One of the possible outlets for pulverized fuel ash (pfa), which was investigated by the Building Research Station, was the production of a sintered aggregate. Much of the ash contains varying amounts of residual fuel. In order to utilize this as part, or all, of the fuel required sinter the ash into an aggregate it was necessary to produce a permeable fire-bed thus allowing access of oxygen. A process of pelleting the ash was evolved and a bed of pellets was then ignited and burned by a through current of air. This paper traces the development of the pelleting and sintering techniques to the pilot-scale stage. It also includes an appraisal of the aggregate produced. Several conclusions were reached from the facts presented in this paper. First, the variation in carbon content of the raw ash presented the principal problem in control of any process for the conversion of pfa into a sintered aggregate and had a marked effect on the quality of the product. Second, the preferred method of manufacture of sintered pfa aggregate is that using a sinterstrand. This permits considerable flexibility in its mode of operation to deal with variations in the properties of the raw material and in the type of product required. It was found possible to operate with a fairly deep bed providing that good quality feed pellets were made. Third, a shaft kiln was found to be capable of producing high quality aggregate when the carbon content was fairly low and closely controlled. Fourth, an inclined disc pelleter with a stepped base was favored to pellet the dampened ash and so provide a fairly permeable fire-bed. No additional binder was required although with many ashes higher output and improved pellet quality were obtained by the addition of one percent of hydrated lime.

  • Corporate Authors:

    Building Research Establishment

    Building Research Station, Garston
    Watford WD2 7JR, Hertsford,   England 
  • Authors:
    • Harrison, W H
    • Munday, R S
  • Publication Date: 1975-1

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: 31 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00125529
  • Record Type: Publication
  • Report/Paper Numbers: CP 2/75
  • Files: TRIS
  • Created Date: Dec 16 1975 12:00AM