IMPROVEMENTS IN MANUFACTURING AMMONIACAL SALTS, AND: UTILIZING CERTAIN WASTE PRODUCTS."
Year: 1878

page_text: LETTERS PATENT to John Barrow, of the Dalton Chemical Works, Clayton,.
near Manchester, in the County of Lancaster, Manufacturing Chemist, for the
Invention of "IMPROVEMENTS IN MANUFACTURING AMMONIACAL SALTS, AND:
UTILIZING CERTAIN WASTE PRODUCTS."
PROVISIONAL SPECIFICATION left by the said John Barrow at the Office
of the Commissioners of Patents on the 5th March 1878.
25
JOHN BARROW, of the Dalton Chemical Works, Clayton, near Manchester, in the
County of Lancaster, Manufacturing Chemist. IMPROVEMENTS IN MANUFACTURING
AMMONIACAL SALTS AND UTILIZING CERTAIN WASTE PRODUCTS."
My Invention has for its object improvements in manufacturing ammoniacal
salts and utilizing certain waste products.
For liberating ammonia from its acid and halloid compounds (to obtain ammo-
niacal salts), recovering sulphur, and producing alkaline and earthy carbonates, I.
use alkaline or earthy basic substances in combination with sulphur, as sulphides or
sulphydrates. For these purposes I use the combinations of earthy basic substances
with sulphur, as existing in waste gas, lime from gas purifiers, either wet or dry,
or as existing in the vat waste of alkali works, or I obtain the combinations of
alkaline or earthy basic substances with sulphur by heating a mixture of spent
oxide of iron and alkaline or earthy basic bodies. By this process the spent oxide
of iron is revivified.
Combinations of alkaline or earthy basic substances with sulphur obtained other-
wise than as above mentioned may be used for the purposes of my Invention.

page_text: ▸
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Barrow in the Great Seal Patent Office on the 3rd September
1878.
JOHN BARROW, of the Dalton Chemical Works, Clayton, near Manchester, in the
"IMPROVEMENTS IN MANUFACTURING
County of Lancaster, Manufacturing Chemist.
AMMONIACAL SALTS AND UTILIZING CERTAIN WASTE PRODUCTS."
My Invention has for its object improvements in manufacturing ammoniacal salts
and utilizing certain waste products.
I use earthy basic substances in combination with sulphur, as sulphides or sul-
phydrates, as herein-after described, for liberating ammonia from its acid and haloid
compounds (to obtain ammoniacal salts), recovering sulphur, and producing earthy
carbonates. The combinations of earthy basic substances with sulphur, to which I
refer, exist in waste gas lime from gas purifiers, either wet or dry, also in the vat
waste of alkali works, or may be obtained by heating a mixture of spent oxide of
iron and milk of lime. Hence by my Invention I utilize waste or spent lime from
gas purifiers, waste or spent oxide of iron from gas purifiers, and vat waste from
alkali works in the manufacture or production of ammoniacal salts, sulphur, and
earthy carbonates, and the lime and the oxide of iron are revivified.
In carrying out my Invention I mix crude aminonia water with either spent gas,
lime, or vat waste, or with sulphide, or sulphydrate of calcium, obtained by heating
a mixture of spent oxide of iron and milk of lime.
The relative proportions of ammonia water and spent gas lime, or vate waste, or
sulphide, or sulphydrate of calcium will of course depend upon the per-centage of
acid and haloid bodies in the ammonia water, and the per-contage of sulphur in the
spent gas lime, vat waste, or sulphide, or sulphydrate of calcium (as the case may be),
which will vary in different cases and should be ascertained by the usual tests. The
proportions employed should be such as to effect decomposition as completely as pos-
sible. By double decomposition and subsequent distillation with fire or steam in
any suitable apparatus, I liberate and separate the volatile compounds of ammonia
and sulphur from the non-volatile acid or haloid compounds of the earthy basic
bodies. employed..
1.47
The volatile compounds I cause to pass into combining vessels containing sul-
phuric or hydrochloric acid in order to form ammoniacal salts, as is well understood,
and the sulphurretted hydrogen gas given off I convert by burning or heating in
contact with atmospheric air or oxygen into sulphurous acid, which may he utilized
in the sulphuric acid chamber or for other purposes, or the sulphurretted hydrogen
gas may bé converted by any well-known method of decomposition into free
sulphur.
The insoluble
The non-volatilé bodies consist in large proportion of carbonates.
carbonate of lime and waste liquor from the distilling apparatus are run off and
allowed to settle.in suitable tanks, then drained, dried, and afterwards calcined by
any of the usual methods, or by the special process herein-after described to restore
the carbonate of lime to the condition of quick lime for re-use in gas purification,
or the carbonate of lime may be again used in the ordinary process of manufacturing
carbonates of soda or potash.
When using sulphide or sulphydrate of calcium obtained by heating together
milk of lime and spent oxide of iron from gas purifiers I wash the sulphide from
the insoluble oxide, and employ this liquor in suitable proportion with ammonia
water in the same way as the spent lime is used, distilling off the ammonium
sulphide and calcining the residual lime carbonate.
The insoluble oxide of iron is drained and partially dried, and is then fit for
re-use in gas purification. The mixing of the bodies may be effected in the distil-
latory apparatus, or they may be decomposed in separate vessels, and only the
soluble sulphide of ammonium, along with the soluble compounds of the earthy

