IMPROVEMENTS IN PRING PREPARATIONS OF IMINA AND IN PURIFYING THE SAME AFTER THEIR EMPLOYMENT IN CLARIFYIN, UICES OR FLUIDS
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Lloyd Wise at the Office of
the Commissioners of Patents on the 10th April 1879. (A communication
from abroad by Doctor Friedrich Loewig, of Goldschmieden, near Deutschlissa,
Silesia.)
WILLIAM LLOYD WISE, of No. 7, Whitehall Place, in the City of Westminster.
"IMPROVEMENTS IN PRING PREPARATIONS OF IMINA AND IN PURIFYING
THE SAME AFTER THEIR EMPLOYMENT IN CLARIFYIN, UICES OR FLUIDS." [A
communication from abroad by Doctor Friedrich Loewig. f Goldschmieden, near
Deutschlissa, Silesia.]
This Invention as communicated to me as aforesaid has reference to improve-
ments in producing preparations of alumina and in purifying the same after
their employment in clarifying juices or fluids and comprises the following
features.
(1). It relates to the production of a standard solution of chloride of aluminium
or hydrochloric alumina. Gelatinous alumina as described in Specification of
Letters Patent, No. 1556, of A.D. 1877, and as employed for purifying the vegetable
fluids used in dyeing, contains about ninety per cent. of water and ten per cent. of
alumina (in the anhydrous state). This alumina is exposed to a temperature of
from 120° to 150° Fah. which causes it to lose the greater part of its water, leaving
a loose (i.e., not dense) tender bydrate (similar to white magnesia), which hydrate
possesses but few discoloring properties. This dried alumina is dissolved in an
equivalent proportion of highly concentrated hydrochloric acid (in a vessel by
preference of wood or stone) and thus a highly concentrated solution of chloride
of aluminium is obtained.
(2). The Invention relates to the production of basic chloride of aluminium or basic
hydrochloric alumina in a solid or liquid form, for which purpose a standard solution
of hydrochloric alumina is evaporated to a perfectly dry state, when one third of
the hydrochloric acid will have escaped, the residue being an easily pounded and
not hygroscopic mass (similar to gum arabic) of basic hydrochloric alumina which
is perfectly soluble in water, and which solution can be evaporated without

page_text: decomposition. This basic solution may be evaporated without any loss of hydrochloric
acid, and it has the capacity, more particularly in a concentrated state, to dissolve
a still further quantity of gelatinous alumina. Such super-basic combinations are
best obtained by dissolving the gelatinous alumina in hydrochloric acid up to
perfect saturation and to do this it is best to employ a surplus of gelatinous alumina
to be afterwards separated from the solution by decantation or filtration. These
superbasic solutions may be again evaporated without decomposition.
The same superbasic combinations are obtained mixed with other chlorides by
the following plan:-A precipitant, such as pure and carbonate of ammonia,
carbonic alkali, pure alkali, or carbonic earthy alkali (to which may be added
pure magnesia or the aluminate or carbonate of same) is gradually added to the
standard solution of chloride of aluminium the whole being continuously agitated
until an actual precipitate is produced.
By this process three parts of the acid may be withdrawn from the ordinary
hydrochloric alumina without producing any precipitation of alumina; a com-
paratively small quantity of the precipitant will then suffice to precipitate the
entire quantity of the aluinina all at once in tlie gelatinous state from such basic
solutions. In obtaining these solutions it is preferred to use wooden vessels.
(3). The Invention relates to the employment of the basic hydrochloric alumina
for industrial purposes. A number of materials are capable of abstracting the
surplus alumina from the solutions of these basic combinations, leaving an acidulous
hydrochloric alumina (bi-muriate of alumina) solution behind. This acidulous
solution is again converted into a basic one by dissolving in it gelatinous
alumina.
If unsized paper (water leaf) be dipped into a solution of basic hydrochloric
alumina, and afterwards into pure water, it will take ink like sized paper; conse
quently this solution will not pass through filter paper, and will be particularly
adapted as a mordant in dye works. It may be used in many cases as an equiva-
lent for acetic alumina, also for tawing purposes.
In the manufacture of sugar this solution may be advantageously employed for
clarifying muddy juices, even such as would resist tannic acid.
In manufacturing purposes, where alumina is separated by a precipitant, much
less of the precipitant will be required if basic hydrochloric alumina be used, by
reason of its considerable intrinsic contents of alumina in proportion to the alumina
to be separated. For the same reason the basic hydrochloric alumina may be sub-
stituted advantageously for sulphate of alumina and alum.
(4). The Invention relates to methods of purifying preparations of alumina such
as hereinbefore referred to, or others, after they have been used for clarifying; these
methods are as follow:-
It is to be remarked that in the following description the materials considered
best adapted for the purpose are mentioned, but others may be substituted. Thus,
in lieu of the alkaline earths, chlorides, and carbonates, other similar alkaline earths,
chlorides, and carbonates respectively may be substituted. In place of the hydro-
chloric acid, or of some of it, other suitable acid may be employed.
First Method. (Treatment of the Alumina with Lime or Carbonate of Lime).-
According to this method pounded lime or milk of lime is mixed with the alumina,
by preference in the proportion of one equivalent of alumina to one of lime, whereby
aluminate of lime is formed. After drying, this mass is heated to destroy the
organic matters, and separate therefrom the carbon, which may be subsequently
removed by subjecting the mass to a red heat and admitting air; this however is
not necessary, because after the ensuing solution of the alumina lime either the
carbon may be removed before precipitation of the alumina by filtration or any
other known means, or the alumina may be produced and employed mixed with
carbon, which is rather beneficial than otherwise in clarifying.
If the alumina slime to be operated upon contains nitrogen the gaining of ammonia
may appropriately be combined with this process.

