A Coal Preparation Plant (CPP) is a facility that washes coal of soil and rock, preparing it for transport to market.
A Coal preperation plant, nestled among the mountains. Coal Preperation plants generally use gravity process equipment to separate the refuse from the product (coal). Coal has a specific gravity between 1.35 and 1.5, while the refuse rock has a Specific Gravity of 2.1 to 2.3. Heavy Media is the most popular method of cleaning coarse sizes, jig plants are probably the second most common method used for coarse coal. Heavy media cyclones are being used more often for fines size fractions. Flotation is generally used to clean the -28 mesh size fraction, although spirals and heavy media cyclones have shown success in cleaning down to 100 mesh coal feed. Spirals are generally used for middling sizes ( 10 mesh to 60 mesh)
At this prep plant, all feed coal (ROM) is crushed to -2″ before entering the plant circuits. The 2″ x 10 mesh coal is screened and goes to the primary dense medium cyclone circuit. The 2″ x 10 mesh coking coal is recovered from the refuse here. The middlings (-10 mesh x 60 mesh) are processed in the Secondary Dense Medium Cyclone Circuit to recover the coal here, this produces a higher ash coal and is used as steam coal. The coking coal product conveyor has an intermediate screen that enables material to be diverted in varying proportions to steam coal if necessary to enhance the coking properties.
The -10 mesh coal is deslimed at 100 mesh and then sized at 10 mesh x 100 mesh is processed in the spiral circuit to produce coking coal. The -100 mesh slimes and -60 mesh coal is then processed in the flotation circuit to produce coking coal.
The cleaned coal is dried in centrifuges and a belt filter press. Coarse rejects are crushed and then recombined with the fine tailings for disposal to the refuse fill. All ROM coal production is beneficiated in the coal preparation plant. Approximately 2,000,000 tonnes of cleaned coal is produced annually, with the plant processing about 3,000,000 tons of raw coal annually.To view a larger image of the Flowsheet, click on the text above the Flowsheet.