liquor in
the pan should not rise beyond 170° or 180° Fahrenheit; I prefer to maintain it at
about 150° Fahrenheit. The concentration can be to any desired point; thus the
gum may be obtained in a dry condition, resembling gum arabic, and soluble in cold
water.
I find that a good product for most purposes is obtained when the liquor (hot)
markes 84° Twaddell (1-420 specific gravity), which will give when cold a gravity
of 1.450 to 1.460. To obtain a perfectly clear gum the product after evaporation
should be again filtered. The gum made in this way through having good adhesive
properties is not I believe so strong as when dilution and subsequent evaporation
have been avoided, owing to the fact that more perfect saturation of the acid with
the phosphate takes place when the action occurs at high gravities. In other
words, the liquor which was saturated at 1300 will at 1450 dissolve more
phosphate of alumina.. I sometimes, therefore, digest the concentrated gum at a

page_text: gentle heat with a further quantity of mineral (say, 10 per cent. of that originally
used).
A convenient method is to add the extra phosphate to the weak liquor in the
evaporating pan, and by the time the proper gravity is reached full saturation will
have been secured. The concentrated liquor is in this case readily filtered through
the Needham press; or, instead of the native mineral I employ precipitated
phosphate, which can be readily obtained by the addition to a portion of uncon-
centrated gum of lime, soda, ammonia, or their carbonates. The precipitate may
be separated by the Needham's press. In this precipitated condition the phosphate
more quickly and perfectly saturates the excess of acid in the gum.
The complete saturation of the excess of acid in the gum may be attained by
several other methods; it is obvious that anything that removes or neutralizes the
excess of acid will practically effect this end, lime or its carbonate, phosphate of
lime, ammonia, &c., or alumina precipitated, or in the form of the mineral known
as "bauxite" will answer. I find lime to be very useful for this purpose; the lime
is slacked and made into a "milk" with a small quantity of water, the milk of
lime is added to the dilute gum during concentration. The quantity required will
vary, but may be taken at about 1 lb. of lime for every 20 or 25 gallons of dilute
gum, (1·300 specific gravity). The gum when concentrated to the required strength
is filtered for the removal of sulphate of lime, &c.
When dissolving redonda phosphate in phosphoric acid, much the same treatment
will be necessary as in the case of sulphuric acid.
The phosphoric acid is obtained, as is well understood, by the action of sulphuric
acid on bone earth or mineral phosphate of lime.
A solution of phosphoric acid of 12 or 15 per cent. is convenient for dissolving
the phosphate of alumina; for 100 gallons of the latter, strength about 450 or
500 lbs. of the ground and furnaced redonda phosphate will be required; the
materials are to be boiled, filtered, evaporated, &c., in the same way as when dealing
with the sulphuric acid compound, and final saturation, if necessary, is obtained in
the same manner.
The mineral gum may be made from other phosphates of alumina, such as that
known as alta vela phosphate. The quantity of this phosphate varies so much that
no absolute instructions can be given for its use. The proper plan is to take a
known quantity of oil of vitriol, dilute it with 8 or 10 parts by measure of water,
and to add by degrees the ground and burnt phosphate from a weighed quantity to
the acid, heated to about 150° Fahrenheit, until by the formation of a skin on the
surface and the stickiness of the liquid between the finger and thumb the acid is
found to be fairly saturated. From a small experiment in this way the proportions
for manufacturing purposes may be ascertained.
It is almost unnecessary to state that the mineral gum may be made by dis-
solving precipitated alumina in phosphoric acid, or by treating bauxite, which
contains a large proportion of hydrate of alumina with that acid.
The mineral gum made by the methods now described may be used as a
substitute for gum for adhesive purposes; and instead of glue, in some cases, where
that substance is now employed, for instance, in binding books; for giving substance
and strength to goods made from fibrous materials, as, for instance, in the ma
facture of what is known as papier maché; for strengthening and stiffening paper,
especially. brown and other coarse papers, and in the making of cardboard.
manu-
It may also be employed in stiffening fabrics of cotton, linen, or wool.
The mineral gum may also be employed to give a glaze or varnish, to, paper, but
as it does not bear the .action of water, such surfaces must be further protected by a
slight coat of ordinary varnish to enable them to be washed.
It should be understood, however, that being an acid salt, the gum changes some
colors, and in such cases it is not available.
It can also be applied to wood after sizing in the usual manner.
In combination with Paris plaster the gum makes an excellent, cement, which,
from its superior hardness to ordinary plaster, is very valuable for some decorative

page_text: purposes. The Paris plaster is mixed with the mineral gum instead of part or the
whole of the water; after a short time it sets in the usual way; the proportion of
guin to plaster will vary with the result desired; gum of specific gravity 1450
diluted with half its weight of water, and used in the proportion of two parts by
weight of the diluted gum to three parts of Paris plaster, makes an excellent
material for many purposes.
Having thus described the nature of my said Invention, and the manner of per-
forming the same, I would have it understood that I claim,-
First. The manufacture of a mineral gum, substantially as described.
Second. The preparation of the said gum for, and its application as a cement, and.
for stiffening and glazing, substantially as described.
Third. The mineral gum, herein described, being a new article of commerce.
In witness whereof, I, the said John Thomas Way, have hereunto set my
hand and seal, this First day of May, in the year of our Lord One thousand
eight hundred and seventy-eight.
J. THOMAS WAY. (L.S.)