Application of magnesite bricks and magnesia in nickel iron ore furnace

Application of magnesite bricks and magnesia in nickel iron ore furnace

In addition to the commonly used carbon-based refractory linings in submerged arc furnaces, basic magnesia bricks and magnesia sand-based magnesia refractory linings have also been widely used. For example, in nickel-iron ore furnace, magnesia refractory lining is mainly used.

Nickel-iron submerged arc furnace, as the name suggests, is mainly used to smelt nickel-iron alloys. The nickel-iron submerged arc furnace is different from the submerged arc furnace for smelting other ferroalloys. Most of the domestic smelting methods of nickel-iron alloys adopt the "rotary kiln-submerged arc furnace method", that is, the raw materials are preliminarily dried and reduced in the rotary kiln. The nickel slag at 900~1000℃ is poured into the submerged arc furnace for smelting.

In the smelting process, the lining of nickel-iron ore furnace not only has to bear strong high temperature, but also bear the physical, chemical erosion and mechanical erosion of charge, high temperature gas, molten iron and high temperature slag. In the selection of lining refractory materials for nickel-iron ore furnace, the main requirement is that the lining refractories have low thermal conductivity, mainly magnesia lining, magnesia brick or magnesia chrome brick + magnesia ramming material for furnace bottom, magnesia brick for furnace Masonry, slag, iron mouth area with magnesia-chrome bricks.

magnesite bricks

The main raw material for making magnesia bricks is magnesite, and the binder is water and brine or sulfite pulp waste liquid.

The main performance characteristics of magnesia bricks are: high refractoriness, excellent resistance to alkaline slag; but the thermal conductivity and electrical conductivity at high temperature are large, and the softening temperature under load is low, and the resistance to rapid cooling and rapid heating is poor. Pulverization occurs when exposed to water or steam at high temperatures.

magnesia chrome brick

In the production of ferroalloys, magnesia bricks are used to build the furnace walls and bottoms of high-carbon ferrochromium reduction electric furnaces, medium and low carbon ferrochromium converters, rocking furnaces and refining electric furnaces, and ladles containing ferrochromium and medium and low carbon ferromanganese. Lining etc. Use magnesia alumina bricks instead of magnesia bricks to build the furnace roof. Magnesia has high refractoriness. In ferroalloy production, magnesia is often used to knot the bottom of the furnace, make and repair the furnace wall and bottom, and can be used as a material for plugging holes or making knotted ingot molds.