1
25-039
Geochemistry of Critical Minerals in Mine Waste in Grant,
Sierra, and Socorro Counties, New Mexico
Zohreh Kazemi Motlagh
New Mexico Institute of Mining and Technology,
Socorro, NM
Virginia T. McLemore
New Mexico Bureau of Geology and Mineral
Resources, NMT, Socorro, NM
ABSTRACT
Critical minerals are nonfuel minerals, essential to the U.S.
economy and national security, whose supply chain may
be disrupted. Mine wastes are potential sources of critical
minerals. The goal of this project is to estimate and charac-
terize critical minerals endowment in three mining districts
in New Mexico: Black Hawk (Grant County), Hillsboro
(Sierra County), and Magdalena (Socorro County), and
assess their acid-generating potential. The Black Hawk
district is an arsenide five-element vein deposit (Ag, Ni,
Co, As, U, Bi, and local minerals like Pb, Cu, Zn, W, and
Sn). The Copper Flat mine in Hillsboro district is a copper
porphyry deposit. The Kelly mine in Magdalena was first
mined at 1878 and are carbonate-hosted Pb-Zn deposits.
Mine waste rock piles and tailings are sampled using USGS
Beta sampling procedure. Geochemistry results show that
Black Hawk district mine wastes samples are elevated in
Ag (200 ppm), Co (290 ppm), Ni (2,130 ppm), and
Zn (8,463 ppm). Copper Flat mine tailing is elevated in
Bi (111 ppm), Cu (7,453 ppm), and Zn (2,360 ppm).
Downhole profile plots in Copper Flat show the positive
correlation between Cu, S and Te values. Magdalena sam-
ples are elevated in Cu (5,700 ppm), Zn (129,500 ppm),
and Pb (58,100 ppm). Determination of acid-generating
potential in these areas suggests that Black Hawk district
mine wastes are non-acid-forming while high S present in
some Copper Flat and Magdalena samples can potentially
cause acid mine drainage.
INTRODUCTION
Critical minerals are important for many industries includ-
ing renewable energy, agriculture, and electronics (like
smartphones, computer chips, and laptops) (McLemore,
2020). The definition and list of critical minerals vary
between countries. Based on Energy Act 2020, critical min-
erals are nonfuel minerals that are essential to the United
States’ economy and national security, and whose sources
are vulnerable to disruption. Most critical minerals are
imported into the U.S. Critical mineral resources in New
Mexico must be recognized before government authorities
withdraw land from mineral entry, or make other decisions
regarding land use. Moreover, future mining of these min-
erals will directly enhance the overall economic well-being
of the United States. Figure 1 illustrates the critical miner-
als known to occur in New Mexico. Currently, 53 minerals
are listed as critical for the United States. The nation cur-
rently produces enough copper for domestic use and cop-
per is also imported from countries with which there are
secure trade agreements, so the current supply of copper
for domestic use is not in jeopardy. Therefore, copper is not
considered a critical mineral by the USGS yet, however,
the DOE has noted copper as a critical mineral in 2024.
Uranium was listed as a critical mineral in 2019 because of
its use in Navy nuclear reactors. However, because uranium
is used as a fuel, it was removed from the list in 2022. The
critical minerals list is reviewed by the government agencies
every 2 to 3 years (McLemore and Gysi, 2023).
Mine wastes are important potential resources of critical
minerals, particularly because in the original mine produc-
tion, base and precious metals and not the critical minerals
were produced. Consequently, mine wastes would contain
any critical minerals in addition to those minerals that are
present in the deposit. There are 274 mining district in New
Mexico and tens of thousands inactive or abandoned mine
features. Many of these mine features have mine wastes that
need re-evaluation of the critical minerals potential. There
25-039
Geochemistry of Critical Minerals in Mine Waste in Grant,
Sierra, and Socorro Counties, New Mexico
Zohreh Kazemi Motlagh
New Mexico Institute of Mining and Technology,
Socorro, NM
Virginia T. McLemore
New Mexico Bureau of Geology and Mineral
Resources, NMT, Socorro, NM
ABSTRACT
Critical minerals are nonfuel minerals, essential to the U.S.
economy and national security, whose supply chain may
be disrupted. Mine wastes are potential sources of critical
minerals. The goal of this project is to estimate and charac-
terize critical minerals endowment in three mining districts
in New Mexico: Black Hawk (Grant County), Hillsboro
(Sierra County), and Magdalena (Socorro County), and
assess their acid-generating potential. The Black Hawk
district is an arsenide five-element vein deposit (Ag, Ni,
Co, As, U, Bi, and local minerals like Pb, Cu, Zn, W, and
Sn). The Copper Flat mine in Hillsboro district is a copper
porphyry deposit. The Kelly mine in Magdalena was first
mined at 1878 and are carbonate-hosted Pb-Zn deposits.
Mine waste rock piles and tailings are sampled using USGS
Beta sampling procedure. Geochemistry results show that
Black Hawk district mine wastes samples are elevated in
Ag (200 ppm), Co (290 ppm), Ni (2,130 ppm), and
Zn (8,463 ppm). Copper Flat mine tailing is elevated in
Bi (111 ppm), Cu (7,453 ppm), and Zn (2,360 ppm).
Downhole profile plots in Copper Flat show the positive
correlation between Cu, S and Te values. Magdalena sam-
ples are elevated in Cu (5,700 ppm), Zn (129,500 ppm),
and Pb (58,100 ppm). Determination of acid-generating
potential in these areas suggests that Black Hawk district
mine wastes are non-acid-forming while high S present in
some Copper Flat and Magdalena samples can potentially
cause acid mine drainage.
INTRODUCTION
Critical minerals are important for many industries includ-
ing renewable energy, agriculture, and electronics (like
smartphones, computer chips, and laptops) (McLemore,
2020). The definition and list of critical minerals vary
between countries. Based on Energy Act 2020, critical min-
erals are nonfuel minerals that are essential to the United
States’ economy and national security, and whose sources
are vulnerable to disruption. Most critical minerals are
imported into the U.S. Critical mineral resources in New
Mexico must be recognized before government authorities
withdraw land from mineral entry, or make other decisions
regarding land use. Moreover, future mining of these min-
erals will directly enhance the overall economic well-being
of the United States. Figure 1 illustrates the critical miner-
als known to occur in New Mexico. Currently, 53 minerals
are listed as critical for the United States. The nation cur-
rently produces enough copper for domestic use and cop-
per is also imported from countries with which there are
secure trade agreements, so the current supply of copper
for domestic use is not in jeopardy. Therefore, copper is not
considered a critical mineral by the USGS yet, however,
the DOE has noted copper as a critical mineral in 2024.
Uranium was listed as a critical mineral in 2019 because of
its use in Navy nuclear reactors. However, because uranium
is used as a fuel, it was removed from the list in 2022. The
critical minerals list is reviewed by the government agencies
every 2 to 3 years (McLemore and Gysi, 2023).
Mine wastes are important potential resources of critical
minerals, particularly because in the original mine produc-
tion, base and precious metals and not the critical minerals
were produced. Consequently, mine wastes would contain
any critical minerals in addition to those minerals that are
present in the deposit. There are 274 mining district in New
Mexico and tens of thousands inactive or abandoned mine
features. Many of these mine features have mine wastes that
need re-evaluation of the critical minerals potential. There