A Westinghouse Plasma Corp. gasification plant produces vitrified slag as a byproduct that's inert and safe to use as aggregate or for use in other applications. Slag WOn't contaminate soil or drinking water. Slag from the Mihama Mikata plant was examined against several standards including JLT 46, NEN -7341 and TCLP analysis. These tests were conducted by two independent laboratories Shimadzu Techno-Research Inc. and ALS Laboratory Group. The outcomes demonstrate the Mihama-Mikata slag components are below the evaluation detection limits as well as the slag is considered non-leaching. Below is a graph showing a number of the results from the JLT-46 evaluations.
One hundred percent of the slag from the Mihama Mikata plant is utilized as aggregate for concrete products.
In a Westinghouse Plasma Corp. gasification plant, particulate is removed from the syngas downstream from the gasifier. However, the particulate may be recycled back in the gasifier for destruction (and additionally for further energy retrieval) and so does not become a byproduct that requires disposal.
Instead of slag, incineration plants generate bottom ash and flyash. The flyash needs particular disposal and in many authorities is considered hazardous waste.
In comparison, about 20% to 30% of the waste should be sent to landfill.