Cyanide concentration in the leach tank - …

The free cyanide concentration depends of the size of gold grains in the ore. If there is a little bit of sulphides, it may preg-rob gold if the free cyanide is too low. Determine the effect of free cyanide on the leaching profile and retention time at the lab scale. You may also reduce cyanide concentration by increasing the DO.

Get Price And Support Online

Gold dissolution decreasing with increasing cyanide ...

You concluded that there was an optimum cyanide concentration for good gold recovery rate. Maybe since you increase your cyanide concentration the other base metal from the ore has been dissolve with the solution and hindering for absorption of Activated carbon. So my suggestion regarding this situation you can add more activated carbon or after activated carbon absorption you can do zinc ...

Get Price And Support Online

Sulphide Gold | Gekko - Pre-Concentration

Sulphide Gold Recovery. Pre-concentration of coarse 350 – 500 micron sulphide-associated gold ore, using the InLine Pressure Jig, is required to reject gangue from the high value material.The IPJ, a classic pre-concentration device, is effective in gangue rejection prior to further processing of valuable gold-bearing material.. Other turnkey modular systems for pre-concentrating coarse ...

Get Price And Support Online

Cyanide leaching of gold in solutions containing …

Due to poor cyanide selectivity for gold over the enclosing sulfide mineral matrix, such parasitic reactions inflict utility extra costs and profit losses resulting from high levels of cyanide ...

Get Price And Support Online

Rcovery of gold in pyritic ores - Mine Engineer.Com

Using cyanide to recover gold from sulfide ores generally results in 30 to 35% recovery, and the best I have heard of is around 50% recovery. The fine coating of a iron compound definitely appears to be a key component of the inability of cyanide to efficiently leach low grade pyritic ores. Perhaps there is some room here for a pretreatment, to remove this iron coating and then make the fine ...

Get Price And Support Online

(PDF) Effect of High Concentration of Ammonia in …

Cyanide leaching of the ore resulted in a gold extraction of only 22% while gold extractions as high as ~62% were achieved by ammoniacal thiosulphate leaching. The concentrations of thiosulphate ...

Get Price And Support Online

Cyanidation of a copper-gold ore - ScienceDirect

Conclusions Efficient leaching of a free milling gold ore, with a high copper content, is achieved only under specific conditions using oxygen, lead nitrate and a high concentration of free cyanide. The kinetics of formation of soluble sulphides cannot be used as a direct indication of the length of the pre-leaching required. The addition of lead nitrate results in a higher gold recovery ...

Get Price And Support Online

The effects of dissolved oxygen and cyanide dosage …

The plant processes a blend ratio of up to 1:1 of underground sulphide ore and open pit ore at a rate of 115 tph. The gravity circuit recovers the fine free gold (P 80 ≈75 μm), 10–20% of the total amount of gold inputted into the plant, to produce a gravity concentrate with a fine gold purity of between 75% and 80%.Fig. 1 illustrates the leaching and adsorption circuit schematically ...

Get Price And Support Online

Gold cyanidation - Wikipedia

Gold cyanidation (also known as the cyanide process or the MacArthur-Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex.It is the most commonly used leaching process for gold extraction.. Production of reagents for mineral processing to recover gold, copper, zinc and silver represents ...

Get Price And Support Online

Gold extraction - Wikipedia

Gold extraction refers to the processes required to extract gold from its ores.This may require a combination of comminution, mineral processing, hydrometallurgical, and pyrometallurgical processes to be performed on the ore.. Gold mining from alluvium ores was once achieved by techniques associated with placer mining such as simple gold panning and sluicing, resulting in direct recovery of ...

Get Price And Support Online

Cyanide leaching of gold in solutions containing …

Due to poor cyanide selectivity for gold over the enclosing sulfide mineral matrix, such parasitic reactions inflict utility extra costs and profit losses resulting from high levels of cyanide ...

Get Price And Support Online

The leaching and adsorption behaviour of gold ores

dissociation of cyanide from copper-cyanide complexes can also be used to leach gold from a variety of oxide and sulphide ores. The copper cyanide's fourth ligand readily dissociates at low cyanide concentrations for use in gold leaching. The extent of preg-robbing onto mineral surfaces was also shown to be related to the metal-cyanide complexes in solution, with these complexes serving to ...

Get Price And Support Online

Treatment of copper-rich gold ore by cyanide …

Therefore, ammoniacal cyanide leaching of a copper sulphide-rich, high grade gold ore was investigated using Box-Behnken experimental design to demonstrate the significance of main and interaction effects of concentrations of NH 3 , NaCN and Pb(NO 3 ) 2 on the extraction of gold and copper, selectivity and cyanide consumption. The addition of Pb(NO 3 ) 2 into ammoniacal cyanide …

Get Price And Support Online

Gold cyanidation - Wikipedia

Gold cyanidation (also known as the cyanide process or the MacArthur-Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex.It is the most commonly used leaching process for gold extraction.. Production of reagents for mineral processing to recover gold, copper, zinc and silver represents ...

Get Price And Support Online

(PDF) Treatment of a Copper-Rich Gold Ore by …

Cyanide leaching of the ore resulted in a gold extraction of only 22% while gold extractions as high as ~62% were achieved by ammoniacal thiosulphate leaching. The concentrations of thiosulphate ...

Get Price And Support Online

(PDF) Reactions of gold and sulfide minerals in …

As for the high sulphide ore, cyanidation had to be conducted at 560 ppm NaCN to recover 88.4% Au with a cyanide consumption of 0.80 kg/t. An increase in the amount of lime enhanced oxidation of ...

