PREVIORAL DI BUITIVATION Improvements in and relating to the Treatment of Zinc Ores or Ore-residues in the Production of Zinc, Chlorine, Sodium Sulphate, and other Products.
Year: 1896

page_text: Date of Application, 12th Aug., 1896
Complete Specification Left, 30th Apr., 1897-Accepted, 19th June, 1897
PREVIORAL DI BUITIVATION
Improvements in and relating to the Treatment of Zinc Ores or
Ore-residues in the Production of Zinc, Chlorine, Sodium
Sulphate, and other Products.
I, Dr. HUGO BREWER, of 5 Grünstrasse, Duisburg, in the German Empire,
Chemist, do hereby declare the nature of this invention to be as follows:-
It has already been proposed to modify the production of zinc so as to render it
more profitable by also producing available chlorine with the zinc, this being
effected in such a manner that sulphide ores containing zinc are roasted and
chlorinated by means of chloride of sodium and the lye obtained from the product
of the roasting is converted into a chloride lye by the addition of chloride of
calcium which is easily and cheaply available in the waste lyes of the ammonia-soda
manufacture; in this manner the sodium chloride is simultaneously regenerated and
can be again used in the roasting process. From the lye so produced the zine and
the chlorine in an available form, can then be obtained electrolytically. Should
the lye also contain other metals, they can be separated beforehand in any suitable
manner as desired, either chemically or electrolytically, for example, as described
in the British Specification No. 1348 of 1895.
In the industrial application of this process, it may happen that, by reason of
the particular circumstances, it is advantageous to also obtain the sodium sulphate
produced in the roasting process and only to convert the dissolved residue of
sulphate left behind from this manufacture of Glauber's salt into chloride of
sodium by means of chloride of calcium.
In such cases, according to the present invention, the above mentioned process
should be modified, whilst obtaining the whole quantity of zinc and chlorine, in that
only one part of the chloride of sodium is regenerated with chloride of calcium,
ancther part is allowed to crystallize out in the form of Glauber's salt, so that the
remaining part of chloride of sodium necessary for the roasting process will be
supplied directly to the process.
For this purpose it is only necessary to leach the ores, which have been subjected
to the chlorinating roasting, with the necessary quantity of chloride of sodium, this
lye is first to be saturated by a further addition of solid chloride of sodium, for the
purpose of avoiding the direct vaporization of roast lyes containing chloride of iron
up to the point of saturation whereby (as has been shown by experiments on a
practical scale) the excess amount of chloride of sodium in the lye required for the
purposes of the present invention is simultaneously obtained for producing a pure
Glauber's salt. The lye saturated in this way is cooled for crystallizing out the
Glauber's salt and the mother liquor resulting therefrom is now first displaced by
so much chloride of calcium lye as is necessary for the conversion into calcium
sulphate of the sulphuric acid still contained therein and derived from the roasting
process, as is also the case in the above mentioned process. The iron is preferably
separated in the form of hydrated ferric oxide by the aid of calcium carbonate.
The excess chloride of sodium added, together with the chloride of sodium
formed by the addition of chloride of calcium, is continuously recovered at the
same place and so forms a permanent stock of this substance for carrying on the
process. The direct evaporation of iron chloride lye involves very great technical

