Processing of Rare Earth Metal Oxide for Use as a Master Alloy in the Metallurgical Industry

Consumption of rare-earth metal (REM) oxides, such as cerium and lanthanum, is significantly lower than their production. This discrepancy is attributed to the complex extraction of all REMs, where the share of cerium is approximately 40%. This article proposes a method for processing REM oxides for their use as master alloys in ferrous metallurgy products. REMs, in the form of modifiers for steels and alloys, are widely used. However, despite their wide usage, owing to the complexity of the REM production technology, they tend to have a high market value. This study explores the preparation of a cerium carbide (CeC 2 ) master alloy for the modification of steels and cast irons. The proposed method aims to reduce the cost of the alloying process and simultaneously increase the demand for REM oxides. Using a high-temperature synthesis process, CeC 2 was obtained for the modification of steel and cast iron. For this purpose, cerium dioxide (CeO 2 ), graphite (C), and ARMCO-iron (Fe) were mixed in a specific percentage ratio by weight: 5.4% C, 19.5% CeO 2 , and 75.1% Fe. Following this, the reaction mixture was heated in a furnace to a temperature of 1650°C and held for 30 min, with a residual pressure in the furnace of 10 –1 mbar. The synthesis was performed in the temperature range of 1300–1650°C, with the highest reaction rate of at a temperature of 1520°C. Both elemental and X-ray diffraction analyses indicated that CeO 2 was the end product of the synthesis process. The master alloy does not undergo hydrolysis because CeC 2 is synthesized in the liquid phase of iron. It has been established that the technology for producing a cerium carbide alloy involving high-temperature heating in a resistive furnace, enables the production of a material with reproducible properties.