Leaching Reagents H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching Reagents

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching Reagents

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching Reagents

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching Reagents

Leaching is usually carried out in Water solutions

Often: Addition of other leaching reagents is required

H.Naderi, Mining Engineering Department, Yazd University, 2011

Acids

Bases

Sulphides

Salts

Combination of these

Leaching Reagent Properties

H.Naderi, Mining Engineering Department, Yazd University, 2011

More ExpensiveNegligible Corrosion problemsMore Selective: Limestone, dolomite etc do not react

Leaching Reagent Properties

H.Naderi, Mining Engineering Department, Yazd University, 2011

Insoluble

Foaming

Acid is consumedSolution contamination with Fe+3

Water

• Water alone maybe used for the leaching of roasted

materials such as sulphates and chlorides.

• In the presence of oxygen, some sulphides may be

leached by means of water under pressure and at

temperatures above 150-200 $ C

H.Naderi, Mining Engineering Department, Yazd University, 2011

Water

H.Naderi, Mining Engineering Department, Yazd University, 2011

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Dilute sulphuric acid

•Copper oxide ores

• Zinc Oxide

• Phosphate rock…

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching in a sulphuric acid media under oxidasing

conditions:

Oxygen:

Oxidasion

Easily Soluble metal sulphate

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching in a sulphuric acid media under oxidasing

conditions:

Nitric Acid:

Ferric Sulphate:

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

HCl has replaced sulfuric acid in many reactions involving iron oxid:

Leaching of ilmenite

Nitric Acid:

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

•The use of nitric acid is limited

•Displacing H2SO4 in some uranium extraction operations: Solve

radium gases problems

Solubilize sulphide minerals:

Acids

H.Naderi, Mining Engineering Department, Yazd University, 2011

Aqua regia:

Bases

H.Naderi, Mining Engineering Department, Yazd University, 2011

NaOH:

Bases

H.Naderi, Mining Engineering Department, Yazd University, 2011

Ammonium hydroxide:

Aqueous Salt Solutions

H.Naderi, Mining Engineering Department, Yazd University, 2011

Aqueous Salt Solutions

H.Naderi, Mining Engineering Department, Yazd University, 2011

Aqueous Salt Solutions

H.Naderi, Mining Engineering Department, Yazd University, 2011

Aqueous Salt Solutions

H.Naderi, Mining Engineering Department, Yazd University, 2011

Aqueous Salt Solutions

H.Naderi, Mining Engineering Department, Yazd University, 2011

Leaching Reagents

H.Naderi, Mining Engineering Department, Yazd University, 2011