This standard specifies a method for the determination of calcium content in chromium ores and chromium concentrates by flame atomic absorption spectroscopy (AAS). It is applicable to samples of chromium ores and their concentrates with calcium content ranging from 0.10% to 1.00% (measured as calcium oxidation). The standard calls for the use of sodium peroxide melt analysis samples, dissolved by hot water and treated with acid to remove excess sodium peroxide. Subsequently, EDTA is used as a protective agent and calcium is released through strontium chloride and lithium chloride solutions to prevent interference, and finally the calcium content is determined using Flame Atomic Absorption Spectrometer (FAAS). The standard also cites the relevant specifications for water and Glass instruments used in analytical laboratories to ensure the accuracy of the determination.