High Magnetite Consumption

I would review your processing in these areas....

"Losses of magnetite occur in four main areas:

• With Product Coal
• With Reject material
• Magnetic Separator Effluent
• Leaks & Spillages

Magnetite losses are usually expressed in kilograms of magnetite per tonne raw coal processed (kg/t ROM), although it is becoming more common to express losses in terms of kilograms of magnetite per dry coarse coal feed (kg/t dccf).

Modern coal plants typically have consumption in the order of 0.5kg/t ROM."

You may need consultation from an industry expert.....

"

The Coal Washing Process- a typical Dense Medium Cyclone Plant

Dry Magnetite powder is mixed with water and pumped into the magnetite circuit. A sump containing the suspension at the required density is known as the Correct Medium Sump.

Raw Coal from the Mine is typically crushed to -50mm and is then delivered to a desliming screen where the fine coal (-1.4mm typ.) is rinsed off and is sent to the fine coal and ultrafine coal circuits.

The 50 x 1.4mm is mixed together with the magnetite suspension from the Correct Medium Sump, and is pumped to the Dense Medium Cyclone(s) for separation.

Once separated, the Product and the Reject report to Drain & Rinse screens in order to recover the magnetite. On the first part of the screen, magnetite is drained and reports back to the Correct Medium sump for re-use in the circuit. On the second part of the screen, magnetite adhering to the coal particles is rinsed off with water from the process. This rinsed medium reports to a Dilute Medium sump from where it is pumped to Magnetic Separators that recover the magnetite and bleed fine coal out of the system.

Concentrated magnetite from the Magnetic Separators (RD>2.0 typ.) usually reports to an Overdense Sump from where it is distributed into the required circuit."

http://www.martinandrobsonmagnetite.com/coal-processing

Determine the cost of the lost produce over a one month period.

Then determine the cost of hiring a competent process engineer to visit your plant, survey your equipment and processes and make recommendations to improve the retention of desirable product.

At some point the losses will pay for the competent engineer to fix the process problems for you.

Solar has given a good site to read. We can't do it from the other side of the world.

Hire an engineer, or accept the losses.