Process for recovering course particles from tailings

A process for the treatment of coal tailings containing coal particles having a maximum dimension of less than 2 mm and gangue particles of a density greater than that of coal in order to recover the coal particles from the tailings, comprising the following steps in order:

• forming a slurry of the coal tailings having a pulp density of from 10 to 30% by weight;
• feeding the slurry into a hydrocyclone to produce an underflow stream containing substantially all of the tailing particles larger than a predetermined size and at least some of the gangue particles smaller than said predetermined size and an overflow stream containing substantially all of the coal particles smaller than said predetermined size and the balance of the gangue particles, the hydrocyclone being operated so that the underflow stream has a pulp density of from 40 to 60% by weight;
• adjusting the pulp density of the underflow stream, if required, to from 20 to 50% by weight;
• passing the repulped underflow stream over a vibrating sieve screen deck having a wedge wire sieve screen with a radius of less than 2 m, an arc angle of from 45.degree. to 60.degree. and a slot aperture of from 80 microns to 500 microns to form a coarse stream of particles substantially all having a particle size greater than 65 microns;
• adjusting the pulp density of the coarse stream of particles to from 20 to 50% by weight, and
• passing the repulped coarse stream over a spiral separator to bring about a substantial density separation of the coal particles from the gangue particles and recover the coal particles.