Permanganates, and Arseniates.
Year: 1887

page_text: Date of Application, 10th Oct., 1887
Complete Specification Left, 7th July, 1888
Complete Specification Accepted, 10th Aug.,
1888
Permanganates, and Arseniates.
I, CARL HUGGENBERG, Manufacturing Chemist, of Chemnitz, in the Kingdom of
Saxony, do hereby declare the nature of this invention for, PROCESSES FOR OBTAINING
NITRITES, CHROMATES, MANGANATES, PERMANGANATES AND ARSENIATES, to be as
follows:-
These processes are based on the production of nitrites in carrying out processes
of oxidation in which the salts of oxygen-acids of chromium, manganese and arsenic
are formed from the lower oxygen-compounds or stages of oxidation of these
elements.
I place nitrates in contact with basis which are capable of binding the nascent
oxygen-acids of the said elements, and with the corresponding lower oxygen-com-
pounds of the said elements and subject the whole to a suitably high temperature. I
have found, that in this process the quantity of nitrates must be at least sufficient to
ensure that only one atom of oxygen need be extracted from one molecule of the
nitrate, to supply the quantity of oxygen necessary for the process of oxidation, and
that therefore the reduction of the nitrate is arrested at the formation of nitrites
instead of being continued until the formation of the free base of the respective
nitrate.
By the employment of bases which form insoluble salts by combination with the
hascent acids of chromium manganese and arsenic, the separation of the products
resulting from the process is facilitated.
The following examples may serve to illustrate the principle of my invention.
1. OBTAINING NITRITE IN THE PRODUCTION OF MANGANATE OR PERMANGANATE.
By melting together baric hydrate, manganic peroxide and sodic or potassic nitrate in
proportions corresponding to the following equation, 1 obtain sodic nitrite and baric
permanganate—
D
OTT
1 M
AL NO
B. (OH), Mn O, ¦ Na NO,
=
Na NO, + Ba Mn O, + H, O.

page_text: 3 Ca O+ As, О¸ + 2 Na NO₂
=
3
2 Na NO, Ca, (As O₁),.
The nitrite may be extracted by water and thus separated from the insoluble calcic

page_text: Permanganates, and Arseniates.
1, CARL HUGGENBERG, Manufacturing Chemist, of Chemnitz, in the kingdom of
Saxony, do hereby declare the nature of my invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
These processes are based on the production of nitrites in carrying out processes of
oxidation in which the salt of oxygen-acids of chromium, manganese and arsenic are
formed from the lower oxygen-compounds of these elements.
I place nitrates in contact with bases which are capable of binding the nascent
oxygen-acids of the said elements, and with the corresponding lower oxygen-
compounds of the said elements, and subject the whole to a suitably high temperature.
I have found, that in this process the quantity of nitrates must be at least sufficient to
ensure that only one atom of oxygen need be extracted from one molecule of the
nitrate, to supply the quantity of oxygen necessary for the process of oxidation and
that therefore the reduction of the nitrate is arrested at the formation of nitrite,
instead of being continued until the formation of the free base of the respective
nitrate. To facilitate the separation of the products resulting from the process, I
prefer to employ bases which form insoluble salts by combination with the acids of
chrome, manganese and arsenic.
The following examples serve to show the application of my principle.
1. OBTAINING NITRITE IN THE PRODUCTION OF MANGANATE AND PERMANGANATE.
By melting together baric hydrate, manganic peroxide and sodic or potasssic nitrate
in proportions corresponding to the following equation, I obtain sodic nitrite and barie
manganate.
Ba (OH), Mn 0, + Na NO3
=
Na NO, + Ba Mn O₁ + H, O.
4
It is always advantageous to employ an excess of nitrate, in order to prevent the fused
mass from getting too thick or sticky, and to ensure the complete conversion into
manganate. By lixiviating the fused green mass with water, the sodic nitrite and the
undecomposed nitrate are dissolved, and after filtration, are separated from any
dissolved baric hydroxide, by conducting carbonic acid into the solution. The solution
is then boiled down, during which process the nitrate may be separated from the
nitrite by fractional crystallisation, so as to obtain the latter in a pure state.
The saltpetre is employed for a fresh fusion.
The baric manganate remaining undissolved may be employed as a beautiful
green pigment which is not destroyed by lime, or it may be easily converted into a
permanganate.
For the latter purpose, the baric. manganate is boiled with a solution of alkali-
carbonate, and at the same time carbonic acid admitted to the mixture, thereby
producing a solution of alkali-permanganate and a deposit of baric carbonate with