Improvements in the Treatment of Alkaline Salts, or the Salts of Alkaline Earths.
Year: 1894

page_text: Date of Application, 7th Nov., 1894
Complete Specification Left. 13th May, 1895-Accepted, 29th June, 1895
PROVISIONAL SPECIFICATION.
:
1
Improvements in the Treatment of Alkaline Salts, or the Salts of
Alkaline Earths.
:
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London
Gentleman do hereby declare the nature of this invention (which has been com-
municated to me from abroad by Nicolas Basset and Wladimir de Baranoff both of
21 Boulevard Poissonniere Paris in the Republic of France) to be as follows :-
Two main processes well known and applicable to practical purposes are
employed for treating alkaline salts with a view to obtaining alkaline carbonates
or caustic alkalies, they are used chiefly in the manufacture of soda and carbonate
of soda, one being termed the ammonia process, and the other, Leblanc's process.
They are, both, however, attended with somewhat serious defects.
The ammonia process involves the loss of the chlorine from the chlorides treated
and it cannot be applied, either to potassium chloride KCl, or to sulphates. The
Leblanc process, when applied to chloride of sodium, yields products of less purity
than the first mentioned process, and, although it may be used in connection with
potassium chloride, as well as with sodium chloride, yet in the treatment of
sulphates (for which it can be employed), nearly the whole of the sulphuric element
is lost.
These defects should be obviated, and as it amounts to neglect to allow the
chlorine to be wasted in the treatment of chlorides, so also it is imperative that,
in the treatment of sulphates, the sulphur should be recoverable in a serviceable
form.
By submitting the chlorides NaCl and KCl, simultaneously to the action of a
current of air and a current of acid SO,, the said chlorides are turned into the
corresponding sulphates, with the evolution of chlorine (if the presence of steam
be avoided), or hydrochloric acid (where steam is present), as expressed by the
equations
Whence it follows that the chlorides NaCl, KCl, may in all cases be converted
into sulphates by either of these two formulæ : SO, + 0, or SO, + + HO
with the evolution of Cl or HCl, respectively, either of which may be readily
collected.
This reaction also applies in the case of the chlorides of MgCl and CaCl, the
result being attainable in practice on condition that sulphuric acid can be
inexpensively produced.
By starting with sulphate of lime, and by a very moderate amount of calcination
the products represented by the following equations are obtained
11
(c) CaOSO, + 2 C = CaS + 2 CO,. 2 CO, being collected.
(d) CaS + HO + CO, = HS + CaOCO₂.
ITA
TLA

page_text: upon MgCl. The bye product of these reactions is carbonate of lime, when
CaOSO, is acted upon and the chief product is sulphurous acid.
Where phosphate of lime is taken as the initial or
pon, the following reaction is obtained :-
"
raw material to be operated

page_text: (3) A small loss involved in the employment of tribasic phosphate, and (4) The
cost of the lime.
The positive advantages derived from the improved method are (1) The value
of the chlorine, collected as a bye-product, in the forms of chlorine proper, hydro-
chloric acid, hypochlorite, chlorate and the like. (2) The value of the carbonic
acid which becomes available as compared to the cost of the coal used ; and
(3) The value of the soda or potash obtained as main products, either in the
caustic form, in the condition of hydrated or dry carbonate, or (in the case of soda)
as bicarbonate; besides the many derived products which may be turned to account
in a well fitted manufacturing establishment.
In the present application the invention relates to the manufacture of caustic
alkalies or the carbonates thereof, whether hydrated or dry and the recovery of
the chlorinated bye-products and has for its object a novel application of well
known principles and a rearrangement of certain recognized reactions, which have
not as yet been made serviceable for manufacturing purposes.
And in order that our invention may be more clearly understood we will now
proceed to describe the operation in the different phases of manufacture taking
sodium chloride for example as the initial substance to be operated upon.
The sulphurous acid necessary for either of the reactions (a) or (b) is first
produced by carrying out the reaction (c).
A mixture of one equivalent of sulphate of lime either natural (in the condition
of plaster, waste plaster or plaster dust) or artificial (as obtained from reactions)
with two equivalents of powdered carbon, is introduced into a retort which may be
vertical, inclined, or practically horizontal, or into a cylinder heated externally,
both ends of which may be tightly closed; such supply of mixture being admitted
through one end of the said cylinder or retort, while the opposite end thereof
remains closed, and the inlet orifice being then closed also. The apparatus is
fitted towards its upper part, with a short length of tube communicating with a
gasometer, so that the carbonic gas produced by the reduction of the lime and
sulphuric acid, under the influence of the red hot coal, is conducted to the gasometer,
into which is also sent by suitable suction or pressure apparatus a sufficient propor-
tion of the carbonic acid generated by combustion in the furnace. When the
reduction ceases to produce CO, gas, thereby signifying that the operation is
completed, the valve or cock of the junction pipe leading to the gasometer is
closed, while the discharge orifice is opened and the calcium sulphide is allowed to
drop into an extinguishing or cooling chamber which may be built of masonry or
brick work. The charge is then renewed, and the operation repeated as before.
The cooled calcium sulphide, or if preferred the oxysulphide of calcium which
is left behind as a residue in certain operations is moistened with one equivalent of
water and spread on the shelves of an apparatus similar to that usually employed
for effecting the absorption of chlorine by lime in the manufacture of chloride
(or hypochlorite) of lime. The apparatus is watertight, when closed, and is
provided with two nozzles or short lengths of pipe, one at its lower part, below
the bottom shelf, and the other at the upper part, above the top shelf. Through
the lower nozzle one equivalent of carbonic acid is received from the gasometer
which performs the reaction shewn in the equation d. The H.S. acid, as it forms,
passes off into a closed combustion chamber, where it kindles and, in so doing,
is changed into water and sulphurous acid by the reaction shewn by the
equation e, under the influence of a current of air supplying three equivalents of
oxygen. The current of air is drawn in from outside by means of suitable suction
apparatus and the S.O, gas is forced into a special gasometer.
The chloride is first converted into dry, porous and pervious matter. With this
object in view, it is mixed while moist, with a suitable inert body and compressed
in moulds into blocks, briquettes, balls or cakes of any desired shape. These are
dried first by means of a draught of air and then by means of the waste heat.
The inert body used may be for example, white sand, or pounded sandstone, or
generally a vitrifiable earth or silica incapable of forming silicates under the

page_text: circumstances in which 'the' operation is here performed, as the reaction which it
involves necessitates the cooperation of steam superheated to incandescence.
The agglomerated bodies, after being thoroughly dried, as described, are
introduced into an apparatus, similar to a gas retort or any other suitable shape,
which should be tightly closed by means of removable doors, well fitting at the
joints. It is then heated externally, to or somewhat above a nascent red heat and
receives S.O, gas from the gasometer; such gas entering its front part, below a
perforated double bottom, whereon the dry agglomerated material is placed.
A junction pipe situated at the rear end of the apparatus serves to convey the
chlorinetted products into dissolving receivers or to the spot where the chlorine or
hydrochloric acid is required to form fresh compounds.
It will be understood that the oxygen (or air) for the reactions a and b is
provided by suitable suction apparatus, the action of which also assists the
S.O, gas in gaining access underneath the perforated false bottom. When the
material no longer yields any product of the nature of chlorine, the delivery pipe
is closed, and the discharge of the frits, formed by the soda and silica, is proceeded
with, the same being caused to drop into a cooling or extinguishing chamber, and
a fresh batch'is then introduced. When it is desired to obtain chlorine as a bye-
product, the closing of the apparatus the opening of the discharge pipe, and the
admission of the S.O, gas and dry, air, should not take place until after the
temperature has sufficiently risen to enable perfect stability of production to be
obtained.
The air employed to assist the reaction a is dried by being caused to pass over
the quicklime which is to be hydrated by the reactions ; and k. No such
desiccation is required, for the reaction b, for which a current of steam is brought
down, along with the air and S.O, gas, under the perforated bottom.
The alkaline sulphate thus obtained is dissolved in water, and the remaining
operations are applicable to all alkaline sulphates, no matter how produced.
In accordance with the reaction, powdered tribasic phosphate is introduced,
with a quantity of water sufficient to facilitate the operation, into a series of vats,
which are provided with stirring mechanism and may, or may not, communicate
with each other. The stirring device is then set in motion and the current of
S.O, gas is introduced up to the point of saturation, after which by opening a
discharge valve or cock, the liquidi is caused to flow off into a rat where it is
allowed to rest. The sulphite of lime settles and the clear solution of soluble
phosphate is conveyed into a decomposing tank. This sulphite of lime, after being
washed, drained and dried in the air may be used, for an indefinite length of time,
in conjunction with the sulphate from the reaction or i, for carrying out the
reactions c d and e.
The solution of soluble phosphate is mixed with the solution of sulphate of soda,
in equivalent proportions. The temperature is slightly raised, either by agitating
with steam or by any other suitable means until it attains from about 60° to
75° Centigrade while the mixture is stirred. This leads to the reaction / which
yields soluble alkaline phosphate; and sulphate of lime the latter being finally
restored after being washed drained and dried.
The solution of alkaline phosphate, after being cleared by decantation is
subjected to the reaction j. It receives three equivalents of lime hydrated into
milk, which precipitates the tribasic phosphate, which is thus restored, and leaves
behind a solution or lye of a caustic alkali which is cleared by decantation. The
phosphate is separated, after washing, and dried with a view to its subsequent use
for the reaction f.
The alkaline solution, when saturated with carbonic acid, yields sodic
bicarbonate and after this salt all other sodic products may be obtained by the
usual means.
The treatment of potassium chloride is identical with that of sodium chloride
and when once the reaction (herein before described) has been completed the
alkaline sulphates, whatever their origin, are treated in the same manner.

