Micro closed-cell light-weight corundum refractory aggregate and preparation method thereof

Abstract

The invention relates to a micro closed-cell light-weight corundum refractory aggregate and a preparation method thereof. The technical scheme is as follows: the preparation method comprises the following steps: by using 45-65 wt% of gamma-Al2O3 fine powder, 30-50 wt% of alpha-Al2O3 micropowder and 1-10 wt% of nano aluminum oxide micropowder as raw materials, adding water accounting for 40-80 wt% of the raw materials, and carrying out wet milling with a planet ball mill for 0.5-3 hours; putting the slurry subjected to wet milling in a mold, standing at room temperature for 12-24 hours, and stripping; and drying at 110-200 DEG C for 12-36 hours, and keeping the temperature at 1750-1900 DEG C for 1-8 hours to obtain the micro closed-cell light-weight corundum refractory aggregate. The micro closed-cell light-weight corundum refractory aggregate has the characteristics of low apparent porosity, high closed porosity, low volume density, small average pore size, lower heat conductivity and high molten 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 re...

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 was significantly reduced, but the apparent porosity and pore size were larger; S. J. Li et al. used kaolinite as a foaming agent to prepare a porous corundum-mullite aggregate (S. J. Li, N. Li, Effects of composition and temperature on porosity and pore size distribution of porous ceramics prepared from Al(OH) 3 and kaolinite gangue, Ceram. Int. 33 (4) (2007) 551-556.), the average pore size of the prepared aggregate was small, but the apparent porosity was as high as 40%; R. Salom?oa et al. used the raw material of hydrotalcite Porous alumina-spinel aggregates were prepared by site decomposition (R. Salom?oa, M.V. B?asa, V.C. Pandolfellia, Porous alumina-spinel ceramics for high temperature applications, Ceram. Int. 37 (4) (2011) 1393 -1399.), the prepared aggregate can not meet the production requirements in terms of apparent porosity and pore size

[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.