Article pubs.acs.org/EF
Geochemistry of Trace Elements in Coals from the Yueliangtian Mine, Western Guizhou, China: Abundances, Modes of Occurrence, and Potential Industrial Utilization Peipei Wang,*,†,‡ Xiaoyun Yan,†,‡ Wenmu Guo,†,‡ Siyu Zhang,†,‡ Zhen Wang,†,‡ Yaguang Xu,†,‡ and Lei Wang†,‡ †
State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, China College of Geoscience and Survey Engineering, China University of Mining and Technology, Beijing 100083, China
‡
ABSTRACT: This paper reports the geochemical compositions of coals and non-coal samples from a complete seam section in the Late Permian Longtan Formation from the Yueliangtian mine, western Guizhou, southwestern China. The abundances, modes of occurrence, and origin of elements and minerals in the Yueliangtian coal were investigated using optical microscopy, scanning electron microscopy with an energy dispersive X-ray spectrometer, X-ray powder diffraction, X-ray fluorescence spectrometry, and inductively coupled plasma mass spectrometry. The host rocks (roof and floor) and one parting sample of the coal seam have high TiO2 contents, which is in accordance with the high TiO2 content in the Emeishan basalt from the Kangdian Upland. The coal bench samples are rich in SiO2 (14.52%, whole-coal basis) compared with the average for the common Chinese coals, and the high SiO2 present in this study is consistent with the abundant quartz, which was mainly precipitated from siliceous solutions produced by weathering of the Emeishan basalt. Compared to the average values for world hard coals, the coal bench samples are enriched in V (77.0 μg/g), Cu (41.9 μg/g), Se (4.77 μg/g), Zr (93.8 μg/g), Hg (0.375 μg/g), and Pb (21.4 μg/g). In contrast to many other Permian coals from southwestern China, the transition elements, including Cr, Co, Ni, and Zn, are not enriched in the coal bench samples, possibly due to the input of the terrigenous materials with felsic and felsic-intermediate rock compositions. The highfield strength elements are relatively enriched not only in the parting samples but also in the adjacent coal bench samples, indicating that the partings were subjected to leaching by groundwater during the diagenetic process. Elements in coal, including B, Cr, Co, Zn, and Ni, are mainly associated with clay minerals, while As, Se, Sb, and Pb mainly occur in sulfide minerals (pyrite and marcasite). An intra-seam volcanic ash-derived tonstein layer identified in the coal is characterized by strong negative Eu anomaly in the Upper Continental Crust-normalized rare earth elements and Y distribution pattern, indicating the input of felsic or felsic-intermediate terrigenous materials. mainly composed of the Emeishan basalt,12,23,24,27 (2) the concentrations of Sr and Ba are relatively high in the Late Permian coals from the east part of southwestern China, probably due to the influence of seawater,27 (3) elements in the coal, including Al, Ti, Li, Ta, Th, Ga, U, Sn, Sc, Cr, Cu, Rb, Co, and Se, are associated with aluminosilicate minerals,23,24,27 and (4) the highfield strength elements (HFSEs), including Zr, Nb, Hf, REY, and U, occur not only in zircon but also in anatase.23 Most of previous studies have paid much attention to the Late Permian coals in southern Sichuan, Chongqing, and eastern Yunnan with limited studies related to the mineralogy and geochemistry of coals from western Guizhou,13,14,17,18,26−28 especially from the Yueliangtian coal mine, which is one of the most important mines in southwestern China. Wang et al.26 made a comparative study between the Late Permian coals from western Guizhou and eastern Yunnan, with an emphasis on the mineral compositions. In the present study, we reported the abundances and modes of occurrence of the trace elements in the coal benches, host rocks (roof and floor strata), and parting samples of a Late Permian coal seam from the Yueliangtian
1. INTRODUCTION The abundance and occurrence modes of trace elements in coal result from the interaction of the coal generation material with detrital input and circulated solutions in the coal basin1−4 along with the influence of the botanical, biochemical, and geological factors during the coal formation and epigenetic stages.1,4−6 Trace elements in coals from southwestern China have attracted much attention because they can provide not only geologic information about depositional conditions of coal and coalbearing sequences and regional tectonic history7,8 but also practical information for potential industrial utilization of rare metals (e.g., Nb, Ta, Zr, Hf, rare earth elements and yttrium (REY, or REE if Y is not included), and Ga) during coal mining and combustion.4,8−11 Guizhou Province, known as “Southern Sea of Coal”, provides an important energy resource base for southwestern China. A number of investigations have been reported on the geochemical characteristics of the Late Permian coals in southwestern China,4,8,12−24 which have shown that the dominant sediment source region for these coals is the Kangdian Upland, located to the west of the studied coal basin.25,26 Previous studies have suggested that (1) trace elements, including V, Sc, Co, Ni, Cu, Zn, Se, Zr, Nb, Hf, and Ta, are enriched in the Late Permian coals owing to the sediment-source Kangdian Upland, which is © 2016 American Chemical Society
Received: September 6, 2016 Revised: October 16, 2016 Published: November 1, 2016 10268
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels
Figure 1. Location of the Yueliangtian mine in western Guizhou Province, southwestern China (after Dai et al.12).
coal mine and discussed geological factors that may have significantly influenced the geochemical and mineralogical compositions of the coal seam. Due to their unique chemical properties, REY have been widely used in various fields, such as electronics, aviation, atomic energy, metallurgy, magnetic materials, transportation, agriculture, and medicine.7 The ever-increasing demand of REY has stimulated an emphasis on economically feasible approaches for REY recovery. In the present study, a comparison of REY concentrations between the Yueliangtian coal and the conventional rare-metal ore deposits was carried out to estimate the potential of Yueliangtian coal as REY raw materials.
