IMPROVEMENTS IN THE MANUFACTURE OF EPSON AND OTHER MAG- NESIAN SALTS, ALSO ALUM AND SULPHATE OF AMMONIA
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
RICHARDSON, of the Town and County of Newcastle-upon-Tyne, Chemist, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-sixth day of
January (One thousand eight hundred and fifty), in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Thomas Richardson, my exors, aduiors, and assigns, Her especial
license, full power, sole privilege and authority, that I, the said Thomas
Richardson, my exors, admors, and assigns, or such others as I, the said
Thomas Richardson, my exors, admors, or assigns, should at any time agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention of "IMPROVEMENTS IN THE MANUFACTURE OF EPSON AND OTHER MAG-
NESIAN SALTS, ALSO ALUM AND SULPHATE OF AMMONIA;" in which said Letters
Patent is contained a proviso, that I, the said Thomas Richardson, should cause
a particular description of the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Richardson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawing hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
My Invention consists, first,. of employing magnesia, or baryta, or strontia,
or lime, and also in employing sulphurets of potassium, sodium, ammonium,
barium, strontium, calcium, or magnesium, for separating the impurities from
solutions of sulphate of magnesia; and this part of my Invention also consists
of making a double salt of sulphate of magnesia and ammonia.
Secondly, my Invention consists of improvements in the manufacture of
alum, by the use of means hereafter described, for exhausting calcined shale
more advantageously than heretofore.
And, thirdly, my Invention consists of improvements in manufacturing sul-
phate of ammonia.
And in order that my Invention may be most fully understood and readily
carried into effect, I will proceed to describe the means pursued by me.
In carrying out the first part of my Invention, I take rough Epsoms dissolved
in water, or I obtain or prepare a solution containing impure sulphate of mag-
nesia, and the precipitating agent I prefer should be made up into a state of
cream by the admixture of water therewith; and I believe the best precipi-
tating agent to be magnesia, and I pour the cream thereof into the solution of
impure sulphate of magnesia and agitate the whole, preferring to apply heat,
which I do by means of steam pipes, until a portion of the liquid filtered from
the precipitate obtained does not change on the addition of sulphuret of ammo-
nium. The solution thus treated is then allowed to stand and the precipitate
subside, the clear liquor is drawn off, evaporated to strength, allowed to
crystallize, and the process finished in the ordinary manner of making Epsom
salts. The precipitate is repeatedly washed with water, and the liquor taken
off by subsidence or filtration, until nearly the whole of the salt is obtained.
By this means I not only get pure Epsom salts, and comparatively a large
product therefrom, but I also avoid the expensive process of calcination here-
tofore employed. I would remark, that when acting with baryta, strontia, or
lime in order to purify solutions of impure sulphate of magnesia, I employ
them in like manner to that above described when using a cream of magnesia,
but as these substances combine with the sulphuric acid in the solution and
form insoluble compounds, I prefer to employ magnesia when employing
sulphurets of potassium, sodium, ammonium, barium, strontium, calcium, or

