Gold Extraction

Cyanide Destruction Hypochlorite / Chlorine

In the Cyanide Destruction by Hypochlorite reaction, the pH has a strong inverse effect on the ORP. Thus, wastewater treatment facilities must closely control the pH to achieve consistent ORP control, especially if they use hypochlorite as the oxidizing agent. Adding hypochlorite raises the pH, which, if unchecked, lowers the ORP. calling for additional hypochlorite. Controlling the pH at a setting above the pH level where hypochlorite has an influence and separating the ORP…

Alkaline Chlorine-Hypochlorite Oxidation: Chlorine was used for cyanide destruction in the early

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By | 2017-03-19T08:37:04+00:00 March 13th, 2017|Categories: Cyanide Leaching, Reagents and Chemicals|Comments Off on Cyanide Destruction Hypochlorite / Chlorine

De-Silverizing Bullion

The de-silverizing of base bullion is carried out in accordance with the principles of the well-known Parkes process.

The base bullion produced by the blast furnace department carries (apart from silver values) impurities, the chief of which are copper, antimony, and arsenic.

In order to more clearly indicate the grade of the base bullion, the following analysis, representative of a half-year’s production of base bullion, is submitted:De Silverizing Bullion

Ag………………………………………………..68.6 oz. Au………………………………………………0.096

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By | 2017-03-17T19:08:11+00:00 December 22nd, 2016|Categories: Gold Refining, Laboratory Procedures|Tags: |Comments Off on De-Silverizing Bullion

Carlin Style Mineralisation Deposit Examples


goldstrike deposit Carlin Style Mineralisation Deposit Examples at Goldstrike

This section on Carlin Style Mineralisation Deposit Examples will give you a quick run through of a couple of actual Carlin deposits to give an idea of their characteristics; we will begin with Barrick’s goldstrike deposit, it’s in the north of the Carlin trend. Gold strike is the mother and father of Carlin deposits and is responsible for Barrick being the biggest gold producer in the world today. As you can see the geology exhibits

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By | 2017-03-17T19:12:19+00:00 November 24th, 2016|Categories: Geology, Gold Extraction|0 Comments

Fire Assay Procedure

Fire assaying has been practiced since ancient times and has proven to be very reliable in the determination of precious metal. References to fire assaying are found in the old testament of the Bible and artefacts in past civilizations’ ruins. Assaying began to appear in French and English literature in the 12th century and from there spread to the rest of Europe shortly after. The substances that can be fire assayed can be ores, metallic solutions and any material that are thought to be containing gold and silver. It uses scientific methodology and it is branch of analytical

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By | 2017-03-22T10:13:44+00:00 November 23rd, 2016|Categories: Gold Extraction, Laboratory Procedures|Tags: |Comments Off on Fire Assay Procedure

Mesothermal and Greenstone Gold Deposits AKA Orogenic Geology Formation

online-geology-courseMesothermal gold deposits form half way up through the rise of the melt from the deep crust to the surface usually at a depth of less than 10 km but greater than 1 km. temperatures at these depths are generally somewhere between 450 degrees and 250 degrees Celsius. The term mesothermal veins is really a sack term, referring simply to the depth formation.  It pays little attention to the origin of mineralizing fluids. This group of deposits forms throughout the earth’s long history all the way from the earliest Archean, say more than 3.4 billion years ago right up until today.

As I mention

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By | 2017-03-17T19:12:24+00:00 November 23rd, 2016|Categories: Geology, Gold Extraction|0 Comments

Gold Bullion Assay Procedure

The procedure for assay of gold bullion, as described has for its sole object the estimation of the percentage of gold present in the alloy, all other constituents being disregarded. In the first instance, the simple case of the assay of gold alloys containing appreciable quantities of only copper and silver will be dealt with. Refined gold ingots and the alloys used for coinage, and for almost all jewellery, come under this head. The effect of large quantities of other impurities and the precautions thereby rendered necessary will be discussed later.

The method universally employed is that

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By | 2017-03-17T19:12:33+00:00 November 21st, 2016|Categories: Gold Extraction, Laboratory Procedures|Tags: |Comments Off on Gold Bullion Assay Procedure

How to Make Gold

The purest gold obtainable is required for use as standards or check pieces in the assay of gold bullion. The following method of preparing it is now in use at the Mint. Gold assay cornets from the purest gold which can be obtained are dissolved in nitrohydrochloric acid, and the excess of nitric acid expelled by evaporation with additional hydrochloric acid on a water bath. The blackish-red fused product, smelling of chlorine and consisting chiefly of AuCl3. HCl, or HAuCl4 (chlor-auric acid), is then poured in a thin stream into a large glass vessel full of distilled water, and a solution of

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By | 2017-03-17T19:12:36+00:00 November 21st, 2016|Categories: Gold Refining, Laboratory Procedures|Tags: |Comments Off on How to Make Gold