This project looks at the potential for re-use of quarry wastes, in particular, Hassock, from the Lower Greensand, Hythe Beds, which in one Ragstone quarry alone, amounts to 100,000 tonnes of material annually. Quarry wastes have been solidified with a range of other waste products including Cement Kiln Dust, Ground Granulated Blast-furnace Slag and Pulverized Fuel Ash. The mixes were subjected to a CO2 atmosphere for varying lengths of time, to determine their carbonation potential and optimum CO2 exposure time, in order to produce pellets with optimum strength, measured by Aggregate Impact Value. Pellets that had been hydrated before carbonated were stronger than those carbonated immediately. However, carbonating the mixes during pelletization was found to have a beneficial effect on final pellet strength. After further hydration in air for 6 weeks, the pH of these pellets was reduced considerably, when they were further carbonated for 24 hours in the CO2 chamber. Furthermore, strength was found to be substantially increased. The manufacture of these carbonated pellets will recycle CO2 and up to 4 waste streams and modify the quarry waste by reducing the dust component to a mere trace. The Aggregate Impact Value of pellets ranges from 14 to 19 and they have a bulk density of 1030 to 1100 kg/m3, making them potentially suitable for use as Light Weight Aggregates.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:443634 |
| Date | January 2007 |
| Creators | Padfield, Anne Michele |
| Publisher | University of Greenwich |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://gala.gre.ac.uk/6262/ |
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