CMIE LMC Monolithic Magnesia

Monolithic magnesia refractories include gunning material, ramming material, castable material, coating material and mortar which are mainly used for the making and mending of bottoms and linings of high temperature furnace. Since the manufacturing processes of most of these materials are of similarity here we basically introduce that of gunning material.

It takes sintered magnesite and/or sintered dolomite and some materials of magnesium and calcium substance as main feed and is made with which under specific blending ratio and various additives and inorganic binders. It is featured by quick solvency, instant hardening, low rebound elasticity and easy gunning operation. It is mainly used for the mending of magnesia carbon based or magnesia based linings of various basic steel making furnaces.

Specs \ Brand		PB-88G	PB-22W	PB-8216	PB-8210	PB831	PB833	PB837	MC802
MgO %		≥88	≥78	75-80	80-86	≥86	≥74	≥74	≥92
Refractoriness SK		38	37	≥38	≥38	38≥	≥38	≥38	≥38
Sizing % mm	≤0.044	-	≥29	-	-	-	-	-	-
	≤0.074	-	-	32-42	32-42	25-30	20-30	20-30	-
	0-1	-	＞49	-	-	-	-	-	-
	1-3	-	＞22	20-30	20-30	-	-	-	-
	1-4	-	-	-	-	-	60-75	60-75	-
	1-5	-	-	-	-	50-70	-	-	-
Bulk Density g/cm³		3.15	-	-	-	-	-	-	-
Bending Strength^*MPa		-	1.75	-	-	-	-	-	-
*It is tested under 1,400 ºC for 0.5 hours.

It is made of some high purity materials finely through processes of batching, shaping, sintering and synthesizing then crushing, screening and final blending. It is featured by quick sintering, high density, high strength, good thermal resistance and volume stability and widely used in making the bottoms of various electric arc furnaces. Its characteristics have come up to Austrian standards of same kind and its serving lives have come up to and even beyond the standards of same kinds imported from some Western countries.

Properties / Product Series		MCF-5	MCF-7
MgO %		88.0	83.6
CaO %		4.8	7.2
Fe2O3 %		5.0	7.0
Al2O3 %		0.4	0.5
SiO2 %		1.2	1.3
L.O.I. %		0.2	0.2
Sizing in mm		0-8 or 0-5	0-8 or 0-5
Bond Character		ceramic	ceramic
Crushing Strength MPa	1,200ºCx3hours	27.2	33.6
Crushing Strength MPa	1,600ºCx3hours	58.5	65.8
Bulk Density g/cm3	1,200ºCx3hours	2.78	2.86
Bulk Density g/cm3	1,600ºCx3hours	3.04	3.08
Linear Change at 1,600ºC %		<1.8	<2.0
Limited Temperature in Use ºC		1,850	1,850
Operating Method		paving at normal temperature and dry ramming	mending under thermal state

This product is made of tow kinds of high quality magnesia adding some auxiliary materials such as composite binders, composite antiknock reagent, intensifying agent, plasticity agent and water reducer. It is featured by many excellent performances like easy operation, non-cracking under firing, good resistance against molten steel and slag corrosion and easy disassembly.

Chemical & Physical Properties		Factory Standard Values	Typical Values
Bulk Density g/cm3	110ºCx24h	≥2.0	2.08
Bulk Density g/cm3	1500ºCx3h	≥2.0	2.12
Bending Strength MPa	110ºCx24h
Bending Strength MPa	1500ºCx3h
Crushing Strength MPa	110ºCx24h	≥5.0	8.6
Crushing Strength MPa	1500ºCx3h	≥10.0	15.8
Linear Change after fired %	1500ºCx3h	-2.0 ~ -4.0	-2.35
Chemical Composition %	MgO	80-89	86.5
	CaO	≤2.5	1.74
	SiO2	≤8.0	7.52
	Fe2O3		1.33
	Al2O3		1.25
	L.O.I.		1.50
Size mm		0-3	0-3
Moisture %		14.0-17.0	15

This product is made of finely ground magnesia and featured by good evenness and stability of chemical composition and sintering by air-hardening. It is favorable refractory mortar for furnace mending and magnesia based refractory bricks laying.