Cyanide Leaching

Small Gold Leaching Circuit Design

The gold cyanide leaching mill site is centrally located with respect to the mine, water supply and improved highway. This selection reduced both the length of the haulage road from mine to mill and main water supply line to a minimum. The location provided a sloping mill site, adequate tailings disposal area, housing space for … Read more

Electrolytic Oxygen in Cyanide Solutions

There are two conditions generally prevailing upon the earth—those within atmospheric influence, tending towards oxidation, and those away from atmospheric influence, tending towards reduction. Practically all mineral substances from mines of any depth are in a reducing condition. Since the cyanide process, in order to dissolve silver or gold, requires that the prevailing conditions under … Read more

Fine Grinding in Cyanide Plant

This plant, near Marysville, Montana, was planned to treat the ore from the Piegan and Gloster mines, the latter being one of the early and famous producers of the Marysville district. When the mill was closed, treatment consisted of stamp milling, followed by pans and settlers for pan amalgamation. The extraction was evidently poor, because, a … Read more

Silver Flotation Concentrate Leaching and Filtration Circuits

  Producing a Silver Flotation concentrate from this EXAMPLE Argentite (cubic silver sulfide (Ag2S)) Flotation Circuit enters the first of four successive Argentite leach tanks. The purpose of this leach circuit is to dissolve the silver and gold recovered in the Flotation Circuit. A high strength solution of sodium cyanide, air, and lime are added to the … Read more

Dissolve Gold and Silver with Cyanide

The addition of gold or silver to an alkaline sodium cyanide solution will cause the gold and silver to react with the cyanide and dissolve into the solution in a process called cyanidation. This process is more frequently referred to as leaching. As well as reacting with the precious metals, the cyanide will react with … Read more

Why Oxygen is Important in Cyanidation

The Rule and Function of Oxygen in Cyanidation.—Oxygen appears to be an indispensable factor, either directly or indirectly, in the dissolution of gold and silver by cyanide solutions, except in the case of the haloid compounds of silver. Whether the action of oxygen in the dissolution of gold be a direct one, as illustrated by the … Read more

Sodium Cyanide Safety – Poisoning – HCN Vapor

Almost all solutions in the plant contain cyanide, and in the absence of any other information it should be assumed that all solutions contain cyanide. Because of the toxicity of sodium cyanide, it is important that all persons coming in contact with it be completely familiar with and observe the established safety practices. Sodium cyanide … Read more

Diagnostic Gold Leach Testing

A Gold Diagnostic Leach Test is used to evaluate the distribution or deportment of gold in various minerals is determined by a series of selective leaches, usually by increasingly stronger oxidative acid leaches. Between each stage, cyanide leaching is used to extract the released gold. In this study a total of ten analysis stages were carried out for the … Read more

Cyanide Bottle Roll Leach Test – Leaching Procedures

List Equipment Required to Perform of a Standard Bottle Leach Test Winchester bottles, with tops Plastic tape to seal tops of bottles Flexible air lines for possible aeration requirements Magnetic or mechanical stirrer for agitation Timer, pH meter, thermometer and weighing device Leachants, i.e. acid, alkaline or neutral solutions, or specific solutions Filter: vacuum or … Read more

Sulphide Leaching

Methods of leaching sulphide ores can be: in absence of oxidizing agents in presence of oxidizing agents Bacterial leaching Absence of oxidizing agents Acid leaching: Dilute acids dissolve some metal sulphides with liberation of H2S, e.g. ZnS + 2H+ ^ Zn2+ + H2S Three types of sulphides can be encountered. Completely soluble sulphides: Zns, CoS, … Read more