Process of using magnesia-calcium-carbon balls in LF steel making

The invention discloses a process of using magnesia-calcium-carbon balls in LF (ladle furnace) steel making. The process comprises the steps that dolomite and graphite carbon are uniformly mixed, then crushed, and pulverized till the particle size is below 1mm; the pulverized dolomite and graphite carbon are then put into a ball pressing machine to allow carbon, and calcium carbonate and magnesium carbonate that are in dolomite to be pressed together to form a homogeneous body of carbonate and carbon; and the homogeneous body is made into deoxidant carbon balls capable of replacing calcium carbide. Computational formulas of adding amounts of carbon and dolomite are as follows: (1) the content of carbon is controlled at 45%, the content of carbon in dolomite is assumed to be alpha, the content of carbon in graphite is assumed to beta, the adding amount of graphite is Q, then the computational formula of the adding amount (Q) of graphite is as follows: Q is equal to (45-100alpha)/(beta-alpha); and (2) the adding amount (G) of dolomite is controlled in accordance with 100-Q. When aluminium killed steel is smelted in a rotary furnace, according to the principle of replacing calcium carbide at the equal adding amount, the above deoxidant carbon balls are added, and are used according to the traditional steel melting process.