Science Unit 4 Lesson 5 Flashcards
What are copper, silica sand, and coal used for?
copper for wiring, silica sand for smartphone screens, coal for energy production, and more.
What happened at the copper mine in Copiapó (2010)? What did it show us/what did we learn from that situation?
In 2010, a gold and copper mine collapsed in Copiapó, Chile. Thirty-three miners were trapped 2,300 feet underground for a record 69 days. Rescuers drilled a narrow borehole to provide needed supplies to the trapped miners then worked to drill a wider shaft and a special capsule to bring the miners back to the surface. All 33 miners survived the ordeal, but the Copiapó incident highlights the real risks that must be managed in mining.
How do longwall mines work?
In longwall mines, hydraulic supports are used to hold up the roof while miners cut away ore
How do room-and-pillar mines work?
In room-and-pillar mines, columns of ore are left in place to support the
roof while ore in between the columns is removed.
Without proper ventalation in underground mines what could happen?
underground mining can release methane gas. This gas can cause explosions underground if the gas ignites. Without excellent ventilation systems, gases like methane can build up and oxygen can become depleted.
What are the dangers of coal dust?
Coal dust is easily ignited, which creates another risk for mine explosions and underground fires.
What is rock burst?
Rock burst is also a threat in underground mines. Rock masses
underground are under tremendous pressure. Drilling a mining shaft or removing material can cause rock to suddenly dislodge or explode away from the walls of the mine. Rock burst can lead to mine collapse.
In the United States, the majority of mining injuries and fatalities are caused by what?
Injuries and fatalites are mainly caused by machinery and transportation
equipment. Noise-induced hearing loss is another occupational riskrelated to the use of heavy equipment.
How does surface mining compare to underground mining?
Surface mining carries significantly less risk of mine collapse, fires, or explosions than underground mining. Surface mining also hasfewer ventilation challenges than underground mining. Compared to underground
mining, surface mining requires similar heavy equipment and comes with a similar risk of noiseinduced hearing loss. Workers in surface mines do have a greater risk of UV exposure from the sun compared to underground miners.
What are tailings?
Tailings are the chemicals and dust particles left over from extracting valuable minerals from mined ore.
What are tailings dams?
structures used to hold the chemicals and dust particles left over from extracting valuable minerals from mined ore
What would happen if tailings dams break?
Tailings dams hold in tailings ponds where these leftover toxic materials are stored. If these tailings dams break, the flood of toxic sludge can cause death and destruction.
In the U.S., is underground mining or surface mining more dangerous? How do you know?
In the U.S., underground mining is generally more dangerous than surface mining. In 2015, there were 2.08 deaths per 10,000 workers in underground mines, but about one-third of that number in surface mines. In terms of nonfatal injuries, there were 284.3 nonfatal lost-time injuries per 10,000 workers in underground mines, but less than half of that, 125.6 per 10,000 workers, in surface mines.
The Federal Mine Safety and Health Act of 1977 set health and safety standards for mines and mandated multiple mine inspections each year. What data trend does the passage of this law help explain?
The annual number of coal mining fatalities in the U.S. dropped sharply between 1970 and 1980, from 18.00 fatalities per 10,000 workers to 5.26 fatalities per 10,000 workers.
