How to Use
Reading 3: Producing Copper
The Quincy Mining Company was one of the largest copper-producing companies in the 19th century. Part of the success of the Quincy Mining Company was that it owned and operated every building necessary to process the copper from start to finish. Raw, copper-bearing rocks went through three steps before it was the pure copper that the Quincy Mining Company could sell. These steps were mining, milling, and smelting. Mining was taking the rock with copper in it out of the earth. This was the first step. The second step was separating the copper from the rock. This is milling. The last step was smelting, which was melting pieces of copper mineral together to make concentrated metal. Quincy Mine employees did all three steps in the mine’s own facilities.
The first facility copper went through was a shaft-rockhouse. A shaft-rockhouse covered the underground shaft entrance and above-ground it was the rock-processing center. The shaft-rockhouse allowed rock to be processed as soon as it was brought up from below. Rock used to be processed in separate shaft-houses and rock-houses. It was sent up to the surface to the shaft-house and then moved to the rock-house for processing. This was not as efficient as a combined shaft-rockhouse. The shaft-rockhouse’s height allowed different materials to be dumped on different levels. This meant different tasks could take place in one building. At a shaft-rockhouse, three men could move about 1,000 tons of rock in 12 hours.1
Before workers could process the copper, they needed to dig it out of the ground. Shafts (mining tunnels) had to be created so miners could dig out the rock. These shafts were named in the order that they were created. Men who mined on the bottom level spent their entire 10-hour shift working more than a mile underground. After the workers dug out the rock, they put it in a bin and sent up the shaft’s lift into the shaft-rockhouse. Workers pulled the bins up to the surface by a hoist. After the bins passed through processing in the shaft-rockhouse, workers moved the copper-heavy rocks to a stamp mill. The bins traveled to the stamp mill on a surface tramway or railroad. At the stamp mill, the rocks were crushed (stamped) and washed. Stamping the rocks concentrated the copper mineral by separating it from the rock. The leftover pieces of rock were mixed with water, sent from the mill through a trough, and dumped in Portage Lake or Torch Lake.
Back at the stamp mill, the concentrated mineral, now 60 to 80 percent copper, was sent to the smelter. At the smelter, workers melted the mineral in a furnace. Larger pieces of mass copper also went into the furnaces. Furnacemen dipped ladles into the liquid, molten copper and poured it into molds to make copper ingots. When it cooled, these solid bars of copper were ready to be shipped across the lakes and sold.
Quincy Mine built its first shaft-rockhouse in 1892. By 1901, a combined shaft-rockhouse was at mine shafts No. 2, 6, 7, and 8.2 The historic No. 2 Quincy Shaft-Rockhouse was built for Quincy's deepest mine. It extended over 9,000 feet at an angle and reached a total depth of 6,225 feet below the Earth’s surface. It was built in 1908 during some of Quincy’s most productive years. Production stopped at this Shaft-Rockhouse in 1945. It is one of the oldest intact buildings at the site.
Questions for Reading 3
1) What are the three steps for making copper ingots?
2) What is a shaft-rockhouse? Why was it important to the mining process?
3) What dangers do you think the Quincy employees faced during each step of copper production?
Reading 3 was adapted from the National Register of Historic Places Nomination Form, Quincy Mining Company Stamp Mills Historic District, Washington, DC: U.S. Department of the Interior, National Park Service, 2007; “Quincy Mine’s Shaft-Rockhouse”Keweenaw National Historical Park, National Park Service; “An Interior Ellis Island: Ethnic Diversity and the people of Michigan’s Copper Country,” Michigan Technological University Archives and Copper Country Historical Collections.
1 "No. 2 Shaft-Rockhouse, 1908.” Sheet 17 of 34. Library of Congress, HAER Record.