A scale-up approach for industrial flotation cells based on particle size and liberation data

Abstract

The current scaleup approaches usually consider the overall metallurgical results, without including the efficiency of flotation machines at different particle size and liberation classes. This approach can limit the prediction of the industrial metallurgical performance, mainly when the mineral feed characteristics change significantly over time. This paper presents a scale-up approach, which allows for estimating scale-up factors per size and liberation class. The plant survey was developed in a copper concentrator in Chile. Plant kinetic testing on three rougher circuits of 130 and 300 m3 cells, in parallel with batch flotation tests using the same rougher feed samples, allowed the estimation of average scale up factors in the range of 1.8–2.2, which are in good agreement with the typical values observed in flotation scale up. All the samples included sieving, and chemical and mineralogical analysis. Scale up factors, batch-plant, showed a correlation with particle size classes, where the scale up factor increases (1.5–2.5), when particle size increases (20–150 µm), according to the data. This effect becomes stronger for particle sizes larger than 100 µm, reaching scale up values around 3–4. This means that the scale up factors are sensitive to the particle size distribution in the plant feed and must be considered.An alternative estimation of scale up factors in terms of the mineral liberation showed a similar trend with those of particle size classes, where the less liberated (mainly coarser sizes) minerals have the largest scale up factors, while decreasing for the highly liberated (mainly finer sizes) minerals.