Improvements in Extracting Substances Dissolved in the Waste Water of Paper Manufacture.
Year: 1890

page_text: Date of Application, 28th Jan., 1890-Accepted, 1st Mar., 1890
COMPLETE SPECIFICATION.
Improvements in Extracting Substances Dissolved in the Waste
Water of Paper Manufacture.
I, FRANZ CARL ALKIER, of Wieselburg %, Erlauf, in the province of Lower
Austria Austrian Empire, Pasteboard 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:―
In the manufacture of paper or pasteboard from pulp consisting wholly or partly of
steamed ground wood, the wastewater contains methylic alcohol and acetic acid.
This invention relates to the extraction of these substances from the waste water in
a cheap and simple manner. For this purpose, when it is required to add water to
the pulp under treatment, the waste water of previous operations, instead of fresh water,
is mostly employed, so that the waste water becomes gradually concentrated until it is
sufficiently rich in acetic acid and spirit to admit of these substances being profitably
extracted. In subsequent operations a small quantity of concentrated waste water is
withdrawn to be treated as hereinafter described, and an equivalent quantity of fresh
water is added to the pulp, or this diluting water may be composed partly of fresh
water and partly of concentrated waste water, so as to maintain the contents of the
collecting tank at the requisite degree of concentration.
As the acetic acid when concentrated to a certain degree would corrode the metal
parts of the machine, it is necessary, continually to neutralize it by adding to the
waste water, a suitable quantity of alkali, preferably for cheapness, hydrate of lime or
soda ash.
When a sufficient quantity of the concentrated and neutralized waste water is
collected, it is subjected to distillation by which the wood spirit is separated, and after-
wards the residuary liquid is ovaporated to dryness in order to extract the alkaline
acetate, which, if hydrate of lime is used for neutralizing is acetate of lime (grey
acetate), or if soda ash is used is acetate of soda. As is well known, the acetic acid
may be separated from the acetate of lime by subjecting it to distillation with
hydrochloric acid and from the acetate of soda by distillation with sulphuric acid.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :-
1. The herein described process for extracting substances dissolved in the waste
water of paper manufacture from wood pulp by first concentrating the waste water by
repeated use in treating the pulp and neutralizing the acid in the liquid under con-
centration then separating the spirit by distillation and evaporating the residuary
liquid to dryness, substantially as described.
2. The herein described process for extracting substances dissolved in the waste
water of paper manufacture from wood pulp, by first concentrating the waste water to
a given degree by repeated use instead of fresh water for treating the pulp, neutralizing,
the acid in the liquid while being concentrated, with drawing from time to time a
portion of the concentrated and neutralized liquid, and adding an equivalent quantity
of water or of water mixed with the concentrated and neutralized liquid so as to
maintain a uniform condition of concentration, and finally separating the spirit and
alkaline acetate, substantially as described.
Dated this 28th day of January 1890
ABEL & IMRAY,
Agents for the Applicant.