Improvements in or relating to Obtaining Chlorine.
Year: 1889

page_text: Date of Application, 26th Mar., 1889
Complete Specification Left, 27th Dec., 1889-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in or relating to Obtaining Chlorine.
I, RICHARD DORMER, F.C.S., of the Laboratory, Garston, in the County of Lan-
caster, Analytical Chemist, do hereby declare the nature of this invention to be as
follows:-
In the ordinary process of producing chlorine by acting upon peroxide of manganese
with hydrochloric acid, only one half of the chlorine in the hydrochloric acid is obtained,
the other half remaining in solution as chloride of manganese. This manganous chloride
is as a rule utilized for the recovery of the manganese as peroxide by the well known
processes of Weldon & Dunlop in which processes the chlorine combined as man-
ganous chloride is converted into calcium chloride, which said calcium chloride is
usually run to waste, the chlorine contained in the same being lost. By my invention
however both atoms of the chlorine are obtained in the free state.
For this purpose
I add sulphuric acid to the mixture of hydrochloric acid and peroxide of manganese,
the reaction being as follows:-
Mn O2 + 2 HCl + H₂SO₁ = 2 Cl + Mn SO. + 0 H₂.
.
The manganese is thus left in the state of sulphate of manganese, and I propose
PROVISIONAL SPECIFICATION.
Improvements in or relating to Obtaining Chlorine.
I, RICHARD DORMER, F.C.S., of the Laboratory, Garston, in the County of Lan-
caster, Analytical Chemist, do hereby declare the nature of this invention to be as
follows:-
In the ordinary process of producing chlorine by acting upon peroxide of manganese
with hydrochloric acid, only one half of the chlorine in the hydrochloric acid is obtained,
the other half remaining in solution as chloride of manganese. This manganous chloride
is as a rule utilized for the recovery of the manganese as peroxide by the well known
processes of Weldon & Dunlop in which processes the chlorine combined as man-
ganous chloride is converted into calcium chloride, which said calcium chloride is
usually run to waste, the chlorine contained in the same being lost. By my invention
however both atoms of the chlorine are obtained in the free state. For this purpose
I add sulphuric acid to the mixture of hydrochloric acid and peroxide of manganese,
the reaction being as follows:-
:-
Mn O₂ + 2 H Cl + H₂SO₁ = 2 Cl + Mn SO̟ + O H
+
The manganese is thus left in the state of sulphate of manganese, and I propose
by this invention to convert the said sulphate of manganese into chloride of manganese
by the addition of a solution of an alkaline earth chloride (preferably chloride of
calcium) in excess. This chloride of calcium is obtained as a bye product from the
Weldon or Dunlop recovery processes, which said chloride of calcium is at present
run to waste.
The chloride of manganese is treated for the recovery of the manganese or Weldon
mud and the resulting chloride of calcium utilized again. The precipitated sulphate
of lime can be utilized as a fertiliser or otherwise.
1 1000
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Obtaining Chlorine.
I, RICHARD DORMER F.C.S., of the Laboratory, Garston, in the County of Lancaster,
Analytical Chemist, do hereby declare 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 :--
In the ordinary process of obtaining chlorine by acting upon manganese
dioxide, Mn O,, or Weldon mud, with hydrochloric acid, H Cl, one half only of the
chlorine, Cl, in the hydrochloric acid, H Cl, used, is by theory evolved, the other half
remaining in solution as manganese chloride, Mn Cl₂, thus
Mn O, 4 H CI
=
Mn Cl₂ + Cl2 + 2 H₂ O (1).
By this invention I propose, firstly, to obtain the whole of the chlorine in the
hydrochloric acid, H Cl, by taking advantage of the fact that in the presence of
sulphuric acid, H, SO, hydrochloric acid, H Cl, acts upon the manganese
dioxide, Mn O₂, usually in the form of Weldon mud, according to the following
reaction :-
4'
(2) Mn O₂ + 2 H Cl + H, SO₁ = 2 Cl + Mn SO + 2 H₂ O
2

page_text: water, H, O, as may be found most convenient. Or it may be filtered through a filter
ress or other suitable separator and washed in order to cleanse it from the manganese
olution.
The manganese is now in solution as inanganese chloride, Mn Cl,, and consequently
uitable for the recovery of the manganese by the usual method of Weldon or Dunlop
s at present by means of lime and chalk respectively.
The calcium sulphate, Ca SO,, can be dried and used for any convenient purpose.
In practice, I find that it is not necessary, or even, as a rule, desirable to work the
nvention in two stages, but that the full amount of chloride of calcium required by
the process can be added before the still operation is finished. The reaction in the
chlorine still is then as follows:-
Mn O, + 2 H CI + H, SO, + Ca Cl, = Mn Cl₂+ 2 Cl + Ca SO, + 2 H, O.
4
The above equation assumes the use of pure Mn O₂ but in the general practice the
manganese material used is Weldon mud, which contains, besides Mn O₂, an appre-
ciable quantity of other matters, notably Ca Cl₂, Mn O, and Ca O, in which case an
additional quantity of H. SO, is required, namely, sufficient to convert the Ca O into
Ca SO, and also the Mn O into Mn SO; the Ca Cl, being used in quantity sufficient
to leave the whole of the manganese as chloride.
From the foregoing description of this process, it will be seen that, in order to
obtain the whole of the chlorine in the hydrochloric acid, EL Cl, used, the only extra
cost of material is that of the sulphuric acid, H, SO.
In the ordinary process the chlorine produced is theoretically 50 per cent. of the
amount contained in the HCl, whilst the various practical losses in the production of
bleaching powder, or chloride of lime, reduce the practical production to about one
half the theoretical, equal to a loss of say 25 per cent. of the chlorine.
By this invention the chlorine produced is theoretically 100 per cent. of the amount
in the HCl, and taking the same practical loss as before, namely, 25 per cent., the
practical result is say three times that of the ordinary process.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In the manufacture of chlorine, the combined use of sulphuric acid or of sulphate
of manganese and of chloride of calcium, substantially as and for the purposes described,
whereby theoretically the entire yield of chlorine present in the hydrochloric acid used
is secured, and also a very pure and useful form of sulphate of lime is obtained as a
bye product, while manganeso chloride applicable for the Weldon or Dunlop process
is left.
2. The process, taken as a whole, for obtaining chlorine substantially as herein
described, no claim being here made for any part taken separately or used for a