NICKEL AND COBALT RECOVERY FROM LOW-GRADE NICKEL OXIDE ORES BY THE TECHNIQUE OF HEAP LEACHING USING DILUTE SULPHIRIC ACID AT AMBIENT TEMPERATURE

摘要

Nickel and cobalt recovery from low-grade nickel oxide ores by the technique of heap leaching using dilute sulphuric acid at ambient temperature. A new hydrometallurgical method for nickel and cobalt leaching from low-grade to extremely low-grade nickel and cobalt oxide ores is suggested, by the use of the sulphuric acid heap leaching method. The nickel and cobalt recovery is made possible by the suggested method, by the use of multiple dilute sulphuric acid solution recyclings, through one or more ore heaps. According to the suggested techniques, before every recycling the acidity of the solution is regulated to a fixed value (technique II) or the solution is replaced by a new one when its acidity falls below a predetermined value (technique I). The leaching abilities of the various elements that are contained inside the ore are given at Figures 1-25. The various leaching factors were also studied and the best leaching conditions that result by the up-to-now available facts are being suggested.