CON 123 - Session 2 - Raw Materials and Grinding

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CON 123 - Session 2 - Raw Materials and Grinding

  1. 1. CON 123Cementitious MaterialsSession 2Raw Materials & Manufacturing
  2. 2. Rotary kiln (furnace) for manufacturing Portland cement clinker.Inset view inside the kiln.
  3. 3. Raw Materials and Grinding Raw materials preparation Kiln systems Fuels  Natural gas  Coal  Coke  Syn-fuels
  4. 4. Primary Components of Raw MaterialsNecessary for Portland Clinker ProductionMaterials used in the manufacture of Portlandcement must contain appropriate proportions: Calcium Silica Alumina Iron
  5. 5. Sources of Raw Materials Used in Manufacture of Portland CementCalcium Iron Silica Alumina Sulfate· Aragonite · Blast-furnace · Calcium · Aluminum-ore · Anhydrite· Calcite flue dust silicate refuse · Calcium· Cement-kiln · Clay · Cement rock · Bauxite sulfatedust · Iron ore · Clay · Cement rock · Gypsum· Cement rock · Mill scale · Fly ash · Clay· Chalk · Ore washings · Limestone · Copper slag· Clay · Pyrite cinders · Marl · Fly ash· Limestone · Shale · Ore washings · Limestone· Marble · Quartzite · Ore washings· Marl · Rice-hull ash · Shale· Shale · Sand · Slag· Slag · Sandstone · Shale · Slag
  6. 6. QuarryLimestone, a primary raw material providing calcium in making cement,is quarried near the cement plant. 25,50, 0r 100 ton trucks.
  7. 7. QuarryQuarry face may varydepending on limestonedeposit.10ft-40ft quarry face.
  8. 8. Steps in the Traditional Manufacture of Hydraulic Portland Clinker1. Stone is first reduced to 125 mm (5 in.) size, then to 20 mm (3/4 in.),and stored.
  9. 9. Crusher located at quarry pit
  10. 10. Automatic measurement of chemical composition
  11. 11. Raw material storage
  12. 12. 2. Raw materials are ground to powder and blended.or2. Raw materials are ground, mixed with water to form slurry, and blended.
  13. 13. Raw Mill grinding
  14. 14. Raw Mix Chemistry Bogue Potential CompoundsTricalcium silicate C3SDicalcium silicate C2STricalcium aluminates C3ATetracalcium Aluminoferrite C4AF
  15. 15. Bogue Equations(C3S) = (4.071*%CaO) - (7.600*%SiO2) - (6.718*%Al2O3)- (1.430*%Fe2O3)(C2S) = (2.867*%SiO2) - 0.7455*%C3S)(C3A) = (2.650*%Al2O3) - (1.692*%Fe2O3)(C4AF) = (3.043*%Fe2O3)
  16. 16. Moduli for Burning Lime Saturation (LSF)  Ca/(2.85Si + 1.18Al +0.65Fe) Silica Ratio (S/R)  Si/(Al +Fe) Alumina Ratio (A/F)  Al/Fe
  17. 17. Pyro-Processing Systems Wet Process Dry Process Dry Pre-heater Dry Precalciner
  18. 18. Steps in the traditional manufacture of Portland cement (continued)3. Burning changes raw mix chemically into cement clinker.
  19. 19. Slurry tank storage
  20. 20. Slurry tank storage
  21. 21. Clinker Cooler. Cools clinker from discharge of 2700 degrees F to 200 degrees F.
  22. 22. 2. Raw materials are ground, to powder and blended.Steps in the modern dry-processmanufacture of Portland cement.
  23. 23. Dry raw mix typically labeled Dry KilnFeed
  24. 24. Steps in the modern dry-process manufacture of Portland cement (Continued)3. Burning changes raw mix chemically into clinker. Note four stage preheater, flash furnaces, and shorter kiln.
  25. 25. Combustion  Limestone + Heat = CaO + CO2 (0.50 tons)  Fuel Contribution = CO2 (0.50 tons)  Total CO2 Contribution of 1 ton per clinker tonContribution of CO2 emissions duringPortland clinker production.
  26. 26. Clinker & Gypsum Clinker GypsumPortland cement clinker is formed by burning calcium and siliceous rawmaterials in a kiln. This particular clinker is about 20 mm (3¼ - 4 in.) indiameter.Gypsum, a source of sulfate, is interground with Portland clinker to formPortland cement. It helps control setting, drying shrinkage properties, andstrength development.
  27. 27. Steps in the modern dry-process manufacture of Portland cement (Continued)4. Clinker with gypsum is ground into portland cement and shipped
  28. 28. Finish mill grinding
  29. 29. Storage of Cement Right click to play
  30. 30. Delivery of Cement Right click to play
  31. 31. Hydraulic Portland CementBy definition:“a hydraulic cement produced by pulverizingclinker consisting essentially of hydraulic calciumsilicates, usually containing one or more of theforms of calcium sulfate as an intergroundaddition, and up to 5% limestone.”
  32. 32. Raw Materials and GrindingPlease return to Blackboard and watch thefollowing video: Video 1: Storage

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