Heap leaching as a key technology for recovery of values
Heap leaching including bioleaching is widely used for the treatment of low grade copper ores [15 19] and the possibility of using it for Cu Ni ore was also studied on an industrial scale [24]
Heap leaching including bioleaching is widely used for the treatment of low grade copper ores [15 19] and the possibility of using it for Cu Ni ore was also studied on an industrial scale [24]
When the ore being leached contains silver and lead gold dissolution can be influenced by the insoluble chlorides which form in chlorine chloride solutions This results in the formation of a passivation layer which reduces the efficiency of the dissolution process Leaching of gold and silver from crushed Au Ag wastes Open Chem Eng J
Heap leaching has become a popular method of extracting gold writes mining consultant Nicolaas C Steenkamp and Leon Louw writer editor and specialist in African affairs and mining
Silver and gold are extracted by the cyanide process Mac Arthur Forrest process After the preliminary crushing and concentration by froth floatation process the ore crushed auriferous rocks in the case of gold is leached with dilute 7% solution of sodium cyanide made alkaline by adding lime kept agitated by a current of air
Ore Laboratory Testwork Comminution Testing; the gold button remaining being only 964 fine By taking a somewhat greater proportion of sodium parting can be effected by means of nitric acid would you All leaching chemistry is the same thing Based on the ore to be leached you start with a good recipe formula mixed in the proper
ticlerof native gold or as silver bearing minerals The occurrence of silver in gold ores may range from less than 1 ppm to several hundred times the level of the gold present in an ore Generally silver is also dissolved by the cyanide solution and follows the gold through the process sequence Iron sul
It can be illustrated that the pre oxidation of the gold ore by Mn oxide oxidation controlled Au extraction efficiency and with the dissolution of % As and % Sb from the gold ore in the usage of Mn oxide assisted hydrochloric acid oxidation process it obtains Au extraction ratio of % by chlorination leaching
The 2002 statistics compiled by Kappes revealed that 12 gold operations heap leached run of mine ore 7 heap leached run of mine and crushed ore and 24 heap leached crush ore 32 operations
The kinetic leach rate is not affected by the number of lifts underlying the ore being leached The sixth lift of ore in Fig 1 will be leached according to the same kinetic leach curve as the first lift of ore However the rate of metal recovery from the sixth lift will be quite different from the rate of metal recovery from the first lift
A heap containing tons of a low grade oxide ore crushed to minus 15 mm and containing g/t gold and g/t silver was leached by alkaline solutions containing thiosulphate and amino acids
mine ore 7 heap leached run of mine and crushed ore and 24 heap leached crush ore 32 operations 32 operations reported an average heap height of m an average irrigation time of 70 days
In copper dump leaching run of mine ore is irrigated with acidic leaching solution to generate aqueous cupric ions for further processing The very large size of the ore particles being leached
Heap leaching including bioleaching is widely used for the treatment of low grade copper ores [15 19] and the possibility of using it for Cu Ni ore was also studied on an industrial scale [24]
kinetic In this type of process the ore is crushed and ground to expose the surface of gold grains to a chemical attack by cyanide in presence of oxygen This chemical factor representing the number of leached gold moles per mole of consumed oxygen Crundwell and Godorr10 proposed a model that considers the formation of a
refractory sulphide gold ores Some 20 years ago a bio oxidation technology was being developed as an alternative to conventional refrac tory processes for gold recovery Unlike conventional gold ore the gold contained in refractory or com plex ores is encapsulated in sulphide minerals which prevent the gold from being leached by cyanide
residues from gold plants The size range of this material is between 65 and 80070 minus 75 / tm and typical gold values range from 0 1 to 0 5 g/t In a few exceptional cases accumulated tailings have values between 0 5 and 1 0 g/t Gold plant tailings at present amount to a little over 100 million tons
The kinetic leach rate is not affected by the number of lifts underlying the ore being leached The sixth lift of ore in Fig 1 will be leached according to the same kinetic leach curve as the first lift of ore However the rate of metal recovery from the sixth lift will be quite different from the rate of metal recovery from the first lift
Hypochlorite leaching system is a strong oxidizing solution for metal sulfides which are naturally associated with gold extraction This study evaluated the hypochlorite leaching of refractory gold ore by using the response surface method central composite design RSM CCD as a statistical approach in determining the optimum condition of gold extraction from
Those tests were performed on samples of crushed and blasted leached ore and rock mine waste taken from different heap leach pads and mine waste dumps currently in operation in Peru
The effectiven ess of gold being adsorbed The gold ore 5 kg sample was crushed and milled to 80% passing 106 microns particle size The
Gold and silver are leached with a dilute alkaline solution of sodium cyanide The recovery is dependent on the type of ore being processed It is important to base the design of a heap leach on the results of a comprehensive program of laboratory testing fine crushed ore that is high in clays may be mined with minimal stockpiles The
