IMPROVEMENTS IN OBTAINING PRODUCTS PROM ALKALI WASTE AND GAS LIME REFUSE
Year: 1861

page_text: LETTERS PATENT to Alfred Noble, of the City of Bristol, Analytical
Chemist, for the Invention of
"IMPROVEMENTS IN OBTAINING PRODUCTS
PROM ALKALI WASTE AND GAS LIME REFUSE."
Sealed the 19th November 1861, and dated the 6th July 1861.
PROVISIONAL SPECIFICATION left by the said Alfred Noble, at the Office
of the Commissioners of Patents, with his Petition, on the 6th July
1861.
I, ALFRED NOBLE. of the City of Bristol, Analytical Chemist, do hereby
declare the nature of the Invention for "IMPROVEMENTS IN OBTAINING PRODUCTS
FROM ALKALI WASTE AND GAS LIME REFUSE," to be as follows:-
This Invention has for its object improvements in obtaining products from
alkali waste and gas lime refuse. For this purpose alkali waste is allowed to
stand in a heap or in vats for a few days, after which water is poured upon it,
and it is permitted to remain on it for a short time; the liquor is then run off.
This liquor, or the liquor which drains from alkali waste heaps, is mixed or
brought in contact with sulphurous acid, either in a gaseous state or in solu-
tion, or with atmospheric air. By these means sulphur is precipitated in a
marketable form; the clear supernatant liquor also contains hyposulphite of
lime.
This solution of hyposulphite of lime may either be boiled down to obtain
solid hyposulphite of time, or may be decomposed with carbonate of soda te
Price 1

page_text: obtain hyposulphite of soda, or may be decomposed with hydrochloric acid to
obtain sulphur and sulphurous acid. In like manner the refuse from lime
purifiers of gasworks is treated to obtain like products.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Noble, in the Great Seal Patent Office on the 4th
January 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
NOBLE, of the City of Bristol, Analytical Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of July, in the year of our Lord One
thousand eight hundred and sixty-one, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Alfred Noble, Her special licence that I, the said Alfred Noble, my
executors, administrators, and assigns, or such others as I, the said Alfred
Noble, 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, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPкOVEMENTS IN OBTAINING
PRODUCTS FROM ALKALI WASTE AND GAS LIME REFUSE," upon the condition
(amongst others) that I, the said Alfred Noble, my executors or adminis-
trators, 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 1, the said Alfred Noble, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
This Invention Iras for its object improvements in obtaining products from
alkali waste and gas lime refuse. For this purpose alkali waste is allowed to
stand in a heap or in vats for a few days, after which water is poured upon it,
and it is permitted to remain on it for a short time; the liquor is then run off.
This liquor, or the liquor which drains from alkali waste heaps is mixed or
brought in contact with sulphurous acid, either in a gaseous state or in solu-

page_text: tion. By these means sulphur is precipitated in a marketable form; the clear
supernatant liquor also contains hyposulphite of lime.
This solution of hyposulphite of lime may either be boiled down to obtain
solid hyposulphite of lime, or may be decomposed with carbonate of soda to
obtain hyposulphite of soda, or may be decomposed with hydrochloric acid to
obtain sulphur and sulphurous acid. In like manner the refuse from lime
purifiers of gasworks is treated to obtain like products.
Having thus stated the nature of my Invention, I will proceed to describe
the manner in which I prefer to conduct the process. In treating alkali waste
I place it in a heap or in an iron vat, the latter being preferable as it retains
any liquor which runs from the material. The waste is laid lightly in the
vat or heap so that the air may be able to penetrate it freely, and in this way
it is left for about three days, during which time it is as often as it may
require it sprinkled with a small quantity of water to keep it just moist. At
the end of three days the heap is turned over, and is then again left for about
two days more, being as before kept moist by sprinkling it with water should
it, prove necessary. I would remark that the time of exposure to produce the
best result varies according to the weather and the quality of the waste; but
I judge from the appearance of the material. When the exposure has been
sufficient the waste at the commencement of. the process is black or nearly so;
during the exposure it becomes a darkish green mixed with spots or small
particles of a yellow color; when the greenish color is fully developed the
duration of the exposure has been sufficient. If the exposure is continued
longer a loss of product will result. I then run water on to the waste to
dissolve out all that is soluble. 1 usually employ from 10 to 15 gallons of
water to one hundredweight of waste. I sometimes stir the waste up with the
water, and then draw off the liquid, and treat it with sulphurous acid. For
this purpose I employ a tower of brickwork of convenient size, say, 20 feet.
high and 3 or 4 feet diameter. This tower is filled with silicious stones about
the size of a man's fist; the liquid is pumped to the top of the tower, and
allowed to trickle down over the stones and escape at the bottom of the tower.
The sulphurous acid gas obtained by burning pyrites, or in any convenient
manner, is introduced by a flue into the bottom of the tower, and rises up
through it. The quantity of gas employed should not be greater than the
liquid descending the tower can readily absorb, otherwise a loss of gas will
result. The liquid after passing through the tower should smell distinctly of
sulphurous acid. If the acid is considerably in excess I add to the liquor
which has descended the tower some liquor which has not been so treated, and
this I continue to do until the excess of acid is absorbed or nearly so. The

page_text: liquor is now left to stand until the sulphur which it contains in suspension is
deposited. The sulphur thus obtained is drained and dried; it is then suitable
for use for the manufacture of sulphuric acid, or for other purpose for which
commercial sulphur is now or may be used. The clear liquid may be eva-
porated to obtain hyposulphite of lime for commerce, or carbonate of soda may
be added to it until it no longer produces a precipitate; and when the pre-
cipitate, which is carbonate of lime, has separated, the clear liquid may be
evaporated to obtain hyposulphite of soda; or hydrochloric acid may be added
to the clear liquid from the tower until one half the sulphur of the hyposulphite
of lime is precipitated, the other half remaining in solution as free sulphurous
acid. This free sulphurous acid is utilized by adding to the liquid already
holding sulphur in suspension some of the original waste liquor until the free
acid is absorbed. The resulting mixture is treated in the same manner as the
liquid from the tower, so far as concerns the draining and drying the sulphur,
the supernatant liquid, which contains chloride of calcium, not being of any
practicable value.
When treating the refuse from the lime purifiers of gas works, in place of
alkali waste, I proceed as already described, except that the exposure of the
material in heaps or vats to the air may be dispensed with advantageously,
and the material be at once treated with water, or it is possible to proceed
exactly as with alkali waste.
Having thus described the nature of my Invention, and the manner of
performing the same, I would have it understood that I do not confine myself
to the exact detail described; but what I claim is the treatment of alkali waste
and the refuse from the lime purifiers of gasworks with sulphurous acid, as
described.
In witness whereof, I, the said Alfred Noble, have hereunto set my
hand and seal, this Third day of January, in the year of our Lord
One thousand eight hundred and sixty-two.
ALFRED NOBLE. (L.S.)