What is the difference between cil and cip

Figure 13b shows the impact of a shorter elution cycle on the variable cost compared to the increased tailings loss as a result of the less efficient elution.

Although the impact is less than in the CIP case study, due to the CIL plant being much smaller with much reduced feed flow rates, it still shows that a high elution efficiency will be beneficial to the cost balance sheet. The effect of carbon concentration is shown in Figure 14a.

This plateau is due to leaching and adsorption taking place concurrently in the CIL circuit. Adding more carbon to enhance adsorption while the leaching remains slow, will therefore not increase value. The actual plant carbon profile for the six tanks was reviewed. The carbon concentration in the lead tank tank 1 was found to be consistently higher than for tank 6. An example of this profile is shown in Figure 15a. Figure 15a shows the carbon profile, while Figure 15b shows the change in solution concentration.

The benefit of equal amounts of carbon per tank, as well as the swopped carbon profile, lies in the higher amount of carbon in tank 6, which prevents Au losses to the tailings. For the equal and swopped carbon profiles, a higher Au solution concentration in the first two tanks as per Figure 15b occurs and the risk of preg-robbing by natural carbon fines increases the primary reason for a CIL circuit.

Two case studies CIP and CIL processes were simulated to determine the sensitivity of the plant to certain changing variables. These were combined with an economic analysis to determine the operating parameters that yield the highest value. To achieve maximum value, the operating conditions need to be monitored and readjusted, if required, as they are strongly dependent on both extrinsic commodity prices and inflation and intrinsic factors feed rate, gold grade, elution efficiency.

The authors would like to thank the respective plants for their assistance and provision of the plant data. Baily, P. Adsorption plant design. Fleming, C.

Factors influencing the rate of gold cyanide leaching and adsorption, and their impact on the design of CIL and CIP circuits. Minerals Engineering, vol. Nicol, M. The adsorption of gold cyanide onto activated carbon. The kinetics of adsorption from pulps. Factors influencing the rate of loading and the equilibrium capacity. Oladele, T. The effect of temperature, contact time and agitation speed during pre-treatment on gold elution.

Southern African institute of Mining and Metallurgy, Johannesburg. Paper received Aug. All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License.

Services on Demand Article. English pdf Article in xml format Article references How to cite this article Automatic translation. Access statistics. Cited by Google Similars in Google. Model development It is widely accepted that the performance of the adsorption circuit directly influences the elution and regeneration circuits.

The rate of gold adsorption onto activated carbon is described by: This rate equation can be combined with a mass balance Equation [2] over the entire countercurrent CIP adsorption circuit to yield a model that can be used to describe the performance of the circuit.

CIP base case A base case representing the daily operation of the plant was chosen. Carbon advance rate The carbon advance rate or carbon residence time is one of the easiest parameters to change on the plant and will basically determine the amount of Au the carbon is loaded to before elution takes place upgrade ratio. Elution efficiency The importance of efficient elution and the impact on the adsorption section in terms of potential gold losses have already been stated.

Carbon concentration The effect of carbon concentration is shown in Figure 7. Gold grade Except for a blending strategy and perhaps some influence in ore selection, plants usually have limited control over the feed Au grade and simply have to treat what is being fed to the plant.

Optimized conditions The impact of carbon residence time, carbon concentration, and solids-liquid ratio on the differential revenue for this case study is shown in Figure Model calibration The values for k, K, and k L as per Equations [1], [2], and [3], were determined through empirical fitting by averaging plant data over 3 days as input parameters to the model.

CIL base case As per the previous case studies, the plant was evaluated by determining the differential revenue or loss that can be realized if some of the operating parameters are changed.

Spiral Chute Washer. Thickening Efficient Improved Thickener. Efficient Thickener. Peripheral Transmission Thickener. Efficient Deep Cone Thickener. High-Frequency Dewatering Screen.

Vacuum Filter. Drum Filter. Ceramic Filter. Auxiliary Equipment. Agitation Tank. Agitation Tank for Chemical Reagent. Pendulum Feeder. Chute Feeder. Plate Feeder. ZSW Vibrating Feeder. Screw Conveyor. Belt Conveyor. Walled Belt Conveyor. Metal Detector. Electromagnetic Iron Remover. Electronic Belt Scale. Pipeline Sampler. Flocculants System. NC Reagent Feeder. Mobile Pump Station. The activated carbon is loaded into each adsorption agitation tank, and the adsorption agitation tank is equipped with an interstage filter, the air lifter and so on.

In the carbon adsorption process, screens are used in many places, the purpose is to first screen out the wood and coarse ore in the slurry, often using a spacer screen or a vibrating screen. Finally, it is the desorption of gold-loaded carbon, this operation is carried out by dissolving the gold attached to the surface of the activated carbon in a solution, and then reusing the carbon after activation.

After filtering, the pregnant solution enters the electrolytic cell for electrolysis. The gold is in the form of flakes or flocs, which are deposited on the anodized titanium plate, and then scraped down to concentrate the ingot.

Eco-friendly Gold Leaching Reagent. Online Service. First it is passed through a trash screen to remove tramp oversize, plastics, wood, and other debris. It is then thickened to a requisite percent solids prior to leaching. This range of pulp density keeps the activated carbon suspended in the pulp and is suitable for the subsequent leaching operation.

Following leaching, the pulp flows into the carbon-in-pulp circuit which operates in counter-current fashion. Usually five stages of adsorption are employed. Traditionally, 6 by 16 mesh activated carbon is added to the number 5 carbon-in-pulp tank and advanced to the number 4 tank and so on by air lift. The pulp is advanced from the number 1 tank to number 1 tank and so on by a second series of air lifts.

One of the most important factors in the carbon-in-pulp process is the minimization of gold losses on fine carbon reporting to the tailings. To date, the most abrasion resistant plus surface-active carbon has been found to be coconut shell carbon. Normally, the carbon consumption will average between 0.

The loaded carbon containing adsorbed gold and silver plus base metal cyanides is screened and conveyed from the carbon-in-pulp circuit to the stripping circuit. The traditional process for gold recovery from cyanide leach liquors has been the countercurrent decantation process.

Following leaching, countercurrent decantation takes place in a series of thickeners in which the leach pulp is washed by the countercurrent flow of barren solution. The classified pregnant solution is treated for gold recovery with zinc dust.

The precipitate may be acid digested. It is then smelted into bullion bars. The barren solution from zinc precipitation is returned to the last thickener.