As alternatives to cyanide leaching, some noncyanide leaching processes such as those using hypochlorous acid, bromine, thiosulfate, and thiourea have been proposed. However, these new processes also suffer from their own drawbacks as follows. ... Effect of solid/liquid ratio on the adsorption of gold using cotton adsorbent from the leach ...
However, at more acidic pH conditions, hypochlorous acid (HClO) forms, which is a stronger oxidizing agent than ClOe, resulting in faster gold-leaching kinetics (Jeffrey et al., 2001a,b). The form of hypochlorite used appears to have some effect on gold-leaching kinetics.
Direct leaching of ores becomes very expensive using chlorine systems. I have tested leaching of gold in worked out mining areas using thiourea in an acid environment - results, leaching and absorption onto carbon was remarkable. The problem however was the environmental issues associated with thiourea. There is a lot of literature on this.
About Te Kiri Gold. The Science of Hypochlorous Acid. As long ago as 1800, researchers in electricity realised that if you ran an electrical current through a solution of pure salt water and put a porous divider between the two compartments (designated “positive” and “negative”), that you could isolate different solutions in each ...
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several authors have pointed out that less than 60% gold recovery by direct cyanide leaching, after fine grinding of mineral indicates a refractory mineral . The refrac- tory ore must be destroyed or attacked by chemical ... (Cl2(aq)), hypochlorous acid (HOCl) and hypochlorite ions
Leaching of an oxide gold ore with chloride/hypochlorite solutions. Author links open overlay panel Morteza Baghalha. Show more. ... reaching 67% gold extraction in 4 h. It also causes a faster consumption of hypochlorous acid, through catalytic decomposition (by NiO and CuO) and disproportionation. ... For an industrial gold leaching ...
A method for recovering silver, gold, antimony, copper and lead from lead anode slime uses hydrochloric acid to leach out antimony and copper, uses sodium chlorate-hydrochloric acid-sodium chloride to leach out gold and uses ammonia to leach out spongy silver. Its leaching time is short, leaching effect is good, acid consumption is low and cost is low, and its direct-yield rate is up to above ...
Jul 28, 2018· I am contemplating adding cyanuric acid to my hypochlorous acid leach. I have used this leach on my sluice concentrates at ph 5 with addition of non iodized salt with good success. However, the hypochlorite consumption is rather high and the chlorine leaves solution rapidly.
The leach solution is then cooled to precipitate the silver as silver chloride. The solid residue containing the gold is then leached with hypochlorous acid to dissolve the gold, and after separating the solids form the gold-containing hypochlorous acid leach solution, the gold is precipitated by contacting the solution with sulfur dioxide.
Leaching of an oxide gold ore with chloride/hypochlorite solutions. ... It also causes a faster consumption of hypochlorous acid, through catalytic decomposition (by NiO and CuO) and ...
It has been found that more than 90 pct extraction of both chalcopyrite and sphalerite can be achieved in one hour using less than 0.3 molar hypochlorous acid at room temperature. The primary leach products of chalcopyrite and sphalerite were sulfur and sulfate in the mole ratios of 1 …
hypochlorous acid products are produced with electrolysis and are classified among biocidal substances. The technology has demonstrated efficacy and safety for pre-and postprocedure use. The safety of hypochlorous solution use demonstrated to be comparable to that of standard local antiseptics. Small studies demonstrated
In this solution depending on pH, various species of hypochlorite ion (pH > 7.5), hypochlorous acid (3.5 < pH < 7.5) and chlorine gas (pH < 3.5) are produced. Among these species, hypochlorous acid (HOCl) is the most effective oxidant to leach gold as the [AuCl 4] − …
May 29, 2008· This compound becomes hypochlorous acid (HOCl) by hydrolysis: NaOCl + H2O ↔ HOCl + Na+ + OH-Actually the chlorine in the bleach exists as hypochlorous acid. This compound is so oxidative that it has a property of bleaching and sterilization. Gaseous chlorine is generated when hypochlorous acid is mixed with hydrochloric acid.
