Heap Leaching Silver

Leach Pad Construction: After the site of this Silver Heap Leaching pad was prepared, a pad base consisting of about 15 inches of mill slimes or a fine bentonitic clay from an old nearby tailings pond was laid down. The pad was constructed slightly larger than the dimensions of the heap to go on it; i.e., about … Read more

Laboratory Gold Ore Chlorination Testing Procedure

Experience has shown how difficult it is to obtain information regarding laboratory tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore chosen was … Read more

Gold Leaching of Pyrite Concentrate

The ore consisted of quartz, in which, above the 250-ft. level, the iron-minerals were largely oxidized and some free gold was visible; below that level few traces of oxidation occurred, and pyrite constituted the principal mineralizer in the quartz, together with occasional pockets of galena and a few eccentric specks of covellite. The 20-stamp mill … Read more

Bromine Cyanide Gold Leaching: Cyanogen Bromide

Although the bromo-cyanide or Diehl process for the extraction of gold from its ores is used on several of the Kalgoorlie mines, very little information has been published on the original process, and no details are available from the various mines now using it. The following description of the process as carried on at the … Read more

Effect of Silver on Chlorination & Bromination of Gold

When dry chlorine gas is made to act in the cold upon finely- divided gold, it converts the latter with evolution of heat into auro-auric chloride, Au2Cl4, a hard, dark-red, hygroscopic salt. Moisture splits this salt into aurous and auric chloride, Au2Cl4 = AuCl + AuCl3 ; treatment with water converts it into auric chloride … Read more

Refining Zinc Precipitates: Cyanide Leaching of Gold & Silver Extraction

Attempts to discover, for the cyanide process, a better precipitant than zinc have been unsuccessful. Hydrogen sulphide, sulphurous acid, ferrous sulphate, etc., precipitate gold and silver from cyanide solutions either not all or incompletely. Aluminum has been tried, but it costs too much, and cannot be used in solutions containing lime. Charcoal has been used … Read more

Sulfuric Acid Resistant Alloys

“At-a-glance” corrosion chart for sulfuric acid is based on an extensive survey of construction materials; gives rough indication of suitable alloys. A variety of methods have been proposed many are used for the presentation of corrosion data in concise form. The authors are basically opposed to the presentation of information in simplified chart form if … Read more

Control Corrosion in Copper Recovery Operations: SX-EW Plants

Stainless Steel Offers Many Advantages for containing strongly acidic leaching reactions in copper recovery operations. Hydrometallurgical techniques for copper extraction have been known probably since 1752, but the dissolution of copper by leaching and the recovery from solution by precipitation or electrowinning did not become significant in the US until the mid-1960s. Today, hydrometallurgy accounts … Read more


LIX 64N Reagent is a water insoluble mixture of substituted oximes, which form water insoluble complexes with metallic cations, principally copper. Chemical Reactions LIX 64N Reagent is a hydrogen ion donor, and its chemical reactions when used as a copper extractant may be compared to an ion exchange resin system operating on a hydrogen ion … Read more

SX Solvent Extraction Equipment – Process Function

Mixer Settler The Mixer-Settlers are of the pump-mixer type in which the Mixer Impellers, in addition to mixing the process liquors, also provide the pumping head necessary to transfer them between stages. The variable speed Impellers can be used either with, or without, spoiler blades, the design of which is such that when fitted the … Read more