The performance of the furnace lining refractory material fundamentally affects the performance of the furnace and restricts the service life of the furnace. Good refractory materials should have the following characteristics:
(1) Furnace refractories must have high refractoriness, can resist high-temperature thermal loads without softening and melting, and at the same time have high volume stability, with no volume shrinkage or only uniform expansion at high temperatures.
(2) Impurities in refractory materials form low-melting substances at high temperatures, reducing their refractoriness and performance. Therefore, the lining raw materials should ensure the quartz content and strictly control the impurity composition. The composition of the furnace lining sand is controlled as follows: ω (SiO2) ≥ 98.0%; ω (Al2O3) ≤ 0.5%; ω (Fe2O3) ≤ 0.5%; ω (TiO2) ≤ 0.05%; ω (H2O) ≤ 0.5%.
(3) The refractory material should have a reasonable particle size ratio, so that a dense structure can be easily formed during the furnace building process, and defects are not likely to occur during use. The following is a set of reasonable ratios: 3.35mm～5mm, 0.85mm～1.70mm, 0.1mm～0.85mm, and the proportions below 0.1mm are 17%, 33%, 20%, and 30% respectively.