Des Homewa ATHMINAR Sour OR SHATE
Year: 1872

page_text: LETTERS PATENT to Sydney William Rich, of Chenies Street, in the
County of Middlesex, Analytical Chemist, for the Invention of "AN
Des
Homewa ATHMINAR Sour OR SHATE"

page_text: found suitable for the purpose:-I first burn the schist in heaps, and
then saturate or otherwise treat it with water so as to dissolve all the
soluble matter it may contain; the water with the substances in solution
is then drained off, and a fresh supply of water having a quantity of
sulphuric or hydrochloric acid mixed with it is added to the burnt schist
to obtain a second solution; the two solutions are then mixed together
and percolated through powdered magnesia, lime, carbonate of magnesia,
or carbonate of lime, or other kindred reagents, to cause a double
decomposition of the chlorides or sulphates of alumina, lime, magnesia,
and iron, thus producing sulphate of magnesia and lime or chlorides of
the same metals, and the hydrates of iron and alumina.
In lieu of the above the solution may be mixed with chloride of
sodium, chloride of calcium, or chloride of magnesium, and the resulting
mixture dried and calcined so as to drive off the acid, thereby leaving a
residue of sulphate of soda, lime, or magnesia, and also a residue of
hydrate of iron and alumina.
I separate the several products thus obtained either by crystallization
or by acids or other known means.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Sidney William Rich in the Great Seal Patent
Office on the 19th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SIDNEY
WILLIAM RICH, of Chenies Street, in the County of Middlesex,
Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of February, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Sidney William Rich, Her special
licence that I, the said Sidney William Rich, my executors, adminis-
trators, and assigns, or such others as I, the said Sidney William Rich,
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,

page_text: ,,,
exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "AN
IMPROVED PROCESS FOR TREATING ALUMINOUS 'SCHIST' OR 'SHALE,'
upon the
condition (amongst others) that I, the said Sidney William Rich, 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 Sidney William Rich, 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 thereof, that is to say :-
This Invention relates to an improved process for treating aluminous
schist or shale for the purpose of procuring chemical bodies therefrom of
great commercial value.
I carry my process out in the following order, reserving to myself the
right to vary the treatment and to employ any apparatus that may be
found suitable for the purpose:-I first burn the schist or shale in a heap
about fifteen feet more or less in diameter, such heap being made above
a cell built of any suitable material into which the shale or schist is
allowed to sink as it burns. The interior diameter of the upper part of
the cell equals the diameter of the base of the heap, whilst at its lower
part the cell tapers inwardly until at the bottom the interior has no
greater diameter than two-thirds or thereabouts that of the upper part,
say about ten feet. The cell may be about 10 or 15 feet in depth. At
the lowest part of the cell suitable holes about 2 feet in diameter are
made, from which to withdraw the contents of the cell when working.
I find it convenient to make four of these holes at equal distances one
from the other. In the interior of the cell a solid cone is built up from
the bottom, about 5 feet in height and 5 feet in diameter at the base,
tapering towards the top. This cone serves to direct the contents of the
cell towards the holes which are made in its circumference.
When it is intended to burn schist or shale the cell is filled with
loose dry rubbish, and a fire kindled on the top at first of wood, but
subsequently of schist or shale only; the wood serves to set fire to the

page_text: The
shale, which once alight will continue to burn without any fuel.
schist or shale is piled on in the form of a round heap having its base
of equal diameter with that of the upper part of the cell. In course of
time, about 12 hours, this heap will be burnt through to the surface
when a quantity of the loose rubbish in the cell is withdrawn from the
holes, whereby the heap of burnt schist or shale is made to sink
uniformly over its whole surface into the interior of the cell. When the
heap shall thus have been made to sink to a level with the top of
the cell a further quantity of schist or shale is piled on and allowed to
burn through, and this operation is repeated until the whole of the
rubbish shall have been removed from the cell and its place taken up by
the burnt schist or shale.
When this has been effected the second part of my Invention comes into
play, videlicet, the treatment of the hot burnt schist or shale after it is
withdrawn from the cell. It should be explained that as the burnt
material is withdrawn from the cell a fresh supply of raw schist or shale
is piled on at the top so as to keep up a continuous supply; and further
that the heat of the burnt mass is sufficient to ignite and cause the
combustion of such fresh supply. It is necessary to be careful that the
schist or shale be quite burnt before it is allowed to enter the cell,
otherwise the increased draught so augments the heat that caking is
very liable to take place.
The object in using the cell is to keep the burnt material quite hot
ready for use as described below, and also to afford a continuous supply
of burnt material from a heap which shall be continuously burning at a
low temperature. The burnt schist or shale is then treated with water
so as to dissolve all the soluble matter it may contain. This is effected
in an improved manner by placing the burnt material while still hot
from the cell in tubs made of wood or iron. Eight or ten or other
suitable number of these tubs when filled are arranged on an inclined
tramway, and have pipes so fitted that when the upper tub is filled with
water the overflow may pass into the next lower one, and so on until it
reaches the lowest in the series. By this flow of water through the tubs
the contents of the upper tub are thoroughly washed and the whole of
the soluble matter removed, while on the other hand the lower part of
the stream as continuously coming in contact with a fresh supply of
burnt material acquires increased strength. The material still retaining
its heat imparts a high temperature to the water, of which the solvent

