Plant Equipment and Hire August 2017 | Page 36

Crushers and Screens
Product focus
ADTS RDTs Skid-steers Telehandlers
Articulating boom
Telescopic boom lifts
Graders Dozers Excavators Loaders TLBs Pad foot Smooth drum PTR Tandem Mobile cranes Tower cranes Crawler cranes
Mobile crushers
Mobile screens
Bucket crushers
Generators
Mobile compressors
Hydraulic breakers
Crushers and Screens
BR Howard & Associates
A trip hammer produced in the 1700s.
Jet Lowe Jet Lowe
Detail view looking down at the Blake jaw crusher at the Standard Gold Mill in Mono County, California— an intact example of the stamp mill that developed in the wake of the California gold rush.
Ruffner Red Ore Mine gyratory crusher in Birmingham, Alabama. screen area usage as well as processing capacity and capability.
In 1960, the feeder-breaker was developed for underground coal mining, to follow the continuous miners. These are low-headroom machines that consist of a flight bar feeder and a rotating breaking drum with teeth or picks. The material is transferred to the tail end of the feeder, dragged towards the head end, and crushed in-line as the material passes under the drum. These machines have now been modified and upgraded to handle limestone and other non-abrasive materials. Some manufacturers identify the rock machines as impact horizontal roll crushers.
It was also in the 1960s when vibrating screens were developed and introduced. This technology still forms the basis of modern machinery today, where developments are in the form of screen types, multiple decks, and wet and dry processing.
In the early 1980s, low-speed sizers were introduced, representing one of the only fundamental developments in primary crushing machines of the 20th century. Conventional roll crushers are suitable for crushing soft to medium-strength materials and are generally designed with high
peripheral speeds, making uneven wear a major potential problem. The low-speed sizer exploits the 10:1 ratio of compressive strength to tensile and shear strength found in the majority of rocks, breaking the rock in tension using its‘ snapping’ and chopping action, rather than the compression used by conventional crushers. The positioning of the teeth on the rolls also allows undersize material to fall directly through, resulting in high throughputs at very low rotational speeds and in greatly reduced wear, increased energy savings, and better control of discharge size.
Current look
Today, we find crushers in various scales and configurations, depending on their application, and typically accompanied by a mechanical screening system with various set-up options, in mining and quarrying specifically, but also in the agricultural sectors, construction, and recycling, from woven wire cloth mesh, perforated and punched plates, to synthetic screen media( typically rubber or polyurethane). Advancements currently focus on efficiency of the machines, and adopting different technologies, materials, and durability. n
Sources
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911 Metallurgy. 2016. Gyratory Crusher Lube System [ video ]. https:// www. youtube. com / watch? v = LcaoFTan _ hA.
2.
BR Howard & Associates. 2008. Hay Creek Trip Hammer. http:// www. brhoward. com / hay _ creek _ trip _ hammer. html.
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crusher & mill. 2014. The history of vibrating screen in China. https:// sbjawcrusher. wordpress. com / 2014 / 10 / 03 / the-history-of-vibrating-screen-in-china.
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History. com. 2010. The Gold Rush of 1849. http:// www. history. com / topics / gold-rush-of-1849.
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King, R. P. 2001. Modeling and Simulation of Mineral Processing Systems. Delhi: Butterworth-Heinemann. https:// miningandblasting. files. wordpress. com / 2009 / 09 / modeling-and-simulation-of-mineral-processingsystems
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Leachman, J. 2016. Intro to the Uganda Rock Crushing Project. Hydrogen Properties for Energy Research( HYPER) Lab, Washington State University. https:// hydrogen. wsu. edu / 2016 / 04 / 02 / intro-to-the-ugandarock-crushing-project
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Lynch, A. J. & Rowland, C. J. 2005. The history of grinding. Littleton, CO: Society for Mining, Metallurgy and Exploration( SME). https:// www. 911metallurgist. com / blog / the-history-of-grinding.
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McGrew, B. 1953. Crushing practice and theory( reprinted from Rock Products). Appleton, WI: Allis-Chalmers Manufacturing Company.
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Michaud, D. 2016. Screening 101. 911 Metallurgist. https:// www. 911metallurgist. com / blog / screening-ore-rock.
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Michaud, L. D. 2015. Crushing. 911 Metallurgist. https:// www. 911metallurgist. com / blog / crushing.
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Michaud, L. D. 2015. Rock crusher history. 911 Metallurgist. https:// www. 911metallurgist. com / blog / rock-crusher-history.
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Screening Systems International. 2017. History. http:// www. screeningsystems. com / PageDisplay. asp? p1 = 11484.
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Shanghai Yingji Machinery Trading Company. [ n. d.]. History of crushers. http:// www. machinerychina. org / faq / crusher-history. html
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Singh, P. 2013. Tata Hitachi Zaxis-210 LCH, with Daemo DMB 210 rock breaker [ video ]. https:// www. youtube. com / watch? v = kMSGMNtKAkw.
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Stairs, D. 2017. Screening 101. Aggregates Equipment. http:// aeiscreens. com / screening-101.
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ThomasNet. 2017. Industrial history: The history of the steam engine. http:// www. thomasnet. com / articles / custom-manufacturing-fabricating / steam-engine-history.
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Triphammer Bierwerks. [ n. d.]. What’ s a triphammer? http:// www. triphammerbierwerks. com / whats-a-triphammer.
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Usher, A. P. 1988. A history of mechanical inventions, revised ed. Mineola, NY: Dover.
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Woods, M. & Woods, M. B. 2000. Ancient machines: From wedges to waterwheels. Riley, J. E. & Drits, D.( eds.). Ancient Technology series. Minneapolis, MN: Runestone Press.
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