Kirihou Whakamatau

Refractory plastic has fairly good plasticity and is suitable for casting construction. Mouldable plastic refractory is produced by mixing quantitative refractory aggregate, power, fireclay, binder, and other additives and squeezing to brick green body shape.

Plastic refractory still has good plasticity when properly packed and stocked for a certain time. According to different kinds of aggregate, plastic refractory can be classified into high alumina plastic refractory, fireclay-based, corundum, silica, magnesia, chromite, zirconia, carborundum plastic refractory, etc. Plastic moldable refractory is a great solution when refractory castable and pereki whakaahuru are too complicated or cumbersome and formwork is unavailable. Plastic refractory possesses excellent strength and high density, as well as abrasion, slag, and spall resistance, and can be used in a wide range of applications. Ramming plastic refractory is also resistant to molten metals, which makes it perfect for applications such as boiler work, forge furnaces, tundish linings, ladle linings, burner blocks, and patches.

Physical and chemical indicators of refractory plastics

Items		RSA-45	RSA-60	RSA-70	RSA-75	RSA-80	RSA-90
Dry Density (g/cm3) ≥		2.3	2.5	2.6	2.65	2.7	3
Chemical (%)	Al2O3 ≥	45	60	70	75	80	90
	ZrO2	—	—	—	—	—	—
Modulus of Rupture(Mpa)	110℃×24h ≥	5	8	9	9	10	12
	1500℃×3h ≥	8(1350℃)	10 (1450℃×3h)			12	15
Compressive Strength(Mpa)	110℃×24h ≥	30	40	40	45	45	60
	1450℃×3h ≥	60	80	80	85	90	85
Linear Dimensional Change After Fired (1500℃×3h) % ≤		±0.5	±0.5	±0.5	±0.5	±0.5	±0.5
		1350℃×3h	1450℃×3h	1450℃×3h	1450℃×3h
Refractoriness(℃) ≥		1710	1740	1790	1790	1790	1790
Working Temp (℃)		1450	1450	1500	1550	1600	1650

Characteristics of plastic monolithic refractory

1. High strength: Plastic refractories have high compressive strength and flexural strength, and can withstand greater pressure and impact.
2. Good refractory performance: The refractory temperature of refractory plastics can reach above 1000℃, and can maintain good performance in high-temperature environments.
3. Wear and corrosion resistance: Refractory monolithic plastics have good wear and corrosion resistance, and can maintain a long service life during use.
4. Strong plasticity: Plastic refractories have good plasticity and can be easily processed into products of various shapes and sizes.

Fire-resistant plastic construction

Construction method of fire-resistant plastic

Plastic monolithic refractory has strong plasticity and is usually constructed by the ramming method. After strong ramming and high-temperature baking, it forms a ceramic structure. The medium and high-temperature structure has high strength, strong wear resistance, and excellent thermal shock resistance.

Construction precautions for plastic monolithic refractory

1. During or after construction, plastic masonry is not allowed to come into contact with water. During winter construction, attention should be paid to anti-freezing.
2. During construction breaks, the rammed body should be cut into straight surfaces, that is, the plastic ramming surface should be perpendicular to the furnace shell. It should be covered and wrapped with plastic film to prevent water loss. If digging continues, the dried surface should be cut off and shaved.
3. When constructing castables at the contact point with plastic, plastic waterproofing should be done well.