SU137126A1 - Method for producing carbon-free ferrochrome - Google Patents

Description

With the known methods for producing carbon-free ferrochrome, performed at high temperatures, an increased power consumption occurs.

To eliminate this drawback, a method is proposed for producing carbon-free ferrochrome, which is carried out when calcined pellets or powders made from finely ground chromium ore and limestone are introduced into liquid silicochrome.

The method consists in grinding chrome ore or chrome concentrate with limestone to a grain size of 60-103. Niemxon. Pellets are made from the resulting mixture. Then the pellets are subjected to oxidative roasting in any kiln at IIOO-1400 °.

When firing, a part of chromium oxide (Cr20z) is converted to chromic anhydride (CgOz) with the formation of calcium chromatochromite (9 CaO 4 CgOz CgaOz). At the same time, during firing, all carbon contained in the ore is oxidized.

Then the heated pellets without cooling are mixed with liquid silico-chrome (or ferrosilicon). In this case, the excess heat from the exothermic reactions taking place is spent on the melting of the ore-limestone pellets.

As a reducing agent, either silicon with high silicon content or rich in ferrosilicon (75-85% Si) can be used.

Subject invention

The method of producing carbon-free ferrochrome using liquid silicon-chromium (or ferrosilicon), characterized in that, in order to reduce energy consumption, liquid silicone-chromium (or ferrosilicon) is mixed with powders or pellets made from mixtures of chrome ore (or concentrate) and limestone ka and subjected to oxidative roasting to a temperature of 1100-1400.