CN1078189C - Low magnesium oxide heat-insulation materials and its production - Google Patents

Abstract

The present invention discloses low magnesium oxide heat-insulation materials and a productive method thereof, which is used for the fire proofing and heat insulation of the smelting industry or the building industry. The heat insulating materials are formed by that dolomite, deoxidizing slag from a pure oxygen top blowing converter, solid paper pulp and glue in No. 0 are mixed, pressed, formed and sintered. The heat insulating materials have the ingredients that SiO2 is from 2 to 3%, MgO is from 28 to 32%, C3O is from 35 to 42%, A12O3 is from 21 to 28%, and Fe2O3 is equal to or less than 2%. The performance of the heat insulating materials of the present invention can reach the indexes of similar products both in China and other countries, raw materials are rich and cheap, and therefore, the selling price of finished products is only about 5 % of imported products from other countries to China. The present invention which is used as heat insulating and fire proofing materials can be widely used for the metallurgy and building industry.

Description

Low magnesium oxide heat-insulation materials and production method thereof

The present invention relates to a kind of thermal insulation material that is used to smelt with the thermal insulation material, particularly a kind of low magnesium oxide of heat-insulating.

In steel-making and each production link of continuous casting, be unable to do without thermal insulation material.That uses at present has two kinds, and a kind of is silicious, and major ingredient is SiO ₂This material harm workers ' health is eliminated gradually.Another kind is a magnesium thermal insulation board, major ingredient is MgO, particularly the heat-insulating shield of continuous casting tundish contains especially that the very high material of MgO makes, in the world with Britain Foseco company and Japanese GarNex company produce best, China Qinhuangdao refractory factory also can be produced this material in recent years.But because of the plate of this material is to be raw material with magnesia, thereby the cost height, raw material supply is also at full stretch.

The purpose of this invention is to provide a kind of excellent property and low magnesium oxide heat-insulation materials and production method thereof with low cost.

The object of the present invention is achieved like this: the composition of low magnesium oxide heat-insulation materials is, contains SiO ₂: 2-3%, MgO:28-32%, CaO:35-42%, Al ₂O ₃: 21-28%, Fe ₂O ₃≤ 2%.Its preferred version is: contain SiO ₂: 3%, MgO:32%, CaO:42%, Al ₂O ₃: 21%, Fe ₂O ₃: 2%.

Production method according to the low magnesium oxide heat-insulation materials of above-mentioned component content is:

A) adopt following raw material and weight percent prescription: ground dolomite: 84%, granularity 〉=500 orders; Slag 1% after the oxygen top-blown deoxidation, granularity 〉=500 orders; Solid paper pulp: 9%, granularity 〉=500 orders; No. 0 glue: 6%;

B) above-mentioned ground dolomite, slag, solid paper pulp were done mixed 35-40 minute, added No. 0 glue, mixed 30 minutes again;

C) above-mentioned mixed material is injected the mould that gives the system shape, by shaper compression moulding, pressure: 250--300kg/cm ²

D) from mould, take out and put into electric furnace and go out finished product by following heat-agglomerating:

I) time from the beginning to the 2nd hour, temperature at the uniform velocity is heated to 100 ℃ from 10 ℃ of normal temperature;

Ii) from the 2nd hour to the 3rd hour, temperature at the uniform velocity was heated to 290 ℃ from 100 ℃;

Iii) from the 3rd hour to the 4th hour, be incubated at 290 ℃;

Iv) from the 4th hour to the 6th hour, temperature at the uniform velocity dropped to 160 ℃ from 290 ℃;

V) from the 6th hour to the 7th hour, temperature at the uniform velocity drops to 50 ℃ from 160 ℃, naturally cools to normal temperature then.

The present invention compare with siliceous thermal insulation material have pollution-free, do not endanger the advantage of workers ' health, compare with the magnesium thermal insulation board material, its performance index reach external like product standard (seeing attached list), remarkable advantage is, the raw material of producing this low magnesium oxide heat-insulation materials is very abundant, and price is comparatively cheap, therefore, production cost reduces greatly.According to initial estimate, the finished product price of producing only is 5 percent of external imported product price.Subordinate list: low magnesium oxide heat-insulation materials and domestic and international same type of material index contrast table

	Britain Foseco company	Japan GarNex company	The fire-resistant factory in Qinhuangdao	Ministerial standard	Low magnesium oxide heat-insulation materials
						Volume density g/CM	1.19～1.27	1.1～1.75	1.2～1.6	1.2～1.6	1.14
Folding strength Kg/CM	17～42	15～50	35～45	≥25	32.53
						Thermal conductivity W/MK	0.25	0.34～0.43	0.35～0.4	≤0.35	0.29
Refractoriness ℃	1730	1690	1690	≥16690	1710～1730

Annotate: the exhausted testing of materials result of low magnesium oxide is provided by refractory quality supervision inspection center of Luoyang Ministry of Metallurgical Industry.