2. GEOLOGICAL SETTING The Yueliangtian coal mine is located in western Guizhou Province (Figure 1), and the coal reserves in this coal mine are estimated to be 157.19 Mt as of 2008. The Upper Permian Longtan Formation, deposited in a continental-marine transitional environment, is the major coal-bearing sequence in the Yueliangtian mine, mainly made up of fine sandstone, siltstone, pelitic siltstone, silty mudstone, mudstone, and coal seams. The Longtan Formation is conformably overlain by the Triassic strata and disconformably underlain by the Emeishan basalts. The lowermost portion of the Longtan Formation is a bauxite layer occurring between the Longtan Formation and the Emeishan basalts (Figure 2). The Kangdian Upland, consisting of Emeishan basalts in the lower section and a few felsicintermediate rocks in the upper section, is the dominant sediment source for the coal-bearing strata in the study area.29−33 The coal-bearing strata contain 12 minable coal seams, among which the no. 19 coal is one of the most important workable seams in this area. The no. 19 coal seam is located in the middle section of the Longtan Formation with an average thickness of 1.32 m. It contains relatively abundant discrete particles and fracture-fillings of pyrite.17,26
Figure 2. Sedimentary sequences in the Yueliangtian mine (after Wang et al.26). 10269
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels
Table 1. Ash Yield (%), Volatile Matter (%), Total Sulfur (%), Forms of Sulfur (%), and Mean Random Vitrinite Reflectance (%) of the No. 19 Coal Samples and Data for Quartz, Clay Minerals, and Sulfide Minerals (wt %) in All Coal Low-Temperature Ash and Non-coal Samplesa clay minerals sample YLT19-1r YLT19-2c YLT19-3c YLT19-4c YLT19-5p YLT19-6c YLT19-7c YLT19-8p YLT19-9c YLT19-10c YLT19-11c YLT19-12f
thickness (cm) 20 24 26 4 20 20 5 20 20 20
Ad 36.02 19.44 15.32
Vdaf 26.31 16.68 31.5
Cdaf 88.16 89.21 87.03
St,d
Sp,d
0.28 0.35 0.53
Ro,ran nd nd 1.05
40.37 22.74
35.67 30.43
83.84 87.09
4.14 2.02
3.51 1.71
1.03 1.03
19.58 12.87 19.38
32.34 29.38 30.55
84.68 90.56 89.14
4.76 0.85 1
3.93
1.01 1.04 0.96
Qu
Kao
9.1 82.5 62.5 52.4 5.3 7.7 28.3 9.2 25.5 39.2 17.7 6.3
34.9 17 19.2 34.9 72.1 67.1 57 90.8 44.4 52 70.6 27.9
illite
I/S
sulfide minerals Cha
10.3 12.9
4.2
Py
Mar
1.5 7.2 5.8 5.4
1.9 4.7 8.4
23.4 2.5 2
5.5 4.4 4.1
48.9
a
Data compiled from Wang et al.26 A, ash yield; V, volatile matter yield; St, total sulfur; Sp, pyritic sulfur; Ss, sulfate sulfur; So, organic sulfur; ad, airdry basis; d, dry basis; daf, dry and ash-free basis; Ro,ran, average vitrinite random reflectance; Qu, Quartz; Kao, Kaolinite; I/S, mixed-layer illite/ smectite; Cha, Chamosite; Py, Pyrite; Mar, Marcasite; nd, not detected.
world hard coal40 were also listed in this table for comparative purposes. Compared to the average values for Chinese coals,8 SiO2 and TiO2 are enriched in the no. 19 coal. However, the concentrations of the major-element oxides, including Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, and P2O5, are much lower. Compared to the average values for world hard coals,39 elements V, Cu, Se, Zr, Hg, and Pb are slightly enriched (2 < CC < 5) (CC, concentration coefficient, the ratio of trace element concentration in coal samples investigated to averages for world hard coals41); some elements, including B, F, Rb, Sr, Cs, Ba, Tl, and Bi, are depleted (CC < 0.5). The remaining elements (0.5 < CC < 2) are close to the average values for world hard coals (Figure 3A). Compared to the average values for world clays,42 the partings are significantly enriched in Se and Hg (10 < CC < 100); Bi (CC = 5.34) in the partings is enriched, and elements Li (CC = 3.60), Ga (CC = 2.11), Nb (CC = 3.61), Mo (CC = 4.09), Sn (CC = 2.14), and Ta (CC = 2.08) are slightly enriched. The remaining elements (0.5 < CC < 2) are either close to the average values for world clays or depleted (Figure 3B). On the basis of the correlation coefficient (r) between elemental concentration and ash yield, the determined elements in the no. 19 coal can be classified into three groups: (a) elements with relatively high correlation coefficients (r > 0.75), including