A kind of beta cellulose and alpha cellulose composite diphase material and preparation technology thereof
Technical field
The invention belongs to fire resisting material field, particularly a kind of oxynitride multiple phase refractory material.
Background technology
Coal gangue is the main waste of coal industry, the coal gangue that conventional colliery coal separation or coal washing brought is than coal ultimate production height, because coal gangue complicated component, except that being used on a small quantity the material of construction, a large amount of coal gangues is in discarded state, take a large amount of soils, wasted the valuable resource and the energy, and brought the serious environmental pollution.
The main component of coal gangue is silicon-dioxide, aluminium sesquioxide, carbon, and association magnesium oxide, calcium oxide, ferric oxide etc., and a certain amount of residual carbon is arranged simultaneously.Silicon-dioxide, aluminium sesquioxide are the main components of refractory materials, therefore, utilize coal gangue to prepare refractory materials and once carried out research, but, owing in coal gangue, have the carbon of some amount and calcium oxide, ferric oxide etc., therefore, adopt ordinary method to utilize coal gangue to prepare refractory materials and have technical difficulty, because the existence of impurity element will have a strong impact on the resistance to elevated temperatures of coal gangue refractory materials, wastes a large amount of residual carbon resources simultaneously.
The tradition refractory materials mainly is oxide refractories, oxide refractories have the chemical stability advantages of higher, but, its anti-erosion, resistance to heat shocks can be poor, for this reason, at present refractory materials is just from being to act the leading role to change to oxide compound and non-oxidized substance is laid equal stress on the oxide compound, and payes attention to compound special refractories.Total trend is to develop to the direction of boride, nitride, oxynitride and matrix material thereof from traditional oxide compound, silicate material.Wherein, Sai Long (aluminum oxynitride silicon) refractory materials is an application prospect oxynitride refractory materials the most widely.Sai Long is the general name of a class oxymtride material, comprises the grand and grand polytype of match of β-Sai Long, α-Sai Long, O-match etc.
β-Sai Long is at β-Si
3N
4In solid solution part A lN, Al
2O
3The sosoloid that forms, α-Sai Long then is at α-Si
3N
4In solid solution part A lN, Al
2O
3The sosoloid that forms, α-Si
3N
4Be at Si
3N
4Form behind other oxide compound of solid solution part, therefore, α-Sai Long has been equivalent on the basis of β-Sai Long solid solution other oxide compound of part is as calcium oxide etc.Relevant report (the Xu Lihua of the β-Sai Long of preparation such as useful coal gangue once, Dong Guiwen, Qian Yangbao, Dong Guiqiang: the preparation method who utilizes the grand composite diphase material of the synthetic match of industrial residue original position, Chinese patent: 01144655.2,2002), still, when using coal gangue to prepare β-Sai Long, a large amount of non-silicon, aluminum oxide in the coal gangue, to remain in the refractory materials as calcium oxide, ferric oxide, magnesium oxide etc., and have a strong impact on the resistance to elevated temperatures of this material, therefore be not suitable for as refractory materials.
Summary of the invention
The present invention seeks to solve when using coal gangue to prepare β-Sai Long a large amount of non-silicon, the problem that aluminum oxide (as calcium oxide, ferric oxide, magnesium oxide etc.) remains in the resistance to elevated temperatures that has a strong impact on material in the refractory materials in the coal gangue.
A kind of is β-Sai Long and the α-Sai Long composite diphase material that main raw material adds small amount of aluminum alumina, carbon black preparation with the coal gangue, the raw materials quality ratio must be controlled at following scope: coal gangue 40-90%, bauxitic clay 0-55%, carbon dust 5-20%, adjusting according to carbon residue in the coal gangue is different of carbon dust with addition of amount, the total carbon ratio is controlled at mass ratio 10~25%; Wherein the raw material compositing range of coal gangue is: SiO
2Mass percent is 40%~80%, Al
2O
3Mass percent is 10%~40%, carbon content 5%~15%, and other impurity component 5~15%, β-Sai Long for preparing and α-Sai Long composite diphase material β-Sai Long and α-Sai Long ratio is respectively 60~90% and 10~40%.
The synthesis technique of β-Sai Long and α-Sai Long composite diphase material is a nitrogen atmosphere, and pressure is 0.1MPa~50, and temperature is 1450-1650 ℃, is incubated about 1~4 hour.
