Abstract：The ferrous oxide in iron ore is easily oxidized during detection process. The determination by potentiometric titration can be conducted by directly inserting electrode into closed container, thus avoiding the oxidization of ferrous ions. Consequently the determination method of ferrous oxide in iron ore by potentiometric titration was established. The sample was dissolved with hydrochloric acid. 0.5g of ammonium fluoride was added to fully decompose the silicate. The resolving time of sample was 15min. The addition of mixed sulfuric acid and phosphoric acid was not required. The titration method was replaced by potentiometric titration. The working conditions of instrument were optimized by orthogonal experiments. The equivalence point criterion (EPC) of potentiometric titration was 20, the minimum dosage of sample solution was 20μL, and the signal drift rate was 50mV/min. The proposed method was applied for the determination of ferrous oxide in four standard samples of iron ore and rock. The relative standard deviations (RSD, n=10) of measured results were not more than 0.40%. The found results were basically consistent with the certified values. The relative errors (RE) were not more than 0.33%. The content of ferrous oxide in nine standard samples of iron ore and rock were determined according to the experimental method, and the found results were consistent with those obtained by national standard method (GB/T 6730.8-2016).
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ZHANG Ke, MA Ming, MA Long, CAI Meng, LI Yan-xiang. Determination of ferrous oxide in iron ore by potentiometric titration method. , 2018, 38(5): 66-71.
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