What is a “slaker” and why can I not simply mix quicklime in a simple mixing tank?
As a general rule “pebble quicklime” requires the use of a slaker whereas “hydrated lime” can be mixed with a standard mixer. To understand this it helps to visualize the pebble quicklime as identical to the original limestone pebbles that it was created from, except that it’s about 44% lighter. (The carbon dioxide, produced during the dissociation of calcium carbonate into calcium oxide and carbon dioxide, escapes through the porous limestone.) When these pebbles drop into a simple mixer they go immediately to the bottom of the container, reacting as they go. A layer of “reacting rocks” builds up on the bottom of the tank and consumes the water in the surrounding layer of quicklime. The result is that all of the quicklime may not react. Un-reacted quicklime that gets into a pipe can cause problems because of the steam emitted as it converts to the hydrated form. To avoid this problem, a slaker is used which can be thought of as a “specialized mixer”. The quicklime pebbles encounter a
