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Friday, October 28, 2011

How a Mine is Created

An example of a shaft mine, the Oryx Mine in South Africa
Photo by Babakathy

A recent question that was posed to the author on was how a mine came into being.  The questioner realized that a mine is usually large, but how they came into being just eluded him.  He thought spelunkers, cave explorers, discovered the minerals while exploring the cave.  A few working mines probably were discovered this way.  Most mines are purpose dug excavations with three types of mines that are recognized.  The people that develop a mine are called mine developers.  Although it is nothing more then a large construction job there are enough differences so sometimes this is a specialty in the construction industry.

An excavator and trommel in action at a placer mine in Alaska
Photo by Dennis Garret

The first of these mines is the placer mine where through the process of weathering the valuable minerals are released from the bedrock that encloses them.  Most of these deposits find their way through the process of soil creep to an ocean or river where they are found in the bedload mixed with many other lighter minerals.  Another type of mineral deposit found is the result of weathering in place.  The deposits are usually found in the tropics between 32 degrees north and south of the equator.  Many of these are found associated with quartz that remains in place while the other minerals are turned to clay around them.  The gold and other minerals stay more or less in place waiting to be mined.  A placer mine is usually limited to gold production although there are exceptions to the rule other placer mines also produce tin and rare earth minerals.

Loading ore at an open pit mine in Nevada.
Photo by Cornelius M. Keyes

Other mines are located in bedrock, and usually are called lode mines if they are for mining gold.  Basically there are two types open cast that is nothing other then a large hole in the surface of the earth.  The other type of bedrock is one underground.  Mines of this sort are further subdivided by their way of entrance.  One type of mine has a shaft going into the ground with tunnels reaching out from the bottom of the shaft.  Some of these mines have several layers reaching out from a central shaft.  Other mines of this sort have more then one shaft entering the mine.  The other type of bedrock mine uses an “Adit”  that is a tunnel going more or less horizontal to the surface of the ground.  It costs less to build a mine with an adit then one with a shaft.

An adit leading into an underground mine in Australia.
Photo by Flagstaffotos 

Before any mine is created there must be lots of preliminary work done first.  Placer mines are called “poor mans mines” because the preliminary work is often kept to a minimum.  The work can be done by one man or a small workforce.  Bedrock mines are for more capital intensive then a placer mine sometimes for a truly large mine it exceeds 1 billion dollars before any ore is extracted. 

Monday, October 24, 2011

Introduction to Mining

This piece of art is composed of earth materials.

There are about 7,000 active mines on the face of the earth as we speak for a wide variety of minerals and ores that are produced to support our way of life and indeed our civilization.  The products from these various minerals range from arsenic to zirconium with the minerals in demand at a particular moment in time causing a situation that might just as well be called, “The Mineral of the Month Club.”  Another way to put it is what mineral is in style?

It seems that at this moment the supply of rare earth minerals (REM) are scarce. The hunt is on worldwide for these minerals that at present are mainly found in the clay deposits of China.  The Chinese, the world's largest producer of REM have restricted the export of these elements from China causing a worldwide search for REM minerals or replacements for them. This has become finding these minerals a high priority for prospectors worldwide.

This Rolls Royce Phantom was also made from earth materials.
Photo by Brett Weinstien 

From these mines are produced many of the things that we take for granted. In two of the products produced from mines that account for some of the highest tonnages are sand and gravel, and crushed stone. For the most part these commodities are invisible to the average person although our civilization is built upon them. There is hardly a facet of our civilization that is not touched in one way or another by mining. It is man's use of these materials upon which our civilization is built. If there were not further products of various minds we would probably still be living in trees. The oldest mine in the world is located in Eastern Africa is the Lion Mine that produced iron ore that was used by early man for decorating his body about 70,000 years ago.

Mines are the source of all the metals you see in buildings, cars, airplanes and all household products you see around you. They also produced many of the raw materials that were used in construction. Other minerals are used in the chemical industry. The energy industry is also a large user of other minerals like coal or oil or uranium. Uranium itself accounts for a good share of electricity that is used in the world. Some of the largest deposits of uranium bearing minerals are found in northern Saskatchewan.

