Use of chars in gold recovery began in the late 1800s. The
1930s and 1940s were periods of experimentation in North America, resulting in
new or improved approaches for carbon use, both in pulverized and granular
form. 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, 6×12 or 6×16 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 activatedcarbon 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:
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
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
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