Method for improving mechanical performance and thermal shock resistance of compact heavy refractory product

Abstract

The invention relates to a method for improving the mechanical performance and the thermal shock resistance of a compact heavy refractory product, which is characterized by comprising the following steps of: immerging the produced compact heavy refractory product into a phosphate solution which is formed by adding phosphorous acid with the concentration not less than 85wt% into active magnesium oxide and / or active aluminum oxide with the phosphorous acid weight of 3-5wt% for reaction, wherein the previous and subsequent weighing change is larger than 5-8 percent; taking out the mixture, drying and carrying out medium temperature processing at the temperature of 600-800 DEG C, thereby not only improving the mechanical performance of the refractory product, for example, the density is improved by 3-6 percent, the intensity is improved by about 20-40 percent, the high temperature folding strength at the temperature of 1,100 DEG C is respectively improved to 28 (porzite-silicon carbide) from the original about 23 and improved to 25 (porzite) from the original about 18, and the porosity is also reduced; but also improving the toughness of the compact heavy refractory product, for example, the porosity is reduced, the thermal shock resistance is improved, the times of water cooling at the temperature of 1,100 DEG C are respectively increased to 70 times (porzite-silicon carbide) from the original about 50 times and increased to 14 times (porzite) from the original 3 times, and wearing resistance tests are decreased to 5.4 percent from the original 6.3 percent (a weighing method), so that the service life of a dry coke quenching furnace can be prolonged by 1-2 times.

Description

technical field [0001] The invention relates to a method for improving the mechanical properties and thermal shock resistance of dense heavy refractory products, in particular to dense heavy refractory products for dry quenching coke ovens. Background technique [0002] The support beam (commonly known as the corbel) in the CDQ coke oven chute area, due to long-term operation in the harsh environment with frequent alternating cold and hot, the temperature changes greatly, and its upper part bears a heavy pressure (about 190 tons). At the same time, it is washed by airflow and dust, Impact, and coke extrusion, especially because it protrudes from the large wall, bears greater resistance and pressure from all sides, resulting in easy damage. Existing techniques usually use AL 2 o 3 ≥35%, SiC≥30% mullite-silicon carbide dense heavy refractory bricks, such as Chinese patent CN1854106 mullite-silicon carbide refractory material for CDQ, using 3-15wt% metal silicon, 35-65wt% Si...

AI Technical Summary

Problems solved by technology

Similarly, impregnated phosphoric acid cannot completely react with alumina, silica, and magnesia in refractory materials to form phosphate, and it is easy to precipitate after long-term use at high temperatures, so it can only be used for non-contact high-temperature lightweight refractory products. For direct contact with high temperature The modification effect of dense heavy refractory products is not ideal, and secondly, the modification only improves the compressive strength, but does not suggest that it can improve the thermal shock resistance

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