Carbon brick used for blast-furnace bottom hearth and its preparation method

Abstract

The invention relates to a carbon brick used for a blast-furnace bottom hearth and its preparation method. According to the technical scheme of the invention, the carbon brick comprises the following raw materials: 30-45 wt% of electrically calcined anthracite, 18-30 wt% of amorphous graphite, 33-42 wt% of blended powder, and additionally a binder of thermosetting phenolic resin accounting for 10-20 wt% of the above materials. The method comprises: according to the content of the above raw materials and binder, subjecting electrically calcined anthracite and amorphous graphite to mixed milling for 3-5min, then adding thermosetting phenolic resin for 5-7min of mixed milling, then adding blended powder for 15-40min of mixed milling, conducting compression molding or vibration molding, then carrying out drying at a temperature of 180-220DEG C, and finally performing sintering in an embedded carbon atmosphere at a temperature of 1200-1500DEG C. The method of the invention is characterizedby low production cost and simple technology. And the prepared carbon brick used for a blast-furnace bottom hearth has a molten iron corrosion resisting index less than 7%, thermal conductivity over 30W / (m.K) and a volume of pores less than 1 micrometer over 80%. Therefore, the carbon brick used for a blast-furnace bottom hearth has excellent molten iron corrosion resistance, high thermal conductivity and high microporosity.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a carbon brick for a blast furnace bottom hearth and a preparation method thereof. Background technique [0002] With the rapid development of the iron and steel industry and the continuous improvement of ironmaking technology, blast furnaces are developing in the direction of large-scale and long-life. The main link that restricts the longevity of the blast furnace is generally considered to be the bottom of the hearth. This is because after the intensified smelting of a modern large-scale blast furnace, the circulation of molten iron has a huge impact on the bottom of the hearth. In the brick lining, the brick lining is severely corroded and extremely difficult to repair, which seriously affects the life of the blast furnace. Therefore, for the hearth bottom, the quality of the carbon brick is particularly important. It can be said that the life of the...

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Problems solved by technology

[0003] "A Highly Corrosion-resistant Microporous Calcined Carbon Brick for Blast Furnace Lining" (ZL00116085.0) and "Microporous Self-Baking Carbon Brick for Ironmaking Blast Furnace Lining" (ZL00116084.2) The introduction of metal titanium powder into bricks not only makes the raw material titanium powder expensive, but also leads to an increase in the production cost of carbon bricks, and the erosion resistance of carbon bricks is slightly improved; "A carbon brick for ironmaking blast furnace lining and its preparation method" (ZL200410061026.3) patented technology, introducing titanium dioxide powder into carbon bricks, which improves the corrosion resistance of carbon bricks to a certain extent, but cannot meet the requirements of modern large-scale blast furnaces; "ultra-microporous carbon bricks for furnace lining and its manufacturing method" (ZL200410026087.6) patented technology, although the pore volume of <1 μm reaches more than 80%, but its molten iron dissolution rate is relatively high, which is 20%; ) patent technology, the molten iron dissolution rate of the prepared carbon brick is about 15%, "a carbonaceous refractory material for furnace lining and its preparation method" (CN200910060989.4) patent technology, earthy graphite is used instead of electric forging anthracite to prepare carbon bricks The main raw material of the carbon brick only improves the microporosity and corrosion resistance of the carbon brick to a certain extent (its corrosion resistance index is greater than 9%); another method is to impregnate the carbon brick in a solution containing zirconia (Materials and Corrosion, 2005, 56: 475-480), although its corrosion resistance has been improved to a certain extent, but its preparation process is complicated and the production cost is high, which is not conducive to the reduction of blast furnace ironmaking cost