Year: 1896

page_text: Date of Application, 29th Dec., 1896
Complete Specification Left, 26th Aug., 1897-Accepted, 2nd Oct., 1897
CO,+H,0+2 KCN=2 HCN+K,COgi
When the same air or gas is circulated over and over again, the limited quantity
of carbonic acid contained in the air which
in the air which is passed through the
drying apparatus is of little moment; but if fresh air was introduced
into the apparatus, fresh carbonic acid would also be introduced and
thus destroy the cyanide; unless the air was drawn through lime which, considering
the large quantity of fresh air that would be necessary, would be expensive.
The air must not be heated to a higher temperature than that of the boiling
point of water otherwise the cyanide will be decomposed into ammonia, I therefore
prefer in the carrying out of my invention to use the condensed water from any
steam or steam power which there may be on the premises.
The continuous circulation of the air through the aforesaid drying apparatus
may be effected by any ordinary fan, or pump.
In my said method of drying alkaline cyanides, I may use an atmosphere of any,
indifferent gas, preferably atmospheric air.
Dated this 28th day of December. 1896.

page_text: cyanide to be dried. In so doing, the heated air takes up the moisture from the
cyanide whereby the cyanide is dried. The same air now passes on to any ordinary
condenser whereby the moisture taken up by the air in passing over the cyanide is
condensed. The same air then passes back again into the heater and then over
a fresh quantity of cyanide. There is thus a continuous circulation of the same
air. The object of using the same air over and over again is to prevent the intro-
duction of any fresh or further carbonic acid (which exists in the air) from acting
on or destroying the cyanide, thus
CO,+HO+2 KCN=2 IICN+K,CO.
When the same air or gas is circulated over and over again, the limited' quantity
of carbonic acid contained in the air which is passed through the drying apparatus
is of little moment; but if fresh air was introduced into the apparatus, fresh
carbonic acid would also be introduced and thus destroy the cyanide; unless the
air was drawn through lime which, considering the large quantity of fresh air that:
would be necessary, would be expensive.
Tlie air must not be heated to a higlier temperature than that of the boiling
point of water otherwise the cyanide will be decomposed into ammonia, I therefore
prefer in the carrying out of my invention to use the condensed water from any
steam or steam power which there may be on the premises.
The continuous circulation of the air through the aforesaid drying apparatus
may be effected by any ordinary fan or pump.
In my said method of drying alkaline cyanides, I may use an atmosphere of any
indifferent gas, preferably atmospheric air
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:-
In the drying of alkaline cyanides by means of heated air, the alternate heating
and cooling of the same air in a continuous circulation over the cyanide, by means
of which decomposition of the cyanide is prevented; in the manner as described.
Dated this 25th day of August, 1897.
JOHNSONS,
115 St. Vincent Street, Glasgow,. Applicant's Agents.