The reducing roasting of low-grade high-iron saprolite ores in the temperature range 1300–1350°C is studied to form nickel-rich ferronickel balls. The nickel-lean (1.01%) high-iron (24.3% Fe) nature-mixed ore of the Buruktal deposit is analyzed. The influence of the amounts of a solid reducer (mixture of brown coal and coke) and flux additives (limestone, quartz sand, bauxite, kaolin clay, fluorite) on the limitation of the reduction of iron oxides from a silicate slag and on the coarsening of metallic particles in roasting is investigated. When 18–21% kaolin clay and 2–4% limestone are added to a charge, the reduction of iron from a slag to a metallic phase is strongly limited. The introduction of 1% fluorite into a charge leads to a noticeable decrease in the melting temperature and the viscosity of an acid silicate slag and creates favorable conditions for the coarsening of metallic particles during reducing roasting of the charge in the temperature range 1300–1325°C. As a result, the optimum charge composition and roasting parameters are determined. At these composition and parameters, metallic ferronickel granules rapidly form, and a slag becomes almost fully free of fine metallic particles because of a high surface tension between the slag and metallic phases. The nickel content in metallic granules reaches 10–13% under these roasting conditions in the presence of an excess solid reducer.