In most of the mining operations, a process is used to separate the values of the tailings, or in the other case to separate the concentrate from the water in both procedures this happen in an equipment called thickener, in this article we will see in a simple way, its parts and the control parameters for its proper functioning.

The parts of a thickener are the following:

  1. The tank, this part is usually an inverted cone with a diameter much larger than its height to help the movement of the concentrated solids and their discharge is in the bottom part.
  2. The rake, this element is formed by rods and is attached to the main shaft, its function is to move the load of solids towards the bottom of the tank and prevent this load from settling too much and cannot be discharged.
  3. Discharge cone, located in the center of the thickener and serves to discharge the solids to the pumps, either concentrates or tails.
  4. Overflow channel, this channel is a ring that receives the “clean” water from the thickener and sends it as the case may be, to process or to filtering.
  5. Mechanisms of elevation and movement, these mechanical systems are responsible for giving the necessary lift and force to the rake, so that it does not get stuck and does not raise the already settled solids.

Regarding its operation, the thickener has 3 distinctive zones:

  1. Classification zone, this zone is where the water, already clarified and separated from the solids rises and overflows to the overflow channel.
  2. Sedimentation zone, this is where the feed of the thickener is, a charge receiver minimizes turbulence and balances the solids of the feed with those already are inside the thickener.
  3. Compression zone, in this area the solids themselves compress and release water while being moved by the rake.

Having said that, we now can comment on the main objectives of thickening, such as having a continuous and adequate feed, that the overflow is as clean as possible, and that the thickened product has the density required at the time of discharge.

In order to achieve these objectives, a series of measurements are necessary, from the height of the rake level, to the density of the solids in discharge, which allow us to optimize the entire thickening process.

 

 

In this link https://www.endress.com/en/Endress-Hauser-group/Case-studies-application-notes/thickener-optimization I share a case studies about the optimization of thickeners from our business partner, Endress + Hauser.

 

Thanks for reading, regards.