gold ore crusher milling equipment

By G.P. ThomasBack to BasicsAt its very lowest level, mining is simply
digging in the ground to find something of use. It has been a part of life since
antiquity and it is still the backbone of the world’s commerce and production.
Well, if it isn’t broken…!There are two basic classes of mining: mining at the
Earth’s surface and mining underground. This article will concentrate on crusher
manufacturer in china the former. Surface mining accounts for two thirds of
the world’s solid minerals, and is predominantly used in obtaining sand, gravel,
crushed stone, phosphates, coal, copper, iron and aluminium. The majority of
surface mining occurs in the USA, but there are sites all across the globe with
Canada and Australia also heavily involved. There are 5 main types of surface
mining, which are used in various degrees and for different resources. These
mining categories are: strip mining, open-pit mining, mountaintop removal,
dredging and high wall mining. All methods of surface mining will remove the
waste material, or overburden, above the desired resource. Surface mining is
often preferred to sub-surface (underground mining) by mining companies for
several reasons. It is less expensive, there are fewer complications in terms of
electricity and water and it is safer. However, surface mining can be
environmentally more damaging than subsurface mining. This article will give a
brief overview of the different types of surface mining techniques, what they
can be used for and how important they are in the global mining community. mining
machinery manufacturer Open-Pit MiningOpen-pit mining, or open-cast mining,
is the most common type of surface mining. Open-pit mines are holes in the
ground on a giant scale, which increase in size by blasting and drilling rock
apart. The mine develops into a conical shape with Benches (or steps) in cross
section which spiral round from top to bottom of the mine so that trucks can
drive down the sides and collect blasted debris.Open-Pit mining is usually
utilised for near surface deposits, such as gravel and sand. The term Quarry is
often used to refer to an open-pit mine where the product is rock, commonly
building stone. Examples include gravel, sand and dimension stone. Open-Pit is
relatively safe, cheap and results in a high yield of product. Image
Credit:Environment CanadaThe width and depth increases throughout the lifetime
of the mine and some of the largest can be more than 2km in width and hundreds
of metres deep. The largest open pit mine in the world is the Bingham Canyon
Mine in Utah, USA. It gold
ore crusher milling equipment is roughly 2.5miles wide and 0.75miles deep .
At its peak, 400000 tons of rock per day was being removed and to date it has
produced over 17 million tons of copper, along with a huge amount of gold,
silver and molybdenum. Other open-cast mines of note include Nchanga Copper Mine
in Zambia, the second largest pit in the world, and the Kalgoolie Super Pit, the
largest open-cast gold mine in Australia. The Bingham Canyon copper mine near
Salt Lake City, Utah, USA. Image Credit: www.kennecott.comStrip MiningUsed
predominantly in coal extraction, strip mining can also be used in the
extraction of phosphates, clays and tar. If the resource that needs to be mined
is in a flat, horizontal layer close to the surface, strip mining is the ideal
technique.It is essentially the process of removing a thin strip of overburden
above the deposit and, dumping the waste behind the deposit, continuing along
the length of the deposit. Once the resource under this strip has been exploited
another parallel strip is started, with the waste dumped on top of the first
strip. This continue until the resource has been completely excavated, or at
least until it becomes economically unviable.