Improvements in the Treatment of Certain Residual Liquors from Copper Works and Chlorine Manufacture to Obtain Sulphate " 1 J of Lime and Oxide of Iron.
Year: 1884

page_text: Improvements in the Treatment of Certain Residual Liquors from
Copper Works and Chlorine Manufacture to Obtain Sulphate
"
1 J
of Lime and Oxide of Iron.
U :
T
We GEORGE LLOYD WIGG, MATTHEW STEELE and WALTER JOHN WIGG all of
the, Old Quay Copper and Alkali Works Runcorn in the County of Chester Copper
and Alkali Manufacturers, do hereby declare the nature of the said invention for
"IMPROVEMENTS IN THE TREATMENT OF CERTAIN RESIDUAL LIQUORS FROM COPPER
WORKS & CHLORINE MANUFACTURE TO OBTAIN SULPHATE OF LIME AND OXIDE OF
IRON to be as follows:-
The object of the invention is to treat the residual liquor obtained in the
précipitation of copper by the wet process and the residual chloride of calcium
liquor obtained in the manufacture of chlorine by the Weldon Process in such'
manner as to obtain sulphate of lime or pearl hardening practically pure and in fit
condition for use by paper makers, and also oxide of iron ready for use as a
pigment.
The first part consists in obtaining pure sulphate of lime by adding the Weldon
residual liquor to the residual copper liquor above mentioned in separating the
precipitate of sulphate of lime by filtration through a filter press, by decantation
or otherwise and in washing the separated precipitate with hydrochloric.or other
acid capable of removing any iron carried down mechanically with the precipitate..
The second part consists in precipitating iron from the filtrate obtained as above
setforth, or from the residual copper liquor direct by means of milk of line, or the
like and by oxidizing the iron by forcing or blowing air chlorine or other oxidizing
agents through the liquor. The precipitate is then separated from the liquor in
any convenient manner is purified and furnaced so as to complete the oxidation
and render it suitable for use as a pigment.

page_text: Improvements in the Treatment of Certain Residual Liquors from
Copper Works and Chlorine Manufacture to Obtain Sulphate
of Lime and Oxide of Iron.
We GEORGE LLOYD WIGG, MATTHEW STEELE, and WALTER JOHN WIGG all of
the Old Quay Copper and Alkali Works Runcorn in the County of Chester
Manufacturers, do hereby declare the nature of the said invention for "IMPROVE-
MENTS IN THE TREATMENT OF CERTAIN RESIDUAL LIQUORS FROM COPPER WORKS
& CHLORINE MANUFACTURE TO OBTAIN SULPHATE OF LIME AND OXIDE OF IRON
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :—
"
The object of the invention is to treat the residual liquor obtained in the
precipitation of copper by the wet process, and the residual chloride of calcium
liquor obtained in the manufacture of chlorine by the Weldon Process, in such a
manner as to obtain sulphate of Lime as Plaster of Paris, or Pearl hardening
practically pure, and in fit condition for use by paper makers; and also oxide of
iron ready for use as a pigment. And in order that our said invention may be
fully understood, we shall now proceed to describe the system, mode or manner, in
or under. which the same may be carried into practical effect.
In the first place after determining from the strengths of the liquors their fixed
proportions, the residual copper liquors (which may be neutralized or not as
circumstances demand) and the residual chloride of calcium liquors, are brought
together in large vessels, and thoroughly agitated by manual or mechanical power,
until the whole mass becomes homogeneous. During the time and immediately
succeeding the time, occupied in this operation the free sulphates contained in the
residual copper liquors, combine with the calcium contained in the residual chloride
of calcium liquors, forming a white bulky precipitate which we now allow to settle.
When the separation is complete we arrange the clear liquor, and the white
precipitate thus obtained in different receptacles, proceeding with the two distinct
branches of our invention, at one and the same time in the following manner-
To obtain Pearl hardening, plaster of Paris or Sulphate of Lime the white
precipitate is first treated with dilute hydrochloric acid for the purpose of clearing
it of any iron. It is then passed through filter presses, or other mechanical
appliances for the purpose of washing out all impurities, and pressing to such a
consistency as the requirements of the trade demands. Treating this same
precipitate with gentle heat we obtain a Parian Plaster or Plaster of Paris of the
first quality.
To obtain oxide of iron, we treat the clear liquor already referred to, or from
residual copper liquors direct with an equivalent of milk of lime for the purpose
of precipitating the iron as an oxide. The dark green precipitate which readily
forms is then further oxidised by injection of air, chlorine, or other oxidising agent,
washed through filter presses, or other mechanical appliances, and furnaced to
obtain the various shades of colour.

page_text: Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed we declare that what
we claim is
First. Obtaining pure sulphate of lime from Weldon and copper sulphate residual
liquors substantially as setforth:
Second. Precipitating iron from the filtrate obtained under the first part, and
oxidizing the same substantially as setforth.