OH&S News

Mobile screen processes glacial outwash from great river

Welch Sand & Gravel is a 50-year-old American family-owned company. It was founded by Charlie Welch (more than 90 years old) and is now under the management of his sons Jim and Ron Welch, both company vice presidents.

Welch’s aggregate products are widely used by concrete and asphalt producers, and by private and public contractors. The company has grown to consistently rank in the top 10 of Ohio’s largest sand and gravel producers.

Now Welch Sand & Gravel is participating in a unique environmental project to keep glacial outwash from affecting a key recreational area of the Great Miami River.

First, the natural outwash is removed from a section of the river, and then the gravel is processed efficiently with a new Metso Lokotrack ST3.8 mobile screen.

At one time, glaciers up to 1.6km thick covered two-thirds of Ohio. When the last ice age in North America ended about 10,000 years ago, the receding glaciers left behind large deposits of highly permeable sand and gravel, known as glacial outwash. Today, the Great Miami River transports a large amount of this outwash and deposits it where flow conditions change, including in the slower currents running through the city of Hamilton.

The local water authority contracts with Welch Sand & Gravel to remove outwash from a 6ha section of the river in Hamilton.

{{quote-A:R-W:300-Q:"Our customers want equipment that will last. Metso’s mobile screens are not only built sturdier, but most of the key parts are galvanised for longer life at no additional cost."-WHO:Gary Honchell, PMI senior sales manager}}Welch is allowed to excavate only to a depth of 91cm to 121cm, to prevent the outwash from moving further downstream and to keep the summer pool area open. The popular pool is used by the local community for recreational activities including fishing, boating, canoeing and other water sports.

Welch operates the ST3.8 mobile screen at the Black Street Bridge site in Hamilton, where the company has a seasonal permit to mine river gravel from March through to December. The company has had the permit for this work since 2004, and the amount of material removed each year varies depending on the weather.

“We have done as much as 119,000 tonnes, with an average of 50,000 to 78,000 tonnes out of the Great Miami River operation,” Welch’s production manager Rick Goessling said. “It all depends on the amount of rainfall and flooding that takes place.”

The ST3.8 replaces an older model Metso ST356 screen, in operation since 2006.

“We ran that ST356 mobile plant for about 10 to 11 years, and we wore it out,” Goessling, who has been with the company since 1981, said.

“We ran millions of tonnes of gravel through that thing, and we just decided it was time to update.”

He contacted Process Machinery Inc (PMI), Metso’s distributor in the state of Ohio.

After conferring with PMI senior sales manager Gary Honchell, Welch Sand & Gravel purchased the ST3.8.

“Our customers want equipment that will last,” Honchell said. “Metso’s mobile screens are not only built sturdier, but most of the key parts are galvanised for longer life at no additional cost.”

The mining process at Black Street Bridge is a one-stop operation. Welch operators use a hydraulic excavator to remove material from the river and transport it by truck to the Black Street Bridge site.

The wet river gravel is dumped on the ground and allowed to dry for 24 hours, and then processed through the ST3.8.

Any material pulled from the river becomes Welch’s responsibility, to either process or properly dispose of in accordance with strict environmental regulations. This includes everything from tree branches to old tyres and general river debris.

On average, Welch Sand & Gravel processes between 1500 and 2000 tonnes per day of outwash material through the ST3.8. The screening plant combines a 5m x 1.5m double-deck screen, with an advanced process control system and fuel-efficient engine package. Welch produces a minus 38mm product from the top screen deck, and everything from 9.5mm pea gravel all the way down to sand from the second deck.

“The ST3.8 is a great choice for medium- to large-scale operations,” Metso’s Atlantic USA distributor manager Scott Yablonsky said.

“With the double-deck design, customers can produce and sort up to three different sized end products.”

Goessling said: “So far we are very happy with the ST3.8 and how fast we can move it, set up and run. There have been some great changes that make it so much more user-friendly, and I think it will do a great job for us.”

He also spoke highly of the PMI team’s support. “They have always been very professional, willing to teach or show new products, and they are proud of representing Metso equipment.”

Most importantly, the ST3.8 helps Welch Sand & Gravel keep its commitment to the local community.

As Goessling put it: “Metso, Gary Honchell and Process Machinery help us fulfil our obligations and continue our positive relationship with the city of Hamilton, Ohio.”

In Australia, the distributor of Metso Lokotrack mobile plant is Tutt Bryant Equipment.

Source: Metso

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