IMPROVEMENTS IN THE MANUFACTURE OF THE ALKALINE EARTHS, AND THEIR OXIDES AND ACIDS OR OTHER COMPOUNDS, BY CALCINATION OR THE ACTION OF AZOTIC ACID
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Arthur Charles Henderson at the
Office of the Commissioners of Patents on the 2nd November 1883. Commu-
nicated to bim from abroad by Jules Edme Maumené of Lyon in the
Department of Rhone in the Republic of France
"
ARTHUR CHARLES HENDERSON of 47 Museum Street Oxford Street in the Parish
of Bloomsbury and county of Middlesex IMPROVEMENTS IN THE MANUFACTURE
OF THE ALKALINE EARTHS, AND THEIR OXIDES AND ACIDS OR OTHER COMPOUNDS,
BY CALCINATION OR THE ACTION OF AZOTIC ACID A communication to me from
abroad by Jules Edme Maumené of Lyon in the Department of Rhone in the
Republic of France
31
The earthy oxides, baryta, strontia and others having become a desideratum in
various industries, the inventor has studied to find the most economical method of
obtaining these, and has discovered the following process, which may become
henceforth of general application: that is to say he employs azotic acid for
converting the salts, carbonates, and so forth into sulphurs phosphorus et cætera,
and in calcining the nitrates in retorts lined with clay, without the loss of any
product, and what is a special feature the regeneration or reproduction of azotic
acid.
This acid can be regenerated by directing bypoazotic acid, and what remains of
free oxygen into a silicious chamber with irregular divisions arranged contrariwise
in which a current of water is made to flow in opposite directions, and which is
regulated so as not to dilute the reproduced azotic acid too much.
The oxygen being likely to fail on account of its retention by the earthy alkali
(the more so, the less it is calcined) a certain quantity of air is admitted into the
chamber by means of a fan, blower, air pump or some equivalent, without
disengaging the least particle of nitrous gas, or peroxide of nitrogen whilst
completely restoring the azotic acid.
On the other hand the sulphuretted bydrogen can be usefully employed,
by absorbing it in ammonia. or soda for forming industrial products such as
hydrosulphate of ammonia, sulphuret of sodium and potassium crystallized, or
sulphocarbonates.
Or it is burnt and converted into sulphurous acid, the absorption of which by
lime or soda produces sulphites, bisulphites and hyposulphites,

page_text: By this means the baryta, and strontia can be obtained at a price sufficiently
low to admit of their employment either directly in the manufacture of sugar, by
dissolving them in the juices of the sugar cane, beetroot, or other sugar containing
substances, or they may be used in extracting sugar from molasses and also in
obtaining pure oxygen gas.
The various operations by which the new process is conducted are sufficiently
well known individually to require neither description nor illustration, and the
form of the apparatus employed may vary as well as their mode of construction.
It is clear that any other means of obtaining the nitrate may be employed, and
in lieu of the sulphurs; carbonates and borates may be used; in a word any salts
producing nitrate even partially. It is merely their cost which gives them the
preference.
It is the regeneration or reproduction of the azotic acid which forms the principal
means of obtaining the alkalis or other compounds such for example as stannic
acid, at a cheap rate.
The accidental losses of hyponzotic acid caused by the apparatus or by other
means are repaired by an addition of azotic acid, but these losses are always very
small in a well managed factory.
The organic acids such as oxalic acid whose production by azotic acid is costly,
can henceforth be obtained at a much less cost. The same is the case with
all compounds in which the reproduction of azotic acid diminishes the cost of
manufacture.
Finally it is the ensemble of the process and more especially the reproduction of
the azotio acid, the calcination in retorts lined with clay, the combustion of H.S.
(to transform it into S.O³) in gas lighting, and the treatment of the sulphurs in
slate vases or silicious substances, which constitute the invention.