Determination of Total Manganese in Manganese Ores with an Automatic Potentiometric Titration Method

In the batch analysis of manganese content in manganese ore with artificial titration method, it consumes a large amount of manual labor. With the popularity of automatic potentiometric titrator, it is possible to complete the volumetric titration using the instrumental equipment. The manual titration is conversed to the automatic potentiometric titration is the urgent study subject to be solved. In the paper, a method for the determination of manganese content in manganese ores with automatic potentiometric titration was established. The related titration parameters and the equivalence point identification standards is identified. Manganese ore sample was decomposed with hydrochloric acid and phosphoric acid, the carbon and organic matters in the sample were removed with nitric acid, then the sample solution was prepared with perchloric acid. In the experiment, at first, the platinum composite electrode was indicator electrode, the oxidation and reduction titration was made for the pre-pipette potassium dichromate standard solution and the blank solution with ferrous ammonium sulfate standard solution, the concentration of ammonium ferrous sulfate standard solution was calculated. Then, the oxidation and reduction titration was made for the sample blank solution and sample solution, the content of manganese was calculated. The detection range of the method for manganese is 5%-60%. The method was used to the determination of national standard reference materials, the accuracy and precision were high. A plurality of ore samples with different level of manganese from different mine area were determined using this automatic titration method, the analytical results had no significant difference with manual method by t-test. Titration method and high degree of automation, methods of robust, suitable for smelting enterprises, the port inspection and other industries, has the value of popularization. The automatic titration is robust, and is suitable for ore analysis in smelting enterprises and port inspection.