page_text: magnesium. I employ-solutions of these substances to precipitate the im-
purities contained in solutions of sulphate of magnesia, using agitation when
mixing the same; and when a portion of the filtered liquor is not changed by
the test above mentioned the process is complete, and pure Epsom salts are
obtained by evaporation and crystallization, as before stated. It should be
remarked that it is not essential that the impure sulphate of magnesia should
be in a state of solution when acting on it with the matters herein described,
as a similar effect may be obtained by mixing and grinding these matters in a
moist state and then dissolving out the Epsom salts. From the sulphate of
magnesia! obtained by any of the means above described, I make carbonate of
magnesia in the ordinary manner. In making a double salt of sulphate of
magnesia and ammonia, I mix a solution of impure sulphate of magnesia with.
gas water, preferring to employ heat until the liquor is rendered nearly neutral.
The precipitate which is formed during this process is allowed to subside, and.
the clear liquor boiled down to about fifty degrees or sixty-five degrees Twaddel,
when it is set aside to crystallize. The salt so obtained may be employed as a
manure; and in the manufacture of alum. Instead of mixing gas water with
the impure sulphate of magnesia, I find it advisable in some situations first to
neutralize the gas water with sulphuric acid in the ordinary manner and then
add the equivalent quantity of rough Epsoms or impure sulphate of magnesia,
boiling to strength and crystallizing in the usual way; or I can make such
double salt by employing sulphate of magnesia, purified as above described or
in its impure state, either in solution or in a damp state, and a current of
ammonia procured by distilling gas water, guano, or any other body capable
of producing. ammonia by destructive distillation with quicklime. In such
cases the ammonial gas is.to be purified by, passing it through water, so that
the magnesia which is obtained may be white and suitable for the market, and
when not sufficiently pure for this purpose it will be found well adapted for
use in purifying impure sulphate magnesia by the methods already described.
The liquor which holds the magnesia in suspension, and from which it is
separated by subsidence or filtration, contains the double salts of sulphate of
magnesia and ammonia.
I will now proceed to describe my improvements in the manufacture of
alum. In lixiviating the calcined shale for the purpose of obtaining the raw
alum liquor, I employ an arrangement of pits, as explained in the Drawing
annexed, which represents a series of pits furnished with pipes B, B, B, for
the purpose of conveying water or liquor from one to another, the pipes being
stopped with taps or cocks E. Water is run from the service tank A through
the pipe C into No. 6, until it flows over through the pipe B', and passes
:

page_text: through pipe D to the bottom of the pit No. 1, through which it rises until
the pit is filled, exhausting the soluble ingredients in its passage.
After
standing some days the supply of water is continued as before in No. 6 pit,
which causes the liquor in pit No. 1 to flow down the pipe B', the cock E¹ of
which has been removed or opened; the liquor then ascends through the mine
ro calcined shale in No. 2 pit, in the same way and for the same purpose as it
did in No. 1. After standing a further period of some days the liquor is forced
through No. 3 pit by similar means, and this is repeated with successive pits as
often as the liquor man finds necessary to bring the liquor up to twenty-eight
degrees Twaddel, or such higher strength as is desired, when it may be drawn
off by the tap F. As soon as the mine or calcined shale is exhausted in any
one of these pits it is removed and replaced by a supply of fresh mine, and the
process is continued as before. Of course, as the operation go on week
after week, it will become necessary to commence the supply of the water from
the service tank A to the different pits in succession, which may be done as 1
above described, or by allowing it to run at once down the pipes B, B, B, from
taps in pipe C. By the use of this arrangement of apparatus the labour of
pumping the liquor from one pit to the other will be saved, and the process of
exhaustion rendered generally more convenient, and the result will be a more
perfect exhaustion of the shale.
.
In carrying out the third part of my Invention, I employ the double salt of
magnesia and ammonia, obtained as described under the first part of my
Invention, and I cause the same to be sublimed in the way usually practised
in preparing salammoniac.
Having thus described the nature of my Invention, and the manner in which
the same is to be performed, I would have it understood that I do not confine
myself to the details as herein described, so long as the peculiar character of
any part of my Invention be retained; but what I claim is,-
First, the improvements herein described in manufacturing Epsom and other
magnesian salts.
Secondly, I claim the improvements herein described in the manufacture of
alum.
And, thirdly, I claim the improvements herein described in the manufacture
of sulphate of ammonia.
In witness whereof, I, the said Thomas Richardson, have hereunto set g
my hand and seal, this Twenty-third day of July, in the year of our
Lord One thousand eight hundred and fifty.
THOMAS (L.s.) RICHARDSON.

page_text: AND BE IT REMEMBERED, that on the Twenty-third day of July, in
the year of our Lord 1850, the aforesaid Thomas Richardson came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Twenty-fifth day of July, in the year of our Lord One
thousand eight hundred and fifty.