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Comminution Energy Reduction by Two - Stage Classification

  • D. A. Dahlstrom
  • W.-P. Kam

Abstract

A previous computer study indicated that significant comminution energy savings could be experienced by use of two stage, counter-current cyclone classification. To further prove this important potential a pilot plant was constructed which permitted analysis of energy savings for two stage as compared to single stage classification. Because energy input to the ball mill was constant, savings potential are actually illustrated by the greater percentage of minus 400 mesh solids generated by two stage classification at the same circulating load and product production rate. It was shown that the following conclusions can be made:
  1. 1.

    Energy savings increase as the fineness of grind increases.

     
  2. 2.

    As recycle ratio decreases, energy savings increase.

     
  3. 3.

    Energy consumption savings ranged from 7 to over 40% to date.

     
  4. 4.

    For existing ball mills either capacity can be increased at the same grind or a finer grind can be produced at the same tonnage rate.

     
  5. 5.

    Overgrinding is reduced at the percent minus 400 mesh is always less than single stage at the same grind.

     
  6. 6.

    Pilot plant results to date exhibited 6 to 8 percentage points greater amount of minus 400 mesh solids by two stage classification at constant energy input and similar product production rate.

     
  7. 7.

    Two stage countercurrent classification yields a slightly lower product solids concentration.

     

Keywords

Energy Saving Ball Mill Stage Classification Mesh Solid Energy Consumption Saving 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    Pitt, C. H. and Wadsworth, M.E., “An Assessment of Energy Requirements in New Copper Processes,” U. S. Dept. of Energy, Division of Industrial Energy Conservation, Final Report, 1980, Contract No. EM–78–5–071743.Google Scholar
  2. 2.
    Herbst J. A. (Chairman), “Comminution and Energy Consumption,” U. S. Dept. of Energy, National Materials Advisory Board, Committee on Comminution and Energy Consumption, Publication NM+FB-364, National Academy Press, Washington, D.C.Google Scholar
  3. 3.
    Dahlstrom, D. A. and Kam, W.-P., “Influence of the Classification Circuit on Energy Consumption in Comminution,” Annual Meeting, Society of Mining Engineers of AIME, February, 1988.Google Scholar
  4. 4.
    Herbst, J. A., Lo, Y. C. and Rajamani, K., “Population Balance Model Predictions of the Performance of Large-Diameter Mills,” Minerals and Metalluraical Processing, Society of Mining Engineers of AIME, 1985.Google Scholar
  5. 5.
    Herbst, J. A., Schena, G. D., and Fu L. S., “Computer Aided Design of Comminution Circuits,” Annual Meeting AIME, 1986, New Orleans, LA.Google Scholar
  6. 6.
    Dahlstrom, D. A. and Kam, W.-P., “Potential Energy Savings in Comminution by Two-Stage Classification,” International Journal of Mineral Processing. Vol. 22, p 239–250, 1988.CrossRefGoogle Scholar

Copyright information

© Elsevier Science Publishing Co., Inc. 1990

Authors and Affiliations

  • D. A. Dahlstrom
    • 1
  • W.-P. Kam
    • 1
  1. 1.Metallurgical Engineering DepartmentUniversity of UtahSalt Lake CityUSA

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