LIGNITE REMOVAL

When lignite, or “brown coal”, is present in deposits of sand and gravel it poses a significant challenge. Lignite compromises the final quality and commercial value of sand and aggregate products, so its removal is crucial. CDE’s specialist wet processing plants allow for the efficient removal of lignite contamination from sand & gravel or rock deposits.

Where a deposit is contaminated with lignite the sand and aggregates will not be suitable for a range of construction applications such as concrete sand and plastering sand.

Effective removal of lignite contamination can be achieved with our Counter Flow Classification Unit (CFCU). This provides a means of density separation and its basic operation involves floating the lighter lignite particles off the top while the sand product (being heavier than lignite) sinks to the bottom of the tank before being discharged to the integrated dewatering screen.

In the majority of cases, lignite contamination is dealt with at the sand washing stage. Due to its brittle nature it is broken up into particles at the lower end of the sizing scale. If, however, there is lignite contamination within the aggregate fraction we can also introduce an attrition system or logwasher.

The configuration of the processing system required is entirely dependent on the level of lignite contamination, which can vary extensively depending on the geology of the deposit.

The design and delivery of the optimum lignite removal plant for your operation involves extensive material testing to ensure suitable equipment is specified.

The introduction of our lignite removal washing equipment will typically involve the production of a number of different sand specifications:

• Concrete sand (coarse)
• Building/plastering sand (fine)
• Cable sand (ultra fine)