Be, F, Sc, Cu, Zn, Ga, Rb, Sr, Zr, Cd, In, Ba, and Hf and indicating a high inorganic affinity; (b) the correlation coefficient of these elements such as Li, B, V, Cr, Co, Ni, Nb, Sn, Cs, Ta, Bi, Th, and U, which ranges from 0.43 to 0.63, suggesting a prevailing inorganic affinity; and (c) the remaining elements, including Ge, As, Se, Mo, Sb, Hg, Tl, and Pb, which have negative or low positive correlation coefficients, indicating an organic−inorganic affinity.43 The high correlation coefficients for Ga−Ash (r = 0.95), Ga−SiO2 (r = 0.83), Ga−Al2O3 (r = 0.94), Zr−Ash (r = 0.91), Zr−SiO2 (r = 0.81), Zr−Al2O3 (r = 0.84), Hf−Ash (r = 0.92), Hf−SiO2 (r = 0.81), and Hf−Al2O3 (r = 0.87) indicate that the elements Ga, Zr, and Hf may occur mainly in the kaolinite.44,45 Moreover, elements Zr, Hf, Th, and U, as well as the LREY show similar variations through the no. 19 coal section (Figure 4), suggesting the same occurrence mode of these elements.4,34
3. SAMPLES AND ANALYTICAL PROCEDURES A total of 12 bench samples, including 8 coal benches, 2 partings, 1 roof, and 1 floor sample, were collected from the no. 19 coal seam at the Yueliangtian coal mine. The bench sample was cut over an area 10 cm wide and 10 cm deep. Each sample was milled to 200 mesh prior to further geochemical analyses. Each coal bench sample was subjected to low temperature ashing; after that, the low temperature ashes (LTAs) and non-coal samples (roof, floor, and partings) were analyzed by X-ray diffraction (XRD). Quantitative analysis of minerals was conducted using the Siroquant technique. The scanning electron microscopy equipped with energydispersive spectrometry (SEM-EDS) was used to identify the mineral phases in the polished coal pellets. Details of the XRD and SEM-EDS techniques have been described in Wang et al.26 The percentage of major element oxides, including SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O, and P2O5, was determined by X-ray fluorescence (XRF) spectrometry on high-temperature ashes (HTAs, 815 °C). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of trace elements following the method described by Dai et al.34,35 and Li et al.36 Fluorine was determined by pyrohydrolysis combined with an ionselective electrode based on ASTM method D5987-96 (2002).37 A Milestone direct mercury analyzer (DMA-80) was used to analyze mercury in the samples. The detection limit of Hg is 0.005 ng, and the linearity of the calibration is in the range 0−1000 ng.38
4. RESULTS AND DISCUSSION 4.1. Coal Characteristics. Table 1 lists the ash yield, volatile matter, total sulfur, forms of sulfur, and mean random vitrinite reflectance of the no. 19 coal samples, as well as quartz, clay minerals, and sulfide minerals in the coal LTAs and host rock samples, as reported by Wang et al.26 According to the classification of the American Society for Testing and Materials,39 the samples present in this study are medium volatile bituminous coal. The coals have medium ash yields and sulfur contents. The percentage of total sulfur in the middle and lower benches is obviously higher than that in the upper benches. As indicated in Table 1, pyritic sulfur is the dominant form in the middle and lower benches, in accordance with the relatively high content of sulfide minerals (pyrite and marcasite). 4.2. Geochemical Associations. The concentrations of major-element oxides and trace elements in the no. 19 coal are given in Table 2. Average values for Chinese coals8 and 10270
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
80.54
87.39
81.08
YLT19-9c
YLT19-10c
YLT19-11c
10271
SiO2
0.65
2.4
1.57
1.31
1.61
1.76
1.73
2.07
1.38
2.89
3.16
1.62
0.91
0.62
2.27
Ge
1.71
8.47v
14.52
44.81
10.06
8.33
10.05
41.56
13.45
18.54
29.90
10.38
12.70
32.64
46.47
TiO2
1.95
8.3
16.2
0.87
1.41
1.75
88.5
0.37
4.65
28.1
17.9
1.01
1.20
2.62
2.47
As
1.46
0.33v
0.48
5.37
0.76
0.21
0.13
0.53
0.26
1.96
3.39
0.23
0.13
0.17
6.53
Al2O3
3.67
1.3
4.77
1.55
3.14
3.68
17.0
2.31
3.57
5.94
9.34
1.81
1.65
1.32
4.57
Se
0.76
5.98v
4.54
23.54
5.58
2.88
3.99
28.40
5.55
12.27
20.02
2.14
1.94
1.99
23.94
0.07
18
1.19
9.99
1.97
0.05
0.08
1.82
0.55
5.40
16.8
0.40
0.51
0.58
29.2
Rb
0.41
4.85v
1.99
5.90
1.78
0.62
4.89
0.88
2.44
5.27
5.87
