Submerged arc furnace refractory materials requirements

The submerged arc furnace is used for the reduction and smelting of metal oxide ore, so it is also called the submerged arc reduction electric furnace.

When the submerged arc furnace is used to produce ferroalloy, it is called ferroalloy furnace; when it is used to produce calcium carbide, it is called calcium carbide furnace; when it is used to produce yellow phosphorus, it is called yellow phosphorus furnace; when it is used to produce matte, it is called matte furnace; it is used for ferroalloy refining When it is used to melt the pre-reduced charge and separate the metal from the slag, it is called a melting furnace.

Requirements for refractory materials for submerged arc furnace

In the smelting process of submerged arc furnace, electrode accidents caused by equipment, raw materials, operation and other factors mainly include electrode sliding, electrode sintering premature or under-burning, electrode hard breaking, electrode leakage paste, electrode soft breaking, etc. How to reduce electrode accidents, improve the operation rate and reduce the occurrence of accidents in production is very important for improving the economic indicators of smelting.

The refractory masonry for the submerged arc furnace is also the furnace lining masonry. Because the molten pool of the submerged arc furnace not only withstands strong high temperature action, but also is eroded and mechanically scoured by the charge, high temperature furnace gas, molten iron and high temperature slag, specific refractory materials must be selected.

Requirements for refractory materials: high refractoriness, large changes in shape and volume at high temperature, high temperature strength, good slag resistance, good chemical stability at high temperature, various refractory materials should be kept clean in appearance and complete in structure. There is no defect in the corner and no crack on the surface.

Submerged electric arc furnace refractory material

In the masonry of the submerged arc furnace, the refractory materials for the submerged arc furnace are mainly made of refractory bricks, and the refractory castables are the auxiliary masonry configuration. The choice of material can refer to the following introduction:

1. Carbon brick

Carbon brick is a kind of carbon material. It is made with crushed coke and anthracite. Its specifications are: section 400mm×400mm (allowable error is ±30mm), length is 800~1600mm (allowable error is ±5mm).

The advantages of carbon bricks are high refractoriness, strong thermal shock resistance, high compressive strength; good stability, especially volume stability, and good slag resistance. However, it is easy to oxidize at high temperature, and the oxidation speed will increase with the increase of temperature.

Therefore, the carbon material cannot come into contact with gases such as air and water vapor at high temperatures. Carbon materials have high thermal conductivity and poor thermal insulation performance. In the submerged arc furnace, carbon bricks can be used as the lining material for all varieties that are not afraid of carburization in smelting, and self-baking carbon bricks are used in the submerged arc furnace.

2. Composite brown corundum brick for submerged arc furnace

The main component of composite brown corundum brick is AI2O3, its refractoriness is above 1790℃, its apparent porosity is extremely low, its strength is high, its corrosion resistance and scourability are strong, etc. It is suitable for the lining of synthetic ammonia reformer.

3. Clay bricks

Clay bricks are weakly acidic refractory materials that can resist the erosion of acid slag, and refractory clay bricks cannot be used at high temperatures.

In summary, the selection of refractory materials for submerged arc furnaces should be professionally configured according to the actual smelting environment and smelting raw materials. High-alumina bricks can also be used instead of clay bricks in the melting pool of submerged arc furnaces. In terms of performance, high-alumina bricks have more advantages. Among the unshaped refractories, cold ramming pastes and high-alumina castables are the main ones.

4. Magnesia brick for submerged arc furnace

The main component of magnesia brick is magnesia, its refractoriness is above 2273K, and its alkali resistance is very strong; but its softening point under load is low, and its thermal shock resistance is poor. Most of the refining furnaces are smelted in an alkaline environment, and alkaline refractory materials that resist alkaline corrosion should be used, such as magnesia bricks as linings.

Manganese-silicon submerged arc furnace building material requirements

The furnace lining is to build the furnace lining, and the quality of the furnace lining determines the length of the furnace age. During use, the furnace lining not only has to withstand high temperatures above 2000 °C, but also bears the mechanical pressure, flow erosion and physical and chemical erosion of the furnace charge, high-temperature furnace gas, molten iron, etc. If the material is improperly selected or the quality of the masonry does not meet the requirements, it will accelerate melting, erosion or cracking, resulting in iron leakage and affecting production.

The quality requirements of the furnace building materials are as follows:

1. High refractoriness, that is, high temperature resistance.

2. Higher load softening.

3. The density meets the requirements, the volume expansion coefficient is small, and the resistance to heat and cold is good.

4. Good resistance to chemical corrosion and mechanical erosion.

5. Good thermal insulation performance.

6. High machining accuracy, in line with relevant national standards.

7. All kinds of materials should be properly stored and stored, classified and stored to prevent rain and moisture and storage and transportation damage.