Monthly Archives: September 2008

A Tale of Two Launders

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After scaling the stamp sand cliffs along the shore, we found ourselves standing on the lip of a vast barren landscape known as the Gay Sands. Of course we have been to these sands before, but each time their vast ... More »

Yet Another Beach Stroll

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Along the Keweenaw the big lake encounters one of four basic types of topography along the shore. The most common is one dominated by large rocky outcroppings consisting of basalt (either Copper Harbor Conglomerate or Portage Lake Volcanic). Second is ... More »

Ghosts of Calumet

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Before moving on with my Anatomy of a Mill series (is that groans I hear?), I decided to give you all a little break and present something a little fun. I have had many requests for more installments of our ... More »

Anatomy of a Mill (Jigs)

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A long line of refining jigs at the Quincy Mill After leaving the final stages of the sizing process, the copper ore that entered the mill as pieces of rock have been reduced to a coarse gravel and mixed with ... More »

Anatomy of a Mill (Final Sizing)

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The process of ore production neither begins or ends at the stamp mill, but instead stretches from the dark drifts of the underground right up to the smelter docks. This process consists of three main stages: sizing and sorting, separation, ... More »

Last Stamp Standing

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&oiDuring the Copper Empire’s peak, over 100 steam stamps were in operation across the peninsula. As mines and their mills succumbed, these massive stamps were quickly sold or scrapped for quick cash. With the arrival of the Second World War ... More »

Anatomy of a Mill (Stamps)


The processes of mill work can be separated into four distinct stages. The first stage involves breaking down the copper bearing rock from the mill into small pieces - a process known as stamping. These small particles of rock are then passed onto a series of roughing jigs followed by a series of refining jigs. In the last stage the remaining rock is sent to the wash floor, where a series of slime tables are used to remove the last traces of copper from the rocks before being discarded. We start today with the first and most important step of the entire process: the stamps. More »