Note Pack 40 Chapter 16 Mining and Mineral Resources Section 2: Mineral exploration and Mining

Mineral Exploration 1st step in finding an ore deposit is exploring rock for mineralization. Planes carry instruments that identify patterns in the land 2nd step rock samples are taken from the areas and analyzed to determine ore grade

How are planes used to find rich ore deposits? Knowledge Check How are planes used to find rich ore deposits?

Subsurface Mining Subsurface mining is how ore deposits beneath Earth’s surface. Room-and-pillar mining is a common method used to extract coal and salt. Networks of entries (rooms) are cut into a horizontal layer of coal. Between each room is a pillar of coal left to support t the roof. When mining is complete the pillars of coal are removed.

Longwall Mining Longwall mining is a more efficient way to remove coal form a subsurface seam. A machine (shearer) moves back and forth across the face of a coal seam. The coal is sheared from the surface and falls on a conveyor then transported out of the mine.

Solution Mining Soluble mineral ores can be removed by solution mining. Hot water is injected into the oar and dissolves it. Compressed air is pumped into the dissolved ore and lifts it to the surface.

Surface Mining Surface mining methods used when ore deposits are located close to Earth’s surface. Open-pit mining is often used to mine large quantities of near-surface Ore is mined downward, layer by layer.

Surface Coal Mining Overburden is rock that covers near-surface coal seams 1st step is to remove and set aside the soil 2nd overburden is removed by heavy equipments. 3rd loaders enter the pit and remove the exposed coal 4th once coal is removed the pit is filled with overburden, contoured and covered with the soil

Quarrying Building stones (granite and marble) are mined in quarries. Aggregates (sand, gravel, and crushed rock) are the main products of quarrying.

Knowledge Check Describe what happens to the overburden once all the coal has been taken out of a surface coal mine?

Solar Evaporation Solar evaporation is the process of placing sea water into enormous shallow ponds. Sun evaporates the water and increases the concentration of sodium chloride This method of salt production is used in areas that receive little rainfall and have high evaporation rates. Solar evaporation is used largely in developing countries and 30% of worlds salt comes from solar evaporation.

Placer Mining Placer deposits are minerals that are concentrated by wind and water into surface deposits. Streams transport mineral grains to a point where they fall to the streambed and are concentrated. Stream placers often occur at bends in rivers where the current slows. Gold, diamonds and other heavy minerals are mined by dredging.

Smelting Smelting is where crushed ore is melted at high temperatures in furnaces to separate impurities from molten metal. Flux bonds with impurities and separates them from the molten metal Molten metal falls to the bottom of the furnace and is recovered. The Slag (impurities)form a layer on the top Gases (sulfur dioxide) are captured so they do not enter the environment

Undersea Mining Ocean floor contains significant mineral resources Cost and great waters depths at which minerals are found are two reasons undersea mining has not been successful.