0.43
0.38
0.13
2.99
Fe2O3
MnO
0.49
100
48.7
366
41.4
21.0
15.8
13.6
25.4
137
177
50.2
69.5
29.1
315
Sr
0.25
0.015v
0.004
0.004
0.003
0.002
0.001
0.001
0.002
0.008
0.019
0.006
0.009
0.001
0.012
2.60
36
93.8
581
130
51.8
54.5
238
85.3
275
488
48.3
20.9
84.7
677
Zr
0.40
0.22v
0.09
1.40
0.16
0.03
0.06
0.16
0.06
0.21
0.38
0.05
0.08
0.05
1.06
MgO
CaO
2.01
4
8.05
11.3
1.87
4.78
4.47
17.4
7.07
36.4
67.5
5.42
2.28
2.11
95.1
Nb
0.48
1.23v
0.59
0.40
0.21
0.23
0.10
0.09
0.19
0.28
0.19
1.05
2.51
0.12
0.95
Na2O
1.26
2.1
2.65
0.07
0.66
0.56
4.04
0.69
2.23
11.2
13.8
1.17
0.95
0.33
3.15
Mo
0.32
0.160v
0.050
0.623
0.051
0.030
0.030
0.230
0.049
0.137
0.230
0.043
0.028
0.036
0.572
K2O
1.06
0.2
0.21
0.97
0.26
0.10
0.22
0.33
0.20
0.64
1.06
0.09
0.06
0.13
1.09
Cd
0.22
0.190v
0.042
1.434
0.064
0.009
0.010
0.126
0.028
0.155
0.463
0.022
0.021
0.026
1.384
P2O5
0.84
0.04
0.034
0.147
0.044
0.028
0.032
0.089
0.032
0.084
0.139
0.012
bdl
0.004
0.158
In
0.21
0.092v
0.019
0.115
0.017
0.011
0.015
0.039
0.012
0.056
0.048
0.010
0.016
0.017
0.499
Li
0.65
1.4
0.91
0.48
bdl
0.68
0.93
9.75
1.38
2.76
4.64
0.39
0.10
0.17
5.43
Sn
1.16
14
16.2
26.9
27.3
19.6
19.1
303
23.9
27.3
58.6
4.55
3.11
4.99
24.7
Be
1.28
1
1.28
0.01
0.02
0.34
6.83
0.31
0.60
0.83
0.61
0.20
0.15
bdl
0.24
Sb
0.88
2
1.75
4.44
2.21
1.95
1.50
2.17
1.46
2.24
2.82
2.09
1.62
0.94
3.21
B
F
Ba
0.25
82
20.7
408
25.1
11.8
11.0
124
15.5
71.7
179
11.3
12.8
6.65
772
37.9
31.5
52.3
41.3
65.3
21.9
21.7
63.7
0.06
1.1
0.065
0.37
150
55.2
0.572 349
0.074
bdl
bdl
bdl
0.045
0.262 170
0.384 336
0.003
0.003
0.003
1.307 516
Cs
0.11
47
5.20
13.9
2.54
4.58
2.20
10.8
18.3
4.36
7.14
0.91
bdl
3.58
11.9
Sc
1.99
1.2
2.38
12.9
2.83
1.55
1.75
6.90
2.54
7.06
11.4
1.36
0.60
1.39
16.1
Hf
1.21
3.7
4.46
35.9
6.34
4.13
4.00
7.77
3.74
5.78
24.3
4.36
2.24
5.13
27.3
V
1.62
0.3
0.49
0.68
0.09
0.33
0.29
2.20
0.47
2.39
3.79
0.14
0.10
0.07
5.17
Ta
2.75
28
77.0
134
111
32.6
28.5
27.0
63.9
240
327
52.1
25.9
62.4
532
Cr
3.75
0.1
0.375
0.607
0.211
0.235
0.926
0.542
0.438
1.139
1.477
0.033
0.010
0.005
0.040
Hg
1.32
17
22.4
119
37.5
13.1
9.02
5.76
14.1
59.8
120
15.8
13.0
16.6
355
Co
Ni
20.9
14.5
13.1
17.8
3.21
2.64
6.07
8.59
Pb
1.71
17
29.0
81.8
17.2
5.87
10.4
3.50
19.2
66.7
131
32.6
41.0
39.2
165
0.43
0.58
0.248
0.052
0.026
0.002
2.38
9
25.8
19.0
19.6
Bi
Th
0.29
1.42
0.68
1.1
0.75
8.37
8.35
3.94
3.65
7.20
4.63 1.45
3.2
12.0 45.4
17.6
10.2
9.65
13.7
14.5
1.17
1.9
2.23
5.26
1.98
0.91
4.69
9.62
3.09
5.44
6.99
0.98
0.33
0.40
3.11
U
0.61
28
17.2
190
2.40
18.5
8.22 19.9 104
1.11
1.36 51.0
2.78
0.39
Zn 234
1.98
2.86 16.9
0.04
0.13
0.16
4.67 11.4
2.62
16
41.9
267
43.6
24.4
32.2
9.82
38.5
132
140
9.37 bdl 21.4
Cu 247
5.99 bdl
7.16
0.188 118
0.020
0.181
1.086
0.996
0.002
bdl
bdl
0.074
Tl
1.79
6
10.7
31.8
6.20
2.34
3.65
1.42
6.42
29.7
73.3
14.4
13.2
9.97
105
LOI, loss on ignition; bdl, below detection limit; nd, no data; CC, concentration coefficient. bAverages for coal bench samples. vAverages for Chinese coals (data from Dai et al.8). dAverages for world hard coals (data from Ketris and Yudovich40). eThe ratio of major element oxides in coal samples to averages for Chinese coals and trace element concentration in coal samples to averages for world hard coals.
a
1.10
6
worldd
CC
6.59
averageb
e
9.72
42.8
YLT19-12f
3.70
YLT19-11c
5.30
YLT19-10c
19.8
YLT19-6c
YLT19-9c
38.0
YLT19-5p
6.67
3.28
YLT19-4c
30.5
2.78
YLT19-3c
YLT19-8p
1.50
YLT19-2c
YLT19-7c
Ga
45.7
sample
YLT19-1r
nd
27.84
YLT19-8p
CCe
77.69
YLT19-7c
nd
60.63
YLT19-6c
Worldd
38.23
YLT19-5p
15.65
84.82
YLT19-4c
77.18
80.67
YLT19-3c
Averageb
64.62
YLT19-2c
YLT19-12f
LOI
14.58
sample
YLT19-1r
Table 2. Concentrations of Major Element Oxides (%) and Trace Elements (μg/g) in the Coals, Partings, and Host Rocksa
Energy & Fuels Article
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels
Figure 3. CC of trace elements in the no. 19 coal. (A) Normalized by average trace element concentrations in world hard coals.40 (B) Normalized by average trace element concentrations in world clays.42
Figure 4. Concentration variations of transition elements and HFSEs as well as ash yield through the no. 19 coal seam section. LREY: La, Ce, Pr, Nd, and Sm. MREY: Eu, Gd, Tb, Dy, and Y. HREY: Ho, Er, Tm, Yb, and Lu.
