CN104803690A - A method for preparing sucrose-phenolic resin combined with SiC-Si3N4-C composite refractory material - Google Patents

Abstract

The invention relates to a method for preparing a cane sugar-phenolic resin combined SiC-Si3N4-C composite refractory material and belongs to the field of a refractory technology. According to the invention, SiC and Si3N4 are used as aggregates, and cane sugar and phenolic resin are used as binders. When the binders are phenolic resin, flexural strength of the composite refractory material which has undergone heat treatment of 1100 DEG C is 5.97 MPa, compressive strength is 55.38 MPa, and volume density is 2.77 g/cm<3>. When the binders are cane sugar, properties of the composite refractory material are best, flexural strength of the composite refractory material which has undergone heat treatment of 1100 DEG C is 17.10 MPa, compressive strength is 79.65 MPa, and volume density is 2.23 g/cm<3>. In comparison with the prior art, the invention has the following characteristics when cane sugar is used as a binder to replace or partially replace phenolic resin: sources of the raw material are wide; production costs are low; the material is green and environmentally friendly and has good performance; the preparation technology is simple to operate; and remarkable economic and environmental benefits can be produced.

Description

A method for preparing sucrose-phenolic resin combined with SiC-Si3N4-C composite refractory material

Technical field:

The invention relates to a method for preparing a sucrose-phenolic resin combined SiC-Si ₃ N ₄ -C composite refractory material, which belongs to the technical field of refractory materials.

Background technique:

Carbon-containing refractory is an important part of the refractory system. It is a high-performance refractory developed to adapt to the new technology and new technology of iron and steel metallurgy. It has high thermal conductivity, low thermal expansion, thermal shock resistance and slag erosion resistance. Such excellent properties can greatly increase the service life of refractory materials, improve the quality of steel and reduce the unit consumption of metallurgical refractory materials, resulting in significant economic and social benefits. Its system mainly includes Si ₃ N ₄ -SiC-C, Sialon-SiC-C, MgO-C, Al ₂ O ₃ -MgO-C and other carbon-containing refractory materials. Among them, the binder is the core issue in the production of carbon-containing oxide-non-oxide refractory materials, and is an important guarantee for the normal and medium-high temperature strength of carbon-containing oxide-non-oxide refractory materials. The quality of the binder affects the production and quality of these high-performance refractory materials to a large extent. It has a great influence on the mixing and forming properties of the blank, as well as the microstructure of the product.

At present, the binders of carbon-containing refractory materials are mainly asphalt and phenolic resin. The most commonly used binder for the production of carbon-bonded refractories in the past has been coal tar pitch. The main fatal flaw of coal tar pitch is that it contains carcinogenic aromatic hydrocarbons, especially benzopyrene. Studies have shown that coal tar pitch contains (10000～13000)×10 ^-6 benzopyrene, which has brought great harm to human health and the environment, and its use has been greatly restricted. Petroleum asphalt needs to be heated and formed when it is used. Although its benzopyrene content is only 1/15 of that of tar pitch, its carbon residue rate is relatively low. In recent years, phenolic resin has been widely used as a high-performance carbon-containing refractory due to its good adhesion, high carbon residual rate, mixing and molding at room temperature, good wettability with graphite, and high strength of the formed green body. material binder. However, phenolic resin is produced by the reaction of phenol and formaldehyde. When used as a carbon-containing refractory binder, a certain amount of harmful gases such as formaldehyde and phenolic compounds will be released during the process of research and development, production and use. Among them, phenolic resin The resin contains 5-6% of free phenol and 1.2-1.5% of free aldehyde. Long-term exposure to these harmful gases can induce a series of cancers in the nasal cavity, oral cavity, nasopharynx, throat, skin and digestive tract. Therefore, we urgently need to find new environmentally friendly binders to replace phenolic resin and coal tar pitch. In view of the serious harm to human health and environment caused by phenolic resin and coal tar pitch, the present inventor proposes to use sucrose as a binder to prepare carbon-containing refractory materials. The carbon-containing refractory material has the characteristics of wide source of raw materials, low production cost, environmental protection, good performance, simple preparation process and operation, and can produce significant economic and environmental benefits.

Invention content:

The purpose of the present invention is to propose a new type of environmentally friendly sugar as a binder for carbon-containing refractory materials in view of the outstanding problems of environmental pollution and damage to human health when phenolic resin and coal tar pitch are used as binders for carbon-containing refractory materials.

