Study On Copper Ion Extraction By High Gravity Technology In Copper Hydrometallurgy Process

Copper is widely used in electric power industry and machinery manufacturing because of its excellent conductivity and heat transfer properties.More and more attention is paid to copper hydrometallurgy process because of its low energy consumption,environmental friendliness,and high product purity.Copper hydrometallurgy process uses solvents to leach copper ions and then extracts the copper from the solution by extraction and electrodeposition.The extraction section is the main section of the whole process,and its extraction efficiency will significantly affect the copper production and energy consumption.As an effective means of mass transfer enhancement,high gravity（HiGee）technology is expected to be applied to copper ion extraction section in copper hydrometallurgy process.In this work,the water-kerosene-benzoic acid system was used to carry out the liquid-liquid mass transfer experiment in the rotating packed bed（RPB）,to explore the influence of operating conditions such as rotational speed,total flow rate and oil-water ratio,as well as packing parameters such as radial thickness,mesh size and hydrophilicity on the mass transfer process.By integrating the experimental results,the corresponding correlation formula of the volumetric mass transfer coefficient was obtained.The application of the rotating packed bed in the extraction section was studied by the industrial copper extraction system,and the correlation formula of the volumetric mass transfer coefficient was also tested.The main research contents are as follows:（1）Liquid-liquid mass transfer experiments were carried out using water-kerosene-benzoic acid system.The results showed that the percentage of raffinate（φ）decreased with the increase of rotational speed,the increase of radial thickness of packing and the decrease of oil-water ratio.With the increase of total flow rate and mesh count,the φ fluctuated.With the increase of rotational speed and total flow rate,the volumetric mass transfer coefficient（KLa）increased.The volumetric mass transfer coefficient decreased with the increase of the oil-water ratio and radial thickness of packing.The volumetric mass transfer coefficient fluctuated with the increase of mesh count.Mass transfer experiments with packings of different wettabilities showed that the mass transfer performance of hydrophilic packings was better than that of hydrophobic packings.Based on the influence of experimental parameters on the volumetric mass transfer coefficient,the corresponding correlation was obtained as follows:The results showed that the fit was good and the deviation of between the calculated values of most correlation formulas and the experimental data is within± 25%.（2）The extraction application study was carried out using the industrial system of copper extraction in copper hydrometallurgy process.The percentage of raffinate decreased with the increase of rotational speed.When the total flow rate was 230 mL·min^-1,with the rotational speed increased from 900 r·min^-1 to 2100 r·min^-1,the percentage of raffinate decreased by 10.7%from 82.3%to 73.5%.By multistage extraction,the residence time of the fluid in the rotating packed bed was extended.When the extraction times reached 5,the percentage of raffinate obtained at the rotational speed of 900 r·min^-1 to 2100 r·min^-1 could meet the corresponding industrial requirements.In the process of reverse extraction,when the total flow rate was 230 mL·min^-1,with the rotation speed increased from 900 r·min^-1 to 2100 r·min^-1,the percentage of raffinate decreased by 11.4%from 89.3%to 79.1%.When multistage reverse extraction was carried out,the extraction percentage of raffinate could reach the corresponding industrial extraction percentage when the rotational speed was 2100 r·min^-1 and the extraction times were up to 4.The experimental results show that the rotating packed bed has a good prospect in liquid-liquid extraction.