Magnesium composite brick for nickel-iron electric furnace and preparation method of magnesium composite brick

The invention provides a magnesium composite brick for a nickel-iron electric furnace and a preparation method of the magnesium composite brick. The magnesium composite brick is relatively good in heat conduction, slag iron corrosion resistance and slag adhesion property. The magnesium composite brick for the nickel-iron electric furnace comprises the following raw materials in parts by weight: 20-22 parts of fused magnesite (with the particle size being 5-3 mm), 8-9 parts of special-grade alumina (with the particle size being 5-3 mm), 14-15 parts of fused magnesite (with the particle size being 3-1 mm), 4-5 parts of special-grade alumina (with the particle size being 3-1 mm), 6-7 parts of special-grade alumina (with the particle size being 1-0mm), 3 parts of special-grade alumina (with the particle size being 1-0 mm), 16-18 parts of fused magnesite (with the particle size being less than or equal to 0.076 mm), 8 parts of special-grade alumina (with the particle size being less than orequal to 0.076 mm), 8-10