Method of Agglomeration

Abstract

A method of agglomerating a nickel laterite ore comprising the steps of: i) feeding a nickel laterite ore material to be agglomerated into an agglomeration circuit; and ii) adding a sulfuric acid containing agglomerating solution to the ore material in the agglomeration circuit to provide an agglomerated ore material, wherein the acid concentration of the agglomerating solution is between 100 to 400 g / L.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a method of agglomeration of nickel laterite ores, particularly to the agglomeration of ores for the purpose of heap leaching.BACKGROUND ART[0002]The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.[0003]Heap leaching is one method for economically extracting metals from low-grade ores. Generally, it involves piling raw ore into heaps and introducing a leaching solution over the top of the heap to percolate down through the heap. The leaching solution extracts the desired metal values from the ore and is collected as a pregnant leach solution (PLS), for example, in perforated drainage pipes located beneath the heap. The PLS i...

AI Technical Summary

Benefits of technology

[0014]The applicant has found that despite the teaching of prior patent publications, nickel laterite ore is optimally agglomerated using an agglomerating solution having a sulfuric acid concentration of between 100 to 400 g / L and preferably between 140 to 280 g / L. Optimal agglomeration of nickel laterite ore improves the permeability of the ore heap, and enables the agglomerated ore to be piled in higher heaps as compared to prior agglomerated ore, which in turn allows a heap leaching process to achieve more efficient recovery rates, increase output rates and reduce costs.

[0018]In some embodiments, it may be advantageous to reduce the size of the ore before the agglomeration step. In these embodiments, the process of the present invention further includes a step prior to the ore feeding step of reducing the size of the nickel laterite ore material to be agglomerated to less than 1 inch. The ore can be reduced in size using any suitable size reduction equipment including ball mills, crushers, hammer mills or the like.

Problems solved by technology

However, one of the main problems with using concentrated acid solutions for agglomeration is that the resulting agglomerates can become friable, resulting in blockages in the heap once agglomerates begin to break into smaller particles.