In the slag discharge from the gasification furnace, how is glass fiber formed? And how can the condition of the slag be analyzed?

Glass fiber is silicon dioxide; it results from high furnace temperatures, and is commonly referred to as “drawn fiber”.

Wire drawing is the result of poor flow behavior of the ash slag, combined with a high gas flow rate. A brief mention of temperature control at this point.

Normal ash should have a uniform particle size (around Ф5mm), a smooth surface, and an appropriate amount of ash; it is advisable that the ash content make up more than 50% of the total ash volume. There is a considerable amount of fine slag; the total amount of slag is high, but no stringing phenomenon occurs, which indicates that the furnace temperature is too high. However, the slag has good fluidity, so it is possible to lower the temperature slightly in order to reduce the O/C ratio ； There is an excess of fine slag, and its color is yellow-green; the analysis shows a high Cr2O3 content. At this time, the furnace temperature is high, so it is necessary to gradually reduce the O/C ratio and lower the operating temperature step by step ； There is drawing phenomenon, and the amount of slag is moderate, which indicates that the fluidity of the slag has decreased and the slag outlet is blocked, resulting in an irregular shape; therefore, the temperature should be increased appropriately to raise the O/C ratio ； If the filaments are like rock wool, with no formed slag lumps or particles and in relatively large quantities, it indicates that the slag outlet or downcomer is blocked severely; in such cases, it is necessary to reduce the load or shut down the operation ； The presence of coarse slag particles, along with a small number of irregularly shaped pieces, and an appropriate amount of slag indicate that the furnace temperature is too low, resulting in reduced fluidity; therefore, the temperature should be increased accordingly ； The coarse particles have increased significantly; larger slag lumps and adhering slag are present, and their shape is very irregular. This indicates that the furnace temperature is low, and the furnace temperature should be raised to improve slag management ； The slag consists of both lumps and filaments; its amount is moderate. Analysis shows a high carbon content in the slag, indicating poor atomization effect in the burner or uneven spraying, which leads to incomplete gasification and results in large temperature variations in the slag holding plate ； An excessive amount of slag indicates a high ash content in the coal; it is necessary to raise the furnace temperature or reduce the load, as well as to improve operational practices ； If the amount is low, scum or slag may form; backflushing or load reduction can be employed ； In practical operation, decisions regarding treatment should be made based on a comprehensive assessment of the slag, DCS operation instructions, as well as the CS concentration and coal quality analysis.