Removal of arsenic from arsenic tailings slurry in a concentrator by sulfide-sulfate method

In sorting arsenic-containing non-ferrous metals and precious metal ores process, it is discharged to the tailings slurry discarded tailings are contaminated arsenic. This is because in the process of sorting the ore, and leaching arsenic is arsenic from arsenic in the tailings, into the mineral (e.g., scorodite, arsenic, pyrite, etc.) - the results of step by washing. In order to prevent arsenic-containing sewage and its infiltrating polluted water system, it is necessary to reduce the arsenic content in the slurry discharged into the tailings by using a stable sediment which converts arsenic into easy-to-preserve and a method of arsenic removal from the slurry. Emission standards.

The arsenic removal process for tailings slurry developed by the National Institute of Nonferrous Metals of the Soviet Union is based on the method of precipitating arsenic from solution using iron monosulfide. This - process is characterized by using a single iron sulfide with a mixture of ferrous sulfate. The amount of ferrous sulfate added must be such that the pH of the tailings slurry is reduced to 6.7~7.2 . Far multi-metal joint company - holder of mineral scheelite processing plant using this - Arts and several other ore deposits were tested. In all cases, the concentration of arsenic is reduced by the purification to a specified discharge standard (ie less than 0.05 mg / l).

The sulphide - sulphate process from the tailings slurry of the concentrator is: preparing iron sulphate and sodium sulphide solution, using ferrous sulphate and iron monosulfide formed during the mixing of sodium sulphide and ferrous sulphate solution. The mixture is used to treat the slurry, allowing the slurry to settle in the tailings and returning the clarified water from the slurry (see figure).