Feb 01, 2014· Read "Chloride–hypochlorite leaching and hydrochloric acid washing in multi-stages for extraction of gold from a refractory concentrate, Hydrometallurgy" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Leaching of an oxide gold ore with chloride/hypochlorite ... Since the oxidant Cl 2 /HClO is formed insitu upon reaction of Cl − and MnO 2 (Leon and Quispe, 1986), for insitu chlorine/hypochlorous acid formation, MnO 2 have been used in NaCl and H 2 SO 4 solution to leach gold from anode slimes (Hait et al., 2002). Read More
Sep 13, 2013· If you attempt to leach gold with this solution in an open container, you will fail and end up with a solution that has lost its hypochlorous acid (or part of it) to the atmosphere. In the next post, I will explain the complicated mechanical portion of using this leach, although it is nothing that someone handy with tools cannot overcome.
Chlorine bleach is a solution of sodium hypochlorite and water. Chlorine gas is produced when sulfuric acid is mixed with chlorine bleach. This reaction is a function of the change in pH of the solution from alkaline to acidic combined with the strong oxidant properties of hypochlorous acid. Acids and Bases An acid …
Hypochlorous acid (HOCl) is produced by the human body’s immune cells to fight infections. It is effective against a broad range of microorganisms. It is non-toxic, non-irritant and non-corrosive at proper usage concentrations. There are some available commercial products that contain HOCl.
Jun 20, 2018· Description. Field of the Invention  The present invention relates to a method of leaching of metals from sulfide ores and/or concentrates containing such. More particularly, the method for leaching of the present invention utilises a chlorine-based oxidising species in the form of hypochlorous acid.
Jun 01, 2007· Leaching of an oxide gold ore with chloride/hypochlorite solutions Baghalha, Morteza 2007-06-01 00:00:00 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.
gold. Oxidation of iron sulfide and leaching of gold by hypochlorous acid are expressed temperature and stirring speed of 500 rpm, extracted 80% of gold from an oxide tailing using hypoch hypochlorous lorite acid solution at pH range of and in chloride media can Soo Nam et al. ] using sodium hypochlorite
sivation of minerals surfaces (Marsden and House, 2005). In hypochlorous acid solu-tions, gold is also dissolved as the [AuCl 4]¯ complex. Therefore it is possible to oxi-dize sulfides and leach gold simultaneously by this oxidant (Welham and Kelsall, 2000). Leaching of gold with hypochlorous acid follows reaction (1) (Jeffrey et al., 2001):
Apr 25, 2017· How to Leach Gold Ore With Chlorination ... The use of chlorine is both the cheapest and most plentiful method for leaching gold. When you mix sodium chloride and hydrochloric acid together, you produce a form of electrolysis that removes gold from rock and soil.
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
In this research, oxidation of sulfide minerals and leaching of gold from a gold bearing sulfide concentrate using chloride hypochlorite solution was investigated.
Hypochlorous acid is a weak acid found in many cleansers and is also found in some topical treatments for skin conditions such as rashes. It has been shown to kill acne bacteria in the lab, and it may also help the skin heal faster. But is it an effective acne treatment? We dont know yet.
In this solution depending on pH, various species of hypochlorite ion (pH > 7.5), hypochlorous acid (3.5 < pH < 7.5) and chlorine gas (pH < 3.5) are produced. Among these species, hypochlorous acid (HOCl) is the most effective oxidant to leach gold as the [AuCl 4] − complex in chloride media (Jeffrey et al., 2001).
Leaching of Gold. Examples of adequate oxidants for gold in chloride media are nitric acid (aqua regia), chlorine, hypochlorous acid, and hypochlorite acid. Complexation of gold with bromide ions can generate stable Au(I) and Au(III) complexes.