CHPP process

Coal preparation plant CPP

also known as Coal handling and preparation plant (CHPP)

The purpose of CHPP is to get rid of waste material from coal, to reduce the total ash content

The raw coal delivered to CHPP is called Run-Of-Mine coal, or ROM coal. It contains coal, rock, middlings, minerals and contaminations.

The process firstly crushes ROM coal into reasonable size, so reducing the top size, and nothing is too big.

After that, rounds of separation. The main purpose is to target material with different sizes by different equipment's.

Screening / jig groups material into ranges by size. Coarse coal and fine coal follow different processing paths.

For coarse coal, a dense medium cyclone DMC use medium (water + magnetite) to separate coal and rock by density difference.

For fine coal, a hydro cyclone use high speed spinning and difference in centrifugal forces to separate fine and ultra fine coals by density & size difference.

Fine coal further goes through spirals to use centrifugal forces to separate from waste.

Ultra fine coal instead goes through floating cells with chemicals to attach bubbles to coal, so coal rises and waste stays in bottom.

At the end, coal either coarse or fine, is collected, dewatered and conveyed to stockpile, while waste is rejected and dumped.

The actual process can be more detailed and complicated with more screens, cyclones, classifier, centrifuge in between each steps.

Below is an general flow of CHPP

Some example illustrations. Note implementation can be different from mine to mine.