Lightweight and high-strength heat-insulating refractory castable

Abstract

The invention discloses a lightweight high-strength heat-insulation refractory castable. The castable comprises the following raw materials by weight: 30 to 40% of lightweight mullite aggregate, 5 to 10% of an aluminum-rich spinel hollow sphere, 5 to 8% of andalusite, 6 to 9% of aluminum-rich spinel powder, 5 to 7% of kyanite powder, 5 to 8% of silicon powder, 5 to 10% of rho-Al2O3 micro powder, 12 to 18% of calcium aluminate cement, 3 to 6% of a refractory fiber, 0.05 to 0.15% of sodium hexametaphosphate, 0.05 to 0.15% of an organic water reducing agent, 0.04 to 0.07% of an organosilicon coupling agent and 0.01 to 0.02% of a defoaming agent. According to the invention, the heat insulation performance of the lightweight refractory castable is guaranteed, close bonding between aggregate and powder in the refractory castable is improved, mechanical strength, capacity of resisting mechanical and thermal shock damage, anti-permeability and comprehensive usage performance at high temperature of the refractory castable are enhanced, and cost for the refractory castable is reduced, thereby finally achieving the comprehensive targets of reduction of heat loss in cooling of furnace beams and columns, prolongation of the service life of a heat insulation lining, improvement of heating quality in a furnace, reduction of energy consumption and maintenance cost, etc.

Description

technical field [0001] The invention belongs to the field of refractory materials, in particular to a light-weight, high-strength heat-insulating refractory castable for heat insulation of water-cooled beams and water-cooled columns of a walking heating furnace. technical background [0002] The furnace beam and column are one of the important structures of the walking heating furnace. They not only bear the full weight of the billet in the furnace, but also bear the heavy responsibility of the material moving forward in a step-by-step manner. Therefore, the furnace beam and column are guaranteed to be The mechanical strength is very important. In order to prevent the strength reduction and deformation of the furnace beam and column under high temperature conditions, it is necessary to cool the furnace beam and column. The early cooling method is open-circuit cooling through water, so it is also called water-cooled beam and water-cooled column. Due to the large heat loss of ...

AI Technical Summary

Problems solved by technology

However, in the actual production and application process, due to the thick outer castable and high thermal conductivity, the overall thermal insulation performance of the thermal insulation lining is affected, resulting in large water cooling heat loss and low thermal efficiency of the heating furnace; in addition, due to the high temperature of the refractory fiber blanket Shrinkage and thermal expansion of refractory castables lead to the formation of gaps between the outer layer of castables and the refractory fiber blanket layer, destroying the integrity and structural stability of the heat insulation lining, and easily causing high-temperature oxidation of the Y-shaped anchors and the refractory castable layer Thermal shock cracks and structural peeling not only affect the heat insulation effect of the furnace beam and column insulation lining, but also the high cooling heat loss of the furnace beam and column, and the service life is limited

[0004] In view of the shortcomings of the above-mentioned composite heat insulation lining structure, through the analysis of the performance requirements of the walking furnace beam and column heat insulation lining, it is considered that the heat insulation lining should not only have good heat insulation performance, slag infiltration and erosion resistance, but also meet the requirements of The technical requirements for the heat insulation of the furnace beam and the column and the erosion caused by the falling of the oxide scale are also required. At the same time, sufficient high-temperature mechanical properties and volume stability are required to meet the high-temperature resistance, vibration and shock resistance, and thermal shock resistance of the heat insulation lining. Integrity and other requirements; for the existing refractory and heat insulation material technology, lightweight refractory castables are the most promising to achieve the above goals, but the current lightweight refractory castables generally have low mechanical strength, high brittleness, and poor resistance to slag infiltration and erosion , low operating temperature and other deficiencies, such as: the Chinese invention patent with the publication number of CN102161593B discloses "a light-weight refractory castable for CSP furnace roll insulation lining", which provides a refractory fiber reinforced lightweight mullite Although refractory castables have excellent mechanical properties and thermal shock stability, they have insufficient slag penetration resistance and high temperature resistance, and it is difficult to meet the technical requirements of high temperature heating and oxide scale erosion in walking furnaces; although some experts have proposed Lightweight refractory castables were used to wrap single-layer structure heat insulation linings, but in the end it was not implemented due to technical limitations of lightweight refractory castables; for this reason, it is necessary to further develop the heat insulation of walking furnace beams and columns Research on new heat-insulating refractory materials for lining, improve the thermal insulation performance and damage resistance of the furnace beam and column refractory lining, reduce the energy consumption of the heating furnace, prolong the service life of the furnace beam and column refractory lining, and reduce heating Comprehensive goals such as furnace maintenance costs