floor (YLT19-12f), and parting sample (YLT19-5p) are 7.64, 6.37, and 5.49%, respectively, much higher than that in the intra-seam volcanic ash-derived tonstein layer (sample YLT19-8p). The ratio of TiO2/Al2O3 is a useful indicator to track the source of detrital sedimentary rocks and volcanic ash-originated intraseam tonsteins due to their stability of Ti and Al during the weathering process.13,33,38,52−54 Generally, the TiO2/Al2O3 values for felsic, intermediate, and mafic tonsteins are 0.08,12,13,34 respectively. As indicated in Figure 5A, both the host rocks (roof and floor) and parting YLT19-5p have high TiO2/Al2O3 values (0.27, 0.23, and 0.17, respectively), consistent with the high Ti concentration in these three samples and indicating a mafic composition for the terrigenous source rocks. However, the parting sample YLT19-8p has a TiO2/Al2O3 ratio of 1), M-type (MREY; LaN/SmN < 1, GdN/LuN > 1), and H-type (H-REY; LaN/ LuN < 1).70 In addition, a mixed type of REY enrichment also occurred in the no. 19 coal based on the classification. The REY enrichment patterns in most coal benches (YLT192c, YLT19-4c, YLT19-7c, and YLT19-10c) are characterized by H-type enrichment (Figure 9A). The REY in coal samples YLT19-3c and YLT19-9c have similar distribution patterns,
from Guangxi province, southwestern China.46 The concentration of Hg in the coal bench samples of the no. 19 coal varies from 0.005 to 1.139 μg/g with an average value of 0.375 μg/g, much higher than the average value for both Chinese coals (0.163 μg/g)8 and world hard coals (0.1 μg/g).40 4.3.5. Niobium, Ta, Zr, Hf, Th, and U. Nb, Ta, Zr, Hf, Th, and U are known as HFSEs. Nb and Zr are slightly enriched in the coals, while the concentrations of the remaining elements are close to the average value of the world hard coals. It is noted that the concentrations of Nb Ta, Zr, Hf, Th, and U are higher in the coal bench samples YLT9-6c and YLT19-7c, interlayered between the parting samples YLT19-5p and YLT19-8p, than those in other coal samples (Figure 4). A possible interpretation is that the HFSEs were leached from the overlying parting by groundwater and immediately incorporated into the organic matter.67 The highfield strength elements show significantly positive correlations with SiO2 and Al2O3 (Table 3), indicating that these elements in the no. 19 coal are associated with aluminosilicates (e.g., clay minerals). Alternatively, the positive correlations between the HFSEs and Al2O3 in coal probably reflect a common source. Positive correlations between these high field strength elements and clay minerals (the sum of kaolinite, illite, mixed-layer illite/smectite, and chamosite) are shown in Figure 8, suggesting that these highfield strength elements are mainly associated with clay minerals. 4.4. Rare Earth Elements and Yttrium (REY). 4.4.1. Distribution Patterns of REY in Coal and Host Rocks. The REY 10275
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Figure 8. Relation of: Nb to clay minerals, Ta to clay minerals, Zr to clay minerals, Hf to clay minerals, Th to clay minerals, and U to clay minerals.
Table 4. Concentrations of Rare Earth Elements and Y in the Coals, Partings, and Host Rocksa element
YLT19-1r
YLT19-2c
YLT19-3c
YLT19-4c
YLT19-5p
YLT19-6c
YLT19-7c
YLT19-8p
YLT19-9c
YLT19-10c
YLT19-11c
YLT19-12f
La Ce Pr Nd Sm Eu Gd Tb Dy Y Ho Er Tm Yb Lu REY REYb REO REOb δEu δCe LaN/LuN LaN/SmN GdN/LuN type
80.6 199 21.4 83.1 14.7 3.79 14.2 1.71 8.98 40.3 1.63 4.56 0.60 3.99 0.52 479 561 576 674 1.34 1.09 1.56 0.82 2.17 L-M
9.91 15.3 1.63 6.15 1.01 0.31 1.18 0.18 1.29 6.28 0.25 0.79 0.11 0.77 0.11 45.3 128 54.4 154 1.39 0.85 0.88 1.47 0.83 H
9.15 20.5 2.58 10.3 2.03 0.53 1.98 0.26 1.48 6.07 0.27 0.80 0.11 0.76 0.11 56.9 294 68.3 353 1.34 0.96 0.83 0.68 1.42 M-H
5.13 9.56 1.17 4.83 1.11 0.32 1.30 0.21 1.47 6.94 0.30 0.95 0.14 0.94 0.13 34.5 227 41.5 274 1.29 0.89 0.40 0.69 0.81 H
71.2 149 16.2 63.2 12.0 2.92 12.1 1.53 8.59 38.3 1.47 3.98 0.50 3.31 0.43 385 623 463 749 1.24 1.00 1.65 0.89 2.21 L-M
34.6 76.3 7.72 30.8 5.59 1.33 5.63 0.70 3.90 15.4 0.71 2.03 0.27 1.85 0.26 187 475 225 571 1.21 1.06 1.35 0.93 1.73 L-M
9.91 23.9 2.76 11.2 2.47 0.50 2.86 0.49 3.30 15.8 0.68 2.16 0.31 2.15 0.30 78.8 353 95.0 426 0.88 1.04 0.34 0.60 0.76 H
84.0 155 21.3 80.8 16.3 2.17 15.7 1.86 7.99 18.6 1.09 2.59 0.31 2.14 0.30 410 568 490 680 0.70 0.83 2.85 0.77 4.21 L-M
36.7 79.5 9.01 34.3 7.30 1.16 8.39 1.31 8.09 38.6 1.55 4.58 0.61 4.08 0.57 236 1212 284 1459 0.71 1.00 0.64 0.75 1.16 M-H
11.8 26.4 3.08 11.9 2.70 0.55 3.22 0.55 3.79 20.2 0.77 2.40 0.33 2.24 0.31 90.3 716 109 864 0.87 1.00 0.38 0.66 0.81 H
16.4 39.8 4.24 16.4 3.38 0.77 3.37 0.47 2.70 9.29 0.48 1.36 0.18 1.18 0.16 100 529 120 636 1.12 1.09 1.04 0.73 1.68 L-M
154 338 40.8 167 30.0 7.05 25.7 2.82 13.9 59.2 2.34 6.38 0.81 5.43 0.73 855 1013 1025 1216 1.30 0.97 2.11 0.77 2.77 L-M
Units: μg/g on whole-coal basis. REY, sum of rare earth elements and yttrium; REO, sum of oxides of rare earth elements and yttrium. bValues on an ash basis. δEu = EuN/(0.67 × SmN + 0.33 × TbN). δCe = 2CeN/(LaN + PrN). N, values normalized by the average REY content of Upper Continental Crust.70 a
possibly related to natural waters.71,73,74 The coal bench samples YLT19-6c and YLT19-11c as well as the roof, floor, and two parting samples have a L-M-type enrichment (Figures 9C and D).
