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McLanahan Thickeners Provide Efficient and Sustainable Water Recycling

In the aggregate industry, the main function of a Thickener is to separate suspended solids from plant effluent to reduce the total volume of waste while returning water for immediate reuse in the process.

Sustainable Water Recycling

Thickeners not only help create a more sustainable site by producing reusable process water, they also minimise the environmental impact and safety risks associated with multiple or large settling ponds. Separating the liquids from the solids decreases the volume headed to the pond, allowing producers to reduce or potentially eliminate their ponds.

McLanahan Thickeners are ideal for sites where:

  • Water is scarce or expensive.
  • Land is scarce or there is no space for ponds.
  • Ponds may not be an option from a regulation standpoint.
  • Maintaining ponds and the expenses associated with that is a concern.
  • Ponds would potentially cover up mineable reserves. 

“Any wet based process system that’s located in an area with a high population density, where land or water is expensive, or where pond permitting is an issue would benefit from a Thickener,” said Scott O’Brien, Global Director of Process Engineering at McLanahan Corporation. “If you have a deposit that you’re going to mine in the future and you don’t want to put a pond on top of it, a Thickener can also help with that.”

Selecting a Thickener

McLanahan offers a wide range of Thickeners and Thickener styles that are designed for each application’s unique requirements. Selecting a Thickener design begins with establishing what the customer wants from the thickening process.

“There are a number of choices we can make depending on what they want as far as style of Thickener — whether it’s a High-Rate Thickener, High-Density Thickener or a Paste Thickener, whether it’s a thickener that’s going to go right on the ground or elevated up on legs,” O’Brien said.

After discussing the style of Thickener, McLanahan tests a sample of the customer’s material in its in-house laboratory to design the Thickener the customer needs.   

“We do quite a bit of testing to understand what the mud is going to do, how it’s going to behave and what’s going to be necessary as far as installation goes in order to make it successful,” O’Brien said. “The tests typically include a dilution test to make sure that we optimise the flux, or the amount of solids we can get through the Thickener for a given area. We do static settling tests and dynamic settling tests, which allow us to set up a real-time simulation of what is going to be happening in the Thickener. We’ll look at the mud for properties such as yield stress, which is important for mechanical design as well as defining how we might have to pump the mud away from the plant to a tailings storage facility or downstream process such as filtration.”

All these tests ensure the Thickener will operate successfully once it arrives on site.  

“The benefit to doing all the preliminary testing is that when the Thickener is put into operation, it does what the customer expects it to do,” O’Brien shared. 

The McLanahan Advantage

In addition to material testing capabilities and a highly trained and experienced team, McLanahan has the knowledge that comes with 185 years of designing aggregate processing equipment.

“The main advantage of working with McLanahan is that you not only get the experience we have with Thickeners but also the mindset that comes with dealing with many of the other unit operations in the plant as well. We understand what’s coming down the pipe to the Thickener,” said O’Brien. “McLanahan is involved in nearly every aspect of the aggregate processing plant, from feeding and crushing, to washing and classifying, through to the tailings part of the plant.”

Another benefit to working with McLanahan is that the company doesn’t just design and build the customer’s Thickener — it provides service and support for the lifetime of the machine. McLanahan also assists with start-up, trains operators and can monitor the Thickener operation remotely from its headquarters in Hollidaysburg, Pa.