The present invention mainly utilizes silicon-dioxide in the coal gangue, aluminium sesquioxide and remaining carbon.With the coal gangue is that main raw material prepares aluminum oxynitride (silicon) composite diphase material, consider carbon remaining in the coal gangue on the one hand, therefore adopt the method for carbothermic reduction-nitrogenize, consider impurity elements such as the calcium oxide that contains some amount in the coal gangue, ferric oxide, magnesium oxide on the other hand, the composite diphase material of the synthetic β-Sai Long of decision and α-Sai Long, because can a large amount of oxide impurity of solid solution among α-Sai Long, and can keep the good temperature resistance energy.Adopt the method for carbothermal reduction-nitridation, can the components utilising coal gangue in remaining carbon resource because the carbon deficiency in the coal gangue, when therefore synthetic, must be according to specific requirement with addition of the part carbon dust.Because therefore silicon-dioxide, aluminium sesquioxide instability in the coal gangue often need add a small amount of natural alumina or silica sand to regulate silicon-dioxide, aluminium sesquioxide content in the raw material in specific implementation process.
The invention reside in the condition of strict control building-up process, make the coal gangue carbothermal reduction-nitridation generate the composite diphase material of β-Sai Long and α-Sai Long.Because β-Sai Long and α-Sai Long have good mechanical performance and resistance to elevated temperatures, and the β-Sai Long of long column shape and etc. axle shape α-Sai Long composite diphase material can form interlacing structure, thereby increase substantially the mechanical property of material.Simultaneously, the impurity element in the coal gangue then can be solid-solubilized among α-Sai Long, thereby has guaranteed the resistance to elevated temperatures of this material.The matrix material of purity at the α-Sai Long of β-Sai Long of 60~90% and 10~40% can be prepared by present method, and processing method is controlled, made full use of the carbon residue in the coal gangue, for the coal gangue comprehensive utilization of resources provides capable effective measures, reduced the manufacturing cost of these environmentfriendly products significantly, improve added value of product, and will improve social environment.
Description of drawings
Fig. 1 is the process flow sheet of synthetic β-Sai Long and α-Sai Long composite diphase material.
Fig. 2 is the X-ray diffraction result (among the figure: α represents the diffraction peak of α-sialon, and b represents the diffraction peak of β-sialon) of synthetic β-Sai Long and α-Sai Long composite diphase material.
Fig. 3 is the stereoscan photograph of synthetic β-Sai Long and α-Sai Long composite diphase material.
Embodiment
On the basis of having carried out the design of thermomechanical analysis and physical chemistry,, determined suitable synthesis technique, as shown in Figure 1 by verification experimental verification and exploration.
Embodiment 1: ratio of components: coal gangue, bauxitic clay, carbon black are respectively 40%, 52,8%
The coal gangue composition: mass percent is respectively SiO
262%, Al
2O
322%, carbon content 7%, other impurity component (MgO etc.) 9%.
The bauxitic clay composition: mass percent is respectively SiO
284%, Al
2O
311%, other impurity component 5%.
Synthesis temperature: 1500 ℃
Synthetic atmosphere: industrial nitrogen
Soaking time: 2 hours
Embodiment 2:
Ratio of components: coal gangue, bauxitic clay, carbon black are respectively 60%, 18,12%
The coal gangue composition: mass percent is respectively SiO
262%, Al
2O
322%, carbon content 7%, other impurity component (MgO etc.) 9%.
The bauxitic clay composition: mass percent is respectively SiO
284%, Al
2O
311%, other impurity component 5%.
Synthesis temperature: 1480 ℃
Synthetic atmosphere: industrial nitrogen
Soaking time: 2 hours
Embodiment 3:
Ratio of components: coal gangue, bauxitic clay, carbon black are respectively 80%, 5,15%
The coal gangue composition: mass percent is respectively SiO
262%, Al
2O
322%, carbon content 7%, other impurity component (MgO etc.) 9%.
The bauxitic clay composition: mass percent is respectively SiO
284%, Al
2O
311%, other impurity component 5%.
Synthesis temperature: 1450 ℃
Synthetic atmosphere: industrial nitrogen
Soaking time: 2 hours
, well behaved β-Sai Long suitable in order to obtain to form and α-Sai Long matrix material, the silicon-dioxide in the raw material, aluminium sesquioxide should be in rational proportion scopes.
Obtained the β-Sai Long and the α-Sai Long composite diphase material of excellent performance by test, the X-ray diffraction result of synthetic materials as shown in Figure 2, as can be seen from Figure 2, main component is β-Sai Long and α-Sai Long.To the performance of material carried out microstructure analysis and mechanical property, chemical property detects, wherein microstructure photograph as shown in Figure 3, the long column shape crystalline substance is β-Sai Long, the short cylinder crystalline substance is α-Sai Long, since the brilliant weave in of long column shape and short cylinder, excellent performances such as the gained mechanics of materials.This invention, not only made full use of the coal gangue resource, and made full use of the carbon residue in the coal gangue, for the coal gangue comprehensive utilization of resources provides a capable otherwise effective technique measure, reduced the manufacturing cost of product significantly, improved added value of product, and will contribute for improving social environment.