How Metroplex Sand & Gravel produces 5 in-spec products in a single pass

In this article we will explore the story of how Metroplex Sand & Gravel, Texas, is achieving its sand and gravel production objectives with a lower footprint and 85% recycled water.

 PROBLEM - Needed a high capacity, fast install plant to produce in-spec products in a single pass

 “At our conventional plant we’ve tried to make specialist sands before. But by the time you re-run, re-run and re-run those sand to try to hit the gradations, it’s not economical.”

 When moving into its new plant Metroplex Sand & Gravel’s objectives were:

•      Produce in-spec products in a single pass
•      Reduce its environmental footprint by minimizing water consumption
•      Minimize physical footprint without compromising on production capacity and operations
•      Install a new plant quickly and economically

SOLUTION – A new turnkey plant 

In 2014 Metroplex attended a CDE demonstration event at GS Materials and was impressed by the CDE 300 tons per hour turnkey wet processing plant.

 “We were immediately impressed by the plant’s ability to manage gradation and silt cuts - producing golf course spec sand the first pass. With conventional classifying equipment and sand screws this is difficult to say the least. ”

 Keith Newell, President of Metroplex Sand & Gravel

 In 2015, CDE installed the complete plant solution which consisted of 5 machines, the M4500 modular wash plant, the AggMax portable logwasher, the Counter Flow Classification Unit (CFCU), EvoWash fines recovery unit and the AquaCycle thickener.

 To produce the in-spec sand products in a single pass the plant’s minus ¼” material is sent to the sand washing element of the M4500, which is a CDE EvoWash with a dual pass cyclone arrangement.

 The EvoWash is CDE’s tried and tested hydrocyclone technology, which offers unparalleled control of silt cut points - allowing you to produce the material that your customers need and guarantee the quickest return on your investment.

 The main benefits of the EvoWash are that it:

Guarantees the removal of the minus 200 mesh fraction while retaining all quality fines in your final sand product

Maximizes sand dewatering to between 12% and 15% moisture - ensuring it is ready for market as soon as it hits your stockpile

EvoWash

• Eliminates the loss of quality fines to your settling ponds
• Maximizes your product yield 
• Minimizes operational costs

The sand material is first delivered to two 25” cyclones where the first separation occurs. The material is then discharged from the cyclones to one side of an A-Series VibroSync split dewatering screen before the coarse sand is stockpiled via a radial stockpile conveyor.

 Some material is allowed to pass through the dewatering screen to the sand plant sump and this material is then sent to the Counter Flow Classification Unit (CFCU) which facilitates further density separation by using an upward flow of water to carry lighter particles up while allowing the heavier particles to fall to the bottom of the CFCU tank.

 The material from the bottom of the tank is then delivered to the second side of the split A-series VibroSync dewatering screen and a 100 mesh to 18 mesh fine sand product is stockpiled via the integrated M4500 stockpile conveyor. Meanwhile the lightweight material from the CFCU is delivered to an additional EvoWash 71 where a 200 mesh to 50 mesh cushion sand product is stockpiled.

 The plant’s AquaCycle A600 thickener accepts all the waste water and minus 200 mesh fines which are dosed with flocculants on entry to the tank. This facilitates the settlement of the fine particles to the bottom of the thickener tank while the clean water overflows the peripheral weir and is recycled to the wash plant.

As with all CDE installations the Metroplex project was delivered according to the CDE project management system – ProMan.

This is another benefit of the CDE approach according to Keith Newell, “The design phase, engineering, and installation – the professionalism and expertise of CDE’s personnel clearly matches the quality of their equipment. For example, I couldn’t help but smile when Joe Owens – one of their most experienced installation engineers - having worked six hard days last week – slapped me on the back and stated “Good Stuff” on the idea of working Sundays.”

 CDE's approach to quick and effective installations is to pre-fabricate and test its equipment and plants in the factory before transportation and delivery to the customer's plants.

 “The install took 18 days. That’s pretty remarkable.”

 Keith Newell, President of Metroplex Sand & Gravel

RESULTS – 5 products | minimal water consumption | fast install

“The quality of equipment design and the strength of its manufacturing are truly remarkable as well, as is the precision with which the plant fits together. Perhaps most important, the AquaCycle thickener greatly diminishes our freshwater requirements. Our current plant requires 6,000 GPM; the M4500 – although it uses approximately 2,600 GPM – requires only 300 GPM of new water.”

Keith Newell, President of Metroplex Sand & Gravel

Is producing 5 products including C33 Concrete Sand, Asphalt Sand, Masonry Sand, Cushion Sand, Concrete Rock and Pea Gravel – in a single pass

Runs at 450 tons/hr 17 hours per day, 6 days per week

Is significantly reducing its water consumption compared to its previous plant – only 300 GPM of fresh water is required even though the plant uses 2,600 GPM. This compares to the 6,000 GPM of its previous plant, with no compromise in production, operations or quality

Was installed in 18 days with minimal civils required compared to the 90 square yards of its previous plant

CDE continues to support Metroplex Sand & Gravel and Keith Newell with any issues that emerge.

“You never considered the plant fully commissioned until WE felt were adequately trained.

This plant is actually a better plant today after one year running than it was when we purchased it. That’s with you [CDE] working with us and making improvements were you saw some and we saw some.

So it’s been one [a relationship] of teamwork.”

Keith Newell, President of Metroplex Sand & Gravel