Year: 1894

page_text: Date of Application, 7th July, 1894
Complete Specification Left, 6th Apr.. 1895-Accepted, 18th May, 1895

page_text: steam or either of them, in which case it may be desirable to cool and purify the
hot gases before bringing them into contact with the solutions in the receivers.
When dry distillation is employed the chloride or other salt of ammonia may be
substituted for the sulphate as the source of ammonia the residue formed in the
retort depending on the salt selected and the carbonate used to decompose it.
PROCESS No. 1 B.
Most ammonium salts are produced by neutralizing an acid by ammonia or
carbonate of ammonium. It will therefore be obvious from the foregoing that by
substituting other acids for the nitric acid used in producing ammonium nitrate as
described in Process No. 1A various salts of ammonia may be economically obtained,
for instance, if hydrochloric acid be substituted chloride of ammonium will be
formed or if phosphoric acid be substituted phosphate of ammonium will be
produced. In this way the following acids may be used.
Acetic acid
'Arsenic
'Arsenious acid
Citric acid
Hydroferrocyanic
Hydriodic acid
Oxalic acid
producing acetate
of ammonium
"
arseniate
"
"
arsenite.
"
"
citrate
"
"
ferrocyanide
"
iodide
"
"
"
oxalate
33
In either process basic nitrate of lead may be substituted, for the tribasic acetate
or mixed solutions of basic nitrate and tribasic acetate may be employed.
In the production of chemically pure salts of ammonium the commercial sulphate
of ammonium may be purified before distillation or the evolved gases from the
commercial salt may be freed from impurities by well known methods before
combination with the acid in the receivers.
Dated this 7th day of July 1894.
Improvements in or relating to the Manufacture of White Lead
and Salts of 'Ammonium.
1, HENRY WILCOX of Great Garlands, Stanford-le-Hope, in the County of
Essex, Manufacturing Chemist, do hereby déclare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
The objects of this invention are (1) the expeditious manufacture of commercial
white lead of superior quality by an innocuous process (2) the economical
production of nitrate of ammonium and (3) the obtaining of useful salts of the
alkalies and alkaline earths as bye products.
PROCESS No. 1.
In the production of white lead and to obtain nitrate of ammonium as a
secondary product, commercial sulphate of ammonium dissolved in water is put
into a still, and to this solution is added rather more than sufficient carbonate of
calcium (chalk) to ensure the complete decomposition of the ammonium salt. On
the application of heat to the still, ammonia mixed with carbonic acid and steam
is evolved and sulphate of calcium is formed which remains in the still. The

page_text: =
'ammonia and carbonic acid are evolved in the proportions in which they exist.
in normal or diammonic carbonate (NH),Co, as may be shewn by the following
equation CaCo, + (NH₁),SO, CaSO (NH), Cos. The evolved mixture
of ammonia; carbonic acid and steam which may if desired be passed through a
cooler or condenser, is received in vessels containing a solution of normal nitrate
of lead when further chemical changes ensue. The lead unites with a portion of
the carbonic acid in the formation of commercial white lead, at the same time
setting free the nitric acid which combines with the ammonia to form nitrate of
ammonium. The remainder of the carbonic acid passes by a tubular connection
into one or more receivers containing tri-basic acetate of lead solution; white lead
is here also formed and precipitates. The precipitation continues until the lead
acetate is reduced from the basic to the normal condition. The normal acetate
solution is then decanted from the white lead and re-converted into tri-basic
acetate solution by any of the known methods. when it is again ready for use as
described. The white lead and the nitrate of ammonium are separated and
prepared for market by well-known means.
PROCESS No. 1A.
Instead of employing the solution of normal nitrate of lead, dilute nitric acid
and tri-basic acetate of lead solution in separate receivers may be used in the
following manner. The gaseous mixture of aminonia and carbonic acid with steam
from the still is received in the vessel containing the dilute nitric acid. The
ammonia and nitric acid unite to form nitrate of ainmonium and the whole of the
carbonic acid is passed into the tri-basic acetate solution in the manner already
described.
The carbonates of sodium, potassium, magnesium, barium or strontium may be
employed instead of the carbonate of calcium when the residual sulphate in the
still will be one of sodium, potassium, magnesium, barium or strontium as the case
may be.
hot
Instead of employing a still, the distillation may be effected in closed retorts
such as are used for dry decomposition, with or without the aid of jets of air and
steam or either of them, in which case it may be desirable to cool and purify the
gases before bringing them into contact with the solutions in the receivers.
When dry distillation is employed the chloride or other salt of ammonia may be
substituted for the sulphate as the source of ammonia the residue formed in the
retort depending on the salt selected and the carbonate used to decompose it.
PROCESS No. 1 B.
Most ammonium salts are produced by neutralizing an acid by ammonia or
carbonate of ammonium. It will therefore be obvious from the foregoing that by
substituting other acids for the nitric acid used in producing ammonium nitrate as
described in Process No. La various salts of ammonia may be economically obtained,
Most ammonium salts are produced by neutralizing an acid by ammonia or
carbonate of ammonium. It will therefore be obvious from the foregoing that by
substituting other acids for the nitric acid used in producing ammonium nitrate as
described in Process No. La various salts of ammonia may be economically obtained,
for instance, if hydrochloric acid be substituted chloride of ammonium will be
formed or if phosphoric acid be substituted phosphate of ammonium will be
produced. In this way the following acids may be used.
Acetic acid producing acetate of ammonium.
Arsenic acid producing arseniate of ammonium.
Arsenious acid producing arsenite of ammonium.
Citric acid producing citrate of ammonium.
Hydroferrocyanic acid producing ferrocyanide of ammonium.
Hydriodic acid producing iodide of ammonium.
Oxalic acid producing oxalate of ammonium.

page_text: In the production of chemically pure salts of ammonium the commercial sulphate
of ammonium may be purified before distillation or the evolved gases from the
commercial salt may be freed from impurities by well-known methods before
combination with the acid in the receivers.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of white lead from the soluble salts of lead by the gaseous
mixture of carbonic acid and ammonia.
2. The employment of carbonate of ammonium in the gaseous state for the
precipitation of white lead from the aqueous solutions of the soluble salts of
lead.
3. The precipitation of white lead from the aqueous solutions of salts of lead by
a gaseous mixture of ammonia and carbonic acid in the proportions necessary to
form normal ammonium carbonate with or without the aid of a current of steam or
air substantially as described.
4. In the manufacture of white lead the simultaneous production of nitrate of
ammonium from the soluble salts of lead by the gaseous mixture of carbonic acid
and ammonia substantially as described.
5. The manufacture of white lead and nitrate of ammonium from nitric acid and
tri-basic acetate of lead substantially as described.
6. In the manufacture of white lead and chloride of ammonium and other salts of
ammonium the employment of hydrochloric acid and the various acids enumerated
in Process 1B substantially as described.
Dated this 5th day of April 1805
HENRY WILCOX.
Boult & Wade,
Agents for the Applicant.