Gasifiers are reaction vessels used to process carbon feedstock such as coal and/or petcoke at elevated temperature, high pressure, and in a reducing atmosphere (low oxygen partial pressure); forming CO and H_2 - also called synthesis gas or syngas. Syngas is used as a feedstock raw material for chemical production or in power generation. By-products of the gasification process include: 1) unreacted carbon, 2) hot gases such as CO_2 and H_2S, and 3) slag formed from mineral impurities or organic metallic compounds in the carbon feedstock that liquefy during gasification. In the gasifier, slags interact with the high chrome oxide refractory liner, causing wear by two primary means - spalling (structural and chemical) and chemical dissolution. Phosphate additions to high chrome oxide refractories were recently developed and are known to reduce spalling and lower chemical dissolution of the refractory liner. A discussion of how phosphates influence the brick microstructure to reduce refractory wear caused by coal slag will be presented.
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