The clay fire-resistant mud adopts hard clay clinker as the base material and combines with soft clay or chemical bond. It is mainly used in the joint and repair of furnace body made of clay brick, such as blast furnace, hot blast furnace, coke oven, soaking pit, heat exchanger, boiler, etc.

The powder for making refractory slurry can be selected from clinker with sufficient sintering and various refractory materials with stable volume. The particle size of the powder depends on the use requirements, and its very limited particle size is generally less than 1mm, and some are less than 0.5mm or finer. Reasonable particle composition has a great influence on the construction performance of the slurry, and the same is true for the binder and admixture.

The binder used for ordinary refractory mud is binding clay. With the higher requirements of users, chemical binders are more and more widely used.

Adding various admixtures to the refractory mud can improve the construction performance of the refractory mud, such as adding water-proof agent to prolong the water loss time and ensure the construction quality; adding plasticizer to increase the plasticity of the mud when the amount is small; adding dispersant to improve the fluidity of the mud, etc. Refractory slurry is a kind of unfixed refractory material, which connects refractory bricks or bricks into a solid whole. It not only bears high temperature, but also adjusts the dimension tolerance of bricks and balances the expansion stress between bricks. Therefore, only the use of * fire-resistant mud, can * * long-life kiln.

Project indicators		NN-30	NN-38	NN-42	NN-45A	NN-45B
AL2O3,%		≥30	≥38	≥42	≥45	≥45
Fire resistance, ℃		≥1630	≥1690	≥1710	≥1730	≥1730
Bond flexural strength , MPa	110℃×24hAfter drying	≥1.0	≥1.0	≥1.0	≥1.0	≥2.0
	1200℃×3hAfter burning	≥3.0	≥3.0	≥3.0	≥3.0	≥6.0
0.2MPa load softening temperature (t2.0), ℃		/				≥1200
Linear rate of change PLC,%	1200℃×3hAfter burning	+1～-3
	1300℃×3hAfter burning			+1～-5
Bond time,min		1～3
granularity,%	-1.0mm	100
	+0.5mm	≤2
	-0.074mm	≥50