Drill & Blast

Recycling with Efficiency

Concrete products are manufactured to last almost forever. So why discard the sturdy material just because the useful life of a concrete building or highway has ended?

Landfilling old concrete did not make sense to Terry McAfee and son David; they are on a mission to recycle concrete, and Sandvik equipment is helping them.

The McAfees own and operate DT Specialized Services from their Tulsa, Oklahoma headquarters, where they manage demolition projects across the lower mid-western United States.

Five years ago, while tearing down a concrete structure, they decided the project created an unusually large pile of refuse material, and the McAfees were uncomfortable with hauling it all away to a landfill.

“We realised the sheer volume of concrete debris we created was going to be wasted, rather than recycled,” Terry McAfee said. “That was the cornerstone of our decision to start the crushing business.”

The result is an affiliated company called ReRock Materials, which creates recycled concrete and aggregate products.

Though ReRock is a business and is operated as one, the McAfees are committed to recycling as an environmental best practice, even though they live in a region where natural aggregate is in ample supply and landfill fees are low.

“We want to recycle a large amount of concrete per project,” David McAfee said. “But we are not doing this because, hey, this is a windfall. We are doing it as a commitment to the recycling industry.”

Experienced as David McAfee was in construction and demolition management in 2008, he was a novice recycler. He had seen a rock crusher at ConExpo, and went shopping for more information. After visiting recycling operations and looking over different brands of crusher, he finally bought a mobile jaw crusher and went to work.

Almost as important was his meeting with Brian Costello, co-founder and sales director of Crushing Tigers. The company with the vivid name supplies mobile crusher and screen machines and spare parts in the Oklahoma and Arkansas markets.

Costello sold McAfee an Extec S-3 screen, currently known as the Sandvik QA140, a tracked unit with a 10’ x 5’ screening area and double-deck screen, which exceeded his expectations.

When McAfee discovered that along with supplying a reliable product, Costello was knowledgeable and reliable, he began to look to Costello for further industry insight.

He looked to the right person. When Costello and managing director Pat Doab started Crushing Tigers, they did so with the intention of guiding customers towards ever more efficient crushing and screening operations. In looking critically at DT, the men soon concluded more efficiency for its operations would require a secondary crusher.

CRUNCHING NUMBERS

The problem was David McAfee was not in the market for another crusher.

To convince McAfee, the team demonstrated a Sandvik QI240 Prisec mobile impact crusher. The demonstration and subsequent analysis showed that while the overhead of a second machine had been added to the crushing process, the cost per tonne of crushed concrete decreased. Costello and Doab repeatedly crunched the numbers with McAfee until there was no question in his mind.

ReRock Materials had increased production way out of proportion to the increase in production cost.

“Before adding the Sandvik crusher, we were normally producing 30-50 tonnes of sellable product an hour,” McAfee said. “Now, if we are not doing 200 tonnes an hour, there is something wrong.”

That massive increase in production makes all the numbers look good. The addition of the Sandvik QI240 reduced the cost per tonne to a third of its original figure. Furthermore, with the QI240’s four-bar rotor turning irregular chunks into uniform nuggets, reliance on the original jaw crusher was lessened, extending its working life.

At DT, the QI240 is used mainly, but not exclusively, as a secondary crusher. The only reason the McAfees can use the machine in both capacities is that it is the only impact crusher on the market capable of operating in either a primary or secondary position. This unmatched versatility comes from the patented design of its impactor box.

Besides operating efficiency, what sold McAfee on the QI240 was its portability. The 43-tonne crusher moves on 20-inch wide tracks and is conveniently transported by trailer. The compact machine is just 2.4m wide and 14m long – an easy permit to get for companies wanting to operate the crusher at more than one location at the production rate this machine can achieve. DT is one such company.

CUSTOM CRUSHING

“My bigger motivation in getting the QI240, aside from cost savings, was to have a machine I could throw on a trailer, run 500 tonnes of material in a day, and then move it back off-site,” David McAfee said. “Its mobility is key, and its quick set-up.”

These two attributes of the QI240 – the efficiency of the machine’s crushing process and its portability – have ushered in additional business for DT. First, more rock is being processed by the company for selling and stockpiling against future sales. Second, when work is slow at a demolition site, the QI240 is taken elsewhere for custom crushing.

“I’m glad we started doing business with Crushing Tigers and Sandvik,” McAfee said. “We are better than we were before. Developing the relationship, coupled with the sharing of expert advice, has certainly improved our business.”

Such trusting relationships are precisely what Costello and Doab want to forge with their customers. According to Doab, “the key is working together as a partnership. The relationship is important for sustainability, and the trust creates opportunities for everyone”.

Costello said selling and servicing good machinery was gratifying, but becoming trusted partners with customers topped everything.

“I respect what machines can do, but it is working with people that makes my day.”


Source: Sandvik Construction

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