IMPROVEMENTS IN UTILIZING BYE-PRODUCTS OF THE SODA AND POTASH MANUFACTURES
Year: 1878

page_text: LETTERS PATENT to James Mactear, of Glasgow, in the County of Lanark,
North Britain, Chemist, for the Invention of "IMPROVEMENTS IN UTILIZING
BYE-PRODUCTS OF THE SODA AND POTASH MANUFACTURES."
Sealed the 13th August 1878, and dated the 28th February 1878.
"
PROVISIONAL SPECIFICATION left by the said James Mactear at the
Office of the Commissioners of Patents on the 28th February 1878.
JAMES MACTEAR, of Glasgow, in the County of Lanark, North Britain, Chemist.
IMPROVEMENTS IN UTILIZING BYE-PRODUCTS OF THE SODA AND POTASH MANU-
FACTURES."
This Invention relates to the processes described in the Specification of Letters
Patent obtained by the present applicant, and dated 5 October 1876 (No. 3848),
and in the Specification of Letters Patent also obtained by the present applicant,
and dated 8 September 1871 (No. 2374), and the present improvements consist in
obtaining solutions of bisulphite of lime (otherwise known as solutions of sulphite
of lime in sulphurous acid) for use in the said processes, from the sulphides of
calcium contained in fresh or partially oxidised alkali waste. For this purpose the
fresh or partially oxidised waste in a dry or more or less moist condition is treated
with sulphurous acid.
In practically carrying out the Invention it is preferred to grind up the waste in
water (or in "yellow liquor") so as to form a milk-like mixture; and this mixture
is run down an absorbing tower so as to meet an upward current of gaseous
sulphurous acid which it absorbs. In this way there is obtained a mixture con-
sisting chiefly of bisulphite of lime, sulphite of lime, and sulphur, together with
impurities, such as sand, carbonaceous matter, sulphate of lime, and others; and

page_text: this mixture or the solution, separated from undissolved matters, is to be used in a
manner similar to what is described in the earlier Specification herein-before
referred to, regard being had to the proportions of sulphurous acid and lime in the
solution.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Mactear in the Great Seal Patent Office on the 26th August
1878.
JAMES MACTEAR, of Glasgow, in the County of Lanark, North Britain, Chemist.
"IMPROVEMENTS IN UTILISING BYE-PRODUCTS OF THE SODA AND POTASH MANU-
FACTURES."
My said Invention relates to the processes described in the Specification of
Letters Patent granted to me and dated 5 October 1876 (No. 3848), and in the
Specification of Letters Patent also granted to me, and dated 8 September 1871
(No. 2374), and my present improvements consist in obtaining solutions of
bisulphite of lime (otherwise known as solutions of sulphite of lime in sulphurous
acid) for use in the said processes, from the sulphides of calcium contained in fresh
alkali waste, or in alkali waste which has been partially oxidised through exposure
to the atmosphere or by any convenient artificial process. For the purpose of
obtaining the said solutions, I cause the fresh or partially oxidised waste in a dry
or more or less moist condition to be treated with sulphurous acid.
In practically carrying out my present Invention, I prefer to grind up the waste
in water (or in " yellow liquor") so as to form a milk-like mixture; and I cause
this mixture to be run down an absorbing tower so as to meet an upward current
of gaseous sulphurous acid which it absorbs. In this way I obtain a mixture con-
sisting chiefly of bisulphite of lime, sulphite of lime, and sulphur, together with
impurities, such as sand, carbonaceous matter, sulphate of lime, and others; and
this mixture or the solution separated from undissolved matters, is to be used in the
manner described in the earlier Specifications herein-before referred to, regard being
had to the proportions of sulphurous acid and lime in the solution.
It is a practical advantage of my present Invention that fresh or only partially
oxidised alkali waste is availed of and utilised, whilst at the same time a convenient
medium is provided for applying the sulphurous acid in accordance with my main
system of treating alkali waste.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that what I believe to be novel and original, and
claim as the Invention secured to me by the herein-before in part recited Letters
Patent is: The obtaining of solutions of bisulphite of lime for use in my process

page_text: for utilising alkali waste or the bye-products of the soda and potash manufactures,
by treating fresh or partially oxidised alkali waste with sulphurous acid as herein-
before described.
In witness whereof, I, the said James Mactear, have hereunto set my hand
and seal, this Twenty-third day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES MACTEAR. (L.S.)