IMPROVEMENTS 'IN THE MANUFActure of AlkALI
Year: 1878

page_text: LETTERS PATENT to Holbrook Gaskell, the younger, of Widnes, in the County
of Lancaster, Alkali Manufacturer, for the Invention of "IMPROVEMENTS 'IN
THE MANUFActure of AlkALI.”
Sealed the 11th March 1879, and dated the 25th September 1878.
PROVISIONAL SPECIFICATION left by the said Holbrook Gaskell at the Office
of the Commissioners of Patents on the 25th September 1878.
HOLBROOK GASKELL, the younger, of Widnes, in the County of Lancaster, Alkali
Manufacturer. "IMPROVEMENTS IN THE MANUFACTURE OF ALKALI."
My Invention relates to that stage in the manufacture of alkali in which "black-
ash" is made in revolving furnaces.
As at present manufactured "black ash" usually contains cyanide and sulphide
of sodium, which renders difficult the manufacture from such black ash of soda.
products of the best quality.
Now my Invention consists in completely or partially destroying such cyanide
and sulphide, either by means of air and steam used conjointly or by means of air
or steam employed alone. When air and steam are used in conjunction I accom-
plish the object before mentioned by introducing the air and the steam into the
revolving furnace at any suitable time and in any convenient manner.
When air
is used alone or conjointly with steam, I introduce into the revolving furnace in
any convenient manner, or at any suitable time, air in excess of the quantity
necessary for the combustion of the fuel or fuel gases. When steam is employed
alone in lieu of air and steam, or of air alone, I introduce steam into the revolving
furnace in any convenient manner and at any convenient period of the operation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Holbrook Gaskell in the Great Seal Patent Office on the 19th
March 1879.
HOLBROOK GASKELL, the younger, of Widnes, in the County of Lancaster, Alkali
Manufacturer. "IMPROVEMENTS IN THE MANUFACTURE OF ALKALI."
My said Invention relates to that stage in the manufacture of alkali in which
"black ash" is made, and it has for its object preventing the presence or greatly
diminishing the quantity contained in "black ash" of cyanide of sodium or cyanide
of potassium, as the case may be, according as the Invention is applied to the manu-
facture of soda or potash."
In order to effect this object I bring the "black ash" during the process of manu-
facture in a revolving furnace into intimate contact with either air or steam used
alone, or air and steam employed in conjunction, the same being either superheated
or used at the ordinary temperatures. Or I subject the "black ash" to the action
of the air or steam, or the air and steam in special apparatus provided for the
purpose, into which the "black ash" may be conducted from the revolving furnace,
but it will usually be found most convenient to act upon the "black ash" while still
contained in the revolving furnace. The air or steam, or the air and steam may be
introduced in any convenient manner by any of the well-known appliances for
that purpose. When, however, it is desired to employ a mixture of air and steam
it will usually be found most advantageous to use a steam jet. A current of air is
thereby induced, which passes with the steam, the mixture of air and steam being
discharged upon the surface of the charge through a pipe debouching at the neck of
the revolving furnace (for example), and arranged at any convenient angle.
The air or steam, or the air and steam may be introduced during the whole or a
portion only of the time of the operation upon the charge, but I prefer to introduce
the same during the whole time, as by this means greater security is obtained for
minimizing the amount of cyanide which shall be present in the finished product,
not only by reason of the chemical action of the air or steam, or air and steam, but
also by the introduction of the same, promoting a more complete combustion of the
fuel gases, whereby I am enabled to considerably reduce the amount of slack or
other carbonaceous material usually required in the charge, and thus lessen the
tendency to the formation of cyanide.
Having now described and particularly ascertained the nature of my said Inven-
tion, and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,―
Subjecting "black ash" to the action of either air or steam used alone, or air and
steam employed in conjunction, substantially in the manner and for the purpose
herein-before described.
In witness whereof, I, the said Holbrook Gaskell, the younger, have to this
my Specification set my hand and seal, this Seventeenth day of March,
HOLBROOK GASKELL, JR. (L.S.)