Year: 1887

page_text: Date of Application, 22nd July, 1887
Complete Left, 4th Apr., 1888
Complete Accepted, 4th May, 1888
1 JOHN SAMUEL RIGBY of Heathfield House Holywell in the County of Flint
Manufacturing Chemist do hereby declare the nature of this invention to be as
follows:-
The object is to enable Portland and like cement of high quality to be manufactured
from so called lime mud obtained in the manufacture of alkali by the Leblanc process
and from like waste or impure carbonates of lime containing sulphur compounds
which render the use of the said wasto material inapplicable in the manufacture of
cement of even fairly good quality.
The invention consists essentially in subjecting waste or impure carbonato of lime
contaminated with sulphur to the action of carbonic acid gas or a solution thereof in
water until the sulphur compounds are decomposed. The treated material is then
mixed with the required quantity of clay or shale or suitable aluminous material and
calcined in the usual way.
Carbonic acid gas from a limekiln or carbonic acid gas given off during the
calcination of slurry into clinker in the manufacture of cement may be advantageously
be used for treating the waste or impure carbonate of lime.
Instead of carbonic acid dilute hydrochloric acid may be used, or both carbonic
acid and hydrochloric acid may be employed.
If desired the treated waste or impure carbonate may be washed before it is mixed
with the clay or aluminous material.
T 1
1007
JAMES JOHNSON,
Agent.

page_text: I JOHN SAMUEL RIGBY of Heathfield House Holywell in the county of Flint
Manufacturing Chemist, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
The object is to enable Portland and like cement of high quality to be made from
the lime mud or impure carbonate of lime obtained in the manufacture of alkali by
the Le Blanc process. Such lime mud contains sulphur compounds which render its
use inapplicable in the production of even fairly good cement.
The invention consists essentially in subjecting wasto or impure carbonate of lime
contaminated with sulphur to the action of carbonic acid gas or a solution thereof in
water until the sulphur compounds are decomposed and the sulphur is eliminated as
sulphuretted hydrogen. The treated material is then mixed with the required
quantity of clay, shale, or suitable aluminous material and calcined in the usual way.
Carbonic acid gas from a limekiln or carbonic acid gas given off during the
calcination of slurry into clinker in the manufacture of cement may advantageously
be used for treating the waste or impure carbonate of lime.
The following is an illustration of the method of carrying my improvements into
effect. take a carbonate containing say two per cent. of sulphides, I pass limekiln
gas through it, until all the sulphur passes off as sulphuretted hydrogen, say in about
an hour, I then add about one part of clay to three parts of the carbonate and I
calcine and treat for the production of cement in the usual manner.
When gases
from the calcination of clinker are used the treatment must be continued for a longer.
time than with limekiln gas. Purer carbonic acid gas would require less time to
complete the decomposition.
gas. I
After the impure carbonate of lime has been treated with carbonic acid
sometimes before mixing it with clay wash it say in a tank provided with an agitator.
and separate the moisture therefrom by filtration on any convenient filter bed or
equivalent device. The dryed carbonato is then mixed with clay or aluminous
material and treated as herein before setforth.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is,
First. Carbonating lime mud containing a small percentage of sulphur, mixing the
treated carbonate-with clay, shale, or suitable aluminous material and calcining the
mixture substantially in the manner and for the purpose setforth.
Second. Carbonating time mud containing a small percentage of sulphur, washing
and filtering the treated material mixing it with clay, shale, or suitable aluminous
material and calcining the mixture substantially in the manner and for the purpose
setforth.
1.1
..
"