Process of Treating Wool Washings.
Year: 1892

page_text: Date of Application, 3rd May, 1892-Accepted, 18th June, 1892
COMPLETE SPECIFICATION.
Process of Treating Wool Washings.
I, ROGER BURRILL GRIFFIN a citizen of the United States residing at Revere
County of Suffolk and State of Massachusetts, United States of America 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 of this invention is to attain an inexpensive and efficient method of
separating and obtaining in merchantable condition the grease and other valuable
ingredients contained in the wash waters of wool scouring establishments.
The water that has been used in wool washing establishments for cleaning
or scouring the wool preparatory to spinning contains a large quantity of grease,
and also potash and ammonia, which materials are, however, so intimately mingled
that it is extremely difficult to separate out the pure grease from the water and
other materials so that the wash waters are usually allowed to run to waste. This
not only involves loss of the valuable materials contained in them, but also
produces a large amount of offensive matter which is very difficult to dispose of
and in many cases causes considerable trouble and complaint. by fouling the waters
of running streams into which the wash waters are discharged.
The grease has in some cases been extracted from the wash waters by chemical
processes which result in the loss of the other ingredients and which are moreover
so expensive that they have not been generally adopted, and in some cases the
potash and ammonia have been saved by a process of burning or roasting, which
results in the loss of the grease.
The present invention consists in a process by which the grease can be separated
from the water and other ingredients at a moderate expense and without waste of
the other ingredients of the wash water, the main features of said invention con-
sisting in mixing with the concentrated materials of the wash water an absorbent
material or filler which is of an acid character, and the effect of which is to break
up the emulsion of the grease and water, as well as to separate the ammonia and
potash from the grease which latter may then be abstracted or removed from
the mixture by any mechanical process of separation, as for example by dissolving
out the grease or by straining or pressing in cloth bags, the grease passing out
through the interstices and being substantially pure, while the other ingredients
remain in the cake formed by the absorbent matrial added, which cake is valuable
as a fertilizer.
The grease and other materials may be separated and saved in accordance with
this invention in the following manner, which is believed to be the best manner of
practising my invention.
The wash waters are first concentrated by evaporation in any suitable apparatus.
The residue which still contains a large percentage of water forming an emulsion
with the grease is then mixed with about twenty per cent. of its own weight of an
absorbent material or filler, preferably in powdered form.
Any absorbent material may be used and the proportion employed may be widely
varied from that just stated, but the best results have been attained in practice by
using acid phosphate of lime in about the proportion specified.
If an inert material or other absorbent material than acid phosphate of lime is
employed, it is necessary to add a slight amount of acid to it, in order to effect the
separation of the potash and ammonia from the grease, but when acid phosphate of
lime is used as the absorbent material, no additional acid is required, as the acid
phosphate of lime contains both a sufficient amount of acid to effect the separation

page_text: of the materials and also contains a sufficient amount of insoluble inert material to
form a solid mass or cake from which the grease can be pressed, it being essential
that the material added to the concentrated wash waters should have these
properties.
When these materials have been thoroughly mixed, the whole is heated to about
the boiling point, preferably in a shallow flat-bottomed steam-jacketed pan, so as
to drive off the water that remained in the emulsion before the said absorbent
material was added.
The material should be constantly stirred during the heating operation which
is continued as long as steam arises from the mixture and until a slight smoky
fog appears indicating that the more volatile portions of the grease are beginning
to decompose.
The material, which is then in the condition of a thin paste, is then removed
from the pans and transferred to common bags or cloths suitable for pressing
and straining, and is subjected to pressure while still hot in a suitable press the
effect of which is to extract the grease which passes out through the interstices
of the cloth. Since in this process all the wash water or solution is evaporated,
the final product before pressing must contain all the salts previously dissolved
and the grease; and since the grease is expelled from the interstices or spaces
of the filler, the other materials previously in solution, that is, the potash and
ammonia originally present in the wash water, will remain in the cake of absorbent
or filling material from which the grease has been expelled.
The remaining cake is of value as a fertilizer and the grease is nearly pure
and is suitable for use as a dressing for leather or for any other use to which
wool grease is commonly put.
When acid phosphate of lime is used as the acid absorbent material for
breaking up the emulsion so that the pure grease may be strained out, it retains
its original value as a fertilizer in the resulting cake. The said resulting cake
has its value as a fertilizer still further enhanced by the addition of the ammonia
and potash originally present in the wash water, which materials remain in the
cake in a form readily soluble, or available for plant food.
By this process the pure grease is obtained at moderate expense, the cost of
production being much less than the value of the grease and other valuable
materials obtained, so that the wash waters instead of being an offensive waste
product, become a source of profitable manufacture, the process being carried on
without any waste or worthless residue.
While the manner of effecting the final separation of the grease from the other
valuable products above described, namely by straining, is preferred, it is not
essential to the invention that such final separation should be effected in this
manner, as instead of straining the grease out from the resulting compound, it
might be removed by dissolving by means of ether or any suitable volatile solvent.
The employment of the absorbent material, as described, breaks up the emulsion,
permitting the water to be thrown off from the grease by evaporation and freeing
the grease from the potash and ammonia so that it can be readily separated
therefrom without further chemical action.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The improvement in the art of recovering wool grease from the waste-waters
of wool washings, which consists in concentrating the waste-waters by evaporation,
mixing the residue with an acid absorbent or filler, preferably acid phosphate of
lime, heating the mixture to throw off the water and then separating the grease
from the remaining solid materials, substantially as described.
2. The combined process of recovering wool grease from the waste-waters of
wool washings and forming plant food from the remainder, which consists in

page_text: concentrating the waste wash-waters by evaporation, mixing the residue with an
acid absorbent or filler, preferably acid phosphate of lime, heating the mixture to
throw off the water, and then separating the grease and the residue by mechanical
straining, substantially as described.
Dated this 3rd day of May 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.