Fluidized Bed Boiler Waste as a Source of Nutrients and Lime1
- G. L. Terman,
- V. J. Kilmer,
- C. M. Hunt and
- W. Buchanan2
Fluidized bed boilers for steam electric power plants have been developed recently to improve efficiency and to utilize coal and a wide range of other fuels. The fluidized bed waste (FBW) generated by these boilers is expected to reach large volumes as new plants are built. It is an anhydrous waste containing substantial amounts of CaSO4 and unreacted CaO. Since no previous agronomic evaluation of FBW has been reported, greenhouse pot experiments were carried out.
At moderate rates of application, FBW is satisfactory as a source of sulfur for crops and as a soil liming material. High disposal rates of new waste initially restrict crop growth, apparently because of high alkalinity resulting from the high oxide content of the FBW. On acid Mountview sil, fine (< 0.1 mm) FBW was 47% as effective as fine CaCO3 over a 5-week period for increasing soil pH. Coarse (< 3.4 mm) FBW was only 8% as effective as fine CaCO3, because of less reactivity apparently resulting from its granular nature and CaSO4 coatings on the granules. On pyritic coal mine spoil, lower liming rates did not affect spoil pH, but at higher rates coarse FBW was 44% as effective as fine CaCO3 for increasing spoil pH over a 10-month period.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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