| Abstract
| - The effects of advanced oxidation (AO) processing on theproperties of green sand were studied via pouring castiron into green sand molds. Upon cooling, the green sandmolds were autopsied at various distances from the metal−sand interface. Autopsy green sand samples collected froma mold that incorporated AO water were characterizedand compared to controlled samples collected from a similarautopsied mold made with conventional tap water (TAP).It was found that the AO processing removed a coating ofcoal pyrolysis products from the clay surface thattypically accumulated on the clay surface. As a result,the AO-conditioned green sand retained 10−15% moreactive clay as measured by the standard ultrasonic methyleneblue titration than did the TAP-conditioned green sand.The AO processing also nearly doubled the generation ofactivated carbon from the normalized amount of coalcomposition of the green sand during the casting process.The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditionedgreen sand with higher normalized pore volume, and thushigher normalized m-xylene adsorption capacity, i.e.,relative to before-metal-pouring conditions. Furthermore,mathematical analysis indicated that the AO-conditioned greensand better retained its important properties after pouringthan did the TAP-conditioned green sand. Effectively,this meant after metal pouring, the AO-conditioned sampleoffered about the same net properties as the TAP-conditioned sample, even though the AO-conditionedsample contained less clay and coal before metal pouring.These results conformed to the full-scale foundry empiricalfinding that when AO is used, foundries need lessmakeup clay and coal addition through each castingcycle, and they release less air emissions.
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