Abstract

MASHABA, P.M.  and  BADA, S.O.. Flotation of weathered coal discards using a HIP W/O emulsion binder and kerosene. J. S. Afr. Inst. Min. Metall. [online]. 2022, vol.122, n.8, pp.437-442. ISSN 2411-9717.  http://dx.doi.org/10.17159/2411-9717/2003/2022.

An advanced high internal phase water-in-oil (HIP W/O) emulsion binder and flotation with an internal dispersed water phase of 95 vol% was used to beneficiate South African weathered coal from discard dumps. Five coal samples with calorific values ranged from 8.48 MJ/kg to 20.94 MJ/kg were utilized. The performance of the HIP W/O emulsion was compared to that of kerosene in terms of the physico-chemical properties of the clean coal products. A 5 kg/t emulsion binder addition produced a high-quality coal concentrate with 11.76% ash and a heating value of 28.61 MJ/kg from a sample containing 29.34% ash. Using the same dose and coal sample, kerosene resulted in a clean coal concentrate with 17.47% ash and a calorific value of 26.42 MJ/kg. Further samples were also beneficiated using 5 kg/t of W/O emulsion. The highest increase in calorific value was achieved from the beneficiation of a sample containing 48.71% ash, from 8.48 MJ/kg to 18.16 MJ/kg. It has been established that emulsion binders can upgrade coal samples dumped many decades ago.

Keywords : calorific value; discard coal; rapid beneficiation; W/O emulsion technique; weathered coal.

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