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Bureau of Mines / Minerals yearbook metals, minerals, and fuels 1972
Year 1972, Volume 1 (1972)

Morning, John L.
Technologic trends in the mineral industries (metals and nonmetals except fuels),   pp. 61-82 PDF (1.8 MB)


Page 62

62 MINERALS YEARBOOK, 1972 
crude ore production and waste material handled, and for nonmetal operations,
stone led in crude ore production and phosphate rock in waste material handled.
 Eleven States - (Arizona, California, Florida, Michigan, Minnesota, Montana,
Nevada, New Mexico, Texas, Utah, and Wyoming) compared with 10 in 1971 handled
more than 100 million tons of material. Illinois was dropped from the list,
while Montana and Nevada were added. Three States reported handling between
90 and 100 million tons of material. Arizona and Florida led the nation in
both total material han-died and crude ore output; both States produced over
200 million -tons of crude ore. Arizona and Florida have led the nation in
total materials handled since 1965. 
 Magnitude of the Mining Industry.— Crude ore production was reported
from 13,723 mines and quarries. The data are comparable with 1971 but are
not -comparable with other years owing to elimination from the data of ' brine
and pumping operations. Of the total mines reporting production, clay mines
totaled 1,064; san'd and gravel operations, 6,690; crushed and broken stone
operations, 4,448; dimension stone operations, 391; other nonmetal mines,
531; and metal mines, 5-99. In addition, there were 103 wells, ponds, or
pumping operations. 
 Excluding clay, sand and gravel, and stone operations, a total of 1,130
metal and nonmetal -mines reported production o( crude ore -or waste compared
with 1,299 mines in 1971. Most of the decrease was accounted for -by small
mines producing less than 10,000 tons of crude ore annually. In metal mining,
lead and zinc and uranium mines decreased in number primarily because of
the soft market for lead and zinc and the lack of markets for uranium. Both
placer gold and silver mines showed an increase in number owing ' to increased
prices of these precious metals. The number of mines also decreased for most
nonmetals. Small feldspar mines decreased owing to competition from larger
more economical mines. Phosphate rock mines decreased by 10 owing to changes
in statistical counting. 
 Crude ore production ranged from less than 1 ton of ore to nearly 37 million
tons while total material handled ranged to nearly 125 million tons. 
 The 25 leading metal mines produced 
nearly 384 million tons of crude ore, 8% higher than the figure for 1971,
and accounted for 67% of the total output of crude ore from metal mines.
The same mines also handled 1,147 million tons of material, an increase of
9% over that of 1971, and represented 69% of the total material handled at
metal mines. 
 The 25 leading nonmetal mines produced 169 million tons of crude ore and
handled 409 million ' tons of material. This production represented 8% and
16% respectively, of total cru'de ore and total material handled at nonmetal
mines. 
 Value of Principal Mineral Products.— When possible, the measurement
of value used in table 4 is mine output, the form in which the minerals are
extracted from the ground. For some commodities, the value is of beneficiated
products. Values for some metals are assigned a'ccording to the average selling
price of refined metal. 
 Value patterns -for most mineral commodities rose in 1972 after suffering
a decline in 1971, but a few -commodities remained unchanged and a few declined
in value. Unit values for ore at underground mines were generally higher
than those from surface mining. 
 The contribution of byproducts to the value of ore continued to be more
significant to the output of metal ores than to that of nonmetal ores. Byproducts
accounted for 8% of value of metal ores and 1% of nonmetal ores. Excluding
the large volume commodities of stone and sand and gravel, byproducts contributed
7% to the value of combined metal and nonmetal ores and 3% to nonmetal ores.
Byproducts enhanced the value of ores of lead 28%, silver 20%, zinc 20%,
fluorspar 13%, feldspar 11%, and mi-ca (scrap) 8%. 
 Comparison of Production From Surface and Underground Mines.—Surface
mining continued to account for 94% of all crude ore production and 96% of
total -material handled. Although there is little variation in the year-to-year
ratio of production from surface and underground mines, the long-term trend
indicates an increasing percentage of material mined by surface methods.
In 1963, surface mining accounted for 93% of crude ore production and 95%
of total material handled. The biggest change between the comparison years
was in metal mining as the percentage of surface ' crude ore production increased
from 82% in 1963 to 85% in 1972, and total 


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