Mines 
Material 
treated 
Copper 
 
 
producing 
 
 
 
 
Year 
Lode Tailing 
Ore 
(thou- 
sand 
short 
Tailing 
(thou- 
sand 
short 
Short 
tons 
Value 
(thou- 
sands) 
 
 
tons) 
tons) 
 
 
1963                       
1964                               
1965                               
1966                               
 1967 -      
 10 3 9 3 10 3 10 3 8 3 
7,211 
6,718 
7,368 
8,000 
6,091 
2,226 
2,174 
1,611 
1,851 
1,307 
75,262 
69,040 
71,749 
73,449 
58,458 
$46,361 
45,014 
50,798 
53,133 
44,692 
 THE MINERAL INDUSTRY OF MICHIGANTable 1O.—Mine production of copper,
in terms of recoverable metal 
417 
 
 
 
 
 
 
 
 
 
 
suits, and the second was at a depth of 2,000 feet at yearend. Further drilling
is planned. 
 According to company reports, exploration was designed to determine the
degree of mineralization to the north as well as to give an indication of
the grade and thickness of the vein. At the White Pine mine a new conveyor
system is being installed capable of transporting ore, materials, or personnel
horizontally, on an incline, or vertically without changing the mode of transportation.

 The White Pine Copper Co. is carrying on research in cooperation with the
Institute of Mineral Research at the Michigan Technological University that
has resulted in a process for 90 percent recovery of residual copper lost
in tailings. In the process, sand tailings are treated in three continuous
stages of leaching, precipitation, and regeneration. The process was made
economically feasible on a 7,000-ton-perday basis by the exclusion of air
from the process, thereby reducing reagent loss by oxidation. The White Pine
Copper Co. has been undergoing a three-way expansion encompassing mining,
milling, and refining operations. The new milling and smelting facilities
were operational in April. A new selective mining method called "values only"
is being tested in several development areas of the mine. Essentially, the
method is a refinement of techniques that enables miners to take less of
the surrounding rock, increasing the copper yield per ton of ore. 
 Two companies, Bear Creek Mining Co. and Copper Range Co., had geological

teams searching for ore and performing analytical work at different sites
of the Indiana copper tract in Ontonagon County. 
 
 Iron Ore.—Iron-ore shipments in 1967 reflected a larger proportion
of pellets (73 percent) than in previous years. Consequently, although total
shipments decreased by nearly 2 percent, value of shipments increased by
more than 3 percent. Average weighted mine value for Michigan usable ore
in 1967 was $11.51 per ton compared with $10.95 in 1966. 
 About 82 percent of the crude ore mined came from four open-pit mines, and
the remainder from eight underground mines. Average iron content of usable
ore produced was 60.25 percent natural, compared with 58.87 percent in 1966.

 Michigan iron ore was shipped to producers of pig iron and steel, except
for a small quantity used in manufacturing iron oxide pigments. About 98
percent of the ore was shipped by rail to ore docks in Escanaba and Marquette
and then by water to lower Lake ports. The remainder was shipped by rail
to consuming districts. The lake shipping season for Michigan iron ores opened
at Escanaba on April 7, and closed at the same port on December 
22. 
 For the first time since 1883, there was no production from the Gogebic
Range, and the last shipment from remaining stocks left the Peterson mine
at Bessemer in August. The Hanna Mining Co. began an expansion program at
its Groveland plant that included increasing the output to 2.1 million tons
of pellets per year from 1.6 million.