Pilot-scale evaluation of hyperbaric filtration of ultra fine clean coal

A pilot scale evaluation of continuous pressure filtration was conducted on minus 200 mesh clean coal recovered by column flotation using an Andritz-Ruthner trailer mounted hyperbaric filter. Results showed that increasing vessel pressure for a given cake formation angle (CFA), increased cake thickness and throughput, while decreasing cake moisture. Baseline testing concluded that filter operating parameters of 3 bar pressure, 1.5 rpm filter speed and 165° CFA produced a 15.7 mm thick cake with a cake moisture of 23.7 percent. The air consumption to achieve these results was 242 Nm³/t (452 cfm/t) and the resulting throughput was 793 kg/m²/hr (163 1b/ft²/hr). Using these operating parameters, either nonionic or cationic surfactants effectively reduced cake moisture to below 20 percent at dosages as low as 0.25 kg/t. The use of flocculants increased throughput but also increased cake moisture.