Innovative rear-eject bodies maximize profits for mini-mill operations.

By Josh Swank

How does a business thrive in hard times? That is the question on mini-mill operators’ minds as they experience a decline in the demand for recycled scrap. The answer is with a rich ROI. One key ingredient in achieving ROI is the equipment fleet mills operate, and perhaps the most impactful area on efficiency is the haulage of scrap to the charge bucket. The equipment options for haulage vary from railcars to standard dump bodies, or even custom, high-volume body designs, with the most recent player in the market using rear-eject technology. Because the rear-eject design eliminates the need to raise the truck body while discharging material, operators can safely and efficiently dump materials indoors without concern for potential obstacles overhead. This makes them a safe and effective option for scrap recycling operations, but the benefits do not stop there.

Shopping for Scrap 

Picture the variety of foods in a grocery store. Similar to this, scrap yards present mini-mill operators with a wealth of ingredients for making steel depending on the different varieties, sizes and densities of scrap. Operators see each piece as an ingredient, and the more kinds of scrap they have access to leads to greater flexibility in the types of steel they may produce for customers.

Unfortunately, the hauling equipment selected often limits flexibility. Because of overhead height restrictions in some older mills, the traditional solution for hauling scrap was to use a rail car. While this overcomes height restrictions, it also reduces the type of scrap to the number of rail cars able to fit within the melt shop, with one material in each car. This is where the strengths of off-highway trucks and rear eject bodies come into the picture. Operators gain more control over the amount of scrap, or “ingredients,” they collect thanks to the added mobility. They have the option to use as much as 35 to 50 different types of scrap in a load, providing extreme flexibility in the steel recipes they create. This expands offerings for the steel mill customers—and, in turn, the operation’s profits—because the operation has the ability to produce different grades of steel. This also enhances safety because the truck maintains a low center of gravity. In comparison, raised dump beds have a dynamic center of gravity, which changes as the body raises and the material flows into the charge bucket.

Not only is this technology a great way to increase business, but it also increases efficiency through the process since the truck can move seamlessly from collecting the scrap to unloading it into the charge bucket, minimizing backups within the melt shop with overhead cranes.

It is All About Chemistry

A recipe is more than ingredients; it is a process or set of instructions on how to prepare and mix those ingredients. The same is true with scrap recycling. Recycling professionals know that the right process and mix of materials results in a faster melt into molten steel, which allows them to make more heats in a day.

Ensuring proper melt-in chemistry when unloading scrap into the charge bucket cuts down on cycle time. Rear-eject truck bodies allow operators to use an effective layering technique, which speeds up the melting process. The layering technique is based on the order different scrap densities are loaded into the truck body. For example, operators place light material in the front, the densest materials in the middle and additional light material in the back. When the ejector body empties into the charge bucket, the material maintains that ideal order for melting. The charge bucket empties the scrap into an electric arc furnace where the light material melts quickly and forms a liquid pool of melted steel surrounding the dense material, helping to break it down faster. Traditional dump bodies empty scrap all at once, reducing the opportunity for optimal melting mixes and practically eliminating layering techniques as the material churns as it empties from the body. Ejector bodies also allow operators to control the speed at which the material is released into the charging bucket, protecting the bucket from damage caused by scrap entering too fast.

With the layering technique that rear eject technology allows, an operation can reduce its overall tap-to-tap time, or electric arc furnace operating cycle. While most operations aim for a tap-to-tap cycle time of 60 minutes, some layering techniques have reduced the cycle time to 51 minutes or better. This means the operation has the potential to produce roughly four more taps in a 24-hour day, increasing productivity and profits by 15 percent without increasing labor or equipment expenses.

Once the body is empty, a truck with a rear eject body can quickly return to the scrap yard without the one to two minute delay of waiting for the truck bed to lower. The ejector blade and tailgate return to the load-ready position as the truck drives away. Once again, in addition to convenience, rear-eject technology offers enhanced safety. If a rushed operator fails to wait for the truck bed to completely lower, there is increased potential of harm to the driver, the truck and the structure of the mill should the raised body hit an overhead obstacle, such as a door or other piece of equipment.

The Right Measurements

No two operations are the same, especially when it comes to the charge bucket placement, dimensions or volumetric size. As the charge bucket’s size is determined by the capacity and optimal tap-to-tap times of the furnace, pairing the right number of haul trucks to the operation is critical.

Since all charge bucket sizes are unique between mills, it makes sense to have a custom-sized truck body feeding it. This helps an operation reduce the number of trips to the scrap yard because the body size is designed to fill the charge bucket in as few loads as possible. When a manufacturer is willing to work onsite with a mini-mill operator or scrap handling contractor, custom designs go a long way in maximizing efficiency. Factors like the charge bucket size, placement and whether the charge bucket sits on a dolly and moves to a hoisting position or raises directly from its pit all play a role in the truck body design. Work with a manufacturer that also considers height and width restrictions within the mill, door dimensions and the trucks’ path for moving in and out of the mill.

Some mills incorporate funnels at the top of the charge buckets to help prevent scrap from overshooting the bucket. Scrap that misses the charge bucket often builds up in a pit around the bucket and requires additional labor to clean up, or can lead to thousands of dollars in damages and repair costs. To combat this issue, some manufacturers custom design truck body tailgates to incorporate funnels, minimizing the risk of equipment damage and further customizing the solution to the mill’s requirements.

Ditch The Downtime

Every second counts in an operation in terms of profitability. That is why downtime is not an option when making steel. Purchasing equipment with minimal maintenance requirements makes upkeep simple and reduces costly downtime.

Custom body manufacturers know that fewer moving parts mean minimal breakdowns and maximum uptime. Look for models with low-maintenance hydraulic controls and a mechanical tailgate that opens and closes based on the ejector blade’s location without using additional hydraulics. Also, look for a design that has no grease points as well as ejector body technology that does not require ejector blade or tailgate electrical or hydraulic locking mechanisms. Some manufacturers even incorporate ejector guides inside the body, which provide smooth operation and eliminate rollers that frequently break or bind. At a replacement cost of as much as $1,000 per roller or bearing, the potential savings with a roller- and bearing-free design is huge.

When a body is custom designed for scrap hauling, there is no guessing game on how long it will last. Every aspect from the floor structure to the ejector system considers the application and maximum load capacities, ensuring longevity. This way businesses know they are investing in a machine designed to work with them for years to come. In fact, some scrap bodies last more than 20 years.

A Solid Review

Urbanspoon, Yelp and others are the go-to resource for some when deciding where to go for dinner. That is because reviews matter and that is not exclusive to the service industry. Check out the manufacturer’s Web site, industry blogs, articles and social media sites before purchasing custom equipment with rear eject technology to see what its customers are saying. The right equipment is the secret ingredient leading to increased ROI.

Josh Swank, Vice President of Sales and Marketing for Philippi-Hagenbuch (Peoria, IL), building equipment for off-highway haul trucks since 1969 and a global leader in off-highway truck customization. Josh oversees the steel mill, refuse and mining industry sales group and has been with the company for more than 16 years. Josh also participates in multiple industry and philanthropic organizations, including the National Stone Sand and Gravel Manufacturers & Services Board, the NSSGA Young Leaders and the National Mining Association Board of Governors. For more information, call (800) 447-6464, e-mail [email protected] or visit www.philsystems.com.

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