A blast furnace swing nozzle castable and its preparation process

Abstract

The invention discloses a swing spout castable for blast furnace and a preparation process thereof. The swing spout castable comprises the following components in mass ratio: 20-30 parts of alumina, 5-10 parts of bauxite powder, 25-35 parts of mullite particle, 5-10 parts of mullite powder, 5-10 parts of tabular corundum, 4-8 parts of activated alumina powder, 4-8 parts of silica powder, 1-4 parts of steel fiber, 2-5 parts of silica sol, 1-3 parts of fused MgO powder, 3-8 parts of polycarboxylate superplasticizer, 0.5-2 parts of detonation inhibitor which is a mixture of an azodicarbonamide foaming agent, aluminum lactate and polypropylene fiber, and 0.5-1 part of antioxidant. According to the swing spout castable, carbon-contained components such as brown fused alumina, silicon carbide and asphalt in a conventional swing spout castable are omitted, oxidization is prevented; mullite with low thermal expansivity is introduced and a mullite phase is formed in a substrate so as to reinforce thermal shock resistance and improve high temperature bending strength; compared with the prior art, the swing spout castable has better oxidation resistance, explosion-proof performance and high-temperature strength.

Description

【Technical field】 [0001] The invention relates to the technical field of refractory materials, in particular to a pouring material for a blast furnace swing nozzle and a preparation process thereof. 【Background technique】 [0002] Before the desiliconization process is implemented in front of the blast furnace, the pouring material for the swing nozzle is Al 2 o 3 -SiC-C castable lining. After desiliconization in front of the furnace, the damage to the inner lining of the swing nozzle is very serious, and the service life of the swing nozzle is greatly reduced. The main ways of analyzing its damage are: (1) Impact corrosion of molten iron: due to Al 2 o 3 -The high-temperature strength of SiC-C material is low, and the ability to resist the high-temperature impact of molten iron is weak, resulting in faster corrosion, which is the main damage form of the material; (2) cyclic thermal shock: resulting in a reduction in the structural strength of the material; ( 3) Oxidatio...

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Problems solved by technology

After desiliconization in front of the furnace, the damage to the inner lining of the swing nozzle is very serious, and the service life of the swing nozzle is greatly reduced. The main ways of analyzing its damage are: (1) Impact corrosion of molten iron: due to Al 2 o 3 -The high-temperature strength of SiC-C material is low, and the ability to resist the high-temperature impact of molten iron is weak, resulting in faster corrosion, which is the main damage form of the material; (2) cyclic thermal shock: resulting in a reduction in the structural strength of the material; ( 3) Oxidation damage: The SiC and C components of the system material are easily oxidized, especially the oxidation of the C component, which leads to loose material structure and decreased strength, which is the main reason for the damage of the system material. At the same time, the existing technology Aluminum powder is still the main anti-explosion agent in castables for swing nozzles. Due to the influence of factors such as the type, fineness, addition amount, construction environment, and curing temperature of aluminum powder, the castables with added metal aluminum will generate hydrogen gas. The time and amount cannot be controlled, and problems such as foaming and fine powder floating will occur. In severe cases, cracks or explosions will occur.