page_text: It may happen, in further extending the use of this process that the bye-
products Cl and. SO, have no occasion to be fully utilised and therefore pass off as
practically worthless residues. In this case it may be more advantageous to cause
them to react upon each other, so that the SO, is converted into SO, by the action
of Cl by the supplemental reaction :
SO, HO + Cl
=
SO, + HCl.
When this is done the current of Cl and SO, is conveyed into an earthenware
column filled with pumice stone impregnated with water the said current arriving
in a continuous narrow stream or jet whereby sulphuric acid and hydrochloric
acid are produced, which are then collected in a receiver forining the lower part
of the said column. These bye-products are then properly distributed and
distilled in earthenware pots or receivers.
The pure bydrochloric acid is condensed
by the usual methods while the concentrated sulphuric acid remains in the
distilling receivers which need not be heated to a higher temperature than + 120°
Centigrade.
Dated this 7th day of November 1894.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Treatment of Alkaline Salts, or the Salts of
Alkaline Earths.
I JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of this invention (which has
been communicated to me from abroad by Nicolas Basset, Chemist, and
Wladimir de Baranoff, Doctor of Philosophy both of 21, Boulevard Poissonniere,
Paris in the Republic of France) and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement :-
Two main processes, well known and applicable to practical purposes, are
employed for treating alkaline salts with a view to obtaining alkaline carbonates
or caustic alkalies; they being used chiefly in the manufacture of soda and carbonate
of soda one being termed the "the ammonia soda process" and the other the "Leblanc
process." They are, both, however attended with somewhat serious defects.
The ammonia soda process involves the loss of the chlorine from the chlorides
treated and it cannot be applied either to potassium chloride (KCI) or to sulphates.
The Leblanc process, when applied to chloride of sodium yields products of less
purity than those yielded by the ammonia soda process and although it may be
used in connection with potassium chloride as well as with sodium chloride, yet in
the treatment of sulphates, (for which it can be employed) the whole of the
sulphuric acid is lost.
It is the object of this invention to overcome these defects obtaining the chlorine
in the treatment of chlorides and in the treatment of sulphates, recovering the
sulphur in a serviceable form.
By submitting the chlorides (NaCl and KCI) simultaneously to the action of a
current of oxygen or oxygenized air (air overcharged with oxygen) and a current
of sulphurous acid (SO,) the said chlorides are converted into the corresponding
sulphates, with the evolution of chlorine (if the presence of steam be avoided) or
hydrochloric acid (wbere steam is present) as expressed by the equations

page_text: Whence it follows that the chlorides (NaCl and KCI) may in all cases be
converted into sulphates by either of these two formulæ SO, + O, or SO, +. O
+ H2O with the evolution of Cl or HCl, respectively either of which
readily collected.
may be
By starting with sulphate of lime and with a very moderate amount of calcination,
the products represented by the following equations are obtained.

