METHOD FOR EXTRACTING COPPER FROM AN AQUEOUS SOLUTION

摘要

1. A method for extraction of copper from an aqueous solution containing a large amount of sulphates in liquid-liquid extraction, characterized in that the viscosity of an extraction solution is adjusted within the range of 3-11 cP and that the volumetric ratio of the extraction solution and an aqueous solution in an extraction mixture to between 0.7-1.0, whereby the aqueous solution is dispersed into drops in the extraction solution. 2. A method according to claim 1, characterized in that the viscosity of the extraction solution is raised by raising the content of an extractant. 3. A method according to claim 2, characterized in that the viscosity of the extraction solution is raised by regulating the extractant content of the extraction solution in the range of 15-70 vol. %. 4. A method according to claim 1, characterized in that the ratio between the organic solution and the aqueous solution coming to the extraction stage from outside is regulated in the range of 0.15-1. 5. A method according to claim 3, characterized in that in treating an aqueous solutions with a copper content of maximum 2 g/l, the viscosity of the extraction solution is raised by adjusting the content of the extractant in the extraction solution to the range of 15-25 vol. 6. A method according to claim 5, characterized in that the external pumping ratio of the extraction solution and the aqueous solution is adjusted to the range of 0.2-0.5 and the corresponding external pumping ratio between a stripped copper electrolyte and the aqueous solution of the extraction is adjusted to the range of 0.08-0.02. 7. A method according to claim 3, characterized in that in treating an aqueous solution with a copper content of 2-4 g/l, the viscosity of the extraction solution is raised by adjusting the content of the extractant in the extraction solution to the range of 15-30 vol. %. 8. A method according to claim 7, characterized in that the external pumping ratio of the extraction solution and the aqueous solution is adjusted to the range of 0.3-0.7 and the corresponding external pumping ratio between the stripped copper electrolyte and the aqueous solution of the extraction is adjusted to the range of 0.15-0.25. 9. A method according to claim 3, characterized in that in treating an aqueous solution with a copper content of 4-8 g/l, the viscosity of the extraction solution is raised by adjusting the content of the extractant in the extraction solution to the range of 25-50 vol. %. io. A method according to claim 9, characterized in that the external pumping ratio of the extraction solution and the aqueous solution is adjusted to the range of 0.4-0.8 and the corresponding external pumping ratio between the stripped copper electrolyte and the aqueous solution of the extraction is adjusted to the range of 0.25-0.50. 10. A method according to claim 9, characterized in that in treating an aqueous solution with a copper content of over 8 g/l, the viscosity of the extraction solution is raised by adjusting the content of the extractant in the extraction solution to the range of 40-70 vol. %. 12. A method according to claim 11, characterized in that the external pumping ratio of the extraction solution and the aqueous solution is adjusted within the range of 1-4 and the corresponding external pumping ratio between the stripped copper electrolyte and the aqueous solution of the extraction is adjusted within the range of 0.8-3. 13. A method according to claim 1, characterized in that the viscosity of the extraction solution is raised by using alifatic hydrocarbons, kerosenes, with a viscosity of 2.7-3.2 cP when measured at ambient temperature, as diluting agent for the extraction solution. 14. A method according to claim 1, characterized in that the viscosity of the extraction solution is raised by using aromatic hydrocarbons, kerosenes, with a viscosity of about 3 cP when measured at ambient temperature, as diluting agent for the extraction solution. 15. A method according to any of the above claim, characterized in that the viscosity of the extraction solution is raised by using a mixture of alifatic and aromatic hydrocarbons, with a viscosity of minimum 2.7 cP when measured at ambient temperature, as diluting agent for the extraction solution. 16. A method according to claim 1, characterized in that the sulphate content of the aqueous solution fed to solvent extraction is minimum 40g/l. 17. A method according to any of the above claim, characterized in that the extracting solutions flow through each stage of the extraction equipment at essentially the same time. 18. A method according to any of the above claim, characterized in that the extracting solutions flow through the washing and stripping stages of the equipment more slowly than the actual extracting stages.