A micro-closed cell lightweight corundum refractory aggregate and its preparation method

Abstract

The invention relates to a micro-closed-cell lightweight corundum refractory aggregate and a preparation method thereof. The technical solution is: use 45~65wt% of γ?Al2O3 fine powder, 30~50wt% of α?Al2O3 micropowder and 1~10wt% of nano-alumina micropowder as raw materials, and add 40~80wt% of the raw material water, Use a planetary ball mill to wet grind for 0.5-3 hours; then put the wet-milled slurry in a mold, place it at room temperature for 12-24 hours, and demould; then dry it at 110-200°C for 12-36 hours, Insulate at 1750-1900°C for 1-8 hours to obtain micro-closed-cell lightweight corundum refractory aggregate. The micro-closed cell lightweight corundum refractory aggregate prepared by the invention has the characteristics of low apparent porosity, high closed porosity, small volume density, small average pore diameter, low thermal conductivity and strong slag erosion resistance.

Description

technical field [0001] The invention belongs to the technical field of corundum refractory aggregate. In particular, it relates to a micro-closed cell lightweight corundum refractory aggregate and a preparation method thereof. Background technique [0002] With the development of out-of-furnace refining and continuous casting technology, the ladle has gradually changed from a single-function molten steel container to an out-of-furnace molten steel refining equipment with complex functions. There are two main problems in the current use of ladle lining materials: (1) The thermal conductivity of the lining material is high, resulting in a rapid drop in the temperature of molten steel, which is not conducive to the smooth progress of continuous casting production and has a greater impact on the quality of molten steel , and increased energy consumption; (2) The thermal spalling resistance and slag resistance of lining materials are not excellent enough, especially the slag res...

AI Technical Summary

Problems solved by technology

There are two main problems in the current use of ladle lining materials: (1) The thermal conductivity of the lining material is high, resulting in a rapid drop in the temperature of molten steel, which is not conducive to the smooth progress of continuous casting production and has a greater impact on the quality of molten steel , and increased energy consumption; (2) The thermal spalling resistance and slag resistance of lining materials are not excellent enough, especially the slag resistance performance of lining materials varies greatly under different smelting conditions such as slag systems and steel types

O.Lyckfeldt and others used starch as a binder and foaming agent to prepare porous alumina (O.Lyckfeldt, J.M.F.Ferreira, Processing of porous ceramics by starch consolidation, J.Eur.Ceram.Soc.18(2)(1998)131-140.) , the bulk density of the prepared aggregate is significantly reduced, but the apparent porosity and pore size are larger; S.J.Li et al. used kaolinite as a foaming agent to prepare porous corundum-mullite aggregate (S.J.Li, N.Li, EffectsofcompositionandtemperatureonporosityandporesizedistributionofporousceramicspreparedfromAl(OH) 3 andkaolinitegangue, Ceram.Int.33(4)(2007)551-556.), the average pore size of the prepared aggregate is small, but the apparent porosity is as high as 40%; R.Salom?oa et al. use the in-situ decomposition of hydrotalcite , prepared porous corundum-spinel aggregate (R.Salom?oa, M.V.B?asa, V.C.Pandolfellia, Porousalumina-spinelceramicsforhightemperatureapplications, Ceram.Int.37(4)(2011)1393-1399.), the prepared aggregate In terms of apparent porosity and pore size, it cannot meet the production requirements

[0005] To sum up, the currently prepared lightweight refractory aggregates have the defects of high apparent porosity and large average pore diameter, and it is difficult to meet the requirements of actual industrial production.