Treatment for Disposal of Spent
and Contaminated Soluble-
Oil Mixtures
D. J. Walker
President, Walker Process Equipment, Inc.
Aurora, Illinois
Herein are described the operating conditions and results of two
soluble-oil treatment plants which have been in operation long enough
to draw reliable conclusions, and the design of which was based on
good pilot-plant experimental results.
These two plants successfully deal with relatively dilute and
complex waste oil and emulsions such as are normally encountered
in aluminum rolling-mill and very large machine-shop operation. The
two plants described are installed at the Davenport, Iowa, works of
the Aluminum Company of America and at the Flint, Michigan, works
of the Chevrolet Motor Company. The former plant treats rolling-
mill waste emulsion together with all other waste oils on the premises.
The latter treats machine-shop-waste emulsions together with all other
waste oils, cutting oils, and a multitude of waste products classed in
the general category of oils which are marked for disposal.
It should be pointed out that these wastes are not diluted clean
soluble oils, but instead are a variable and complex mixture of coolants
of all types mixed with cutting oils, lubricating oils, entrained particles,
dirt, and many other contaminating substances which ordinarily make
emulsions even more difficult to deal with. Further, these emulsions
and waste oils fall into the relatively dilute class (running between
1,000 ppm and 2,500 ppm as oil) which is generally considered the
most difficult class of emulsions to break.
Any flow sheet to handle these complex soluble oil and contam¬
inating mixtures must be embellished with wide latitude to be practical
for everyday operation. Recently, two papers appeared in the Sewage
Works Journal which describe an emulsion-breaking operation. These
papers deal with bench-type operation and are extremely interesting
as a matter of contemporary experience and because of the very
excellent background presented.   Both are worthy of review.   Eldridge
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