Elaborate below in conjunction with drawings and Examples:

Accompanying drawing is production method d) step t-℃ of heating curve.

The contriver is through repetition test, and the low magnesium oxide heat-insulation materials that draws following finished product content can reach the similar products at home and abroad performance index.That is: SiO ₂: 2--3%, MgO:28--32%, CaO:35--42%, Al ₂O ₃: 21--28%, Fe ₂O ₃≤ 2%.Its preferred version is: SiO ₂: 3%, MgO:32%, CaO:42%, Al ₂O ₃: 21%, Fe ₂O ₃: 2%.From theory and practice, Al ₂O ₃, MgO, these materials of CaO refractoriness all higher, and at high temperature performance is more stable, if reasonable ratio, promptly the new dot matrix crystalline network that constitutes under microcosmic with these three kinds of materials can reduce hot transmission form-conduction, radiation, convection current effectively.Therefore possessed above-mentioned premium properties.

Be that example illustrates its production method with above-mentioned preferred component content scheme below.

A) composition of raw materials: ground dolomite: 84%, the slag after the oxygen top-blown deoxidation: 1%, solid paper pulp: 9%, above raw material all requires granularity 〉=500 orders.No. 0 glue: 6%.

B) with above-mentioned ground dolomite, slag, solid paper pulp do to mix in mixer contained container in 40 minutes, add No. 0 glue manual mixing after, poured the mixer remix into 30 minutes.

C) above-mentioned mixed material (has the mould that gives the system shape) and is pressed into solid shapes such as smooth plate or curved slab on shaper, and pressure is: 250--300Kg/cm ²

D) sintering: the plate of taking-up moulding or the work in-process of other shape are put into cabinet-type electric furnace and are gone out finished product by the t-℃ of heating curve sintering that accompanying drawing provides.

Claims (3)

1, a kind of low magnesium oxide heat-insulation materials that is used to smelt or build refractory heat-insulating, it is characterized in that: composition contains SiO ₂: 2-3%, MgO:28-32%, CaO:35-42%, Al ₂O ₃: 21-28%, Fe ₂O ₃:≤2%.

2, low magnesium oxide heat-insulation materials according to claim 1, it is characterized in that: composition contains: SiO ₂: 3%, MgO:32%, CaO:42%, Al ₂O ₃: 21%, Fe ₂O ₃: 2%.

3, the production method of claim 1 or 2 described low magnesium oxide heat-insulation materials is characterized in that:

A) adopt following raw material and weight percent prescription: ground dolomite: 84%, granularity 〉=500 orders; Slag after the oxygen top-blown deoxidation: 1%, granularity 〉=500 orders; Solid paper pulp: 9%, granularity 〉=500 orders; No. 0 glue: 6%;

B) above-mentioned ground dolomite, slag, solid paper pulp were done mixed 35-40 minute, added No. 0 glue, mixed 30 minutes again;

C) above-mentioned mixed material is injected the mould that gives the system shape, by shaper compression moulding, pressure: 250--300kg/cm ²

D) from mould, take out put into electric furnace by the following method heat-agglomerating go out finished product:

I) time from the beginning to the 2nd hour, temperature at the uniform velocity is heated to 100 ℃ from 10 ℃ of normal temperature;

Ii) from the 2nd hour to the 3rd hour, temperature at the uniform velocity was heated to 290 ℃ from 100 ℃;

Iii) from the 3rd hour to the 4th hour, be incubated at 290 ℃;

Iv) from the 4th hour to the 6th hour, temperature at the uniform velocity dropped to 160 ℃ from 290 ℃;

V) from the 6th hour to the 7th hour, temperature at the uniform velocity drops to 50 ℃ from 160 ℃, naturally cools to normal temperature then.

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