Gold Dissolution
Essentially state and corrosion resistant, gold dissolution is not easily obtained by just any acid. Use an oxidant like manganese dioxide, nitric acid, oxygen, ferric ions or cupric ions and you will dissolve gold. The formation of Aqua Regia by nitric and hydrochloric acids will break down gold and make it go into solution. In the presence […]
Gold Processing Methods & Gold Ore Extraction
Of all the methods of extracting gold & processing it from its ore, I used a few to evaluate two principal flowsheets in this case study. The flowsheets utilized operations that involved flotation, cyanidation and gravity concentration. Tests that mirror each of these unit operations were utilized to evaluate the principal flowsheets. This page offers a comparative […]
Processing Gold by Cyanidation Leaching
Processing Heap Leachable Gold Ore by Cyanidation Oxide ore (low grades) will be unloaded on the heap leach PAD. Lime must be added during the discharge in order to control pH. Harvesting must be performed after the ore discharge is completed in order to avoid compaction caused by the trucks during the leach cell construction. After […]
Gold Cyanidation Process
The Cyanidation Process or CYANIDE LEACHING is ‘most notably used in the recovery of gold. Safety and environmental concerns are of prime importance in the operation of a cyanidation plant. As we get farther into this type of recovery you will see why. The preparation of the ore for processing is similar to flotation. The […]
Chemical Reaction of Copper Minerals and Cyanide
In discussing the Reaction Products from Copper Minerals and Cyanide you will find that when an excess of copper mineral is acted upon by cyanide solution, dissolution of copper continues at a decreasing rate until equilibrium is established and no more copper goes into solution. The rate will vary with the particular mineral used as […]
Effect of Grind Size on Gold Recovery
Your intuition along with common wisdom will have you believe the Effect of Grind Size on Gold Recovery is always uni-directional or proportional. Truth is it really depends on what your mineralogy tells you and what the effective gold grain liberation size is. If you are already finer than needed, going finer yet will not help. […]
Column Leaching Procedure
1) For better Column Leaching, Agglomerate ore if required. The procedure is to cure for recommended time period. During this time the ore should be kept damp via a wet cloth spread over it. 2) Load ore into the column. This should be done with the column on an angle, and the ore poured gently in to […]
Cyanide Bottle Roll Leach Test – Leaching Procedures
List Equipment Required to Perform of a Standard Bottle Leach Test Winchester bottles, with tops Plastic tape to seal tops of bottles Flexible air lines for possible aeration requirements Magnetic or mechanical stirrer for agitation Timer, pH meter, thermometer and weighing device Leachants, i.e. acid, alkaline or neutral solutions, or specific solutions Filter: vacuum or […]
Sulphide Leaching
Methods of leaching sulphide ores can be: in absence of oxidizing agents in presence of oxidizing agents Bacterial leaching Absence of oxidizing agents Acid leaching: Dilute acids dissolve some metal sulphides with liberation of H2S, e.g. ZnS + 2H+ ^ Zn2+ + H2S Three types of sulphides can be encountered. Completely soluble sulphides: Zns, CoS, […]
Cassiterite & Wolfram and Scheelite Leaching – Oxide
Natural cassiterite on account of its crystalline nature is extremely difficult to dissolve in acids or alkalies. Artificial cassiterite on the other hand is amorphous and soluble in acids. Cassiterite can easily be reduced however to Sn, which soluble in acids or alkalies. Pressure leaching has been applied to cassiterite concentrates using Na2S and NaOH […]