Boyce have learned to control adsorption capacity on gold recovery

Online, May 21, 2010 (Newswire.com) - A major breakthrough was reported by J.B.Zadra of the US Bureau of Mines in 1950. He demonstrated that adsorbed gold and silver values could be desorbed from the carbon by low cost procedures, thereby allowing the carbon to be recovered and recycled to the adsorption circuit.
The carbon-in-pulp (CIP) process for gold recovery has now been in use for more than a decade. Based on this experience, carbon companies and metallurgists are addressing several of the early concepts about the selection and performance of the activated carbon, particularly as they relate to soluble gold loss and/or subsequent efforts to being soluble losses into line. Carbons used in South Africa and North America for gold recoveries are almost exclusively coconut shell-based granular types which are also very popular in Australia. Typically, 6x12 or 6x16 mesh coconut carbons are used in pulp, and 6 x 16 or 12 x 30 mesh are used in columns.
In 1970, the US Bureau of Mines investigated bituminous coal-base carbon for gold adsorption. However it was found that coconut carbons would stand up better in a pulp circuit than other base material carbons. Since coconut carbon was available and worked well, granular carbons from other base materials receives minimal importance.

Selection of activated carbon for gold recovery service includes consideration of:
(a)Presence of other substances that may affect or interfere with loading of carbon (b)
Adsorption capacity(c) Rate of adsorption and desorption (d) Residual gold on stripped carbon.
(e)Resistance to abrasion (f) Reproducibility of test methods (g) Consistency of product for gold recovery service.

Boyce have learned to control adsorption capacity for gold cyanide, providing carbon possessing consistent gold absorption properties. Some users believe that carbons with high adsorption capacity for gold will not strip to low levels. Plant performance is the best proof of how well high capacity/fast loading carbon will strip. Boyce activated carbon is routinely stripped to 20-30 gm/ton in several operating plants. Thus Boyce activated carbon meets all the requirements for gold recovery services.

The product is applied in CIP process and heap leaching by gold extraction and the precious metals extraction, separation of metallurgical industry. It is used the high-quality coconut shell from Hainan as raw material. It is refined by the high temperature steam activation. It has the advantages such as developed pore structure, high specific, surface area, strong adsorption capability, high wear-resistance, and high decolorizing purity, renew ability etc
Boyce would like to prove how to increase your gold yield, and consequently your profits, using a granular activated carbon, or an extruded activated carbon. The granular activated carbon are premium coconut shell-based carbons that are among the best available and have been specially pre-treated to reduce platelet content and initial wear of the carbon, which gives you more carbon for your money. The extruded activated carbon was specifically developed by Boyce to reduce the amount of gold lost during the gold recovery process. It improves plant performance, significantly reducing gold losses to the tailings.
Boyce activated carbon is known for its features of hardness, free of platelets, large pore volume, rapid adsorption and max gold loading, this range exhibits the following advantages: • Low attrition values • Large pores value with selected pore size • Suitable for "carbon in leach"(CIL) and "carbon in pulp" (CIP) process • Available in granular form
Following are the technicalities of this range:
Grade CTC Iodine Adsorption Apparent Density Hardness pH Ash Moisture Mesh Size
BOYCEGAC 60 1150mgm/gm
Min 0.48gm/cc
Min 98% Min 9-11 3%
Max 5 Max 8 x 16
6 x 12
BOYCE GAC 55 1050mgm/gm
Min 0.5gm/cc
Min 99% Min 9-11 3%
Max 5 Max

Boyce superior granular coconut shell based carbon offers:
• Low initial loses due to pre-wear and reduced platelet content
• High gold loading capacity
• High gold loading kinetics, reducing losses by pre-robbers
• Excellent gold release during stripping
• Excellent screen ability, low pegging