August 2, 2011
Portables in the Quarry
Whether it’s a screening plant or a crushing plant, portable plants have carved their way into our quarries.
By Kerry Clines, Senior Editor
Portable crushing plants are now able to handle larger sized rock, making it possible to use only portable crushers throughout an entire operation.
Grasan custom-designed a 3,000-ton-per-hour, tracked, horizontal impactor plant that features a New Holland-type Williams three-blow-bar impact crusher with a Williams 6-foot by 50-foot apron feeder and Simplicity 7-foot by 20-foot grizzly bar scalping screen that handles material up to 60 inches in size. The KRHT-60E measures 47 feet high, 39 feet wide, and 122 feet long, and weighs 1.2 million pounds. The 120-ton hopper is 24 feet wide, 29 feet long, and 9½ feet high. A built-on BTI hydraulic hammer breaks up oversize materials. The chassis mounting consists of two pairs of custom-designed B9 tracks with 40-inch-wide smooth pads and self-leveling stabilizer legs. The twin-track unit is powered by two 300-horsepower electric motors, travels at 0.5 miles per hour, and can turn at various angles up to 90 degrees.
The new MR 110 Z EVO unit from Kleemann features a new material flow concept — the discharge chute under the crusher is 4 inches wider than the inner width of the crusher, and the discharge belt is 4 inches wider than the discharge chute. Rapid flow of the material keeps it away from the critical area under the crusher and reduces wear. An independent vibrating double-decker pre-screen is said to improve cost efficiency. A newly designed crusher bypass includes changes to its geometry and form to boost performance and reduce wear. Optional new and improved screening units are available and are more than 44 percent larger in size than those on previous units, allowing for tonnages of between 350 and 450 tons per hour.
Atlas Copco’s new line of Powercrusher track-mounted mobile crushers and screeners includes jaw crushers, impact crushers, and cone crushers with a crushing capacity from 242 to 606 tons per hour, and screeners with a capacity of 242 to 485 tons per hour. The four jaw crushers incorporate “Quattro Movement” made possible by an up-thrust toggle plate position. This causes a figure-eight motion in the moving jaw, which increases the feeding capacity and produces a post-crush at the crusher outlet. The six impact crusher models use optimized geometry in the crusher box with hydraulically adjustable swing beams, resulting in a minimal percentage of oversized material and high reduction ratios and throughputs.
McCloskey’s new J-40 compact, track-mounted jaw crusher features a true 24- by 40-inch jaw. Additional features include push-button, closed-side setting control; an ultrasonic level sensor in the jaw to automatically adjust feed rate; and a 7.4-cubic-yard hopper capacity. Transport dimensions are 8 feet, 3 inches wide; 41 feet, 7 inches long; and 10 feet, 6 inches high; with a weight of 68,500 pounds. Power requirements are supplied by a 225-horsepower Cat C6.6 ACERT engine driving a high-efficiency hydraulic system.
Kleemann’s MC 110 Z track-mounted jaw crusher boasts a high-torque reversible hydraulic jaw and fully hydraulic gap adjustment. The R version has an integrated grizzly, while the Z version has a fully independent, double-deck pre-screen. The unit can be fitted with an optional final screen and oversize discharge, which allows the operator to produce a final graded product with a single machine. The fuel-efficient crusher uses a Cat C9 engine and is configured for operation by a single person who can feed raw material into the crusher while using a wireless remote-control unit in the cab of an excavator or loader. Crusher transport weight is 99,200 pounds; length is 47 feet, 5 inches; and width is 9 feet, 10 inches.
FLSmidth’s wheel-mounted XL300 and XL400 cone crusher plant options include rear discharge and rear-feed side discharge. Both crushers can be configured with two- or three-deck horizontal screens that are 6, 7, or 8 feet by 20 feet, which provide open-circuit crushing and screening. Hydraulic run-on jacks are available as an option to level the plant after it is pulled on site. A high pivot point and large crushing stroke offer better crushing action throughout the crushing chamber. An active feed opening creates better end-product shape. The crushers also employ “fail safe” hydraulics through an internal relief valve within the dual-acting tramp release cylinders.
Powerscreen’s new 1500 Maxtrak is the largest crusher in the company’s line. The company says the plant can accept an all-in feed from a primary crusher to produce up to 950 tons per hour of material. Features include hydraulic overload protection, hydraulic crusher setting adjustment, excellent product shape, a high reduction ratio, an efficient crusher direct-drive system, a large feed hopper complete with metal detector, and a contaminated material purge facility.