page_text: The solution of the aluminate, as well as the precipitation of the alumina from
the same, is made by the modes already known.
In place of the alkaline earths their carbonates may be used, as by heating
alumina therewith aluminates are formed, as is well known, the organic substances
being thereby also destroyed. In the same manner the organic substances may be
destroyed by heating to a red heat the alumina with alkalies and alkaline salts,
simultaneously forming alkaline aluminates, from which alumina is produced by
the usual modes.
Second Method. (Treatment of Alumina with Chlorides).-The alumina (pre-
ferably undried) to be purified is mixed with chloride of magnesium, and the mixture
is heated when the hydrochloric acid is driven off and destroys the organic sub-
stances, leaving behind aluminate of magnesium.
The escaping hydrochloric acid is collected in condensing vessels, and may serve
later on for dissolving the aluminate of magnesium.
The heating of the above mixture may be continued until all the carbon is
oxidysed, when the aluminate will be freed from organic substances, but, as already
stated with reference to the first method, this is not necessary. The separation of
the alumina from the aluminate is accomplished in the usual manner.
Third Method. (Treatment of the Alumina with Acids).-The alumina to be
purified is dissolved in hydrochloric acid. To avoid unnecessary consumption of
acid the alumina should be as basic as possible. When the alumina is entirely
dissolved, all the foreign substances (i.e., the albuminous substances from the
sacchariferous juice) not in solution may be separated by filtration or otherwise.
Many substances which cannot be separated in this manner may be separated by
the addition of a surplus of alumina to the same, or by precipitation of a part of
the alumina in solution and subsequent filtration, or similar mechanical modes of
separation. These substances are thus kept separate from the undissolved alumina.
If the solution so obtained is not pure enough for further use when precipitating
the alumina, or if the above separations be omitted, dydrochloric acid must be
distilled from the solution until all organic substances have been sufficiently
destroyed. That there may not be undissolved alumina formed by excessive
heating, a surplus of hydrochloric acid is added when requisite, so as to produce an
acid solution of alumina. Such acid may be added before the heating is com-
menced. The alumina is afterwards precipitated as in the "first method," after or
without the previous separation of the carbon, in the usual manner.
Fourth Method. (Treatment of Alumina with Chlorides and Acids).-The alumina
is first dissolved in muriatic acid to remove certain organic substances, afterwards
it is mixed with chloride of magnesium, and by evaporating and heating the
magnesium aluminate is produced, and hydro-chloric acid is obtained both from the
chloride of aluminum and from the chloride of magnesium. The alumina is
separated from the aluminates as usual.
Fifth Method. (Treatment of Alumina with Caustic Alkali).-Alumina to be
purified is dissolved in caustic alkali, whereby portions of the foreign substances
absorbed by the alumina and not soluble in caustic alkali will be rendered capablo
of separation by filtration or otherwise. The alumina may be precipitated from the
solution of the alkaline aluminate as aluminate of alkaline earth portions of the
organic substances remaining dissolved in the caustic alkali; or the solution of the
alkaline aluminate may be evaporated, and the organic substances contained in it
destroyed by exposure to a red heat, the product being again dissolved, and the
alumina precipitated as aluminates of the earths.
Caustic alkalies may be used to free the aluminate of any oxide of iron that it
may have absorbed, either by separating the oxide of iron during the solution of
the alumina in the caustic alkali, or during the solution of the alkaline aluminate.
These alkalies may also be used to obtain substances from the alumina which might
suffer by the action of acids.

page_text: This process may be combined with the preceding methods in various ways.
Foreign substances obtained according to these methods of purifying preparations
of alumina, which have been employed in clarifying juices or fluids, may be used in
the manufacture of other products, as, for example, of ammonia, and also for
manuring purposes.