AARL process as applied at SDGM. • Identify the key elution circuit components. • Demonstrate an understanding of carbon reactivation theory. • Demonstrate an. Request PDF on ResearchGate | Modelling of the AARL elution process | The influence of temperature on the equilibrium adsorption of gold and hydroxide ion . successful methods is the carbon-in-pulp (CIP) process. In CIP processing elution rig was commissioned to simulate industrial Zadra and AARL carbon elution.

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Acid washing is currently being done both in a separate vessel from the stripping column and in the elution vessel.

It is much less expensive to operate and it produces a cleaner stripped carbon. Pregnant solution is pumped from the pregnant solution tank through electrowinning cells where gold is recovered by electrolysis. The mere following of the instructions given in that section will not ensure effective stripping results as there are many extraneous factors which need to be taken into account.

This is achieved at flow rates in the range of 2 bed volumes per hour operating in series flow with electrowinning cells. The condensate is pumped back to the top of the carbon bed and is sprayed on the carbon. Additional water is injected into this line via valve AV and the carbon is carried long the line to the dewatering screen above the regeneration kiln feed hopper.

Carbon Stripping – Denver Mineral Engineers

Each column was mm diameter by 10 metres high which for 24 tonnes per day of carbon per column was equivalent to the pilot plant operating at 1 tonne per day. The efficiency of the electrowinning cells is also significant to procesa efficiency. Proceds greater benefit would have been derived from the provision of an additional eluate tank as it is in the later electrowinning stage that most of the present hold ups occur. The Ok Tedi plant had a nominal design throughput of 24 tonnes of carbon per day.


Acid washing is used with all of the other stripping systems, but it is mentioned specifically with the AARL procedure, elutipn AARL systems generally use the stripping vessel to acid wash and acid washing is, therefore, controlled as part of the stripping sequence.

It is however very reliant upon the availability of an abundant supply of good quality water and its water usage is far greater than that of either the Zadra system or the more recently developed solvent stripping system.

The main advantage of the AARL process is the ability to strip a batch of carbon to low gold residuals in an 8 hour shift. Glycol stripping frequently is used to increase capacity in existing Zadra operations, but economics usually favor conversion to pressure stripping if continuing operation is planned.

Denver Mineral Engineers, Axrl.

Gold is recovered from the pregnant strip solution by electrowinning onto steel proxess. Barren solution is then returned to the barren solution tank for recycle see Figure 4.

Selection of design and operating flows is made on the basis of equipment costs and time constraints. The final eluate exits just below the top compartment as shown in Figure 5. Stripping efficiency decreases as flow rates are increased above 3 to 4 elhtion volumes per hour.

AARL Carbon Stripping System Operation: Elution & Electrowinning

Over the past year the gold extracted has averaged approximately 60 kg per day on a day per year basis. Disadvantages of the AARL process include the requirement for high quality water, high water consumption, the potential for mixing acid with cyanide, and the necessity for automated controls.


Electrowinning One bed volume thirty minutes after the commencement of the elution step 06 the electrowinning cell may aqrl put into operation. The entire stripping cycle takes about 8 hours.

The solution is heated to about deg-F and pumped through the carbon stripping vessel at a flow rate of about 2 Bed Volumes per hour. The advantages of this are dubious in that there would be more than enough time in a twenty four hour period for both steps to be completed in one column.

Should any difficulties occur during the stripping process, possible faults with remedial action have been detailed in part 4 of porcess manual. Carlin Style Mineralisation Deposit Examples.

Carbon Stripping

This offers the potential of either designing for multiple stripping cycles each day and reducing equipment sizes in new processs design, or increasing daily capacity in existing mills by stripping on additional shifts each day.

The condensate recycle spray is stopped and the alcohol is allowed to boil out of the pregnant solution. The time required for pressure stripping is generally from 10 to 14 hours. As the solution flows through the electrowinning cell, gold is plated on to the steel wool cathodes.

The presoak step is started by preheating the carbon with hot water. Factors favoring acid washing in the elution vessel include: