A week ago I received this email from a student:
I am using your blog for last two weeks as a reference for my school home project. It is amazing how much information you have there! But I am still bit lost.
I have to make a project for the school a virtual open pit gold placer mine with 4,000 t per day. For two weeks I am now collecting information but I am still lost. I like mining but it looks to be a large project to a beginner like me .
Do you have any excel sheet or any existing sample cost model of a mine, that you can use as a reference or as a startup for my project. I found one from a zinc mine in Norway but it is a totally different type of mining, compared to a open pit placer gold.
I chose western US as a location for the mine , then getting fuel costs, energy costs and few other costs was easy to find from that area.
I could not help him.
I tuned to Jennifer Leinart of CostMine and she provided this guidance:
I understand why you are having problems coming up with reasonable numbers for open pit placer mines. I have attached an older section of our Cost Models which describe basic costs involved with placer mines. I have also included a 5,000 tonne per day open pit mine so that you can compare. Note the differences based on the amount of waste and ore being mined. The size you selected for the placer mine is large when compared to most placer operations. Hope this gives you some guidelines.
First – terminology: Placer mines are either in a creek or river or on a beach. They are not traditional open pit mines. The material mined is loose, unconsolidated and generally sand or gravels. they can be ancient gravels or sand, but again, usually easy to mine, no blasting required. The typical equipment consists of loaders (or shovels) trommels, screens and sluice boxes to separate the gold from the gravels. Gold is easily separate from the gravels by gravity methods and generally does not take chemicals or grinding/milling to get the gold. Below is an example of a gold placer. These are also generally small.
Open pit mines are different – they mine down and most of the time require some type of blasting. Loading and Hauling are often accomplished using shovels, loaders and trucks. These mines can be small or very large. Often the ore requires blasting and then milling and grinding to free the desired metals from the ore. In addition, chemicals and metallurgical processing is also often required to recover the metals. Below is Bingham Canyon mine as an example of a very large open pit mine.
I hope this helps the student and other faced with the same project. Thanks to Jennifer and CostMine.