Evaluation of Domestic CCPs(Coal Combustion Products) Quality by API Test Method

Abstract

Recently, recycling of industrial by-products and CO2 reduction have been important issues in the world. In this reason, applications and reuse of Fly ash as a binder for concrete, which is generated in thermoelectric power plant, have been one of the effective recycle methods. In order for Fly ash to be applied to concrete, Korean Standard(KS) has selected and managed quality such as SiO2, fineness, specific gravity, ignition loss and activity index. However, there is a limits for activity index, whose test period required is at least 28 days or 91 days. Activity index is the critical indication standard to determine mechanical strength of concrete that contained Fly ash. To complement the disadvantage of test method, this research provided "API test method", which quickly measure Pozzolanic reaction of Fly ash can be considered as a alternative of activity index. Then, the adaptable API test method need to be investigated through comparative analysis with the test result of API, activity index and K-value. The test method can make evaluation of Fly ash quality faster and more accurate. As a result, most Fly ash produced in Korea has not been satisfied in the KS quality standard except water content and specific gravity, and especially fluidized bed boiler ash has its characteristics. Also, API, activity index and K-value have superior interrelationship. The interrelationship between API and activity index and K-value gets increased as the material age gets higher, so API test can be considered as very useful test method for Pozzolanic reaction evaluation of Fly ash.

Study on the Free CaO Analysis of Coal Ash in the Domestic Circulating Fluidized Bed Combustion using ethylene glycol method

“…일반적으로 CaO 함량이 다량 함유된 CFBC 석탄 회는 재활용이 불가능하여 대부분 매립 처리되지만, 현재는 탄산화 연구, 첨가제를 활용한 소재 응용 등으 로 연구가 진행되고 있다 (5)(6)(7)(8)(9) . CFIBF형 비산 재는 대 기 중 CO2 또는 산업에서 발생되는 CO2를 사용하여 탄산화를 촉진시키는 연구가 수행되고 있으며 (10)(11)(12)(13)(14) , CFIBF형 바닥재는 토목, 건축 재료의 첨가제나 정제 기술 (15)(16)(17) …”