A process for the extraction of gold from a gold-bearing ore or concentrate, comprising the steps of leaching the gold-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of at least 90°C and an Eh of at least 900 mV. After a liquid/solids separation step, the solution obtained is subjected to an organic solvent ...
PDF | In this research, oxidation of sulfide minerals and leaching of gold from a gold bearing sulfide concentrate using chloride hypochlorite solution was investigated. The effects of calcium ...
permanganate, hypochlorite) has to be used to obtain practical rates of reaction. ... processes, gold can be recovered from the leach residue, generally using cyanidation techniques; depending on the copper leaching conditions, cyanide consumption can be prohibitively high
This literature review provides an update of ammoniacal thiosulfate as a potential lixiviant of gold, the history of thiosulfate leaching and recent progress on thiosulfate leaching of gold, as well as the production, oxidation, and stabilization of thiosulfate. The leaching results of different types of gold
Oct 24, 2013· As calcium hypochlorite will make a solution with a pH 0f about 10.5 when dissolved in water, it is necessary to lower the pH to convert the hypochlorite ion into the oxidizer hypochlorous acid. However, no information is available to show this was done or what pH the solution would have to be lowered to in order to leach gold and only gold.
Apr 24, 2017· Gold is an almost non-reactive metal, but halogens — chlorine, bromine, fluorine and iodine — can dissolve it. Chlorine is the cheapest and lightest product that can achieve this. Bleach is the chemical compound sodium hypochlorite. When combined with hydrochloric acid, the mixture produces chlorine that dissolves gold from gold ore.
An oxide gold ore was subjected to chloride/hypochlorite leaching at room temperature. The effects of three factors, including Ca(OCl)2 vs. NaOCl, OCl− concentration, and HCl concentration on ...
Apr 25, 2017· Gold can be leached from stone through alkaline or acidic-based products, including halogens, such as chlorine, iodine and bromine. Halogens are reactive, non-metal elements with seven electrons in their outer shell which allow them to easily combine with other elements. The use of chlorine is both the cheapest and ...
Dec 17, 2013· bleach, vinegar and salt dissolve gold; User Info Username: Password: Welcome ... I wish I could post the photos of the tabletop leaching unit I built. It would help to explain things. ... will vary in strength and pH. The same is true of bleach. Clorox bleach has a pH of roughly 12.2, while mixing calcium hypochlorite powder with water will ...
Feb 26, 2018· A good starting recipe for neutral pH leaching is water with 20% salt (supermarket, non-iodised) with 1% calcium hypochlorite, add HCl to pH 7. If you do not have anything present in the leach which will consume high levels of hypochlorite, such as sulfides, then any gold in solution will stay in solution almost indefinitely.
hypochlorite leaching of gold ore 6821 Advances in Gold and Silver Processing. HYPOCHLORITE LEACHING OF GOLD ORE W.T.Yen, R.A.Pindred and M.P.Lam Mining Engineering, Queen's University Kingston, Ontario, Canada K7L 3N6 ABSTRACT Cyanide is a conventional lixiviant for gold extraction but its' toxicity is a major concern for the environmentalist There are
4. HALIDE LEACHING Chlorine, bromine and iodine are well-known lixiviants for leaching gold, as recently reviewed by Tran et al. (2001). Chlorination was applied extensively in the late 19th century before the introduction of the cyanidation process. Bromine/bromide for leaching gold from ores was reported as early as 1846.
Sodium hypochlorite can be used as an alternative for sodium bromate in bromate hydrolysis. Leaching ore . Sodium hypochlorite together with hydrochloric acid has been used for gold ore leaching. For example in the iGoli method. Leaching gold from electronics . I haven't done any research if this is a workable leach of plated objects yet.
Jun 01, 2013· Read "Chloride–hypochlorite leaching of gold from a mechanically activated refractory sulfide concentrate, Hydrometallurgy" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
The hypochlorite to leach 1 mole of chalcopyrite with 1 g of consumption ratio was as high as 57.6 with 1 g of the mineral was 45.88 and that with 10 g was 4.59. These the mineral and decreased to 12.9 with 10 g of the values correspond to 5.4 and 0.54 times as much as the mineral. ... Leaching of an oxide gold ore with chloride/hypochlorite ...