page_text: or for the reaction (4) is lost, unless occasion to utilise it should arise at some later
period.
The expeuse which this method involves comprises
1. The cost of the chlorides or sulphates, either natural, or artificial. (2) The
fuel required for the reactions. (3) A small loss involved in the employment of
tri-basic phosphate; and (4) The cost of the lime.
The positive advantages derived from this method are :—
:
(1) The value of the chlorine, collected as a bye-product in the forms of free
chlorine, hydrochloric acid, hypochlorite chlorate and the like. (2) The value of
the carbonic acid which becomes available, as compared with the cost of the fuel
nsed, and (3) The value of the soda, or potash, obtained as main products, either
in the caustic form, in the condition of hydrated or anhydrous carbonate or (in the
case of soda), as bicarbonate; besides the many bye products which may be turned
to account when the process is conducted on a large scale.
In the present application the invention relates to the manufacture of caustic
alkalies, or the carbonates thereof, whether hydrated or anhydrous and the recovery
of the chlorinated hye products, and has for its object a novel application of well
known principles, and a re-arrangement of certain recognised reactions, which have
not as yet been made serviceable for manufacturing purposes.
In order that this invention may be clearly understood we will now proceed to
describe the operation in the different phases of manufacture taking for the
purposes of explanation sodium chloride as the initial substance to be operated
пров.
The sulphurous acid necessary for either of the reactions (a) or (½) is first
produced by carrying out the reaction (c) (d) and (e).
A mixture of one equivalent of sulphate of lime, cither natural (in the condition
of plaster of Paris, waste plaster, or plaster dust), or artificial (as obtained from
reactions) with a sufficiency of powdered carbon or other carbonaceous matter is
introduced into a retort or cylinder (which may be vertical, inclined or horizontal)
heated externally, both ends of which should be tightly closed; the said mixture
being admitted through one end of the said retort or cylinder while the opposite
end thereof remains closed, the inlet orifice being then closed also. The apparatus
is fitted towards its upper part with a short length of pipe communicating with a
gasometer, so that the carbonic acid gas produced by the reduction of the sulphate
of lime, under the influence of the red hot fuel is conducted to the gasometer, into
which is also sent by suitable suction, or pressure apparatus, a sufficient proportion
of the carbonic acid generated by combustion in the furnace. When the reduction
reases to produce CO, gas (thereby signifying that the operation is completed)
the valve, or cock, of the junction pipe, leading to the gasometer is closed, while
the discharge orifice is opened and the calcium sulphide is allowed to drop into a
cooling chamber which may be built of masonry, or brickwork. The charge is then
renewed, and the operation repeated as before.
The cooled calcium sulphide, or if preferred the oxysulphide of calcium which is
left as a residue in certain operations, is moistened with one equivalent of water
and spread on the shelves of an apparatus similar to that usually employed for
eflecting the absorption of chlorine by lime in the manufacture of chloride (or
hypochlorite) of lime. The apparatus is watertight, when closed, and is provided
with two nozzles, or short lengths of pipe, one at the lower part, below the bottom
shelf, and the other at the upper part, above the top shelf. Through the lower
nozzle one equivalent of carbonic acid is introduced from the gasometer which gas
effects the reaction shewn in the equation (d). The sulphuretted hydrogen (H,S)
produced passes off into a closed combustion chamber, where it is burnt, and in so
doing, is changed into water and sulphurous acid by the reaction shewn by the
equation e under the influence of a current of air supplying three equivalents of
oxygen. The current of air is drawn in from outside by means of suitable suction
apparatus, and the sulphurous acid gas (SO,) is forced into a gasometer provided.
for the purpose.

