Carbon Regeneration Process
The carbon regeneration circuit is a process designed to restore the activated carbons ability to recover precious metals from Leached slurries.
The objective of thermal regeneration is to remove organic species that have accumulated during the adsorption process thus recovering the original porous structure and activity with as little damage as possible to the activated carbon itself.
The generally accepted conditions for thermal regeneration are in the temperature range of 650 - 750°C for a period of 10 to 30 minutes in a non oxidising atmosphere. Steam is the most economical inert atmosphere to blanket the carbon and prevent the oxidation of the carbon at higher temperatures. This inert atmosphere is created in the first or drying stage of regeneration when the moisture in the carbon is driven out of the porous structure of the carbon as steam.
Kemix developed an indirectly fired carbon regeneration rotary kiln which enhances the complete thermal regeneration or reactivation and offers above average service life.
All Kemix kilns are custom designed to meet application requirements with specific regard to mode of firing, voltage, frequency and throughput. Selection of the method of firing is location specific and options include electrical elements, light oil, heavy oil or gas burners.
The kiln components comprise a base frame, heating cabinet, heat source, dewatering feed screw arrangement complete with variable throughput drive, discharge hopper, main and back-up drive units, retort tube, support rollers and a fully integrated control panel.
The retort tube is manufactured from specialised alloys capable of withstanding the high temperatures associated with thermal regeneration. The welding process and method of construction with extremely tight tolerances on both straightness and concentricity on the retort tube ensures longer service life.
The design of the retort tube with consideration to peripheral speed ensures proper carbon bed turnover enhancing the complete thermal regeneration.
All Kemix kilns have an automatic start up and shut down sequence which reduces operator input. Speed variation of the screw feeder facilitates greater flexibility and complete plant integration.