Hebei Messi Biology Co., Ltd. stated that accurately weigh 0.5g of magnesium oxide sample, accurately add 30mL of sulfuric acid titrant (0.5mol/L) to dissolve, add 1 drop of methyl orange indicator solution, and use sodium hydroxide titrant (1mol/L) to dissolve it. L) titration, subtract the amount of sulfuric acid mixed with calcium oxide from the amount of sulfuric acid consumed to obtain the amount of sulfuric acid consumed by magnesium oxide in the test volume. Read the usage amount of sodium hydroxide titrant and calculate that each 1 mL of sulfuric acid titrant (0.5 mol/L) is equivalent to 20.15 mg of magnesium oxide or 28.04 mg of calcium oxide.
Note 1: “Precision weighing” means that the weighing should be accurate to one thousandth of the weighed weight, and “precision measuring” means that the accuracy of measuring the volume should comply with the national standards for pipettes of that volume. Accuracy requirements.
Note 2: “Moisture determination” uses the drying method. Take 2~5g of the test sample and spread it flatly in a flat weighing bottle that has been dried to constant weight. The thickness should not exceed 5mm. The loose test sample should not exceed 10mm. Weigh it accurately. Open the bottle cap and dry it at 100~105℃ for 5 hours. Cover the bottle cap, transfer it to a dryer, cool it for 30 minutes, weigh it accurately, dry it at the above temperature for 1 hour, cool it, and weigh it twice in a row. The difference in weighing does not exceed 5mg. Based on the weight loss, calculate the moisture content (%) in the test sample.
Hebei Messi Biology Co., Ltd. stated that heavy magnesium oxide, molecular formula MgO, relative molecular mass 40.30. White or beige powder, non-toxic, odorless and tasteless, with a relative density of 3.58 and a melting point of 2800°C. It is insoluble in water and organic solvents, but soluble in acids or ammonium salt solutions. It easily absorbs moisture and forms magnesium complex salt when it meets moisture and carbon dioxide in the air. Heavy magnesium oxide is used in the magnetic materials industry for color TV deflection coils (ferrite soft magnets) and other ferrite magnetic materials; as polishing agent in the steel ball polishing industry; as raw material for phenolic resin (bakelite powder) in the electrical appliance industry ; In the dye industry, it is used as an auxiliary material for the production of para-aminophenol. In the leather industry, the modification of heavy magnesium oxide can be used as a safe alkali-promoting agent.
