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Show I. INTRODUCTION Some iron-rich rocks known as a part of coal ash are often found along railroad tracks. However, it is not well known that it could cause trouble when a large amount of such iron compounds is accumulated on the furnace floor. Under normal conditions of operation, the slag in a wet bottom furnace is in a liquid state and it flows out of the furnace through the exit holes on the floor. At the present situation, the iron compounds are gradually accumulated on the floor. After a certain period, the refractory on the floor cannot sustain the load on it and cracks. This causes the molten slag to leak out and to damage the pipes underneath. Therefore the refractory has to be repaired in a short period, sometimes as short as 1 year. As the project was started, published literatures related to the problem were searched. To my surprise, no publication found has addressed directly to the iron formation on the furnace floor. However, some papers closely related to the coal ashes may be mentioned. Borio and Hensel (1972) [1]* studied coal-ash composition as related to high-temperature fireside corrosion and sulfur-oxides emission control. In which the chemical reactions in the process of coal combustion are outlined, the coal-ash composition and its properties are clearly shown. The maximum fluid temperature is found to be 2700+ °F. Wright and Roffman (1976) [2] studied the properties of coal ashes and suggested that coal ash is a potential mineral source. This paper reveals that the iron in coal ash is in the pyritic form and iron can become a byproduct of coal burning furnace. Certainly the previous work done by A. Grogan (1978) [3] at Tampa Electric Co. is closely related to the present study. Grogan studied in detail the chemical reactions leading to the formation of free iron. His work indicates that the formation of the free iron is mainly caused by the reducing agent, carbon monoxide CO, in the coal burning process. Present study is intended to find not only the reasons for the formation of iron compounds but also the ways to detect the possibilities *Numbers in brackets designates references at end of paper. 2 |