METHOD FOR BACK WATER PREPARATION DURING FLOTATION Russian patent published in 2017 - IPC C02F1/52 B03D1/00 

FIELD: chemistry.

SUBSTANCE: method for back water preparation during flotation involves dosing of reagents for back water neutralisation, heavy metals precipitation, and sulfhydryl collectors for electrochemical parameters of the back water. Potential difference between two electrodes, one of which is molybdenum and the other is either argentite, or cadmium, or tin, or antimony, is measured in the water or pulp flow. Based on the measured potential difference deviation of least one bimetal pair from the predetermined optimum value, reactant supply is adjusted. To neutralise the back, an acid, such as sulfuric acid, or alkali, such as lime milk, is used, dose is adjusted by the potential difference of a bimetallic pair including molybdenum and cadmium electrodes, so that an increase in the potential difference Δ(Cd-Mo) increases the dosage of alkali and a decrease in the potential difference Δ(Cd-Mo) reduces the dosage of alkali. Hydrosulphuric acid salts and its derivatives, for example, Na₂S, NaHS are used as a reagent for heavy metals precipitation, wherein the dose is adjusted out based on the potential difference of a bimetallic pair including argentite and molybdenum electrodes, so that an increase in the potential difference Δ(Ag₂S-Mo) increases the reagent dosage, and a decrease in the potential difference Δ(Ag₂S-Mo) reduces the dosage. Bluestone is used as a reagent for sulfhydryl collectors precipitation with dose adjusted based on the potential difference of a bimetallic pair including argentite and molybdenum electrodes, so that an increase in the potential difference Δ(Ag₂S-Mo) reduces the dosage, and an increase in the potential difference Δ(Ag₂S-Mo) reduces the dosage. In case of simultaneous treatment of water to neutralise acidity via dosing alkalis and heavy metal deposition using hydrogen sulfide salts and its derivatives, three metal electrodes are used: argentite, molybdenum and antimony. Alkali feed is adjusted, so that an increase in the potential difference Δ(Sb-Mo) increases the dosage of alkali and a decrease in the potential difference Δ(Sb-Mo) reduces the dosage of alkali. Hydrogen sulfide salts and its derivatives flow is adjusted out so that an increase in the potential difference Δ(Ag₂S-Mo) increases the reagent dosage, and a decrease in the potential difference Δ(Ag₂S-Mo) reduces the reagent dosage.

EFFECT: improved accuracy and reliability of reagent supply at an optimal level, consumption of which is adjusted based on the measured electrochemical potential of the back water.

7 cl, 12 dwg, 8 tbl, 3 ex