Utilization of ash from fluidized bed boilers

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:50754

Takada, Tomoaki ^[1]

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1. Kawasaki Heavy Industries Co., Ltd., Akashi (Japan)

Combustion ash from a fluidized bed combustion (FBC) boiler contains not only carbon, but also silica alumina, quicklime as a sorbent, and a calcium sulfate by-product. These substances react chemically during fluidized bed combustion, and with the addition of water, they start an ettringite reaction and solidify. We determined the conditions necessary for producing hard solids through the study of the composition, curing methods, and characteristics of the solidified ash. We then used two types of road base material, crushed stone and solidified ash from an FBC boiler, to construct a test road at a site with a great deal of heavy traffic. Construction began in 1985, and since then, periodic tests have been performed to evaluate the performance of the road base materials. The testing of the manufacturing techniques centered on the amount and manner that water was added to the mixture and the curing methods of the mixture. Additional testing focused on the handling of the ash powder, the mixtures, and the solidified ash. Since 1991, under the sponsorship of MITI, the Center for Coal Utilization, in conjunction with Naruto Salt Mfg., Ltd., Nippon Hodo Co., Ltd., and Kawasaki Heavy Industries, Ltd., has used the referenced results to undertake a joint research and development project aimed at the eventual practical application of the technology. In 1993, a pilot facility to solidify ash with the fluidized bed boiler of 75 t/h capacity was completed. At present, all the discharged ash from the pilot facility is being solidified, and experiments on solidification and road base application techniques are underway. Actual road base tests are also in progress, and we are continuing research to meet the national certification requirements for road base materials.

• OSTI ID: 50754
• Report Number(s): CONF-9410301--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
ASHES
COAL
COMBUSTION
CONSTRUCTION
FLUIDIZED BED BOILERS
ROADS
SOLID WASTES
TESTING
USES
WASTE MANAGEMENT