| The high energy consumption industries have rapidly expanded and the high temperature thermal quipments have constantly emerged with the development of economy, improvement of the science and technology. The higher the temperature, the higher refractoriness the lining refractories should reach. Now only the high aluminum insulating materials can be widely applied to the high temperature environment. The high aluminum insulating materials can be fallen into two categories. One is prepared by the combustible materials which have large pores. From the analysis of thermodynamics, the large pores maybe adverse to the thermal conductivity and the mechanics performance. Another kind of high aluminum insulating materials which have big bulk density and high thermal conductivity are the alumina hollow ball products. The alumina hollow ball products are usually high preparation cost. It's the effective ways that finding the right method for preparation of the microporous high-alumina insulating materials which has high porosity to solve the problem that almost of the thermal furnace are more heat loss, big volume and low speed of warming.There is no suitable method of preparation of porous high strength high-aluminum insulating materials in the practical engineering. The subject explored the foaming method to prepare the microporous aluminum insulating materials. The subject has systematically researched the technological parameters. Eventually, there are many small pores well-distributed inside of the high-aluminum insulating materials by controlling the high-aluminum insulating materials. The experiment is as follows.(1) The ?-Al2O3 can be use of raw materials to prepare the high-aluminum insulating materials which have high refractoriness and high refractoriness under load because of it's high refractoriness. Through the erperiment found that the aperture of high-aluminum insulating materials are the smallest when the size of ?-Al2O3 is dso=1.26?m. Due to pure ?-Al2O3 slurry made of curing is slow, we can add the light burned MgO Which can produce produces an jelly characteristics with normal temperature water. A small amount of light burned MgO addition can increase the consistency of raw material and short the curing time. In addition, mixing with A1203, the light burned MgO can form solid solution under a certain temperature. The solid solution can promote the sintering of alumina under the high temperature.(2) Based on the performance of materials made by different foaming agent and stabilizing agent, found that SDBS as foaming agent and CMC as a stabilizing agent can form rich delicate and lasting bubbles and prepared the high aluminum insulation stomatal aperture small, high porosity, good mechanical properties.(3) Based on the microscopic structure of the test block under different stirring speed of 400 r/min and 700 r/min, the result shows that when mixing the slurry under the speed of 700 r/min can get high porosity aluminum insulation material with micropores and well-distribution.(4) Drying system has a great influence on the pore structure of the material.The study found that the surface of the green body is perfect when they dry 3 hours in the room temperature.(5) The paper has systemly research the preparation technology parameters, such as foaming dose A, stabilizing B,water added C, and stirring time D. The four factors with three levels orthogonal experiment was designed to verify the influence to block test. Finally, it is concluded that the best testing scheme for A2B2C3D1. Under the optimal scheme, the properity of test block is as follows:porosity is 74.41%, bulk density is 0.9 g/cm3, the pore diameter is 40?m, cold modulus of rupture is 9.13 MPa, cold compressive strength is 20.21 MPa, the thermal conductivity is 0.327 W/m.k (500?). |
PDF Full Text Request