Dewatering of peat slurry produced by wet milling technique

The effects of slurrying, long distance pumping, chemical dosage, pH, dry solid load and pressure on the dewatering of Carex Peat slurry ware studied. Raw peat at 75% moisture was slurried and pumped through a pilot-scale pipeline simulating 20 km transport. The goal was to establish the conditions to achieve a dry solids content (DS) of 35%, which would make the peat a suitable fuel for advanced power plants. It was found that slurry was dewatered to a solids content of 40–45% with a capacity of 10–15 kg(DS)/hm². Pressure was a dominant factor, optimized at 50–60 bar. Long-distance pumping lowered the DS content of the cake only slightly. The required dosage of anionic flocculant was only 0.5 kg/t(DS), and lowering the pH level of the slurry to <3.7 from the natural value of 4.7 was also beneficial. The results indicate the feasibility of obtaining a DS content of 35% with high capacity, and there is at least one suitable type of chamber filter press available on the market. However, more extensive experiments are needed.