Process for Production and Handling
of Lime Slurry for Use in
Chemical Applications
L. JOHN MINNICK
CLIFTON  A.   DANFORTH
G. & W. H. Corson, Inc.
Plymouth Meeting, Pa.
A comparison of the various forms and types of lime available commercially shows considerable differences in physical properties and chemical reactivity. A previous paper (1) has discussed this in considerable
detail. These differences in properties should be considered in selecting
a lime for each specific application. In some cases this may involve the
use of a form of quicklime, in others a form or type of hydrated lime.
Since the hydrated limes show superior tendencies to disperse in
water and can also be made into pumpable slurries with high solids
concentration, they are more convenient to use than the quicklimes.
The latter require special slaking equipment and generally must be
handled as dilute slurries. While hydrated lime contains water of
hydration, (and therefore a lower amount of calcium and magnesium
oxide per ton of material) this is offset in many instances by improved
reaction rates and higher combining efficiency thus resulting in a more
economical product. This is particularly true where the cost of hydrated
lime is equal to, or less than, the cost of quicklime.
In view of the above advantages, it becomes desirable to consider
using hydrated lime in some acid waste treatment plants. Furthermore, the use of wet storage as contrasted to dry storage in bulk
or in bags offers attractive possibilities. The practical development
of these ideas is the subject of this paper, and a process is described
which includes a lime handling system, a method of formation of high
concentration lime slurries, and other plant arrangement details.
One plant which has been evaluating the process is The Electric
Storage Battery Company in Philadelphia (Exide) which is using the
system in a treatment of a sulfuric acid waste. The process has been
in operation at this plant for approximately one year although there
have been several periods when the treatment plant has not been in use.
On several of these occasions modifications have been made to the treatment plant in order to improve the flow of materials and also to make
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