both characterized by M-H-type enrichment (Figure 9B). The H-type enrichment found in the no. 19 coal was probably due to the injection of hydrothermal solutions, while the M-type was 10276
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Figure 9. REY distribution patterns in the coal benches, partings, and host rocks of the no. 19 coal. REY plots are normalized by Upper Continental Crust (UCC).72
in the Yueliangtian coal ashes (Figure 10). The y-axis is the percentage of critical elements (Nd, Eu, Tb, Dy, Y, and Er) in
The coal bench samples in the present study show no pronounced Ce, slight positive Eu, and distinct negative Y anomalies in the UCC-normalized distribution pattern. However, sample YLT19-9c has the highest REY concentration relative to other coal bench samples and the strongest negative Eu anomaly among the coal bench samples (Figure 9B). As reported by Dai et al.,71 the distinct negative Eu anomalies in coals were attributed to the input of felsic or felsic-intermediate terrigenous materials. The REY distribution patterns for the parting (YLT19-5p) and host rocks (YLT19-1r and YLT19-12f) are characterized by distinct positive Eu anomalies (Figure 9D). The similar REY distribution patterns of these samples indicate that the materials of the parting and host rocks were derived from the same sediment source-region. However, parting sample (YLT198p) shows strong negative Eu anomaly (Figure 9D), distinctly different from the parting sample YLT19-5p and host rocks, also suggesting the input of felsic or felsic-intermediate rocks.26,71 4.4.2. Potential Industrial Value of REY in Coal Ashes. The important role of REY in either power or energy-efficient technologies has generated a situation where the demand for REY materials exceeds the supply and has led to a global contest to discover new sources.75 Because coal deposits are expected to promote comprehensive utilization as REY raw materials,8,70,76−80 it is significant to evaluate these potential resources during coal mining and combustion.70,79,81−83 The average REY concentration in the no. 19 coal ash is 558 μg/g (or 0.08% REY oxides, REO). However, the REY concentrations of sample YLT19-9c and YLT19-12f are 1212 μg/g (or 0.15% REY oxides, REO) and 1013 μg/g (or 0.12% REY oxides, REO), respectively, which is higher than the typical REY cut-off grade (0.1% REO) in coal combustion wastes for byproduct recovery.70 A REYdef, rel-Coutl graph, proposed by Seredin and Dai,70 has been adopted to evaluate the potential industrial value of REY
Figure 10. REYdef,rel-Coutl plot for the no. 19 coal ashes, partings, and host rocks. Area I, unpromising; Area II, promising; Area III, highly promising. REYdef,rel is the percentage of critical elements (Nd, Eu, Tb, Dy, Y, and Er) in the total REY; Coutl is the ratio of the relative amount of critical REY metals in the REY sum to the relative amount of excessive REY (Ce, Ho, Tm, Yb, and Lu). 10277
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Dai et al.85 and Tian et al.87 reported abundant ultrafine quartz in Xuanwei coals, probably related to the lung cancer in some townships in Xuanwei County; however, there have not been any reports on human health associated with the abundant quartz in the Yueliangtian coals from Panxian Country in the present study. Even so, the quartz-rich coals in the Yueliangtian coal mine are still worth further studies because the high percentages of quartz may lead to the corrosion of furnaces during the process of coal combustion.88
the total REY (REYdef, rel), and the x-axis represents the ratio of the amount of critical REY metals in the REY sum to the relative amount of excessive REY (Ce, Ho, Tm, Yb, and Lu). The Yueliangtian coal ashes fall mostly in area II of the graph, indicating that the coal ashes can be regarded as promising REY raw materials especially for the recovery of critical elements (Nd, Eu, Tb, Dy, Y, and Er) (Figure 10). 4.5. Associations between Quartz and Selected Elements. Because the mineralogical characteristics of quartz have been discussed in detail by Wang et al.26 in the previous paper, the abundance, occurrence modes, and origin of quartz are introduced very briefly in this paper. As shown in Table 1, the proportion of quartz is significantly high in most coal bench samples. Quartz in the no. 19 coal occurs mainly as two forms: (1) as small irregular particles (mostly ∼10 μm and, in a few cases, >100 μm in size, Figures 11A−C)
5. CONCLUSIONS The coal bench samples in the present study are enriched in V, Cu, Se, Zr, Hg, and Pb, while the non-coal samples are enriched in Li, Ga, Se, Nb, Mo, Sn, Ta, and Hg. The elements were classified into three groups based on the correlation coefficient between elemental concentration and ash yield. B, Cr, Co, Zn, and Ni are mainly associated with clay minerals. Sr and Ba are of terrigenous origin from the Kangdian Upland mafic basalt. As, Se, Sb, and Pb mainly occur in both pyrite and marcasite. The high concentrations of HFSEs in the coal bench samples near the partings are due to leaching by groundwater. In contrast to many Late Permian coals from southwestern China, the REY enrichment patterns of the coal benches in the present study are characterized by alternative H-type and M-H-type enrichment, indicating the influence of natural waters or hydrothermal solutions. The parting sample YLT19-8p, identified as tonstein layers in the coal, is characterized by strong negative Eu anomaly in its REY distribution pattern, suggesting the input of felsic or felsic-intermediate rocks. The no. 19 coal from the Yueliangtian mine and its floor strata can be regarded as potential sources for rare earth elements and Y.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected].
