4
samples collected for this study were determined by ALS
Laboratories and the USGS laboratory. Samples were sub-
mitted to the laboratory when sample preparation occurred.
Duplicate samples and standards were analyzed and uncer-
tainty of analyses is generally 5%. Chemical plots were
created using ioGAS-64 (ioGAS ™ -REFLEX (reflexnow.
com). Chemical analyses will be released in future reports.
Petrography and Mineralogy
Mineralogy of selected samples was determined by visual
and X-ray diffraction (XRD). XRD analysis was performed
on either whole rock or mineral separates performed
on a PANalytical X- Pert PRO ® diffractometer at the
NMBGMR XRD Diffraction Laboratory. Analyses were
conducted using 45 kV X-ray beam tension and 40 mA
Xray beam current. XRD scans were identified using X’Pert
HighScore Plus ® software, which identifies intensity peaks
and matches patterns to a Powder Diffraction File database.
XRD data will be available in the final report.
Paste pH and Fizz Test
A sample is typically considered acid generating if the pH
is less than 4 (Borden, 2001). In order to determine the pH
of the pore water produced by the dissolution of second-
ary mineral phases on the surfaces of oxidized rock par-
ticles, paste tests are used to assess the geochemical behavior
of mine waste materials subject to weathering in the field
(Figure 5). Results are recorded in Table 1.
Also, fizz test was performed to find out how much
hydrochloric acid (HCl) needs to be added to a 2 g sample
in order to digest carbonate (and other neutralizing min-
erals) and then determine the amount of NP (Figure 6).
Results are recorded in Table 1.
RESULTS AND DISCUSSION
Critical Minerals in Mine Waste
Overall, 17 samples were collected and separated as fines
and coarse. Figures 7–10 show some of the whole rock geo-
chemical data of samples from Black Hawk mine wastes.
Figure 7 shows a positive strong correlation (0.94) between
copper and arsenic.
Tellurium (Te) and tantalum (Ta) are critical minerals
and Figure 8 shows correlation of 0.75 between Te and Ta.
Te is by-product of other deposit types (porphyry copper
deposits).
Based on ioGAS correlation matrix and whole rock
geochemistry results, Figure 9 shows a positive and strong
correlation (0.94) between Cadmium (Cd) and Zinc (Zn).
Figure 4. Black Hawk mine waste composite sample
locations
Figure 5. Paste pH test on sieved samples
Figure 6. Fizz test on Black Hawk mine waste sample. The
photo is illustrating that after adding HCl, sample started to
fizz
samples collected for this study were determined by ALS
Laboratories and the USGS laboratory. Samples were sub-
mitted to the laboratory when sample preparation occurred.
Duplicate samples and standards were analyzed and uncer-
tainty of analyses is generally 5%. Chemical plots were
created using ioGAS-64 (ioGAS ™ -REFLEX (reflexnow.
com). Chemical analyses will be released in future reports.
Petrography and Mineralogy
Mineralogy of selected samples was determined by visual
and X-ray diffraction (XRD). XRD analysis was performed
on either whole rock or mineral separates performed
on a PANalytical X- Pert PRO ® diffractometer at the
NMBGMR XRD Diffraction Laboratory. Analyses were
conducted using 45 kV X-ray beam tension and 40 mA
Xray beam current. XRD scans were identified using X’Pert
HighScore Plus ® software, which identifies intensity peaks
and matches patterns to a Powder Diffraction File database.
XRD data will be available in the final report.
Paste pH and Fizz Test
A sample is typically considered acid generating if the pH
is less than 4 (Borden, 2001). In order to determine the pH
of the pore water produced by the dissolution of second-
ary mineral phases on the surfaces of oxidized rock par-
ticles, paste tests are used to assess the geochemical behavior
of mine waste materials subject to weathering in the field
(Figure 5). Results are recorded in Table 1.
Also, fizz test was performed to find out how much
hydrochloric acid (HCl) needs to be added to a 2 g sample
in order to digest carbonate (and other neutralizing min-
erals) and then determine the amount of NP (Figure 6).
Results are recorded in Table 1.
RESULTS AND DISCUSSION
Critical Minerals in Mine Waste
Overall, 17 samples were collected and separated as fines
and coarse. Figures 7–10 show some of the whole rock geo-
chemical data of samples from Black Hawk mine wastes.
Figure 7 shows a positive strong correlation (0.94) between
copper and arsenic.
Tellurium (Te) and tantalum (Ta) are critical minerals
and Figure 8 shows correlation of 0.75 between Te and Ta.
Te is by-product of other deposit types (porphyry copper
deposits).
Based on ioGAS correlation matrix and whole rock
geochemistry results, Figure 9 shows a positive and strong
correlation (0.94) between Cadmium (Cd) and Zinc (Zn).
Figure 4. Black Hawk mine waste composite sample
locations
Figure 5. Paste pH test on sieved samples
Figure 6. Fizz test on Black Hawk mine waste sample. The
photo is illustrating that after adding HCl, sample started to
fizz