The technical scheme of the present invention is as follows: SiC and Si ₃ N ₄ with different particle sizes are selected as aggregates. Pour an appropriate amount of sucrose into alcohol, and stir with a glass rod until there are no obvious particles, then pour the above transparent liquid into an appropriate amount of phenolic resin solution, and stir with a glass rod until it becomes a uniform non-layered emulsion for mixing and combining Use of additives; in order to ensure uniform mixing, a cement mixer is used to mix the materials. First, the coarse and medium-fine SiC and Si ₃ N ₄ are poured into the mixing tank, and the mixer is started to mix SiC and Si ₃ N ₄ of different particle sizes. Evenly; pour the prepared binder solution into the uniformly mixed granular material, start the mixer again and stir for 0.5h until the binder completely covers the particles; then pour in various fine powders, and stir for 0.5h until the fine powder and Granules and binders are mixed evenly. Pour the uniformly stirred material into a tray, let it dry naturally at room temperature for 6 hours, and then put it in an oven for 1 hour at 65°C. The material is formed, and the formed sample is subjected to high-temperature heat treatment at 1000°C, 1100°C, and 1200°C for 1 hour under nitrogen protection atmosphere, respectively, to obtain SiC-Si ₃ N ₄ -C composite refractory material.

The SiC with different particle sizes ranges from 0-0.044mm, 0.1-0.5mm, and 0.5-1mm, with a purity of 95%-97%.

The Si ₃ N ₄ with different particle sizes ranges from 0-0.068mm, 0.1-0.5mm, and 0.5-1mm, with a purity of 90%-95%.

The sucrose is analytically pure.

The beneficial effect of the invention is that the prepared refractory material has the advantages of low cost, high performance, low pollution and the like.

The present invention will be further described below in conjunction with accompanying drawings and examples.

Figure 1 is the effect of sucrose addition amount and heat treatment temperature on flexural strength (mass fraction of sucrose in binder, wt%).

Fig. 2 is the effect of sucrose addition amount and heat treatment temperature on compressive strength (mass fraction of sucrose in binder, wt%).

Fig. 3 is the effect of sucrose addition amount and heat treatment temperature on bulk density (mass fraction of sucrose in binder, wt%).

When the binder is all sucrose and the heat treatment temperature is 1100℃, the performance of the composite refractory is the best, with a flexural strength of 17.10MPa, a compressive strength of 79.65MPa and a bulk density of 2.23g/cm ³ .

Detailed ways:

The technical solutions of the present invention are further described below with specific implementation examples, but are not limited only to the following implementation examples.

Example 1

SiC (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%), Si ₃ N ₄ (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%) ) into the mixing pool, start the mixer, and mix SiC and Si ₃ N ₄ of different particle sizes evenly; pour the prepared binder solution (additional 10wt%, all phenolic resin) into the uniformly mixed particle material, and again Start the mixer and stir for 0.5h until the binder completely covers the particles; then pour SiC fine powder (0-0.044mm: 15wt%) and Si ₃ N ₄ fine powder (0-0.068mm: 15wt%), and stir for 0.5 h until the fine powder is evenly mixed with granules and binders. The material is formed, and the formed sample is subjected to high-temperature heat treatment at 1000°C, 1100°C, and 1200°C for 1 hour under the nitrogen protection atmosphere.

When the heat treatment temperature is 1000°C, the flexural strength of the composite refractory is 9.86MPa, the compressive strength is 46.87MPa, and the bulk density is 3.27g/cm ³ . When the heat treatment temperature is 1100°C, the flexural strength of the composite refractory material is 5.97MPa, the compressive strength is 55.38MPa, and the bulk density is 2.77g/cm ³ . When the heat treatment temperature is 1200°C, the flexural strength of the composite refractory is 9.06MPa, the compressive strength is 35.37MPa, and the bulk density is 1.97g/cm ³ .

Example 2

SiC (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%), Si ₃ N ₄ (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%) ) into the stirring tank, start the mixer, until SiC and Si ₃ N ₄ of different particle sizes are mixed evenly; the prepared binder solution (additional 10wt%, phenolic resin and sucrose mixed binder, wherein sucrose accounts for 40wt% of the binder ) into the uniformly mixed particle material, and start the mixer again to stir for 0.5h until the binder completely covers the particle; at this time, pour SiC fine powder (0-0.044mm: 15wt%) and Si ₃ N ₄ fine powder (0 -0.068mm: 15wt%), and stir for 0.5h until the fine powder, granular material and binder are evenly mixed. The material is molded, and the molded sample is subjected to high-temperature heat treatment at 1000°C, 1100°C, and 1200°C for 1 hour under nitrogen protection atmosphere.