Figure 11. Quartz in the no. 19 coal: (A) Scattered quartz in the collodetrinite (reflected light), (B) quartz in the collodetrinite (reflected light), (C) terrigenous detrital quartz (reflected light), and (D) cell-filling quartz in semifusinite (reflected light).
Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This research was supported by the National Key Basic Research Program of China (Grant 2014CB238902), the National Natural Science Foundation of China (Grants 41420104001 and 41272182), and the Program for Changjiang Scholars and Innovative Research Team in University (Grant IRT13099). The authors greatly thank Prof. Shifeng Dai for his constructive comments, which greatly improved the quality of the paper.
dispersedly distributed in collodetrinite and (2) as cell-fillings of the structured macerals (Figure 11D).26 The modes of occurrence clearly indicate that the quartz in coal is mainly of authigenic origin and to a lesser extent was derived from detrital materials of terrigenous origin. Ward84 has summarized that the authigenic quartz is formed by the silica that either probably released from siliceous phytoliths or leached from the basement rocks or volcanic ashes. In addition, the authigenic quartz may be precipitated from siliceous hydrothermal solutions.12,85 As discussed by Wang et al.,26 the percentage of SiO2 in the no. 19 coal is relatively high in addition to the ratio of SiO2/Al2O3 in accordance with the high percentages of quartz. The upper coal benches (samples YLT19-2c, YLT19-3c, and YLT19-4c) with the major mineral compositions of quartz and, to a lesser extent, kaolinite (Table 1), contain relatively low concentrations of highfield strength elements and REY (Table 4). Wang et al.26 reported that the abundant authigenic quartz in the no. 19 coal is probably precipitated from silica-bearing solutions derived from weathering of the Emeishan basalt in the Kangdian Upland,7,20 while the kaolinite is derived from the weathering residues of the Emeishan basalt.20,86 Because the HFSEs and REY are associated with clay minerals (e.g., kaolinite), this could provide indirect evidence for the terrigenous origin of these trace elements.
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REFERENCES
(1) Swaine, D. J. Trace Elements in Coal; Butterworths: London, U.K., 1990; p 278. (2) Kolker, A.; Finkelman, R. B. Potentially hazardous elements in coal: Modes of occurrence and summary of concentration data for coal components. Coal Prep. 1998, 19, 133−157. (3) Seredin, V. V.; Finkelman, R. B. Metalliferous coals: A review of the main genetic and geochemical types. Int. J. Coal Geol. 2008, 76, 253−289. (4) Zhao, L.; Ward, C. R.; French, D.; Graham, I. T. Major and trace element geochemistry of coals and intra-seam claystones from the Songzao Coalfield, SW China. Minerals 2015, 5, 870−893. (5) Bouška, V. Geochemistry of Coal; Elsevier: Amsterdam, Netherlands, 1981; pp 284. (6) Hower, J. C.; Rimmer, S. M.; Bland, A. E. Geochemistry of the Blue Gem coal bed, Knox County, Kentucky. Int. J. Coal Geol. 1991, 18, 211−231.
10278
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels (7) Ren, D. Mineral matter in coal. In Coal Petrology of China; Han, D., Ed.; Publishing House of China University of Mining and Technology: Xuzhou, China, 1996; pp 67−78 (in Chinese with an English abstract). (8) Dai, S.; Ren, D.; Chou, C.-L.; Finkelman, R. B.; Seredin, V. V.; Zhou, Y. Geochemistry of trace elements in Chinese coals: A review of abundance, genetic types, impacts on human health, and industrial utilization. Int. J. Coal Geol. 2012, 94, 3−21. (9) Liu, J.; Yang, Z.; Yan, X.; Ji, D.; Yang, Y.; Hu, L. Modes of occurrence of highly-elevated trace elements in superhigh-organicsulfur coals. Fuel 2015, 156, 190−197. (10) Dai, S.; Han, D.; Chou, C.-L. Petrography and geochemistry of the Middle Devonian coal from Luquan, Yunnan Province, China. Fuel 2006, 85, 456−464. (11) Zhou, C.; Liu, G.; Yan, Z.; Fang, T.; Wang, R. Transformation behavior of mineral composition and trace elements during coal gangue combustion. Fuel 2012, 97, 644−650. (12) Dai, S.; Li, T.; Seredin, V. V.; Ward, C. R.; Hower, J. C.; Zhou, Y.; Zhang, M.; Song, X.; Song, W.; Zhao, C. Origin of minerals and elements in the Late Permian coals, tonsteins, and host rocks of the Xinde Mine, Xuanwei, eastern Yunnan, China. Int. J. Coal Geol. 2014, 121, 53−78. (13) Zhou, Y.; Bohor, B. F.; Ren, Y. Trace element geochemistry of altered volcanic ash layers (Tonsteins) in Late Permian coal bearing formations of eastern Yunnan and western Guizhou Provinces, China. Int. J. Coal Geol. 2000, 44, 305−324. (14) Zhuang, X.; Querol, X.; Zeng, R.; Xu, W.; Alastuey, A.; LópezSoler, A.; Plana, F. Mineralogy and geochemistry of coal from the Liupanshui mining district, Guizhou, south China. Int. J. Coal Geol. 2000, 45, 21−37. (15) Dai, S.; Ren, D.; Hou, X.; Shao, L. Geochemical and mineralogical anomalies of the Late Permian coal in the Zhijin Coalfield of Southwest China and their volcanic origin. Int. J. Coal Geol. 2003, 55, 117−138. (16) Dai, S.; Li, D.; Ren, D.; Tang, Y.; Shao, L.; Song, H. Geochemistry of the Late Permian No. 30 coal seam, Zhijin Coalfield of Southwest China: Influence of a siliceous low-temperature hydrothermal fluid. Appl. Geochem. 