page_text: powers are thereby greatly increased. Each tub in the series being thus
filled with water and the stream still running, the process is maintained
by the removal at intervals of a tub containing exhausted material
from the top, and the attachment of a tub containing fresh material to
the bottom of the series. The series is then hauled up the incline by
any suitable machinery (so that it may occupy the same relative position
as before. The overflow from the bottom will shortly fill the tub freshly
supplied, and when this takes place another tub of exhausted material
may be removed from the top and another tub filled with fresh material
attached to the bottom, the flow of liquor being maintained as before,
and this may go on indefinitely or until the liquor in the lowermost tub
shall have acquired such a degree of strength as to be fit for use, when
the overflow may be diverted for a while into a suitable cistern. The
overflow pipe from each tub is made to dip to the bottom of the said
tub so that the overflow may be drawn from the bottom and not from
the surface.
It will be seen that by this arrangement two objects are effected,—
1st. The liquor in the tubs has its strength continually augmented by
being allowed to flow, by displacement from above, into contact with
material from which less of the soluble matters have been extracted
than that from which the liquor is just removed. In the bottom tub of
all, filled with quite fresh hot material, the liquor attains a high
temperature and great strength. By this means a very concentrated
solution of the salts contained in the burnt schale or schist is produced,
and a quantity of this solution may be drawn off at intervals.
2nd. The contents of each tub are thoroughly washed with water as
the tub ascends by stages the inclined tramway, and this by means of
the stream of water which is continuously running down. By the time
each tub reaches the top of the series it is found that all matters soluble
in water have been removed.
The material having been exhausted with water may be digested with
sulphuric or hydrochloric acid, so as to dissolve the remainder of the
alumina, and this solution may be mixed with the aqueous solution first
obtained, and the mixed solutions treated as described below. Indeed
more or less dilute sulphuric or hydrochloric acid might be used in the
first instance instead of pure water.

page_text: In any case a solution of salts or liquor will be obtained, the method
of dealing with which I now proceed to give.
I. The solution or liquor may be percolated through powdered
magnesia, lime, carbonate of magnesia, or carbonate of lime, or other
kindred reagent, to cause a double decomposition of the sulphates or
chlorides of aluminum, iron, and magnesium, thus producing sulphate
or chloride of calcium and magnesium, and the hydrates of iron and
alumina.
Or the solution may be mixed with chloride of sodium, chloride of
calcium, or chloride of magnesium, and the resulting mixture dried and
calcined so as to drive off the hydrochloric acid, thereby leaving a
residue of sulphate of sodium, calcium, or magnesium, and of hydrate
of iron and alumina.
In either of the above cases useful products are obtained which may
be separated by crystallization or other known means. The residue of
bydrate of alumina can be used with advantage for the manufacture of
alum by the known methods, or for the manufacture of other aluminous
salts.
II. The solution or liquor obtained from the schist or shale may be
used for the manufacture of alum by the known methods.
III. The solution or liquor may be used for the manufacture of
crystallized sulphate of sodium, crystallized sulphate of magnesium, and
a crude chloride of aluminum by the following process. The liquor is
heated to boiling in lead pans, and a quantity of chloride of sodium is
added exactly equivalent to the sulphuric radicle contained in the liquor.
The boiling is then continued until by evaporation the liquor shall have
become so concentrated that crystals are deposited on cooling. The
crystals formed are removed, when the mother liquor may be again
boiled down and made to produce a second crop of crystals. These
crystals consist of sulphate of sodium, and they may be washed and if
requisite purified by re-crystallization. The mother liquors contain the
chlorides of aluminum, iron, and magnesium.
From these the
magnesium may be obtained in the form of crystallized sulphate of
magnesium by the addition of a quantity of fresh solution or liquor,
the sulphuric radicle contained in which shall be equivalent to the whole
of the magnesium contained in the mixed liquors, and subsequent
evaporation and crystallization. The crystals of sulphate of magnesium

page_text: may be removed, washed, and if requisite further purified by re-
crystallization.
The mother liquor may be made to yield a second crop of crystals by
further evaporation. After the removal of the sulphate of magnesium
the mother liquor consists of a concentrated solution of chloride of
aluminum and iron, which may be evaporated until acid fumes begin
to come off, when on cooling it will form an almost solid mass.
To give it the consistency requisite for packing purposes, it will be
found useful to add to this paste a portion of calcined gypsum which
will absorb a portion of the water. This crude chloride of aluminum
will be found available for various useful purposes, notably as a disin-
fectant and for the treatment of sewage.
The following are the principal points in the above process which I
claim as novel and my own Invention.
a. The burning of the schist or shale in such a manner that the burnt
material may be removed from the bottom whilst a further quantity of
raw material may be piled on above to keep up the combustion and
consequent supply of burnt material.
b. The lixiviation of the burnt material while still hot and the
employment of tubs arranged on the principle described.
c. The use of a solution or liquor so prepared for the manufacture of
the various chemicals.
d. The manufacture of sulphate of sodium, sulphate of magnesium,
and crude chloride of aluminum by the process described, in which
chloride of sodium is treated with a liquor having the composition
of that derived from burnt schist or shale treated as herein-before
described.
In witness whereof, I, the said Sidney William Rich, have here-