Amount of oxidant added for iron removal by oxidation in the solution after copper sulfate displacement
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The copper sulfate solution obtained from the sulfuric acid leaching of ore is subjected to iron displacement; the iron content is 6 grams per liter and the pH is 1.5. Hydrogen peroxide, manganese dioxide, or potassium permanganate are intended to be used for iron removal through oxidation. Please provide the reaction equations or methods for calculating the amount of oxidant required. Thank you.
Oxidative iron removal is usually carried out at a pH of 4.0–4.5; it is quite difficult to remove iron at a pH of 1.5, unless the hematite method or yellow potassium ferrivanadate is used (though iron removal is not complete in these cases). I won’t write down the chemical equations, but I know that generally, the ratio of manganese dioxide to iron is 1.2:1 on a weight basis, while the ratio of potassium permanganate to iron is 0.8:1. These are the approximate values I use in my production process
The reaction equations are as follows: 2H2O + 2MnO4- + 10Fe2+ → 2Mn2+ + 10Fe(OH)3 + 14H+; 4H2O + MnO2 + 2Fe2+ → Mn2+ + 2Fe(OH)3 + 2H+; 4H2O + H2O2 + 2Fe2+ → 2Fe(OH)3 + 4H+. The amounts of potassium permanganate and manganese dioxide used can be those specified on the second floor; the amount of hydrogen peroxide is generally about 4 times the theoretical amount.
It seems like the cost is high, right? How about air oxidation?
Add a 50% solution prepared from sodium chlorate (which is easy to store after dissolution once it catches fire), using an amount of sodium chlorate equal to 0.5 times the amount of iron metal (based on solid mass). Or the air oxidation method using forced ventilation (slower but cost-saving)