page_text: The chloride is first converted into a dry porous and pervious condition. With
this object, it is mixed, while moist, with a suitable inert body, and compressed in
moulds into blocks, briquettes, balls, or cakes, of any desired shape. These are
dried first, by means of a current of air and then by means of the waste heat.
The inert body used may be for example white sand, or powdered sandstone, or
any form of silica incapable of forming silicates under the conditions in which the
operation is here performed, as the reaction necessitates the use of steam superheated
to incandescence.
The agglomerated mass after being thoroughly dried, as describel is introduced
into an apparatus similar to a gas retort, or any other suitable shape, which
should be tightly closed by means of removable doors, well fitting at the joints.
It is then heated externally, to or somewhat above a visible red heat and
sulphurous acid gas (SO,) is admitted from the gasometer, such gas entering at
the front of the apparatus below a perforated double bottom, whereon the dry
agglomerated material is placed. A junction pipe situated at the rear end of the
apparatus, serves to convey the chlorinetted products into dissolving receivers or
to the spot where the chlorine or hydrochloric acid is required to form fresh
compounds.
It will be understood that the oxygen (or oxygenized air) for the reactions (a)
and (b) is provided by suitable suction apparatus, the action of which also assists
the SO, gas in gaining access underneath the perforated false bottom, when the
material no longer yields any chlorinetted product, the delivery pipe is closed and
the discharge of the fritted mass consisting of the sulphate of soda and silica, is
proceeded with, the same being caused to drop into a cooling chamber, and a fresh
batch is then introduced, when it is desired to obtain chlorine as a bye-product,
the closing of the apparatus, the opening of the discharge pipe, and the admission
of the SO, gas and dry air, should not take place until after the temperature has
sufficiently risen to enable perfect stability of production to be obtained.
The air employed to assist the reaction (a) is dried by being caused to pass over
the quicklime which is to be hydrated for the reactions (j) and (k). No such
drying is required for the reaction (6) for which a current of steam is admitted
under the perforated bottom along with the air and SO, gas.
The alkaline sulphate thus obtained is dissolved in water. The remaining
operations are applicable to all alkaline sulphates, no matter how produced.
In accordance with the reaction (f) powdered tri-basic phosphate of lime is
introduced into a series of vats, with a quantity of water sufficient to facilitate the
operation, which vats are provided with stirring mechanism and may, or may not,
communicate with each other. The stirrer is then set in motion and the current
of sulphurous acid gas (SO,) is introduced, up to the point of saturation, after
which, by opening a discharge valve or cock, the liquid is caused to flow off into
a vat where it is allowed to rest until the sulphite of lime settles out and the clear
Bolution of soluble phosphate is then conveyed into a decomposing tank. The said
sulphite of lime, after being washed, drained, and dried in the air, may be used for
an indefinite length of time, in conjunction with the sulphate from the reaction (h)
or (i) for carrying out the reactions (c) (d) and (e).
The solution of soluble phosphate is mixed with the solution of sulphate of soda,
in equivalent proportions. The temperature is slightly raised, either by steam,
or by any other suitable means, until it attains from about 60° to 75° Centigrade,
while the mixture is stirred or agitated which may be effected by the steam when
that is used. This leads to the reaction (4) which yields soluble alkaline
phosphate and sulphate of lime, the latter being recovered, and washed drained
and dried.
The solution of alkaline phosphate, after being cleared by decantation,, is
subjected to the reaction (j). The tribasic phosphate is precipitated by three
equivalents of milk of lime and is thus recovered and leaves behind a solution, or
lye of caustic soda, which is cleared by decantation. The phosphate is separated
and is washed and dried with a view to its subsequent use for the reaction (ƒ). '

page_text: he alkaline solution, when saturated with carbonic acid, yields sodic
rbonate, and from this salt, all other sodic products may be obtained by the-
l means.
he treatment of potassium chloride is identical with that of sodium chloride,
alkaline sulphates, whatever their origin, are treated in the same manner.
[aving now particularly described and ascertained the nature of this inven-
and in what manner the same is to be performed I declare that what I
n is:
process for the transformation of alkaline chlorides into free alkalies, or
onates, with evolution of chlorine, or hydrochloric acid, in which the following
tions are employed.
(a) Reduction of sulphate of lime to sulphide of calcium by heating it with
carbonaceous matter, the carbonic acid evolved being collected.
(b) Decomposition of sulphide of calcium, after cooling in a closed vessel, by
part of the carbonic acid resulting from (a). Sulphuretted hydrogen being
evolved and carbonate of lime left. (Instead of this sulphide of calcium,
the oxy-sulphide of calcium which is left as a residue in certain operations
may be used.)
(c) Combustion of sulphuretted hydrogen producing sulphurous acid.
(d) Action of sulphurous acid at a high temperature in conjunction with air,
aud with, or without, steam upon chloride of sodium, or other alkaline
chloride, when the chloride is converted into sulphate, with evolution of
bydrochloric acid if steam has been used, or of chlorine when steam has not
been used.
(e) Action of sulphurous acid upon phosphate of lime, the sulphite of lime
and mono-calcic phosphate produced being afterwards separated by cold
water.
(f) Action of sulphate of soda or other alkaline sulphate upon mono calcic
phosphate producing mono-sodic (or other alkaline) phosphate and sulphate
of lime.
(g) Action of lime upon the mono-sodic (or other alkaline) phosphate
producing caustic alkali and tribasic phosphate of lime.
(4) Conversion of the caustic soda or other alkali into carbonate, or
bicarbonate of soda, or other alkali, by the carbonic acid from (a) mixed
with that produced by the combustion of the fuel used.
(i) Use of the sulphite of lime from (e) in conjunction with the sulphate of
lime from (f) for carrying out (a) and (b), the process as a whole, being.
conducted substantially as hereinbefore described.
Dated this 13th day of May 1895.
JOHNSONS & WILLCOX,
Agents.