THE RESEARCH OF PROCESS OF LEACHING OF COALCONCENTRATING DUMPS IN POTENTIOSTATIC MODE

Abstract

Determination of influence of potential value of discharge on process of leaching of dump of technogenic origin by mineral solution was the purpose of the research. Object of the research was dump of technogenic origin with long term of natural storage. The electrochemical researches were carried out on the potentiostat ПИ 50.1. in a two-chamber three-electrode cell in mineral solution at a temperature 30°С during 14-15 days. I-E curves before and after the discharge at potential deployment from stationary to cathode or anode area in interval of -0,05÷1,0 V and speed of scanning of potential 20 mV/s were taken. The leaching in potentiostatic mode at potentials 0,65 and 0,25 V was carried. It was established, that the process of leaching for system dump + nutritious environment at potential of discharge 0,65 V occurs only when in solution are present ions Fe2+. At decrease of concentration of ions Fe2+up to minimal, current of discharge decreases up to zero, and process is slowing down for 2 day. At potential of discharge 0,25 V the process of leaching lasts for all the time of experiment, because of electrochemical reduction of ions Fe3+, and in solution is supporting necessary concentration of ions Fe2+. The maximal сapacitance, deter-mining the speed of leaching, for potential 0,25 V is observed on 6-7 day for all 4 stages on a discharging curve.

Keywords

• вилуговування, відвал, потенціостатичний режим