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P&Q University Lesson 9: Washing & Classifying
Materials engineers constantly strive to improve concrete and bituminous mixes and road bases, and clean aggregate is a vital part of that effort. Yet, aggregate producers often find it difficult to meet all the requirements for “cleanliness.” While hydraulic methods are most satisfactory for cleaning aggregate to achieve desired results, they are not always perfect. It is still necessary to accept materials on the basis of some allowable percent of deleterious matter. Photo by Zach Mentz In broadest terms, construction aggregate is washed to make it meet specifications. Specifically, however, there is more to the function of water in processing aggregate than mere washing. Among these functions are: ■ Removal of clay and silt.■ Removal of shale, coal, soft stone, roots, twigs and other trash.■ Sizing.■ Classifying or separating.■ Dewatering. Because no washing method is flawless, and because some materials may require too much time, equipment and water to make them conform to specifications, it is not always economically practical to use such materials. Therefore, it is important to test… Keep Reading
Bucyrus-Erie bulldozer, bullgrader work in tandem
https://youtu.be/KB3GUJsIzNI In this archived video, a Bucyrus-Erie bulldozer and bullgrader are working in tandem. This video was was compiled, narrated and produced by Keith Haddock for the Historical Construction Equipment Association. Keep Reading
Cones offer fast adjustment of closed-side setting
REMco offers the PROcone series of cone crushers for secondary and tertiary crushing applications. It features a rugged cast mainframe, bronze eccentric and mainframe bushings. The crusher boasts a large feed opening that remains consistent throughout the life of the manganese, says the company. No backing is required on the PROcone wear liners, making change-out fast and efficient. Push button, hydraulic controls are designed to provide easy and fast adjustment of the closed-side setting. Hydraulic tramp iron relief protects the crusher from damage owing to the passage of uncrushables through the machine. Multiple liner configurations and several eccentric throws allow the machine to be matched to the crushing application to maximize wear liner and production performance. www.remcoprocone.com Keep Reading
Bucyrus-Erie “Doubler” electric shovel
https://youtu.be/A6FjERWl5FI The Bucyrus-Erie "Doubler" electric shovel doubled the dipper capacity of a standard shovel. The 150-B in this video featured a 13-cu.-yd. dipper when equipped with the Doubler. However, the Doubler never surpassed the prototype stage and was not considered a success because of its complicated bucket linkage system and high maintenance requirements. This video was was compiled, narrated and produced by Keith Haddock for the Historical Construction Equipment Association. Keep Reading
Fifth-generation features larger breaker capability
Breaker Technology Inc.’s maintenance-friendly NT-E Series Rockbreaker System features robust connections, compact pedestal mounting and common cylinders. Its increased strength and optimized hydraulics allow the NT line to support a broader range of breakers, from 800 ft.-lb. class to 3,000 ft.-lb. class (BX8 to BX30) throughout the NT12 to NT24 offerings. The compact pedestal design allows for mounting to competitors’ bolt patterns without the need of an adaptor plate. Dual joysticks operate a fully proportional, load-sensing directional control valve, providing precise control of all boom functions. The basic system can be modified to suit many needs, including radio control pendants for maintenance and long-distance applications. www.rockbreaker.com Keep Reading
Impact crusher designed for versatility in the field
McLanahan’s Next Generation Secondary (NGS) impact crusher is designed to reduce downtime for adjustments, require fewer wear parts to inventory, and be modified in the field to accommodate changes in application and product requirements. It features a hydraulic-shim adjustment on each impact curtain for simplified operation. An optional third curtain can be installed in the field, and allows for further reduction. Other design features include interchangeable liners, extra-large inspection doors, various shaft devices, and a single hydraulic power unit. The disc type rotor is equipped with an S-shaped hammer for maximum sustained productivity. The NGS line of impactors has optional adjust-on-the-fly capabilities with a complete automation package, and is available in seven model sizes. www.mclanahan.com Keep Reading
Video: Bucyrus-Erie 395-B shovel
https://youtu.be/mszfgOm0Llw This video showcases Bucyrus-Erie's 395-B shovel in 1979. With a 34-yd. dipper, the 395-B was the largest mining shovel built by the company up to that time. Watch the shovel in action. This video was was compiled, narrated and produced by Keith Haddock for the Historical Construction Equipment Association. Keep Reading
Hydraulic drive optimizes crusher capacity
The track-mounted GT440 from KPI-JCI and Astec Mobile Screens features an Andreas 4240 Horizontal Shaft Impact (HSI) crusher, available in a three- or four-bar rotor configuration. The GT440 uses a vibrating grizzly feeder (VGF) with a large hopper, and with an optional grizzly pre-screen designed to keep the crusher fed and operating efficiently. The grizzly pre-screen consists of independent vibrating fingers that resist blinding and plugging. The replaceable pre-screen module provides multiple settings for scalping unwanted material. The crusher’s hydraulic drive optimizes crusher capacity without sacrificing blow bar wear, according to the manufacturer. The 5 x 10-ft., two-deck screen offers 100 sq. ft. of screen area. www.kpijci.com Keep Reading
P&Q University Lesson 6: Off-Road Hauling
In most aggregate operations, off-highway trucks provide the production link between the loading face in the pit and the primary crusher or processing plant. Efficient haulage is critical both to meeting production targets and to managing costs. Proper selection and sizing of trucks, efficient operation and timely maintenance, and well-designed and maintained haul roads are the keys to productive and low-cost haulage. RIGID FRAME VERSUS ARTICULATED There are two main kinds of haul trucks: Rigid frame and articulated. Though each type hauls material, the two different truck configurations have different strengths that suit the machines for most efficient operation in different site conditions. No matter what the choice of hauling system is, the machines must perform or participate in several functions: loading, hauling, dumping and returning. Each type of hauling unit has advantages in some parts of the cycle and disadvantages in others, depending on the site conditions. Photo by Joe McCarthy All trucks require the use of a loading tool, and of course the loading machine and trucks must… Keep Reading