When the heat treatment temperature is 1000°C, the flexural strength of the composite refractory material is 11.91MPa, the compressive strength is 50.98MPa, and the bulk density is 2.76g/cm ³ . When the heat treatment temperature is 1100°C, the flexural strength of the composite refractory material is 10.87MPa, the compressive strength is 41.12MPa, and the bulk density is 2.51g/cm ³ . When the heat treatment temperature is 1200°C, the flexural strength of the composite refractory material is 8.1MPa, the compressive strength is 38.41MPa, and the bulk density is 2.87g/cm ³ .

Example 3

SiC (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%), Si ₃ N ₄ (0.5-1mm: 22.5wt%, 0.1-0.5mm: 12.5wt%) ) into the mixing tank, start the mixer, until SiC and Si ₃ N ₄ of different particle sizes are mixed evenly; pour the prepared binder solution (plus 10wt%, all sucrose) into the uniformly mixed granular material, and start again Stir with the mixer for 0.5h until the binder completely covers the particles; at this time, pour in SiC fine powder (0-0.044mm: 15wt%) and Si ₃ N ₄ fine powder (0-0.068mm: 15wt%), and stir for 0.5h Until the fine powder is mixed with granules and binder evenly. The material is molded, and the molded sample is subjected to high-temperature heat treatment at 1000°C, 1100°C, and 1200°C for 1 hour under nitrogen protection atmosphere.

When the heat treatment temperature is 1000°C, the flexural strength of the composite refractory material is 14.51MPa, the compressive strength is 55.38MPa, and the bulk density is 2.79g/cm ³ . When the heat treatment temperature is 1100°C, the flexural strength of the composite refractory material is 17.10MPa, the compressive strength is 79.65MPa, and the bulk density is 2.23g/cm ³ . When the heat treatment temperature is 1200°C, the flexural strength of the composite refractory material is 18.52MPa, the compressive strength is 63.25MPa, and the bulk density is 2.62g/cm ³ .

Claims (5)

1. prepare sucrose-resol in conjunction with SiC-Si for one kind ₃n ₄the method of-C multiple phase refractory material, is characterized in that: SiC and Si choosing different-grain diameter ₃n ₄as aggregate.Poured in alcohol by suitable amount of sucrose, and be stirred to without obvious particle with glass stick, then pour in appropriate liquid phenolic resin by above-mentioned transparent liquid, being stirred to glass stick becomes homogeneous not stratified emulsion, uses to make hybrid junctions mixture; Even for ensureing batch mixing, adopt cement mixer batch mixing, first by coarse particles and in fine grain SiC and Si ₃n ₄pour in agitated pool, start stirrer, to SiC and Si of different-grain diameter ₃n ₄mix; The bonding agent solution prepared is poured in the granule materials mixed, again starts stirrer stirring 0.5h and wrap particle completely to bonding agent; Now pour various fine powder again into, and stir 0.5h and mix with particulate material, bonding agent to fine powder.The material be uniformly mixed is poured in pallet, is placed in seasoning 6h under room temperature, then put into 65 DEG C, baking oven and dry 1h.Material forming, by shaping sample under nitrogen protection atmosphere, carries out high-temperature heat treatment 1h respectively, can obtain SiC-Si under 1000 DEG C, 1100 DEG C, 1200 DEG C conditions ₃n ₄-C multiple phase refractory material.

2. according to sucrose-resol according to claim 1 in conjunction with SiC-Si ₃n ₄the preparation method of-C multiple phase refractory material, it is characterized in that the SiC of described different-grain diameter, particle size range comprises: 0-0.044mm, 0.1-0.5mm, 0.5-1mm, and its purity is 95%-97%.

3. according to sucrose-resol according to claim 1 in conjunction with SiC-Si ₃n ₄the preparation method of-C multiple phase refractory material, is characterized in that the Si of described different-grain diameter ₃n ₄, particle size range comprises: 0-0.068mm, 0.1-0.5mm, 0.5-1mm, and its purity is 90%-95%.

4. according to sucrose-resol according to claim 1 in conjunction with SiC-Si ₃n ₄the preparation method of-C multiple phase refractory material, is characterized in that described sucrose is bonding agent, analytical pure.

5. according to sucrose-resol according to claim 1 in conjunction with SiC-Si ₃n ₄the preparation method of-C multiple phase refractory material, is characterized in that described resol is bonding agent.