The Chemistry of Gold Extraction by John Marsden

     In the gold mining mineral processing separation process valuable minerals from impurities is very important to do, which is mechanically to produce products that are rich in valuable minerals. Currently a lot of various processing techniques used to obtain the maximum results in the gold mining industry is growing very rapidly at this time. I saw some references a book about The Chemistry of Gold Extraction that maybe you can use in the learning process in the gold mining industry

    This technical reference provides the broad base of knowledge necessary for those working in gold extraction and gold processing industries. The Chemistry of Gold Extraction is an extensively revised and comprehensively updated edition of the well-known reference first published in 1992. It provides the broad base of knowledge that is now required by all those working in the gold extraction and gold processing industries. The book The Chemistry of Gold Extraction by  John Marsden bridges the gap between research and industry by emphasizing the practical applications of chemical principles and techniques.

10 world gold mining industries biggest 2012

          Based on data from the U.S. Geological Society, estimated gold ore reserves that have not been mined and available on the planet about 51,000 tons, making gold business is getting bigger. As quoted from the latest data issued by Thompson Reuters and the Metals Economics Group reported by CNBC, Monday (19/03/2012), here are 10 of the world's biggest gold mine owned by public companies. Mines is considered as the greatest because it comes from one mine alone, not the production of several mines which are then combined by a single company.

 
It's her 10 largest gold mine in the world, among others :

1. Grasberg Mine

     Grasberg is a world-class mining complex in Indonesia, where Freeport-McMoRan Copper & Gold is engaged in exploration and development, mining and milling of ore containing copper, gold and silver. The Grasberg mine is located at Tembagapura in Irian Jaya, which is Indonesia's easternmost province, on the western half of the island of New Guinea. The mine is about 60 miles north of Timika, a town of about 100,000 people. There are about two million people living in this region. The Lorentz National Park, which has several glaciers on its peaks, lies to the east of the mine. The mine is 96 km north of the southwest coast of Indonesia at elevations of 2,500 to 4,200 m above sea level. 

•  Location: Papua, Indonesia
• Gold production in 2011: 1.444.000 0z
• The area: 527,400 acres
• Miners: Freeport-McMoRan Copper & Gold
• Type of mine: open mine and underground

Extracting Gold By Carbon In Pulp with Activated Carbon

       Carbon In Pulp is the absorption of compounds into carbon Dicyano Aurrat. In the process extracting gold by carbon in pulp with activated carbon occurs after the leaching of mineral ore slurry in a tank. And during the washing, the carbon-in-leach and adsorption occur simultaneously. In both processes mineral ore leaching slurry will be transferred from one tank into the recovery tank of carbon using a pumping machine.  

This is generally accomplished by passing the slurry through a series of adsorption vessels coupled with the periodic transfer of carbon, usually associated with pulp, and in the opposite direction. Column tanks are often used consists of a large carbon column (diameter 5 to 8 feet) and 15 to 20 feet in height, and filled with activated carbon. Minimum load of carbon rule of thumb is one pound of activated carbon per 0.1 ounces of gold are present in solution, and usually it's a few pounds per 1 / 10 ounce

         Two main methods Carbon In Pulp (CIP) and Carbon Columns may consist of the most widely used technique for extracting gold today. Both methods use a large tank in the column parallel step where gold is dissolved in the slurry (pulp) through a chemical process and combine agitation, oxygen and cyanide. In CIP, the carbon is mixed with a solution of cyanide leach and ore agitated in the Tank leaching, and the adsorption process will separate the gold. 

 This will bring together between carbon and gold cyanide solution which is attached to the carbon. Granular carbon is often hard to use in a variety of sizes between 10-16 mesh. Carbon is then filtered by using the screening, on-screen screening of carbon will settle and the liquid is finely ground ore (-100 mesh) will be screened out through the screen into the tank.CIP treatment system can be described simply as a picture diagram below:

Diagram of the processing of gold with carbon in pulp

Process Electrowinning For Gold Mining

Electrowinning is an electrochemical process used to reduce the metal cations to the cathode surface of an aqueous solution derived from the chemical leaching proces. Electrowinning or often referred to as electroextraction is the electrodeposition of metals from ore minerals that have dissolved into the liquid and will be processed using Electrorefining to remove impurities from the metal. Electrowinning an electrolytic process that is very old in the mining industry. 

The English chemist Humphry Davy first obtained sodium metal in the form of the element in 1807 by electrolysis of molten sodium hydroxide. And then in 1847 Maximilian, Duke of Leuchtenberg first to show an experiment about Electrorefining copper. Then James Elkington patented a commercial process in 1865 and successfully opened the first factory in Pembrey, Wales in 1870. The first commercial plant in the United States is Balbach and Sons Refining and smelting Company in Newark, New Jersey in 1883

     Electrowinning is applied to a variety of chemical solutions that are found in large mining industry. This process involves the use of alkaline cyanide solution as an electrolyte in a cell as the anode and cathode, among others, can use:

ANODE      ( - )	GOLD 99,99 %	STAINLESS STEEL 316	DICOATING MERKURY COPPER	IRON
CATHODE  ( + )	SILVER  99,99	STAINLESS STEEL 316	TIN	ALUMINUM

Cell reaction that occurs is: Merkury dicoating Copper, Lead, Iron, Aluminum
Anode: 2OH-→ O2 + H2O + 2e-
Cathode: 2Au (CN) 2 - + 2e-→ 2Au + 4CN-
Overall: 2Au (CN) 2 - + 2OH-→ 2Au + O2 + H2O + 4CN-

     

How to metal gold testing

        The testing process gold from gold bouillon is very necessary, in which the gold content so that the results we obtain can be seen the most of what percentage of karat or purity levels of the value contained in the gold metal.

How to do metal gold testing, In the process of testing the gold, there are several methods that can be used, ranging from gold assay methods in a simple way to use chemical solutions to using digital tools.

Several types of testing processes such as methods Touchstone testing, Acid testing kits, Electronic gold testers.