New environmentally friendly materials for metallurgical converter repair materials

The refractory materials on the charging side, the tapping side and the furnace bottom of the converter are in a high temperature state for a long time, and are subjected to mechanical stress impact and repeated erosion of the slag, and their structure is easily damaged. At present, most converters at home and abroad are To maintain the normal life of the furnace, repair and maintenance must be carried out at regular intervals.

The traditional materials used for the repair of the large surface and the bottom of the converter are mainly divided into organic combination and inorganic combination according to the combination system. Inorganic combined large surface repair material has the characteristics of good high temperature fluidity, less volatile content and short hardening time, but due to the addition of low melting point inorganic salts, the service life is not long, and it is difficult to meet the requirements of on-site use. Therefore, for a long time, the large-scale repair materials used in domestic converter site maintenance mainly use coal tar, asphalt (about 8%-15%), resin and other organic substances as binders. Among them, the asphalt series has better fluidity, the resin has excellent slag corrosion resistance, the on-site workers are easy to operate, and the furnace is repaired quickly, but there is a problem that the sintering time is too long. No matter what kind of organic binder, there are inevitably the following problems: 1) After the organic matter is burned out, the material has many pores and poor compactness, which leads to inability to slag erosion, low strength and short service life; 2) The combustion of organic matter produces a large amount of harmful smoke It will seriously pollute the workshop environment and have a bad impact on the health of the staff in front of the furnace. Therefore, with the continuous improvement of the country's environmental protection requirements, the promotion and application of large-scale self-flowing materials for environmentally friendly carbon-free "water-based" converters must be the general trend of the entire industry.

Sintering condition after the front face is repaired

Environmentally friendly "water-based" self-flowing material for converter large surface is a new type of furnace repair material, which can be used for repairing and maintenance of the front and rear large surfaces of the converter and the bottom of the furnace. Compared with the traditional carbon-based large surface charging material, the material has the following characteristics: 1) It adopts environmentally friendly liquid binder, does not add organic substances such as asphalt and resin, does not produce toxic gases during sintering, and only a small amount of water vapor escapes. Green and environmental protection; 2) No low melting point inorganic salts such as sodium metasilicate are added, and ultrafine powder technology is used to add an appropriate amount, and a ceramic bond is formed after high temperature sintering; 3) A composite dispersant is used, and a small amount of liquid can be added to obtain a good high temperature Self-fluidity, one time shaking the furnace, self-flow spreading in the furnace, the sintering time per ton of material is less than 20 minutes; 4) The material structure is dense, the porosity is low, and there is no hidden danger of splashing caused by the sandwich layer; 5) The service life is long, under normal circumstances Up to 3 times or more than the traditional charging charge.

Sintering situation after repairing the rear large surface

The self-flowing material is a dry mix that has been strictly batched and pre-mixed. Before use, a special forced mixer is required to mix the dry mix and the liquid binder in a specified proportion. The mixed material is poured into the furnace through the hopper, and the It quickly flows to the parts to be repaired, and after fully sintering with the residual temperature in the furnace, it can be put into use. The industrial field application practice shows that after using the environmentally friendly "water-based" converter with large surface self-flow material, converter maintenance shows great advantages in terms of cost reduction, consumption reduction, production increase and efficiency improvement, and environmental protection.

Sintering condition after furnace bottom repair