EN
Oxidized ores
Oxidized ores are ores whose component composition is represented by oxides, and whose elements are in chemical compounds with oxygen. Oxidized ores are refractory materials, usually loose and contain a large amount of clay substances, such as Al 2 O 3 , as well as moisture.
Oxidized ores contain little sulfur, they are found mainly in the upper layers of the earth's crust, and most of these deposits have already been developed.
The industrial value of oxidized ores is not great, often oxidized ores are found together with sulfide ores. Due to the high moisture content, oxidized ores are crushed and then dried for further processing.
The main flotation methods for enriching oxidized ores include:
- Flotation with sulfhydryl collectors with preliminary sulfidization with sodium sulfide Na 2 S.
- Flotation with oxyhydryl collectors (soaps, fatty acids). The method has limited distribution due to the low selectivity of the process.
- Application of cationic collectors (in flotation of oxidized zinc ores).
- Combined flotation-hydrometallurgical method.
Let's consider the most common ores of the main metals:
The following minerals are most characteristic of oxidized copper ores :
- Malachite - Cu 2 CO 3 (OH) 2 ;
- Azurite – Cu 3 CO 3 (OH) 2 ;
- Brochantite – Cu 4 SO 4 (OH) 6 ;
- Atacamite - Cu 2 (OH) 3 Cl;
- Chrysocolla - CuSiO 3 ×nH 2 O;
- Cuprite - Cu 2 O;
- Tenorite – CuO
Solubility in cyanide is the main criterion for determining the flotation ability of copper oxidized ores. Of the listed minerals, only silicates and copper phosphates do not dissolve in cyanides, but pass into the sulfuric acid extract. Such ores are classified as refractory and are enriched by combined or hydrometallurgical methods.
The main oxidized lead minerals are:
- Cerussite PbCO 3 ;
- Anglesite PbSO 4 ;
- Pyromorphite Pb 5 [PO 4 ] 3 Cl;
- Crocoite PbCrO 4 ;
- Mimetesite Pb 5 [AsO 4 ] 3 Cl;
- Wulfenite PbMoO 4 ;
- Vanadinite Pb 5 [VO 4 ] 3 Cl;
- Plumboyarosite PbFe 6 [SO 4 ] 4 OH 12
The main oxidized zinc minerals are:
- Smithsonite ZnCO 3 ;
- Calamine Zn 4 [Si 2 O 7 ](OH) 2 ×H 2 O;
- Hydrozincite Zn 5 [CO 3 ] 2 (OH) 6
In mixed lead-zinc ores, galena PbS and sphalerite ZnS are very often found, non-metallic impurities include quartz, silicates, calcite, etc. Oxidized lead minerals are floated by sulfhydryl minerals after preliminary sulfidization with sodium sulfide Na 2 S. Oxidized zinc minerals are floated after the extraction of sulfides and oxidized lead minerals.
