The summits of mine dumps may possess a conical shape and stand out as notable landscape features, but they can also be flat and eroded. A mine dump is formed from waste rock delivered from the mine or quarry to the apex of the cone by railcars, skip hoists, or conveyors.
At the Freeport-McMoRan copper mine in Morenci, Arizona.
The open pit copper mine here is one of the world’s largest. I have struggled to find a reference for how impossibly tall this man-made mountain of mine tailings is. The best I can do is estimate from topographic maps, with a guess of about 600 feet (180 meters) from the canyon floor to the top, or just taller than the Washington Monument. I have a long and growing list of places in Arizona I don’t want to be during an earthquake, and this pyramid of rock and debris is now high on the list.
Excerpt from this story from The Conversation/EcoWatch:
Scars from large mining operations are permanently etched across the landscapes of the world. The environmental damage and human health hazards that these activities create may be both severe and irreversible.
Many mining operations store enormous quantities of waste, known as tailings, onsite. After miners excavate rock, a processing plant crushes it to recover valuable minerals such as gold or copper. The leftover pulverized rock and liquid slurry become tailings, which often are acidic and contain high concentrations of arsenic, mercury and other toxic substances.
Mining companies store tailings forever, frequently behind earth-filled embankment dams. Over the past 100 years, more than 300 mine tailing dams worldwide have failed, mainly due to foundation weakening, seepage, overtopping and earthquake damage.
We are research scientists studying how humans affect rivers. In our view, the damage caused by stored mine waste often outweighs the benefits that mining provides to local economies and the technology industry.
This issue is especially urgent now in a region of the Pacific Northwest where Alaska and British Columbia meet. This zone, known as the Golden Triangle, is studded with mineral claims and leases. We believe that rivers in this area could be severely damaged if proposed mega-projects are allowed to proceed.
Terraced tailings and slag from the Miami Copper Mine in Miami, Arizona. The open-pit mine that yielded this debris was dug by the Phelps Dodge mining corporation, now owned by Freeport-McMoRan, the world’s largest copper producer.
The mining town is situated on the banks of the infamous Bloody Tanks Wash.
“The wash was named after an 1864 battle between Colonel King Woosley’s troops, his Maricopa Indian allies, and a band of Apaches. The two sides had met in peace to exchange gifts, but the whites, on a prearranged signal, pulled their weapons and opened fire on the Apaches. The nineteen Indians shot in the encounter crawled over rocks to the creek, staining its water and banks crimson with blood and giving the wash its tragic name.”
This quote is from a travel guide, Scenic Driving in Arizona, by Stewart M. Green (Falcon Guides, 2009). Wherever you drive in America it seems you’re never far from a scene of cruel oppression or unspeakable violence.
best international journal, call for paper economics, list of ugc approved journals
This paper studies the feasibility of utilizing copper mine tailings for production of eco friendly bricks based on the geopolymerization technology. The procedure for producing the bricks simply includes mixing the tailings with an alkaline solution, forming the brick by compressing the mixture within a mold under a specified pressure, and curing the brick at a slightly elevated temperature. Unlike the conventional method for producing bricks, the new procedure neither uses clay and shale nor requires high temperature kiln firing, having significant environmental and ecological benefits. In this study, the effects of four major factors, sodium hydroxide (NaOH) solution concentration (10 and 15 M), water content (8 to 18%), forming pressure (0 to 35 MPa), and curing temperature (60 to 120 0C), on the physical and mechanical properties of copper mine tailings-based geopolymer bricks are investigated using water absorption and unconfined compression tests. Scanning electron microscopy (SEM) imaging and X-ray diffraction (XRD) analysis are also performed to investigate the microstructure and phase composition of the mine tailings-based geopolymer bricks prepared at different conditions. The results show that copper mine tailings can be used to produce eco-friendly bricks based on the geopolymerization technology to meet the ASTM requirements.
