Electrically calcined coal-based carbon brick with high thermal conductivity and high corrosion resistance and preparation method thereof

Abstract

The invention relates to an electrically calcined coal-based carbon brick with high thermal conductivity and high corrosion resistance and a preparation method thereof. According to the technical scheme, 8 to 16wt% of microwave treated electrically calcined coal fine powder, 10 to 25wt% of alpha-Al2O3 micro powder, 4 to 8wt% of silicon powder, 1 to 4wt% of aluminum titanium alloy powder and 2 to 4wt% of high temperature pitch are used as substrates, 50 to 65wt% of microwave treated electrically calcined coal particles are used as aggregate, and thermoset phenolic resin accounting for 10-20wt%of the sum of the substrates and the aggregate is additionally added. The preparation method comprises the following steps: mixing the substrates to obtain substrate fine powder; then putting the aggregate into a mixing mill and performing mixed milling, then adding the thermoset phenolic resin and performing mixed milling; finally adding the substrate fine powder and performing mixed milling; andperforming moulding and drying to obtain green bodies of carbon bricks. The surfaces of the green bodies of the carbon bricks are uniformly sprayed or brushed with a layer of slurry and dried, and the green bodies of the carbon bricks are subjected to thermal insulation in an air atmosphere at 1,150 to 1,250 DEG C for 12 to 24h, thereby obtaining the electrically calcined coal-based carbon brickwith high thermal conductivity and high corrosion resistance. The electrically calcined coal-based carbon brick has the advantage of low cost and is easy to industrially produce, and the prepared products have high strength, high thermal conductivity and excellent property of resisting corrosion of liquid iron.

Description

technical field [0001] The invention belongs to the technical field of electric calcined coal-based carbon bricks. In particular, it relates to a high thermal conductivity and high corrosion resistance electric calcined coal-based carbon brick and a preparation method thereof. Background technique [0002] The life of the carbon brick at the bottom of the hearth of the blast furnace determines the first generation of the blast furnace. In recent years, with the development of large-scale and long-life blast furnaces, as well as the application of enhanced smelting technologies such as high wind pressure, high wind temperature and oxygen-enriched coal injection, higher requirements have been placed on the performance of hearth bottom carbon bricks. Therefore, the development of a new generation of carbon bricks with high thermal conductivity and high corrosion resistance is of great significance to the longevity of blast furnaces. [0003] Blast furnace carbon bricks genera...

AI Technical Summary

Problems solved by technology

[0003] Blast furnace carbon bricks generally use electric calcined coal as the aggregate. Since electric calcined coal is a low graphitized carbon and itself porous, the thermal conductivity of electric calcined coal-based carbon bricks is generally low and the microporous properties are poor.

At present, in order to improve the thermal conductivity of electric calcined coal bricks, most manufacturers at home and abroad use a large amount of high thermal conductivity graphite materials, such as "High thermal conductivity carbon bricks for blast furnaces and their manufacturing methods" (CN1304329C), "Used for ironmaking blast furnace linings, Hot-pressed fired carbon bricks for furnace hearth" (CN1293207C), "High thermal conductivity microporous molded carbon bricks and its production method" (CN1328219C), "A kind of carbon brick for ironmaking blast furnace lining and its preparation method" (CN101514377B), "A carbon brick for blast furnace hearth bottom and its preparation method" (CN102432316A), "A high thermal conductivity ultra-microporous carbon brick and its preparation method" (CN102992805B), "A high thermal conductivity carbon brick and its production method "(CN102992793A), "a carbon brick for blast furnace lining and its preparation method" (CN103613393A), "high thermal conductivity carbon brick" (CN104557065A), "high thermal conductivity high temperature molded carbon brick" (CN103951440A) and "a high thermal conductivity super Microporous carbon brick and its preparation method" (CN102992805B) and other patented technologies, adding more than 30wt% graphite substances in the preparation process of carbon bricks, although the thermal conductivity of carbon bricks has been improved to a certain extent; but in the actual production of blast furnaces Under environmental conditions, these graphite substances are easily dissolved into molten iron, leaving holes in the carbon brick, providing channels for the penetration of molten iron, and causing the carbon brick to form an embrittlement layer, resulting in a carbon brick structure under the scouring of molten iron. sexual exfoliation

In addition, the cost of graphite raw materials is relatively high, adding a large proportion of graphite will definitely increase the manufacturing cost of carbon bricks, which is not conducive to the reduction of blast furnace production costs

[0004] More importantly, the firing process of blast furnace carbon bricks is buried carbon firing, that is, the formed carbon bricks are placed in a fixed cave, and the carbon bricks are completely buried with coke particles for high-temperature firing treatment. The process needs to consume a large amount of coke and is time-consuming, and the firing efficiency is low