Carbon-in-pulp

Gold recovery Operation of carbon in leach, carbon in pulp, and heap leach circuits Recovery of gold from tailings dissolved in sodium cyanide... 

Figure 5.41 Standard cyanide process Figure 5.42 Carbon-in-pulp process,...

CIP (1) [Carbon In Pulp] A general name for hydrometallurgical extraction processes that use activated carbon in slurries of ground ores. One such process is used for extracting gold from cyanide leach liquors. First operated on a large scale at the Homestake lead mine in South Dakota in 1974. See also RIP. 

The ability of activated carbon to absorb gold and silver from solution has been commercially exploited since the beginning of the 1970s [46,47] and the techniques used can be classified in (i) carbon in pulp (CIP) (ii) carbon in leach (CIL) and (iii) carbon in column (CIC) [46,47]. 

T0465 Klohn-Crippen Consultants, Ltd., ChemTech Soil Treatment Process T0469 Kvaemer Metals, Resin-in-Pulp/Carbon-in-Pulp... 

T0469 Kvaerner Metals, Resin-in-Pulp/Carbon-in-Pulp... 

The Resin-in-Pulp (RIP) and Carbon-in-Pulp (CIP) processes were developed for the ex situ treatment of soils, sediments, dredgings, and soUd residues that are contaminated with organic... 

S. M. Bradshaw, E. J. VanWyk and J. B. deSwardt, Preliminary economic assessment of microwave regeneration of activated carbon for the carbon in pulp process. Journal of Microwave Power and Electromagnetic Energy, 32, 131-144 (1997). 

The rewards for being able to understand and control the process of carbonization to give a particular pore structure are potentially enormous, with applications which include catalysis, carbon-in-pulp metal adsorption and separation processing, molecular sieves and bioethical applications. 

FIGURE 9,2-3 Carbon-in-pulp process For recovery or gold at Homestake Mining Company. (Reproduced from McQuislon and Shoemaker,")... 

Hydrogen cyanide Fmnigation, carbon-in-pulp gold plants... 

Some of the causes above suggest the controls to be used, but in addition there is a need to ensure adequate natural or mechanical ventilation, and if the emission is particularly hazardous, automatic detection systems which trigger an alarm. This is used in chlorine production plants, for example. pH control ensures fugitive emissions of hydrogen cyanide in carbon in pulp gold plants are minimized. 

Mixers are used in the gold leaching processes. Special tanks for carbon in pulp (CIP) or carbon in leach (CIL) are built with mixers. The largest diameter of these tanks is approximately 17 m (56 ft). 

A special type of process used to extract gold is based on cyanide leaching. Leached gold is then separated by adsorption, the property of certain materials such as carbon to fix gold on their surface. Carbon spheres are used as an adsorption material. This process is done in special carbon in leach or carbon in pulp circuits with mixing tanks. The transfer of these solutions requires recessed or vortex impellers that can pump without breaking the carbon lumps. The impeller is recessed out of the flow as shown in Figure 8-41. 

The alloy shown in Table 10 7 is sometimes called 15/3 Chrome/Moly Iron, or 16% chrome. It is a martensitic white iron of moderate erosion resistance. It is used for the casting of pumps for a number of applications such as carbon in pulp circuits, coal transfer pumps, sewage treatment, and some newspaper recycling pumps. 

The recovery of gold by the carbon-in-pulp (CIP) method utilizes the strong adsorption of [Au(CN)2 ] onto the surface of activated carbon in alkaline (pH >11) regimes (Adams Fleming 1989 Adams 1993). The same mechanisms can be utilized to adsorb contaminants from a water column. At the present time only experimental studies have been carried out (Hegenberger et al. 1987 McEnamey 1988 van der Merwe van Deventer 1988). The technique has also been applied to volatile and dense organic solvents (Pankow Cherry 1996). 

---