Calcium hydroxide slurry is a suspension of calcium hydroxide in water. The calcium hydroxide or lime slurry results from the mixing of dry hydrated lime with water in a mixing tank equipped with a slurry agitator.
The resulting product is a lime slurry which has a concentration (lime to water ratio) that varies from 0.5% to 30%. For example a 10% lime slurry would equal 100 grams of hydrated lime to 1 Liter of water, or 0.83 pounds per gallon. A concentration greater than 30% would be considered a paste rather than a slurry solution.
If a lime slurry has a lime to water concentration of less than 30%, the solution will be free-flowing, and easy to transfer with many available pumps. We recommend peristaltic (hose pumps) or progressive cavity pumps to transport the lime slurry in an efficient and reliable manner. The lime slurry mixing tank can be attached to the pumps (skid mounted) or can stand alone, either way it is up to the user to determine what level of automation and security he/she would like on their lime slurry system (automatic or manual). Lime slurry is a highly effective, low cost alkali that is easy to feed, monitor, and control. The solution is used in a variety of industrial, municipal, and environmental applications, such as:
- pH adjustment
- Sludge stabilization
- Water Softening
- Metal precipitation
- Odor control
Storage and feed systems are simple but require nonetheless specific and reliable dry storage (silo, hopper, big bag unloader, bin, etc), discharge (mechanical bin activator) and feed systems (screw conveyor, pneumatic transport, etc.). Typical problems with dry-to-slurry feed systems, such as compacted lime, bridging, scaling or dust emission can be easily avoided with an adequate lime handling system.
Efficient lime bulk storage, feed and slurry solution packages provide several environmental and safety advantages, ease air permit requirements and reduce potential injuries associated with dry chemical handling. Calcium hydroxide slurry is a low-cost chemical compared to quicklime, which requires a lime slaker, and its stable pricing allows users to evaluate and manage both short-term and long-term operating budgets.