Get Price And Support Online

Cyanidation of a copper-gold ore - ScienceDirect

Conclusions Efficient leaching of a free milling gold ore, with a high copper content, is achieved only under specific conditions using oxygen, lead nitrate and a high concentration of free cyanide. The kinetics of formation of soluble sulphides cannot be used as a direct indication of the length of the pre-leaching required. The addition of lead nitrate results in a higher gold recovery ...

Get Price And Support Online

(PDF) Cyanidation of a pyrrhotite-bearing gold ore

As for the high sulphide ore, cyanidation had to be conducted at 560 ppm NaCN to recover 88.4% Au with a cyanide consumption of 0.80 kg/t. An increase in the amount of lime enhanced oxidation of ...

Get Price And Support Online

The effects of dissolved oxygen and cyanide dosage …

Oxygen injection, instead of air, gives a high concentration of O 2 and hence high overall gold extraction. Clearly the high concentrations of oxygen and cyanide improve initial gold leaching kinetics and thus reduce the residence time and increase throughput; but high cyanide concentrations also increase cyanide consumption. The reported experimental optimum ratio of [CN

Get Price And Support Online

Sulfide Ores - an overview | ScienceDirect Topics

Sulfide Ores. Sulphide ores were mostly created by (i) the intrusion of molten magma from the mantle into the crust of the earth and (ii) the formation of localized metal-rich sulphide ore bodies by sequential solidification and/or hydrothermal leaching and precipitation. From: Extractive Metallurgy of Nickel, Cobalt and Platinum Group Metals, 2011

Get Price And Support Online

The effects of dissolved oxygen and cyanide …

The plant processes a blend ratio of up to 1:1 of underground sulphide ore and open pit ore at a rate of 115 tph. The gravity circuit recovers the fine free gold (P 80 ≈75 μm), 10–20% of the total amount of gold inputted into the plant, to produce a gravity concentrate with a fine gold purity of between 75% and 80%.Fig. 1 illustrates the leaching and adsorption circuit schematically ...

Get Price And Support Online

(PDF) Leaching of gold ores with high cyanicides: a ...

Processing of gold ores with high sulfide minerals is problematic as they consume cyanide and reduce gold leaching. Optimization of gold leaching and cyanide consumption requires a methodology to ...

Get Price And Support Online

Treatment of copper-rich gold ore by cyanide leaching ...

ammonia pretreatment and ammoniacal cyanide leaching A. D. BAS, E. KOC, E. Y. YAZICI, H. DEVECI Hydromet-B&PM Group, Division of Mineral & Coal Processing, Department of Mining Engineering, Karadeniz Technical University, Trabzon 61080, Turkey Received 28 March 2014; accepted 1 September 2014 Abstract: The treatment of a copper sulphide-bearing gold ore by direct cyanide …

Get Price And Support Online

Cyanidation of a copper-gold ore - ScienceDirect

Conclusions Efficient leaching of a free milling gold ore, with a high copper content, is achieved only under specific conditions using oxygen, lead nitrate and a high concentration of free cyanide. The kinetics of formation of soluble sulphides cannot be used as a direct indication of the length of the pre-leaching required. The addition of lead nitrate results in a higher gold recovery ...

Get Price And Support Online

Gold processing - Mining and concentrating | …

Gold processing - Gold processing - Mining and concentrating: The nature of the ore deposit determines the mining and mineral processing techniques applied. Oxide ore deposits are frequently of such low grade (e.g., 3 to 10 parts per million) that extensive mineral processing cannot economically be justified. In this case they are merely shattered by explosives and then piled into heaps for ...

Get Price And Support Online

Refractory Gold | Mining | SGS

Gold in sulfide minerals could be liberated by oxidization using techniques such as roasting, high temperature pressure leaching or bacterial leaching. Also, grinding the ore to an extremely fine particle size can liberate gold encapulsated in sulfides. SGS has very extensive experience with all the unit operations involved in the processing of refractory gold ores, and in selecting the ...

Get Price And Support Online

Thiourea leaching of a copper-gold ore using …

Thiourea was used to leach gold from ore containing 0.4% Cu and 5.6 g/t Au. The parameters studied were acid pretreatment, leaching time, pH, thiourea concentration and the oxidizing agents used. Gold extraction was 89% and thiourea consumption was 3.9 kg/t. No acid consumption was observed during leaching at pH 3. Pretreatment by acid washing is recommended for improved gold leaching and ...

Get Price And Support Online

Effect of oxygen and lead nitrate on the …

At high cyanide concentration, the rate of dissolution depends only on the oxygen concentration according to: (3) rate = 2 AD02 8-1 102 1 (4) Figure 3 illustrates the effect of oxygen and lead nitrate separately. The addition of 100 g/t lead nitrate yielded the best gold recovery (95.9%) and the lowest cyanide consumption (0.59 kg/t). The increase of lead nitrate addition to 200 g/t and 400 g ...

Get Price And Support Online

FLOWSHEET DEVELOPMENT FOR GOLD OREBODIES

leaching with cyanide. Gold recovery is usually around 80%, but can be as low as 60%. Recoveries can be improved to 95-99% by grinding to fairly fine particle size, gravity separation, cyanidation and flotation, all of which increase capital and operating costs. In some cases, oxidation of sulphide minerals is needed to liberate gold that is occluded within the sulphide matrix. Sulphides can ...

Get Price And Support Online

INFLUENCE OF PRE-AERATION ON CYANIDE LEACHING OF A …

advantage at high cyanide concentrations (Weichselbaum et al., 1989). The present research work aims at evaluating the leaching behaviour of non- refractory sulphide gold-silver ore. First, the characterization of the ore sample was initially accomplished by mineralogical analysis. Then, fundamental industrial cyanidation parameters such as leaching duration, cyanide concentration, …

Get Price And Support Online