Saturday, January 31, 2015

Visiting the ASARCO Mine

I tagged along with the Photo Club on Tuesday to visit the ASARCO mine, located just south of Green Valley, near Tucson.
ASARCO started in 1899 as American Smelting And Refining Company... founding fathers were Henry Rogers, William Rockefeller, Adolph and Leonard Lewisohn and Anton Eilers. It became a publicly traded company on the DOW Jones Industials in 1901. In 1999 It was acquired by Grupo Mexico and now trades on the Mexican Stock Exchange... the most active stock on that exchange. For more history click on this Wikipedia link.

This mine site we toured is called the Mission Complex... named so because of the nearby San Javier Mission, which is visible to the west from Hwy. 19.

As we drove on the bus to the mine I did a little "drive by shooting." The settling pond in the distance is a man-made detention pond where the mine discharges their waste water.

They get their water from the Colorado River... and with the lower water table levels, there is lots of complaining about all the water that goes into mining operations.

For many years when passing on Highway 19 we have seen the huge miles of earth piled high in a straight row... and knew it was a mine site... but didn't know about the possible tour available.

The variety of colour in these piles is from the over burden coming from different levels removed in order to get down to the "good stuff."

We drove past this mine processing plant and aeration ponds on the way to the open pit site.

It just looked like ordinary crushed rock to me... but not to these miners. This company is the third largest copper producer in the world.  Something like 350 million pounds a year!

When the bus stopped we got out and took a few shots into the pit. A couple of trucks are waiting at top of the road, just right of centre.

I zoomed in on those huge trucks that were over a mile away. We learned later why they were parked there waiting. These are the largest dump trucks in the world. I would sure love to take a ride in one of these big trucks!

This retired truck at the visitor centre is about 40 feet long, 24 feet wide, and can carry 170 tons of rock. The driver sits over 20 feet off the ground and they drive on the left side of the road in the mine so they can better see the edge of the road bank. The newer ones made by Caterpillar today can carry twice that capacity!

This sign was posted on the grille of the truck.

One tire costs $80,000 and they have to be replaced about every six months.

I caught this family posing for their mother.  Pretty cool shot, eh? You can't think up this kind of shot... kids are so ingenious... they don't have to be told how to pose.

Our tour guide announced that we were in luck!  They would be setting off a blast right in front of us in just a few minutes. Now we knew why those big trucks were parked and waiting on the hill a mile away.

They told us, "Just focus on the plateau to the right of the excavator and drill rig...

And sure enough, after a couple of horn blasts and a long siren, they discharged the blast.

Next they bused us back to the processing plant.

Constantly the rock is being moved thru the process of being crushed and broken down until it is the finest powder possible.

In this facility their object is to just to get the copper into a powder that can be then trucked to a refinery where it is purified in a furnace.

Our tour guide, in the white hardhat, has done this presentation so many times I think he could rattle it off in his sleep.

The first step is crushing the rock... crushing and screening it... then more crushing and screening.

When it is small enough, the ore gets pulverized to dust in this rotating ball mill.

Next it gets sent to the floatation tanks.  This is an excellent flow chart of the whole process.

There is a couple of large aeration tanks outside...

and inside there are several more tanks.  Water plays a large part in the refining process.

Back in the visitor centre our tour guide continued to wax eloquent with his knowledge. The circular entrance to more exhibits was designed in the shape of the ball roller used in the mine plant.

This mineral discovery center provided a lot of resources... and we watched a movie on the process.

These are actual steel balls used in the ball roller drum.

This close up is an extension cord used to run equipment in the open pit. The mine pays $1.8 million for electricity every month.

This mine is only the fifth largest copper mine in Arizona... it occupies 31 square miles... and they have just revised it's life expectancy for another 26 years.  Last week if we had asked our tour guide he would have told us fifteen years... but they have just announced revised drilling results, and believe that they can continue to operate at this location until around 2041.

In the grounds around the Visitor Center we saw some amazing cactus plants.

What a beautiful cluster!

A collection of historic mining equipment is located around the Visitor Center... like this wooden head frame used in the early 1900's.

The way that ore is moved today is vastly different than in the old days of mining.

I'm sure that when this rail car was built it was the most advanced technology of that time.

Now the newest models of these trucks made by Caterpillar can carry 350 to 400 tons! The width of the dump box is 30 feet... wider than the paved street in front of our house... which is the standard 24 feet paved width.  If my memory is right, these newest mining trucks cost in the 5 million dollar range.

It is interesting to see these old antiques... like this road grader.

and this steam shovel.  New models of this shovel can scoop up to twice as much in their bucket as would fill the common dual wheel dump truck.

As we were leaving the visitor centre I liked the colour of these prickly pear cactus...

Guarding the front entrance was this beautiful Crested Saguaro.

Would it be that we could see these rare specimens more often. I was so delighted to see this treasure here. To see more crested saguaros, I invite you to click on Shirley's recent blog post.  She is keeping an inventory list of our crested saguaro finds.

"Wherever you go becomes a part of you somehow." -Anita Desai


  1. Very interesting tour. I was always interested in what went on beyond those piles of "dirt". Now I know

  2. yes, a very lovely mine. but i was interested in why the San Xavier mission only had one cupola on their two towers.. had to go look that one up!

    1. It looks like the west cupola was never completed but was built in 2009... and they planned to build the second one and have it finished before the 2012 Arizona Centennial. But the Heritage Fund did not have sufficient money to complete it, so they halted proceeding with the work. They still plan to do it as soon as they have the money.

    2. yep, the original building was built late 1700's (1783-1797) but the latest restoration work a few years ago has hit some snags.

      I found the reason that they didn't finish the second tower -- check this out (also check out the cat and mouse..). And I read somewhere else that they won't "finish" the second tower for "historical reasons". Very cool.