A Fly Ash Carbon Treatment for Producing a Marketable Product from Activated Carbon Contaminated Fly Ash

摘要

In the near future,utilities are expected to comply with anticipated restrictions onallowable mercury emissions.The current best available practice for mercury capturefrom flue gas is based on the injection of a powdered,activated carbon.In many cases,the mercury laden carbon will be captured along with fly ash in the ash collectionsystem.This situation leads to ash that is contaminated with small amounts of mercuryand varying levels of activated carbon.This paper reports on the performance of a flyash chemical treatment approach for mitigating against the negative impact thatactivated carbon has on air entrainment in concrete.The process is based on thecontrolled application of proprietary chemical formulations to the contaminated ash.Theformulations consist of assorted sacrificial agents designed to interact with carbon,andthrough a number of mechanisms,minimize the carbon’s negative influence on airentrainment.This technology is particularly well suited for addressing carboncontamination levels that are too low for the more traditional beneficiation technologiesto be effective.