Low-Temperature Ashing Oxidizable Abrasive Only

Low-temperature ashing (LTA) can be used on oxidizable blasting debris — for example, plastic abrasive — to achieve a high degree of volume reduction in the waste. Trials performed with this technique on plastic abrasive resulted in a 95% reduction in the volume of solid waste. The ash remaining after oxidation must be disposed of as hazardous waste, but the volume is dramatically reduced [9], 

LTA involves subjecting the spent abrasive to mild oxidation conditions at moderately elevated temperatures. The process is relatively robust it does not depend on the mechanical properties of the waste, such as particle size, or on the pigments found in it. It is suitable for abrasives that decompose — with significant solids volume reduction — when subjected to temperatures of 500 to 600 C. Candidate abrasives include plastic media, walnut shells, and wheat starch. 

LTA cannot be nsed for mineral or metallic abrasives, which are most commonly nsed in heavy indnstrial blasting of steelwork. However, the lighter abrasives required for cleaning alumininm are possible candidates for LTA. Further work would be required to identify the VOCs generated by a particular abrasive medium before the technique could be recommended. 

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