Ore Concentration
Separating ore from gangue by methods such as froth flotation and magnetic separation.
Separating ore from gangue by methods such as froth flotation and magnetic separation.
Ore concentration, also called beneficiation, separates the valuable mineral from unwanted rock, called gangue, before reduction. The method depends on the properties of the ore. Gravity separation uses differences in density, and magnetic separation uses magnetic ores such as magnetite. Froth flotation is used for sulfide ores: the ground ore is mixed with water, oil and a frothing agent, and air bubbles carry the water-repelling sulfide particles to the surface. Chemical leaching dissolves the metal, for example gold in cyanide solution.
Key ideas: Methods: hydraulic washing for heavy oxide ores based on density, magnetic separation when one component is magnetic (tin stone with wolframite), froth flotation for sulfide ores, and leaching for Al (bauxite in NaOH), Au and Ag (in NaCN with air). Froth flotation uses collectors such as pine oil and xanthates, frothers and depressants: NaCN depresses ZnS while allowing PbS to float. Leaching Ag: 4Ag + 8CN- + O2 + 2H2O gives 4[Ag(CN)2]- + 4OH-.
Common mistakes and connections: Students think flotation separates by density; the sulfide ore is wetted by oil and carried with bubbles, while gangue sinks. Depressants allow selective separation of mixed sulfides. Zinc dust then precipitates Au or Ag from complexes. Links to surface chemistry, complexation and gold extraction.
Gravity separation exploits density differences: the dense ore mineral and the lighter gangue form distinct populations that can be separated. The interactive lesson shows this as a live animation or chart.
Copper sulfide ores are concentrated by froth flotation, in which air bubbles carry the mineral particles to the surface.
Separating ore from gangue by methods such as froth flotation and magnetic separation.
Ore Concentration is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Inorganic Chemistry first: Actinides, Superheavy Elements, Metallurgy.
The next topics in Inorganic Chemistry are Roasting and Calcination and Smelting.
Yes. The interactive lesson includes a self-check question on Ore Concentration, and the Inorganic Chemistry quiz draws on every topic in this area.
Ore Concentration is topic 73 of 113 in Inorganic Chemistry.