Processing Operation

The objective of coal cleaning is to add economic value to a relatively low-margin product and to this end, the Parnaby preparation plant was built in 2007. Located adjacent to the open pit mine, the plant is capable of washing 150-200t of ROM coal per hour, or 300,000t per annum on a single shift basis, at a recovery rate of 50% from ROM coal to clean.

There is potential to increase the throughput by the implementation of a multiple-shift work rota system to achieve a rate of around 450,000 tons per annum.  In addition, the plant is modular so can be upgraded further if necessary.

ROM anthracite is fed into a hopper from the ROM storage bay using a Front End Loader.  Large rock will be manually removed from the plant feed before being conveyed to a fixed grizzly screen and jaw crusher station that sizes the coal to 4” topsize ahead of the coal preparation plant.  Operating capacity is determined by feed size distribution, the amount of waste product in the feed and the plant circuit equipment size.

Coarse refuse is collected on a belt conveyor and discharged to ground storage pile.  Fine refuse from the clarifier is collected in a sump and pumped to a disposal pond.  Up to eight sizes of clean coal products can be produced, from larger “stove” coals, down to smaller “rice” and “barley” coals.