Trial heats were conducted to determine if raw limestone can be used in the production of steel in an arc furnace. The main process parameters were recorded and samples of the steel and slag were obtained during the heats. It was determined that raw limestone can be used in the furnace if there is a shortage of fresh-burnt lime, but the performance indices of the furnace should be expected to decrease in this case. The decrease in performance will be negligible if the consumption of raw limestone is limited to 0.8–1 ton/heat.