Hearth mixture for disposing on the hearth bottom of an electric arc furnace, use of a hearth mixture for disposing on the hearth bottom of an electric arc furnace, electric arc furnace, method for disposing a hearth mixture on the hearth bottom of an electric arc furnace and use of magnesia spinel used in a lining of a cement rotary kiln

An electric arc furnace comprising:

• 11.1 a hearth bottom;
• and
• 11.2 a hearth mixture disposed on the hearth bottom, the hearth mixture comprising the following features:
• 11.2.1 the hearth mixture comprises at least two refractory components, namely,
• 11.2.1.1 a first component in the form of magnesia;
• and
• 11.2.1.2 a second component in the form of recycled magnesia spinel used in a lining of a cement rotary kiln;
• 11.2.2 wherein the hearth mixture has a chemical composition comprising the following oxides in the following proportions:
• 11.2.2.1 Al2O3:
• 0.2 to 13% by mass;
• 11.2.2.2 CaO:
• 6 to 58% by mass;
• 11.2.2.3 MgO:
• 29 to 93.8% by mass.

A method for disposing a hearth mixture on the hearth bottom of an electric arc furnace, the method comprising the following steps:

• C. providing a hearth mixture comprising the following features:
• C.1 the hearth mixture comprises at least two refractory components, namely,
• C.1.1 a first component in the form of magnesia;
• and
• C.1.2 a second component in the form of recycled magnesia spinel used in a lining of a cement rotary kiln;
• C.2 wherein the hearth mixture has a chemical composition comprising the following oxides in the following proportions:
• C.2.1 Al2O3:
• 0.2 to 13% by mass;
• C.2.2 CaO:
• 6 to 58% by mass;
• C.2.3 MgO:
• 29 to 93.8% by mass;
• D. providing an electric arc furnace, comprising:
• D.1 a hearth bottom;
• E. disposing the hearth mixture on the hearth bottom.