(800) 726-4187
February 11, 2013
5 Essential Recommendations to Ensure Supply of High Quality Lime Slurry (Part 1)
Slurry Mixing

I have lost count of the number of municipal plants we have visited that experience problems with dry and liquid lime. It is easy to see why. Operators struggle with dust, clogged lines, and spend tremendous amounts of money on replacement parts while experiencing accuracy and control issues. To eliminate the problems associated with lime many municipalities have installed a CAL~FLO System® and purchase CAL~FLO slurry. However some municipalities still have generic feed systems and purchase generic slurry. The problem with purchasing generic lime slurry is that there are few standards that determine the quality of the product.  Slurry quality can vary dramatically between suppliers. To help municipal superintendents and procurement staff, we put together a list of six recommendations to help ensure that chemical bids result in the delivery of high quality calcium hydroxide slurry. By including these recommendations in the bid specifications, the municipality levels the playing field between vendors and increases the quality of the final product. Why should a municipality care about the quality of slurry? Purchasing a high quality slurry helps a plant reduce the wear on capital lime feed equipment by eliminating a large portion inert particles, grit, and reduces the likelihood of contaminates that can be found in poor quality slurry.

1. ANNSI/NSF 60 Certification

At minimum, your municipality should require and verify any calcium hydroxide slurry is ANSI/NSF 60 certified. ANSI/NSF 60 Certification means that the slurry meets all minimum requirements to be added to drinking water. Even if you are a waste plant, using this requirement can increase the quality of your slurry. Requiring a drinking water certification eliminates generic slurry manufacturers who manufacture products unsuitable for drinking water. Lime slurry can be used to stabilize and harden soil under road beds. However, everyone understands that the quality requirements for “road grade” and drinking water slurry should be very different. Once chemical bids are received from vendors that claim to manufacture ANSI/NSF 60 Certified slurry, the list must be verified. There are at least three organizations that can certify the vendor’s slurry which are Underwriters Laboratories (UL), National Sanitation Foundation (NSF), and the Water Quality Association (WQA). Check out our slurry certification provided by Water Quality Association (WQA).   In the next blog we will discuss what types of references your suppliers need and how to accurately specify the slurry concentration (recommendations #2 and #3).   Author: Dallas Burnett

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Burnett, Inc.     7095 Highway 11      Campobello, SC 29322      1-800-726-4187      (864) 592-1658 tel      (864) 592-1690 fax