{"id":9975,"date":"2016-12-06T13:01:03","date_gmt":"2016-12-06T13:01:03","guid":{"rendered":"http:\/\/admin.acceleratingscience.com\/mining\/?p=9975"},"modified":"2026-01-06T20:50:10","modified_gmt":"2026-01-06T20:50:10","slug":"question-about-limestone-and-clay-blending-in-cement-production","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/mining\/question-about-limestone-and-clay-blending-in-cement-production\/","title":{"rendered":"Question About Limestone and Clay Blending in Cement Production"},"content":{"rendered":"

We recently received an inquiry from one of our readers regarding the blog post\u00a0PGNAA Improves Process and Quality Control in Cement Production<\/a>\u00a0<\/em>in regard to using a CrossBelt online analyzer<\/a>\u00a0for process control.\u00a0Here’s the question:<\/span><\/p>\n

\"cementQuestion: \u00a0<\/span><\/span><\/p>\n

If\u00a0we blend with two types of materials, such as limestone and clay, what parameter is used for control in the pile? \u00a0<\/span><\/p>\n

Answer:<\/span><\/p>\n

If you have only two distinct materials available, without much chemistry variation within those two material types, then in general terms, a single quality control parameter, such as Lime Saturation Factor (LSF) or an estimate of Alite (tricalcium silicate) using the Bogue equation for Ca3<\/sub>SiO2<\/sub> (C3S), could be used to control the quality of the pile. \u00a0If however, the two raw materials you have available actually have chemistry variations such that the limestone and clay can be considered multiple different types of limestone and multiple different types of clay, then in reality there would be more than two materials available for control. Here are some examples:<\/span><\/p>\n

    \n
  1. High Grade Limestone<\/span><\/li>\n
  2. Low Grade Limestone<\/span><\/li>\n
  3. Low Silica\/High Alumina Clay<\/span><\/li>\n
  4. High Silica\/Low Alumina Clay<\/span><\/li>\n
  5. High Iron Clay<\/span><\/li>\n
  6. etc.<\/span><\/li>\n<\/ol>\n

    This is usually the case within a quarry as typically there are fairly significant chemistry variations across an entire quarry with multiple differing grades of material on different mine benches.<\/span><\/p>\n

    In general terms, the number of quality control parameters that can be controlled and met, given different materials, follows the function \u201cN-1<\/em><\/strong>\u201d where N =<\/em><\/strong> the number of materials available with different chemistry.\u00a0 So, if only one type of clay is available and one type of limestone is available (two materials) then only one control parameter can be met and controlled.\u00a0<\/span><\/p>\n

    However, if there are really different types of clay and different types of limestone, then there would really be different materials available and multiple quality control parameters could be met.\u00a0 In an example case where there is:<\/span><\/p>\n

      \n
    1. High Grade Limestone,<\/span><\/li>\n
    2. Low Grade Limestone,<\/span><\/li>\n
    3. High Silica\/Low Alumina Clay, and <\/span><\/li>\n
    4. High Alumina\/Low Silica Clay <\/span><\/li>\n<\/ol>\n

      there would actually be four different materials.\u00a0 These four different materials would allow the control of up to three quality control parameters such as:<\/span><\/p>\n

        \n
      1. Lime Saturation Factor (LSF), <\/span><\/li>\n
      2. Silica Modulus (SM) and <\/span><\/li>\n
      3. Iron Modulus (IM). <\/span><\/li>\n<\/ol>\n

        Or, conversely, using Bogue equations:<\/span><\/p>\n

          \n
        1. C3S, <\/span><\/li>\n
        2. C2S and <\/span><\/li>\n
        3. C4AF .<\/span><\/li>\n<\/ol>\n

          The different materials with different chemistry composition could be from different benches in your quarry.\u00a0<\/span><\/p>\n

          Consistent stockpile and raw mix chemistry is the key to ensuring smooth kiln operation and flexible, controlled quarry operations. An online elemental analyzer<\/a> monitors, in real time, the elemental composition of bulk materials along the entire material stream to troubleshoot issues in pre-blending stockpile control\/quarry management, raw mix proportioning control and material sorting. The result is precise control of the raw mix, chemical uniformity of kiln feed, increased kiln efficiency and ultimately superior performance cement.<\/span><\/p>\n

          If you would like us to take a look at your raw materials and process for a more detailed analysis of what might be able to be accomplished with an online analyzer, please comment below.<\/span><\/p>\n

          Here’s some additional reading about online analyzers:<\/span><\/p>\n