The new Terex Cedarapids CRC380HLS portable crushing and screening plant is designed for constant choke feeding. Its high-lift screen and cone hopper overflow system allow a large head of material to build up, force-feeding the cone crusher. The large cone hopper and overflow chute are said to buffer feed variations and prevent material from backing up to the screen, allowing production rates of up to 1,200 tons per hour with no need to throttle back. The unit’s 6- by 20-foot TSH6203 triple-deck horizontal screen has a blending gate system that allows center and bottom decks to be combined in 25-percent increments. Two large, 30-inch conveyors discharge up to 44 inches beyond the plant frame on either side. The four-axle configuration and a 3+1 axle option provide portability.
Sandvik says its new QH440 track-mounted cone crusher is designed for mobility, ease of transporting, and quick set-up time. The unit features a CH440 cone crusher capable of producing up to 388 tons per hour. Additional features include a heavy-duty, wear-resistant, hydraulically folding feed conveyor; a dual-coil metal detector; automated material-level feed control; four jacking legs for stability; and a wide selection of optional extras. The unit comes with a choice of six crushing chambers ranging from fine to extra course. Product shape and grading can be easily adjusted by changing the throw.
McCloskey says it designed its new I-54 crusher from the ground up to be the most productive track-mounted impactor in the sub 50-ton, “one-piece move” class. It features a 47- by 53-inch four-bar horizontal impact chamber with a 53.3- by 32.5-inch feed opening to allow for large feed sizes. An 8.9-cubic-yard hopper with vibratory pan feeder flows material over a fully independent 4-foot, 6-inch by 5-foot, 9-inch double-deck inclined pre-screen to remove fines. Crushed material is discharged via a heavy-duty, high-energy pan feeder measuring 4 feet, 6 inches by 6 feet, 7 inches located under the impact chamber, which reduces belt wear and the possibility of belt tears. The crusher is controlled by a PLC. A 430-horsepower C13 Cat ACERT engine supplies the power.
Portable screening plants have come a long way from the early years. Most now offer the ability to separate material into as many as three separate sizes and stockpiles.
Deister’s new portable, horizontal screening plants are available in 6- by 20-foot and 8- by 20-foot models, as well as a number of custom configurations, making them suitable for in-pit portability or easy transport from site to site. Features include a walking beam tri-axle suspension, access ladders and walkways on both sides and front of the smaller screen (hydraulic folding on the side of the larger screen), centralized grease points, chutes and hoppers lined or made from AR 400 plate, a 60-inch undersize conveyor below the smaller screen (an 84-inch undersize conveyor on the larger screen), 30-inch motorized head-pulley cross conveyors (36-inch on the larger screen), and self-cleaning wing-type pulleys.
KPI-JCI says its new multi-frequency screen will revolutionize the screening industry. By combining both conventional and high-frequency screen movements, the screen is able to maintain the higher production rates of a PEP screen at a lower angle, while having the ability to handle higher, moisture-content materials. Coarse material requires more amplitude and less frequency, while fine material requires less amplitude and more frequency. The multi-frequency screen combines both theories. By working at a lower operating angle, the overall height of the screen is less, making it safer to maintain and operate.
Sandvik’s new QA331 portable, three-way split screener features a 14- by 5-foot, two-bearing screen box with an increased 6-degree screening angle built into the bottom deck of the screen. Other features include a larger screening surface area, increased throw on the screen box, an I-beam design for maximum durability, a folding access walkway around the screen box to provide easy access for maintenance, a 7-cubic-meter-capacity hopper with a radio-controlled tipping reject grid, and a main conveyor fitted with a 1,050-millimeter heavy-duty belt. The unit’s tracks are 500 millimeters wide.
Screen Machine says its new patented Spyder 512T portable screening plant opens up a new size class of machine. The plant has the same engineered features as its predecessor, the 516T. Features include a 5-foot by 12-foot double-deck, two-bearing screen; Grade 80 high-strength steel construction; and the ability to place materials in windrows in three different sizes with remote operation.
According to Inertia, its new prototype 620 Spec Maker portable screening plant offers a compact design for portability on its own triple-axle chassis, yet delivers 20 percent more screening capacity compared to standard models. The unit features a 6- by 20-foot double-deck, inclined screen; its own onboard fold-down feeding, transfer, side discharge, and stacking conveyors; and a 48-inch belt feeder with hopper and grizzly. It can be combined with any crushing plant in the company’s line to create a closed-circuit operation, without the need for additional transfer conveyors.
Metso says its new Lokotrack ST3.5 can produce two-sized fractions, with an optional two-deck vibrating grid that can be installed to yield three-sized fractions. The unit features an 11-foot, 7-inch by 5-foot screen box with a 57-square-foot screen area and is powered by a 100-horsepower Cat 4.4 engine. Four identical meshes are used on the screen to lower stock requirements.