炭素鋼および低合金鋼中のマンガンの状態分析

抄録

This work, a part of a general investigation on the state analysis of steel, was carried out to develop a systematic method for isolation and determination of manganese compounds in carbon steel and low alloy steel.
1. Isolation of manganese compound from steel.
(a) The steel sample covered with close-texture filter paper as a diaphragm is, as an anode, dissolved into 130 ml of 1% NaC1- 5% EDTA electrolyte (pH 6-7) at a current density of 50 mA/cm² for 2 hr. Remove the anode and the residue is collected into a beaker using methanol.
(b) To the residue add 50 ml of 2% EDTA solution (pH5-6) and shake for 30 min. Filter and wash with water. To the filterate add 10 ml of HNO₃ and 10 ml of HCIO₄, and evaporate to dense white fumes. Determine Mn as carbide in accordance with section 2.
(c) Transfer a part of the electrolyte to a beaker. Add 15 ml of HNO₃ and 10 ml of HCIO₄ and evaporate to dense white fumes. Determine Mn as solid solution in accordance with section 2.
(d) Transfer the paper and residue (paragraph (b)) to a beaker, add 30 ml of 2% EDTA solution and 20 ml of 5% H₂0₂ and shake for 60 min. Filter and wash with water. To the filterate add 10 ml of HNO₃ and 10 ml of HCIO₄ and evaporate to dense white fumes. Determine Mn as sulfide in accordance with section 2.
(e) Transfer the paper and residue (paragraph (d)) to a beaker, add 30 ml of HNO₃ and 10 ml of HC10₄ and evaporate to dense white fumes. Determine Mn as oxide in accordance with section 2.
2. Determination of manganese
Add 50 ml of water, 3 ml of H₂SO₄, 4 ml of H₃P0₄ and 20 ml of 5% NalO₄, solution to each beakers (section 1 (b), (c), (d) and (e)), and boil for 5 min. Cool, dilute to 100 ml. Measure the absorbance of solution against water at 530 mμ.