Although you probably do not see the connection between the paper industry and mining it exists because some of the minerals like limestone when it is crushed into a fine powder is used as a sizing in the manufacture of paper. A good share of this powdered limestone is produced in northwestern Connecticut by Minteq. More powdered limestone as calcium carbonate is mined by Minteq in North Adams, Massachusetts this USP certified for use in medicine. Just think the next time you take an antacid it was dug her from the ground in Massachusetts.

Gold is another metal produced from mines it is not only beautiful when used in the manufacture of jewelry it also has a high monetary value, and is used in many industrial applications such as electronics and even in the aerospace industry.

Mining is decrying being many because of their minds minors are displayed on the earth. The truth is mankind has gotten to be where it is because of its ability to make use of earth materials. Those who think otherwise are either ignorant or foolish, but this feeling is nothing new that occupies most of the first chapter in De re Metallica the first book on Mining engineering written in the early 1500s by Georgius are you Agricola. The first chapter of this book is devoted to exactly the same subject, and Agricola was writing about the same kind of people.

Saturday, October 22, 2011

Ontario’s Ring of Fire

Chromite the mineral of interest in Ontario's Ring of Fire
Photo by Andrew Silver   USGS

Located in northwestern Ontario the Ring of Fire promises to become a decades long mining project.  Although the project promises to become a benefit to the local community it is alarming the local residents and the environmentalists.  These extensive deposits have been discovered just outside Thunder Bay, Ontario causing the mining participants to circle the area, and positioning them to share in the future steel market.

The mineral of attention is chromite, a dark colored ore of chromium that is used for the manufacture of stainless steel and to a lesser extent for chrome plating.  To a lesser extent it is used for tanning leather making use of potassium or sodium chromate in the chrome tanning process.  The chromite deposits found in the Ring of Fire have been dubbed as the greatest deposits of chromite in North America by the Ohio based company Cliffs Natural Resources (NYSE: CLF) that is convinced the deposits of chromite are worth fighting for,  The potential deposit is located under water and rocks close by to major highways and railroads making shipping the ore simple and cost effective.

The region is located near Kenora in western Ontario in an area of muskeg known as the James Bay Lowlands centered on McFaulds lake 500 kilometers northwest of Thunder Bay. The first discovery was made by Noront Resources LTD, a mining company that was in the area in 2007.  On August 28th they announced they had made a large find on the basis of two holes that were drilled.  The first core revealed a strong showing of copper sulfides, and the second had similar results.  A bit later Noront announced they had copper, nickel, platinum and palladium.

Cliffs call this monstrous deposit of chromite the Black Thor Deposit that would place Canada as a player in the worldwide chrome market of which South Africa is the world’s largest producer.  They declare this is the largest deposit to be found in North America.  Chromite is used in the steel industry to produce ferrochrome a precursor of stainless steel where it is battling with China to maintain its dominance of the market.

There are many roadblocks facing Cliffs that is based in the US, not least of which is satisfying both federal and provincial environmental regulations, but it has the added burden of satisfying the members of the First Nations locals that live right in the middle of the deposit.

The representatives of the First Nations communities in the area have called for participation in the review for development of this deposit of chromite in their region.  The Canadian Environmental Assessment Agency has recently issued a statement that the locals are being overlooked in the permitting process.  It is this agency that will take the reigns to study that will determine the access, if any, that the chromite miners will have in the area.

Cliffs wants to construct a processing plant at the site of a former iron mine that will be known as Moose Mountain that was closed over forty years ago.  The proposed plant would process the ore from the McFaulds Lake mine that has been dubbed the “Ring of Fire.”  The proposed plant is located near Caproel, Ontario.

If the project is approved construction of the mine would commence in 2015 with a large enough deposit capable of being mined for at least thirty years.  The deposit produce an estimated million tons of chromite concentrate per year as well as several hundred thousands of ferrochrome per year as reported in the Sudbury, Ontario Star.

Opening the area to development could produce approximately 1000 new jobs if the project is allowed to go foreword with about 500 of them near Caproel.  The other 500 jobs would be at the McFaulds Lake mine.  Needless to say Ontario’s Ring of Fire has attracted a lot of junior explorers to the region having potential world class deposits of chromite.