Improvements in Treating Certain Waste Materials to Produce Valuable Products such as Plaster, or Stiffening, Weighting, and Whitening Materials therefrom.
Year: 1894

page_text: Date of Application, 7th July, 1894
Complete Specification Left, 21st Dec., 1894-Accepted, 16th Mar., 1895
PROVISIONAL SPECIFICATION.
Improvements in Treating Certain Waste Materials to Produce
Valuable Products such as Plaster, or Stiffening, Weighting, and
Whitening Materials therefrom.
W2, JOSEPH HENRY LESTER, M.Sc., F.1.C., of Arcade Chambers, Manchester,
in the County of Lancaster, Analytical and Consulting Chemist, and THOMAS
EDWARD THOMLINSON, of Walmersley Road, Bury, in the county aforesaid,
Manufacturer, do hereby declare the nature of this invention to be as follows
:-
This invention relates to the treatment of any so called waste product or material
containing sulphate of lime, carbonate of lime and lime, more especially to that
produced by the action of lime on sulphate of ammonia in the manufacture of
ammonia or carbonates of ammonia with the object of producing a valuable product
suitable for use as 66
plaster of Paris or for what is known as "mineral" for
stiffening, weighting or whitening textile fabrics and "pearl hardening" in the
manufacture of paper.
"
For this purpose we treat and thoroughly mix the waste material with water
until it assumes the consistency of a thin cream and then run this creamy mixture
through a sieve to remove all lumps of lime, sand or other foreigu matter.
The material after passing through the sieve is received in a tank provided with
a stirring apparatus or in which it is capable of being agitated. To the material
in this tank we add a quantity of sulphuric acid the mixture being kept constantly
stirred or agitated until it has become completely mixed with the acid and the mass
has a neutral reaction or until the lime and carbonate of lime present in the material
are principally or entirely converted into sulphate of lime. The product now
consists of a more or less pure sulphate of lime mixed with water.
To remove the excess of water the mixture or product from the tank is run into
any suitable filter or filtering apparatus the water running away therefrom the
remaining product after being removed from the filter may be dried or not
according to the purpose for which it is required.
66
In this condition the product forms the material known as "mineral" in the
finishing of textile fabrics and as pearl hardening" in the manufacture of paper
aud is suitable and fit for use in the stiffening, weighting and whitening of textile
fabrics and paper during the course of manufacture.
For use as a plaster the more or less pure sulphate of lime thus prepared and
dried is further heated on a circular or other suitable plate or pan provided under-
neath with flues leading from a furnace and provided above with a stirring
arrangement that will keep the material in a state of intermittent agitation. The
heat is raised to such a degree and maintained until the whole mass assumes a
temperature sufficient to drive off most of the water but not exceeding 300° F.
The product thus obtained forms plaster of Paris, and is ready for use as such.
Dated this 6th day of July 1894.
t
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent' Agents.

page_text: Improvements in Treating Certain Waste Materials to Produce
Valuable Products such as Plaster, or Stiffening, Weighting, and
Whitening Materials therefrom.
We, JOSEPH HENRY LESTER, M.Sc., F.I.C., of Arcade Chambers, Manchester,
in the County of Lancaster, Analytical and Consulting Chemist, and THOMAS
EDWARD THOMLINSON, of Walmersley Road, Bury, in the county aforesaid,
Manufacturer, 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 :-
This invention relates to the treatment of any so called waste product or material
containing sulphate of lime, carbonate of lime and hydrate of lime, more especially
to that produced by the action of slaked lime on, sulphate of ammonia in the
manufacture of ammonia, carbonate of ammonia or other salts of ammonia with
the object of producing a valuable product suitable for use as boiled plaster of
Paris or for what is known as sulphate of lime, mineral, or terra alba for stiffening,
weighting, or whitening textile fabrics and is known as pearl hardening, mineral,
or terra alba in the manufacture of paper.
The invention consists essentially in mixing the waste material with water to
reduce it to a creamy consistency, treating it with sulphuric acid to convert all the
lime therein to a sulphate and then drying or boiling the product to render it
suitable for the purpose to which it is to be applied.
We treat and thoroughly mix the waste material with water until it assumes the
consistency of a thin cream and is in such state of division that it will run through
the sieve provided therefor, this creamy mixture is then run through a vibrating,
revolving, or other suitable sieve to remove any lumps of lime, sand, or other
foreign matter.
The material after passing through the sieve is received in a tank provided with
a stirring apparatus or in which tank it is capable of being agitated. To the
material in this tank we add a quantity of sulphuric acid the mixture being
thoroughly stirred or agitated until it has become completely mixed with the acid
and the mass has a neutral or acid reaction, or until the carbonate of line and
hydrate of lime present in the material are entirely, or almost entirely, converted
into sulphate of lime. The product now consists of a more or less pure sulphate of
lime mixed with water. If it is desired to remove the oxide of iron present in
small amounts in the waste product above described an excess of sulphuric or
hydrochloric acid may be added when the iron oxide will be dissolved and the
solution may be separated either by subsidence or filtration.
To remove the excess of water the mixture or product from the tank is run into
or on to any suitable filtering apparatus or hydro-extractor, the water running
away therefrom and the remaining product after being removed from the filtering
apparatus is dried by ordinary methods or not dried according to the purpose for
which it is required.
"
66
In this condition the material forms the substance known as sulphate of lime or
"mineral" in the finishing of textile fabrics and is known as "pearl hardening,"
"terra alba. or mineral" in the manufacture of paper and is suitable and fit
for use in the stiffening,, weighting, whitening, and polishing of textile fabrics and
paper during the course of manufacture.
For use as plaster the more or less pure sulphate of lime thus prepared and dried
or partially dried is boiled on a circular or other suitable plate or pan provided
underneath with flues leading from a furnace and provided above with a stirring
apparatus that will keep the material in a state of intermittent agitation. The

page_text: heat is raised to such a degree and maintained until the whole mass assumes a
temperature not exceeding 300° F. The product thus obtained forms boiled plaster
f Paris and is ready for use as such.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is:-
1. The method. or process of producing a stiffening, weighting, whitening, or
polishing material for textile fabrics, yarns and paper from the waste product
resulting from the action of slaked lime on sulphate of ammonia, consisting in
treating the said waste product with water to reduce it to a creamy consistency,
passing it through a suitable sieve and subsequently treating the mass with
sulphuric acid to convert it into sulphate of lime and then drying it substantially
as and for the purpose described.
2. The method or process of producing boiled plaster of Paris from the waste
product resulting from the action of slaked lime on sulphate of ammonia which
consists in reducing the said waste product to a creamy consistency with water,
removing any lumps or foreign matter therefrom, and subsequently treating the mass
with sulphuric acid, then drying it and boiling it at a temperature not exceeding
300° F. substantially as described.
3. The method or process of treating the waste products resulting from the
action of lime on sulphate of ammonia to produce valuable products substantially
as herein described.
Doted this 18th day of December 1894
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.