IMPROVEMENTS IN PURIFYING ILLUMINATING COAL GAS, AND IN THE PREPARATION OF THE MEANS EMPLOYED THEREFOR
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Samuel Hallsworth and Richard
Bailes at the Office of the Commissioners of Patents, with their
Petition, on the 31st March 1875.
We, SAMUEL HALLSWORTH, of Armley, near Leeds, and RICHARD
BAILES, of Woodhouse Carr, near Leeds, both in the County of York,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN PURIFYING ILLUMINATING COAL GAS, AND IN THE PREPARATION OF THE MEANS
EMPLOYED THEREFOR," to be as follows:-
Our Invention consists in the preparation and use of certain com-
pounds for the purification of illuminating coal gas.
Firstly. We take the waste product or residue of iron pyrites, this
having been previously burnt or calcined for the production of sulphuric
acid, or the residue of iron pyrites that may have been piled upon a heap
and exposed to the weather for the manufacture of copperas and other
purposes. Either of the above is ground in a mortar mill or other
equivalent.

page_text: We mix about three tons of the above-named residue of iron pyrites
in a pulverized state with about one ton of slacked lime, and about four
hundred gallons of the liquor or liquid which runs from the beds of iron
pyrites at copperas works. To them is added about half a ton of
sawdust or other equivalent. The whole is thoroughly mixed together, 5
and forms a compound which we name No. 1 gas purifying mixture.
Secondly. Another compound which we name No. 2 gas purifying
mixture is prepared as follows :-
We take the commercial article known as copperas, or the copperas
sediment known as coolor bottoms, or the sediment from the evaporating 1
and neutralizing pans or boilers at copperas works, or the sediment
made in the manufacture of nitrate of iron, and dry it on a heated floor,
or by other suitable means, so as to bring it to a dry powder.
The copperas or any of the above-named sediments may be dried and
used either separately or combined.
About one ton of slacked lime is mixed with about four hundred
gallons of the liquor or liquid which runs from the beds of iron pyrites
at copperas works. About half a ton of sawdust or other equivalent
is next added, then about three tons of the herein-before mentioned
dried copperas or sediments are added, and the whole well mixed 2
together.
The refuse lime after being used in the distillation of ammonia and
dried on a heated floor, or by other suitable means, may be substituted
for slacked lime in the herein-before mentioned compounds.
These compounds can be used in the ordinary dry lime purifiers. After 2
using these compounds two or three times it is found advantageous to
moisten the materials with a solution of copperas, or the mother liquor
left after the crystalization of copperas, or the herein-before mentioned
liquor or liquid which runs from beds of iron pyrites each time the
compounds are used.
When the liquor or liquid used is from the beds of iron pyrites it is
further neutralized with iron turnings or some other kind of light scrap
iron in order to prevent the acid from acting on the purifiers.
Thirdly. Another compound which we name No. 3 gas purifying
mixture is prepared as follows:-
3

page_text: We mix together about twenty-five hundredweights of the herein-
before mentioned dried refuse lime from the distillation of ammonia, and
about seventy-five hundredweights of the herein-before mentioned spent
residue of iron pyrites in fine powder, and about ten hundredweights of
sawdust or other equivalent. The whole is slightly moistened with
water before being used.