This standard specifies a method for the determination of calcium and mg content in manganese ores by flame atomic absorption spectroscopy (AAS), suitable for the determination of calcium content between 0.050% and 5.00% and mg content between 0.050% and 3.00%. Methods The content of calcium and mg was determined on the Flame Atomic Absorption Spectrometer (FAAS) by muriatic acid and nitric acid analysis of the sample, after treating the residue. The standard provides detailed reagent preparation, Sample Handling and measurement procedures to ensure the accuracy and conformity of the results. It is an important reference for the determination of calcium and mg content in manganese ores.