LMS (Lime Mud Solids)

Proven FT-NIR application for lime mud solids


FITNIR LMS (Lime Mud Solids)

Solids content determination of lime mud for kiln operations relies mainly on oven-dry testing of manual grab-samples from the process line. Many challenges exist with manual sampling: infrequent sampling, inherent dangers with sampling from moving conveyors, test methods where samples immediately evaporate, as well as difficulty in retrieving representative samples. Mills are challenged with finding solutions that provide high-quality and frequent mud solids data to optimize kiln operations. Belt weightometers provide total weight, but do not account for moisture content. Some available conductance measurements require a probe be in contact with the moving lime mud, posing mechanical issues of the probe and a loss of quality measurements.

FITNIR Solution
FITNIR LMS addresses the gap in measurement frequency as well as mechanical challenges inherent with technology available today. Based on NIR spectroscopy, FITNIR LMS characterizes lime mud solids content, and has the potential to analyze other metal oxide properties (i.e., Al2O3, Fe2O3, etc.). Online measurement is performed via an over-the-conveyor, remote sensing head situated above the conveyor that does not contact the moving lime mud.


A broadband light source illuminates the lime mud sample, and its energy is absorbed by the sample’s molecules. The diffusely reflected light is collected and analyzed, directly measuring solids content based on the water absorption. Measurements are done in real-time at an average frequency of one measurement output per minute.

Properties Measured and Applications

FITNIR LMS measures the mud solids content feeding the kiln, providing information for feedback control of mud thickener and feedforward control of the kiln FET (feed-end-temperature). Consequently, fuel consumption and potential kiln operating issues are reduced. When used with a weightometer, dry mass flow can be calculated.

Key Benefits

  • Reduce mud solids variation, leading to lower FET
  • Reduce (fossil) fuel consumption and energy costs
  • Reduce kiln operating issues, such as potential mud ring
  • Increase frequency of mud solids measurements
  • Low maintenance
  • Reduce risk for operators associated with sampling on moving conveyor


Also see related application, FITNIR MC, that measures moisture content.

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Contact FITNIR Analyzers Inc. and we can work together on your lime mud solids operations.


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