page_text: difficulties, and therefore could not be carried out in practice, whilst the
evaporation of chloride of sodium lyes can be very easily effected without damage
to the evaporating apparatus.
After the addition of the chloride of calcium and separation of the gypsum,
the iron oxide, etc., and the chloride of sodium, the solution is electrolysed as already
mentioned above.
..
حيمد
.
1000
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in and relating to the Treatment of Zinc Ores or
Ore-residues in the Production of Zinc, Chlorine, Sodium
Sulphate, and other Products.
I, Dr. HUGO BREWER, of 5 Grünstrasse, Duisburg, in the German Empire,
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 :-
It has already been proposed to modify the production of zinc so as to render it
more profitable by also producing available chlorine with the zinc, this being effected
in such a manner that sulphide ores containing zinc are roasted and chlorinated by
means of chloride of sodium and the lye obtained from the product of the roasting is
converted into a chloride lye by the addition of chloride of calcium which is easily
and cheaply available in the waste lyes of the ammonia-soda manufacture; in this
manner the sodium chloride is simultaneously regenerated and can be again used in the
roasting process. From the lye so produced the zinc and the chlorine in an available
form, can then be obtained electrolytically. Should the lye also contain other
metals, they can be separated beforehand in any suitable manner as desired, either
chemically or electrolytically, for example, as described in the British Specification
No. 1348 of 1895.
In the industrial application of this process, it may happen that, by reason of the
particular circumstances, it is advantageous to also obtain the sodium sulphate
produced in the roasting process and only to convert the dissolved residue of sulphate
left behind from this manufacture of Glauber's salt into chloride of sodium by
means of chloride of calcium.
In such cases, according to the present invention, the above mentioned process
should be modified, whilst obtaining the whole quantity of zinc and chlorine, in that
only one part of the chloride of sodium is regenerated with chloride of calcium,
another part being allowed to crystallize out in the form of Glauber's salt, so that
the quantity of sodium chloride which, in view of the said elimination of one part of
the sodium chloride in the form of Glauber's salt, is still necessary for the roasting
process to replace this eliminated part of the sodium chloride, will need to be
supplied in any suitable form, for instance in the form of rock-salt directly to the
roasting process.
For this purpose it is only necessary to leach the ores, which have been subjected
to the chlorinating roasting, with the necessary quantity of chloride of sodium, this
lye is first to be saturated by a further addition of solid chloride of sodium, for the
purpose of avoiding the direct vaporization of roast lyes containing chloride of
iron, up to the point of saturation whereby (as has been shown by experiments on

page_text: a practical scale) the excess amount of chloride of sodium in the lye required for
the purposes of the present invention is simultaneously obtained for producing a
pure Glauber's salt. The lye saturated in this way is cooled for crystallizing out
the Glauber's salt and to the mother liquor resulting therefrom is now first added
so much chloride of calcium lye as is necessary for the conversion into calcium
sulphate of the sulphuric acid still contained therein and derived from the roasting
process, as is also the case in the above mentioned process. The iron is preferably
separated in the form of hydrated ferric oxide by the aid of calcium carbonate.
The excess chloride of sodium added, together with the chloride of sodium formed
by the addition of chloride of calcium, is continuously recovered at the same place
and so forms a permanent stock of this substance for carrying on the process. The
direct evaporation of iron chloride lye involves very great technical difficulties, and
therefore could not be carried out in practice whilst the evaporation of chloride of
sodium lyes can be easily effected without damage to the evaporating apparatus.
After the addition of the chloride of calcium and separation of the gypsum,
the iron oxide, etc. and the chloride of sodium, the solution is electrolysed as already
mentioned above.
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. In the production of zinc and chlorine by roasting sulphide ores with chloride
of sodium, and subsequently leaching the roasted material and converting the
sulphates (and also the sodium sulphate formed) in the lye into chlorides by the
addition of chloride of calcium with the simultaneous regeneration of the chloride
of sodium, from which lyes, after separation of the chloride of sodium and other
bye-products, zinc and chlorine are obtained electrolytically, the modification of
this process in such a manner that, from the lye obtained by leaching the roasted
material, a part of the sodium sulphate is first separated by cooling, and then the
chloride of calcium is added.
2. In a process such as that claimed in the preceding claiming clause, the
addition of solid chloride of sodium to the lye obtained by leaching the roasted
material, in order to make a saturated lye, for the purpose of better crystallizing out
the Glauber's salt in cooling the lye and of obtaining a purer crystallization-product,
whereafter the said quantity of chloride of sodium (added for the latter purpose)
is recovered as solid chloride of sodium.
Deted the 30th dor of Annil 1807
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.