De-Silverizing Bullion

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 […]

How to Setup a Gold Sluice

So this is a typical sluice, they vary slightly in design but overall the same basic principles are at play. The point is gold is heavy, we’ve said that before but we can’t say it enough, gold is really, really, really heavy. So whenever it has a chance to, gold is going to drop faster […]

Sluicing for Gold – Set up & Operation

And my pan now, what I’m going to do is, I’m going you down to that stinking river I was telling you about, it’s got a little bit of gold in there, don’t ask me where it’s at, because I’m not going to tell you. I’m going to show you the proper way to set […]

Carlin Style Mineralisation Deposit Examples

mineralization_carlin

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 […]

Fire Assay Procedure

fire assay equipment (17)

Fire assaying has been practiced since ancient times and has proven to be very reliable in the determination of precious metals. References to fire assaying are found in the old testament of the Bible and artifacts in past civilizations’ ruins. Assaying began to appear in French and English literature in the 12th century and from […]

Gold Deposits AKA Orogenic Geology Formation

magnetic_map

Mesothermal 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 […]

Gold Bullion Assay Procedure

Amount of Gold

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 […]

How to Make Gold

Glass Tube

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 […]

Fire Assaying Gold Alloys

fire-assay-gold-alloys

It is often impracticable to apply the ordinary parting assay to the examination of low-standard alloys of gold with other metals. These are then tested by various other methods, of which a summary is given below, the alloys being grouped in four series for convenience: A. Alloys requiring scorification. B. Amalgams. C. Alloys containing members […]