This report is a state-of-the-art review of high efficiency separators: the technology and its application in cement finish grinding mills. High efficiency separators have two major effects on cements: a narrower particle size distribution and lower milling temperatures. The narrower particle size distribution will result in higher strength for a given specific surface, but will also increase water demand. Lower milling temperatures may obviate the need for a cement cooler but will result in less dehydration of the gypsum. Thus it may be necessary to adjust the dosage of the gypsum. Optimizing the dosage and degree of dehydration of the gypsum will mitigate the effects of the particle size distribution on water demand. In order to obtain the greatest benefit from a high efficiency separator the operation parameters of the mill circuit should first be optimized. Tromp curves of the separator feed, fines, and tailings will show whether a high efficiency separator could provide any benefit. The entire mill circuit must be considered. A high efficiency separator requires a much greater supply of ambient air, which will generally necessitate additional ducts and fans as well as modifications to the dust collection system. Modifications to the mill may be beneficial with or without a high efficiency separator. After the equipment is installed, the feed rate and other milling conditions should be optimized. The operating conditions that produce the best possible particle size distribution and surface area for the desired strength gain and water demand must be determined by trial and error. The dosage of gypsum must also be optimized. It may be necessary to operate at less than maximum efficiency in order to produce a cement that is acceptable to the user.

  • Availability:
  • Supplemental Notes:
    • Research and Development Bulletin. This research was conducted at Construction Technology Laboratories, Inc. with the sponsorship of the Portland Cement Association (PCA Project Index No. 93-02a). Abstracts on front and back cover are written in four languages - English, French, Spanish and German.
  • Corporate Authors:

    Portland Cement Association

    5420 Old Orchard Road
    Skokie, IL  United States  60077
  • Authors:
    • Detwiler, R J
  • Publication Date: 1995


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 25 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00724527
  • Record Type: Publication
  • ISBN: 0893121320
  • Report/Paper Numbers: PCA R&D Serial No 20,, RD110T
  • Files: TRIS
  • Created Date: Aug 6 1996 12:00AM