Objective
To demonstrate the application of a coal fired fluidised bed combustor of low capital cost in a novel approach to the production of calcined clay for brick and tile manufacture.
Steetley, British Coal and Peabody have completed final plant/equipment design (including final plant specifications and plant arrangements). On-site civil engineering work at Birchenwood and equipment manufacture have been carried out by Peabody and their subcontractors.
Further development work has continued with regard to the conditioning of calcine where water is added to the clay calcine material to ease product handling and to reduce transport costs to the user brickworks. This work entailed the production of clay calcine at the CRE test rig and the conditioning of the material on site using a trial production conditioner unit that was supplied by a leading conditioner manufacturer.
The trials were carried out to simulate the operational conditions that the conditioner would have to cope with although calcine feed rate was difficult to achieve. Whilst the trials were successful in terms of conditioning the calcine, slight modifications and equipment redesign were proved to be necessary to overcome some minor technical problems that occurred during the 5 day trial at CRE.
Sufficient calcine (> 3 t) was produced to warrant a very small scale trial at Steetley's Brownhills paver plant, Stoke-on-Trent, to investigate whether the proposed method of calcine introduction to the clay blend, via a box feeder/gate arrangement, is sufficiently flexible to proportion the calcine product over the range of likely addition rates. Most of the works where trials are scheduled have existing box-feeder type arrangements on site to facilitate the addition of sand or different clays into the main clay feed.
Since the addition of calcine using the box feeder/gate arrangements were successful, the existing mechanism for body additives should prove to be suitable for its introduction.
Mixing of the calcine with the clay feed via the existing single shafted and double shafted mixer proved to be effective in calcine dispersal at a 25-30% addition rate. Although paver productswere successfully extruded, dired and fired, only 2-3000 pavers with a calcine addition where produced which is certainly too small a number to base any findings on its potential in bricks/tile making.
A second-hand Attritor was identified earlier and has now been overhauled.
Clay, heat treated to a high temperature, in a novel fluidised bed, will be used in the heavy clay industry. The plant has a low capital cost and savings are anticipated downstream in the process.
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
ST5 7ES Newcastle under Lyme
United Kingdom