Agglomeration of ore is a method which can be used to eliminate the migration of fine grained particles throughout a leach heap. Without agglomeration, fine ore particles are able to migration within the heap, clogging flow channels and producing large areas where access of the solution is poor. In order to gain the benefits of agglomeration and improve agglomerate strength even further in copper heap leaching, an economical, acid-resistant binder is needed. However, most binders have been used without any systematic reasoning._x000D_
A set of novel testing methods were developed, including a soak test, percolation flooded columns, and larger long-term leach columns. The soak test compares the degree of breakdown when agglomerates are subjected to an acidic environment. While the percolation flooded columns and larger long-term leach columns evaluate the flow of leach solution throughout the ore bed._x000D_
Systematic studies have been completed on a wide range of binders using these novel testing procedures._x000D_
It was found that for a low grade chalcocite ore, which was rich in silica, from a southwest US mine, polyacrylamides reduced the fines migration the best in the novel soak test. The non-ionic binder, in particular, was found to reduce fines migration as much as 93 per cent. Several of the binders tested were shown to increase the hydraulic conductivities of the agglomerated ore up to 2.5 mm/sec, compared to a hydraulic conductivity of only 0.25 mm/sec when no binder was used. These binders also prevented slumping' of the ore, which indicates a decrease in breakdown of the agglomerates. The use of a binder also showed no interference with leaching reactions in long-term leaching experiments._x000D_
CITATION:Lewandowski, K A, Eisele, T C and Komar Kawatra, S, 2010. Agglomeration for copper heap leaching, in Proceedings XXV International Mineral Processing Congress (IMPC) 2010, pp 183-192 (The Australasian Institute of Mining and Metallurgy: Melbourne).