page_text: bodies, passed through or into the distillatory apparatus. I may dissolve out from
the mass of waste earthy sulphides, those sulphides which are soluble and employ
the resulting solution for decomposing ammonia compounds contained in ammonia
water, treating the mixture as herein-before described.
Instead of mixing together ammonia water and earthy sulphides, as before
described, the process may be modified by submitting the ammonia water to distil-
lation alone until all the carbonate of ammonia and sulphide of ammonia it contains
have been driven off, and then adding to the residue in the distillatory apparatus
(which contains acid and haloid compounds of ammonia) the requisite proportion of
earthy sulphides to liberate the remaining portion of ammonia as ammonium
sulphide.
The carbonate of ammonia and sulphide of ammonium I cause to pass into the
combining vessels containing sulphuric or hydrochloric acid to form salts of ammonia,
and the carbonic acid and sulphuretted hydrogen gases liberated in the combining
vessels I cause to pass through layers of spent lime, or vat waste, or other combi-
nation of carthy sulphides in any suitable apparatus, as for instance, a gas purifier,
disconnected from the set and containing foul or spent lime, the effect being the
union of the carbonic acid with the lime and displacement of sulphuretted hydrogen,
which is then carried forward along with the sulphuretted hydrogen originally
contained in the ammonia water for conversion into sulphurous acid, sulphuric acid,
or sulphur, as before described.
In all the processes above described, after all the ammonia has been driven off
and the carbonates obtained by subsidence, the mother or waste liquors contain other
bodies which may be employed for the preparation of any of the alkaline, earthy, or
metallic cyanides or sulpho-cyanides.
It is important to prevent as far as possible access of air or oxygen in any form,
or sulphurous acid, which by acting upon the earthy basic compounds with sulphur
would speedily change the composition of these bodies, and so interfere with my
process.
I employ for calcining the earthy carbonates obtained, as herein-before mentioned,
close air-tight retorts heated in the usual manner externally, as, for instance, the
usual gas retort, and I drive out the carbonic acid liberated by heat from the car-
bonate of lime by jets of steam, employing suitable inlet and outlet pipes for the
steam and gas, and I either absorb it by means of ammonia water for use in the
decomposition of earthy sulphides, as herein described, or I pass it through the
disengaged purifiers containing foul or spent gas lime, or similar apparatus containing
vat waste for the purpose of liberating sulphuretted hydrogen from these com-
pounds. I assist this action when necessary by heating by steam or otherwise the
vessels containing the sulphur compounds to be operated upon, and I regulate where
necessary the flow of these gases by suitable well-known mechanical means.
Where the plant is suitable I prefer to mix the waste or spent gas lime and
ammonia water in the gas purifiers themselves as soon as they are sufficiently foul
and require changing.
The waste gases arising from the combining vessels contain other bodies besides
sulphuretted hydrogen. I remove these other bodies by passing the said waste gases
through an oil scrubber, such as is shewn in Fig. 4 of the Drawings accompanying
the Specification of Letters Patent granted to me the 22nd day of October, 1875
(No. 3675), for " Improvements in Machinery or Apparatus to be Used when
Applying India-rubber to Fabrics, and Conserving the Vapours Evolved during the
Process, and in the Method of Dealing with those Vapours." In using such apparatus
for the purposes of my present Invention, oleaginous absorbent in the form of drops is
made to meet the gases and vapours from the combining vessel or from the fouled
gas purifier, and is afterwards separated by heating the oil and vapours absorbed in
any convenient form of distillatory apparatus, so as to separate the very volatile
bisulphide of carbon from the absorbing oil, and the recovered bisulphide of carbon
is condensed in the usual way, or I cause the vapours to be absorbed by passing
through a body of oil, as also described in said Specification,

page_text: Having described the nature of my said Invention, and explained the manner of
carrying it into practical effect, I hereby declare that what I consider to be novel
and original, and therefore claim as secured to me under Letters Patent herein-before
in part recited, is,―
1. Utilizing spent lime from gas purifiers, substantially as described.
2. Utilizing vat waste from the alkali manufacture, substantially as described.
3. The use or employment in the manufacture of ammoniacal salts of sulphides
or sulphydrates of calcium obtained, substantially as herein-before described.
4. Utilizing; substantially as herein-before described, the sulphurretted 'hydrogen
evolved in manufacturing the ammoniacal salts, as above set forth.
5. The above-described method of separating bisulphide of carbon and other
bodies from sulphurretted hydrogen evolved in the manufacture of ammoniacal salts
from ammonia water or the sulphides of ammonium.
In witness whereof; I, the said John Barrow, have hereunto set my hand
and seal, the Thirtieth day of August, in the year of our Lord One thousand
eight hundred and seventy-eight.
JOHN BARROW. (L.B.)