The analytical methods for calcium-silicon containing a large amount of rare earths: Study on analytical methods of steel making materials. II

A method was presented for the determination of total rare earths, cerium, silicon, iron and calcium in calcium-silicon containing a large amount of rare earths. Total rare earths together with iron were separated from calcium by precipitation with ammonium hydroxide. The precipitate was dissolved in hydrochloric acid, adjusted to pH 2, oxalic acid was added for precipitation of total rare earths and they were weighed after ignition. Cerium in the precipitate was dissolved in sulfuric acid, the solution was oxidized with ammonium persulfate in the presence of silver nitrate and titrated with ferrous ammonium sulfate and potassium permanganate. Calium, iron and silicon were determined by conventional methods. Fundamental experiments have been carried out in detail, and good results were obtained for the analysis of a sample containing 0.05% carbon, 15% calcium, 25% rare earth metals and 5% iron, respectively.