Challenge to process wet, sticky material at Lannon Stone site is resolved with Lippmann plant
by Markham & Associates Advertising, Inc.
Photos provided by Lippmann, Inc.
Lannon Stone Products, Inc. produces and sells construction aggregates from four locations in southeast Wisconsin where they serve the concrete, asphalt, road building, landscape, utility, grading and building stone industries. A third generation family owned company, Lannon Stone has continuously invested in their aggregate business with quality equipment and intelligent processes to offer the highest quality products at the lowest possible cost to their customers.
The company began with their Lannon quarry in 1967, and experienced continuous growth with the addition of a town of Jackson gravel pit in 1970, Richfield gravel pit in 1970, and their Lisbon quarry in 1983. The Lisbon quarry is located just outside Lannon, south of Sussex, and is a 240-acre deposit that consists of three distinct layers. A top layer containing roughly 50% sand and gravel used for concrete and asphalt production, and 50% stone ideal for use in architectural applications. Below that is about a 60’ deep layer of zero chert high quality limestone, ideal for use in producing high strength concrete, riprap or erosion control and general construction products. At the bottom layer is about 160’ of standard limestone that is more typical of the limestone material found in southeast Wisconsin, used to produce road base, clear stone and general construction products.
The immediate challenge at the Lisbon gravel pit, says Hans Dawson, third generation in a line of family owner/operators, was to design a primary plant that could efficiently and effectively process this first layer of material, employing the most productive methods possible. Rock crushing runs through Hans Dawson’s veins. His grandfather started the business. Virgil, Han’s father and his son proudly continue Lannon Stone’s legacy today. Mentored by his father, Hans thoroughly enjoys the material processing business and is a graduate engineer of Colorado School of Mines. Hans quotes a professor, “You don’t design the mine, the mine designs the material processing installation for you.” For years, the mining and cement industries have employed the benefits of rugged, reliable “tractor-type” apron feeders under surge bins, silos and hoppers to meter large, abrasive, heavy rock during wet, sticky or frozen operations. With that in mind, the Dawsons took to exploring a design for the optimal primary crushing system that could handle the difficult material in their Lisbon operation efficiently. Hans and Virgil had no hesitation as to which crushing and screening equipment supplier they would collaborate with that was capable of delivering the customized plant they envisioned. They contacted Lippmann.
“This gravel layer processes well when dry using a conventional vibrating grizzly feeder and primary jaw configuration, but when wet, the plant can’t produce adequately. The material becomes too sticky for the feeder to throw the material up. The material just folds between the grizzlies and becomes impossible to feed, while consuming excessive horsepower,” states Dawson.
The new Lippmann Primary Crushing Station commissioned in August 2013 consists of a heavy-duty Lippmann 3862 Portable Electric Jaw Crushing Plant with a Lippmann 62” x 10’ Scalping Screen, fed by a Lippmann Heavy-Duty Apron Feeder with 59” steel apron pans and 45’ sprocket centers. A 100 cubic yard hopper accepts loading from the rear with a greater than 100 ton live load capacity. The Primary Lippmann Jaw Crusher’s throughput is approx. 700 tph, with the plant currently producing approx. 700,000 tons per year.
Hans indicates that originally they considered using a Lippmann 3048 Jaw Crusher, but stepped up to the new Lippmann 3862 model which features a huge feed opening, yet has a low profile. Hans claims this was an extremely good decision.
“It can handle anything. As you can see there is no hammer required on this plant right now, although we’ll add a breaker later just for safety reasons,” Hans noted. “With the way this apron feeder continuously takes care of the feed control, the system is essentially fully automated.” Hans goes on to indicate that the entire Lisbon quarry operates with only five personnel on site and one individual at the ticketing station. The Lippmann plant also frees up personnel to address other operational needs.
Key to the plant’s productivity, Hans stresses, is that the 62” x 10’ three grizzly section scalper, driven by an LLH-26 vibrating mechanism with two full-length counterweighted solid steel shafts, is very aggressive. “It really gets the clay through the grizzly, it’s 100% efficient.” Fines are allowed to discharge directly into the discharge chute.
The heart of the plant, Lippmann’s heavy-duty 3862 Jaw Crusher, easily devours large feed and features an extra heavily ribbed steel frame, one piece pitman, heat treated forged shaft, oversized tapered roller bearings, reversible manganese jaw dies, Hardox cheek plates, a manual hydraulic toggle, and automatic oil lube system. The massively robust Lippmann Heavy-Duty Apron Feeder lined with ¾” Hardox bolt in liners feeds the crusher. The custom apron feeder features CAT D6 components that include support rollers, chains and sprocket group, with trunion return rollers. The pan flights are UNiCAST double grousers, resulting in a unit constructed for ultimate, rugged, long wear life. “I really like the fact that Lippmann used existing off-the-shelf quality tractor components to design this apron feeder, so parts are readily available. They’ve also designed everything to be easily accessible for maintenance,” Hans confirms.
The custom Lippmann plant incorporates a 60” x 100’ front discharge conveyor, and has a by-pass chute under the grizzly sections of the scalper. The heavy duty I beam support structure with all necessary chutes, guards, operator platforms, walkways and staircases, and a 10’ x 10’ control house to observe the entire crushing station, were all supplied by Lippmann to satisfy every customer requirement. Civil engineering was provided by Lannon Stone.
Hans also credits Dave Phelen and Jeremy Kerber from Lippmann engineering for doing an excellent job. When designing the plant and determining size, tonnage, drive calculations, equipment configurations, etc. to meet specific application needs, Lippmann engineering worked in close collaboration with the Dawsons, showing them the plant in 3D SolidWorks. “That was very helpful with determining our clearances, virtually eliminating post production changes,” says Hans. Dave and Jeremy provided technical expertise on site during the install as well.
When asked about Lippmann’s after sales support, Hans states, “Lippmann personnel have always supported us all the way. Anything they make, we’ve always counted on their field and parts support, they’re great.”
“The plant is performing real well. Admittedly, it outruns our wash plant right now and is overbuilt, but we like it that way. We ship product from two rail lines here, so this operation is designed to primarily serve the current and future demands of the Chicago concrete and asphalt markets with quality material, as well as Milwaukee,” Hans concludes.
All three generations of Dawsons know the value of investing in heavy-duty, rugged and reliable equipment. Experience has proven that continuous trouble-free operation reduces their operating downtime and overall cost. Hans’ grandfather was sold on the reliability of Lippmann equipment early on. He invested in Lippmann equipment decades ago. The Lannon Stone organization currently operates two Lippmann 4248 Stationary Jaws, a Lippmann 3048 Portable Jaw Plant, and a Lippmann 2248 Portable Jaw Plant. Therefore, when it came to engineering a custom solution for the Lisbon quarry, Hans states with conviction “Our Lippmann equipment is proven, we don’t have any problems with it. We’ve worked with Lippmann since 1970. They listen carefully and are capable of providing whatever we ask. We have a great working relationship with them.”
Lannon Stone’s success is rooted in producing valuable products for their customers, operational excellence and community involvement. This clean, low dust emission primary plant at their Lisbon quarry is a prime example. They know that providing quality products used in bridge construction, structural supports, roads, utilities installation and other projects the public safety relies on is something they take seriously. Delivering these products at a competitive cost, frees capital for other projects, ultimately improving the standard of living for communities and businesses alike. That speaks well of Lannon Stone and the suppliers they trust in who are committed to the same values.