An oxide gold ore was subjected to chloride/hypochlorite leaching at room temperature. The effects of three factors, including Ca(OCl) 2 vs. NaOCl, OCl − concentration, and HCl concentration on gold leaching performance were investigated. Due to formation of CaOCl + complex in solution and hence less reactivity, calcium hypochlorite produces a sluggish gold leaching kinetics, taking twice ...
Go down somewhere and buy a bag of dry "swimming pool" Chlorine (Calcium Hypochlorite). Measure out some. For example, 10 tablespoons Put it in a container that you can see through, and add about 5 tablespoons of baking soda (Sodium Bicarbonate, NaH2CO3).
Apr 30, 2018· Using gold concentrate provided by its partner in Chile, DST was able to evaluate the effectiveness of its technology in a live setting. The company requested proposals from a number of suppliers for onsite sodium hypochlorite generation (OSHG) systems to produce the hypochlorite that is critical to the process.
An oxide gold ore from Placer, Surigao Del Norte was subjected to chloride-hypochlorite and cyanide leaching at room temperature at 3 different hours – 4 hours, 12 hours and 24 hours. This project characterized the ore used and assessed the effects
Gold 3 % HC1 and 10 g/L NaCl were added in a extraction was increased with increasing HYPOCHLORITE LEACHING OF GOLD ORE. hydrochloric acid concentration 82 % of the Extracting gold from an ore required gold was extracted with 3 % HCl.
Chloride–hypochlorite oxidation and leaching of refractory sulfide gold concentrate 63 Fig. 1. The Pourbaix diagram of Fe–S at [Fe] –= 10 4 M, [S] = 10– M and 25 C (the chlorine species regions are also marked) (Marsden and House, 2005) Fig. 2.
When the sodium hypochlorite pretreatment was followed by cyanidation, greater than 85 per cent gold extractions were achieved. Gold extraction was shown to be dependent on sodium hypochlorite concentration, heap leach flowrate, temperature and leaching time or bed volumes.
heap-leach technology has developed significantly over the past 15 years. Use of cyanide heap leaching has steadily increased due to its low cost for recovering gold and silver. Northern Nevada was the site of the first small-scale commercial cyanide heap-leach operation by the Carlin Gold Mining Company in the late 1960s (Hiskey, 1985).
In a leaching solution containing 1 g/L NaCl, 1 % HCl and 2 % NaOCl, nearly 90 % of the gold was extracted in only 30 minutes. Additions of hydrochloric acid will reduce the sodium hypochlorite requirement A leach solution containing 1 g/L NaCl, 5 % HCl and 1 % NaOCl achieved nearly the same per cent gold extraction under the same conditions.
Feb 24, 2017· Hypochlorous acid is a weak acid which is typically formed when chlorine dissolves in water. It is referred to by several other names, such as: chloric acid, chloranol, hydrogen hypochlorite and ...
Sep 13, 2013· You will quickly see why this chlorine leaching process, which was the standard recovery method for gold in hard rock mining in the late 1800's, was dropped like a bad habit when cyanide leaching came on the scene about 1900.
In this research, NaCl — NaClO solution is used to leaching gold from a refractory gold concentrate, and the influence of NaCl and NaClO concentration, reaction time to the leaching rate were investigated in this experiment. The raw materials and the leaching residue were characterized by a series of analysis methods such as XRD, XRF, SEM and ...
The leaching of gold using less corrosive fluids without significant losses in the dissolution rate of the metal. 19 C.p. f-crystals, 6 tables, 4 Il. The invention relates to the field of dissolution of metallic gold leaching solution, especially for the hydrometallurgical recovery of gold from ore.
HYPOCHLORITE LEACHING OF GOLD ORE 69 Overall reaction of equations (I), (2) and (3) can be summarized as follows: It is obvious that both hydrochloric acid and sodium chloride have affected the gold dissolution in hypochlorite solution. RESULTS AND DISCUSSION Gold Precipitate The dissolution of gold in dilute hypochlorite solution is very slow.
lurgical gold extraction routes utilize a leaching step to produce a gold-bearing solution as an intermediate product while the recycling of secondary gold from electronic and precious metal scrap is based on the selective and fast dissolu-tion of the precious metal. Therefore, A Method for Leaching or Dissolving Gold from Ores or Precious