Year: 1886

page_text: Date of Application, 13th May, 1886.
Complete Left, 27th Jan., 1887.
Complete Accepted, 1st Mar., 1887.
1 WILLIAM SIMON of Baltimore City State of Maryland United States of America
Chemist,do hereby declare the nature of this invention to be as follows:-
:-
My method for the manufacture of bichromate of potassium consists in the
conversion of chromate of sodium into bichromate of potassium by the addition of
chloride of potassium and of either hydrochloric or sulphuric acid to a solution of
said chromate of sodium when decomposition takes place, bichromate of potassium
being formed which is separated by crystallization, whilst the sodium salts (chloride or
sulphate of sodium) which are formed may be obtained by boiling down the mother
liquor.
The above process may be carried out in two different ways as follows:-
First way. Chromate of sodium, or a solution of this salt, is converted into
bichromate of sodium by the addition of a mineral acid in the well known way,.
and then to the solution of bichromate of sodium thus obtained and also containing
a soda salt of the acid employed (which soda salt may or may not be separated by.
boiling down to a sufficient strength) is added chloride of potassium when the
decomposition takes place which is represented by the following equation :-
Na, Cr, O + 2 KCI
==
K, Cr, O7 +2 Na Cl.
Second way. To chromate of sodium, or to a solution of this salt, are added
hydrochloric acid and chloride of potassium when bichromate of potassium separates
in crystals and is collected, whilst chloride of sodium is obtained by boiling down the
mother liquor and removing this salt and from which mother liquor again bichromate
of potassium crystallizes on cooling. The decomposition taking place is shown by the
following equation:
W. SIMON.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: I WILLIAM SIMON of Baltimore City, State of Maryland, United States of America,
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:-
My method for the manufacture of bi-chromate of potassium consists in the
conversion of chromate of sodium into bi-chromate of potassium by the addition of
chloride of potassium and of either hydrochloric or sulphuric acid to a solution of
said chromate of sodium, when decomposition takes place, bi-chromate of potassium
being formed, which is separated by crystallization, whilst the sodium salts (chloride
or sulphate of sodium) which are formed may be obtained by boiling down the mother
liquor.
The above process may be carried out in two different ways as follows:-
First way. Chromate of sodium or a solution of this salt is converted into
bi-chromate of sodium by the addition of a mineral acid in the well known way
and then to the solution of bi-chromate of sodium thus, obtained, and also containing
a soda salt of the acid employed (which soda salt may or may not be separated by
boiling down to a sufficient strength) is added chloride of potassium when the
decomposition takes place which is represented by the following equation:-
Na, Cr, 0, +
Bichromate of'
Sodium.
2 KCI =
Chloride of
Potassium.
K, Cr, O +
Bichromate of
Potassium.
2 Na Cl.
Chloride of
.Sodium.
Second way. To chromate of sodium or to a solution of this salt are added
hydrochloric acid and chloride of potassium, when bi-chromate of potassium separates
in crystals and is collected, whilst chloride of sodium is obtained by boiling down the
mother liquor and removing this salt and from which mother liquor again bi-chromate
of potassium crystallizes on cooling.
The decomposition taking place is shown by the following equation.
2 (Na, Cr 04)
Chromate of
Sodium.
+
2 KCI + 2 HCI =
Chloride of Hydrochloric
Potassium.
Acid.
K₂ Cr₂ 07 +
Bichromate of
Potassium.
4 Na Cl +
Chloride of
H, O
Water.
Sodium.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1. The process of manufacturing bi-chromate of potassium which consists in
decomposing bichromate of sodium by chloride of potassium substantially as described.
2. The process of manufacturing bi-chromate of potassium which consists in
decomposing chromate of sodium by chloride of potassium and hydrochloric acid
substantially as described.
TI SEMON
TU SIMON
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.