2004, 19, 1315−1330. (17) Zhang, J.; Ren, D.; Zhu, Y.; Chou, C.-L.; Zeng, R.; Zheng, B. Mineral matter and potentially hazardous trace elements in coals from Qianxi Fault Depression Area in southwestern Guizhou, China. Int. J. Coal Geol. 2004, 57, 49−61. (18) Dai, S.; Ren, D.; Tang, Y.; Yue, M.; Hao, L. Concentration and distribution of elements in Late Permian coals from western Guizhou Province, China. Int. J. Coal Geol. 2005, 61, 119−137. (19) Dai, S.; Ren, D.; Zhou, Y.; Chou, C.-L.; Wang, X.; Zhao, L.; Zhu, X. Mineralogy and geochemistry of a superhigh-organic-sulfur coal, Yanshan Coalfield, Yunnan, China: Evidence for a volcanic ash component and influence by submarine exhalation. Chem. Geol. 2008, 255, 182−194. (20) Wang, X.; Dai, S.; Chou, C.-L.; Zhang, M.; Wang, J.; Song, X.; Wang, W.; Jiang, Y.; Zhou, Y.; Ren, D. Mineralogy and geochemistry of Late Permian coals from the Taoshuping Mine, Yunnan Province, China: Evidences for the sources of minerals. Int. J. Coal Geol. 2012, 96−97, 49−59. (21) Zhao, L.; Dai, S.; Graham, I. T.; Li, X.; Zhang, B. New insights into the lowest Xuanwei Formation in eastern Yunnan Province, SW China: Implications for Emeishan large igneous province felsic tuff deposition and the cause of the end-Guadalupian mass extinction. Lithos 2016, 264, 375−391. (22) Dai, S.; Ren, D. Fluorine concentration of coals in China - An estimation considering coal reserves. Fuel 2006, 85, 929−935. (23) Dai, S.; Luo, Y.; Seredin, V. V.; Ward, C. R.; Hower, J. C.; Zhao, L.; Liu, S.; Zhao, C.; Tian, H.; Zou, J. Revisiting the Late Permian coal from the Huayingshan, Sichuan, southwestern China: Enrichment and occurrence modes of minerals and trace elements. Int. J. Coal Geol. 2014, 122, 110−128. (24) Zhuang, X.; Su, S.; Xiao, M.; Li, J.; Alastuey, A.; Querol, X. Mineralogy and geochemistry of the Late Permian coals in the
Huayingshan coal-bearing area, Sichuan Province, China. Int. J. Coal Geol. 2012, 94, 271−282. (25) Xu, Y.; Chung, S.; Jahn, B. M.; Wu, G. Petrologic and geochemical constraints on the petrogenesis of Permian-Triassic Emeishan flood basalts in southwestern China. Lithos 2001, 58, 145− 168. (26) Wang, P.; Ji, D.; Yang, Y.; Zhao, L. Mineralogical compositions of the Late Permian coal from the Yueliangtian mine, western Guizhou, China: A comparative study with coals from eastern Yunnan and with an emphasis on the origin of minerals. Fuel 2016, 181, 859− 869. (27) Li, B.; Zhuang, X.; Li, J.; Querol, X.; Font, O.; Moreno, N. Geological controls on mineralogy and geochemistry of the Late Permian coals in the Liulong Mine of the Liuzhi Coalfield, Guizhou Province, Southwest China. Int. J. Coal Geol. 2016, 154−155, 1−15. (28) Dai, S.; Ren, D.; Ma, S. The cause of endemic fluorosis in western Guizhou Province, Southwest China. Fuel 2004, 83, 2095− 2098. (29) Xu, S.; He, M. Coal Geology of Guizhou Province; China University of Mining and Technology Press: Xuzhou, China, 2003; pp 283 (in Chinese with an English abstract). (30) Dai, S.; Chekryzhov, I. Y.; Seredin, V. V.; Nechaev, V. P.; Graham, I. T.; Hower, J. C.; Ward, C. R.; Ren, D.; Wang, X. Metalliferous coal deposits in East Asia (Primorye of Russia and South China): A review of geodynamic controls and styles of mineralization. Gondwana Res. 2016, 29, 60−82. (31) Liao, B. Petrology and geochemistry of alkaline basalt in the Permian in Guizhou Province.Ph.D. thesis, Chinese University of Geosicences, Beijing, 2013; pp 85 (in Chinese with an English abstract). (32) Xu, L. Geochemical characteristics of Emeishan basalt and mineralization of native copper deposit in junction area of YunnanGuizhou Province, China. MS thesis, Chinese Academy of Sciences, Guiyang, 2006; pp 72 (in Chinese with an English abstract). (33) He, B.; Xu, Y.; Zhong, Y.; Guan, J. The Guadalupian-Lopingian boundary mud-stones at Chaotian (SW China) are clastic rocks rather than acidic tuffs: Implication for a temporal coincidence between the end-Guadalupian mass extinction and the Emeishan volcanism. Lithos 2010, 119, 10−19. (34) Dai, S.; Wang, X.; Zhou, Y.; Hower, J. C.; Li, D.; Chen, W.; Zhu, X.; Zou, J. Chemical and mineralogical compositions of silicic, mafic, and alkali tonsteins in the Late Permian coals from the Songzao Coalfield, Chongqing, Southwest China. Chem. Geol. 2011, 282, 29− 44. (35) Dai, S.; Song, W.; Zhao, L.; Li, X.; Hower, J. C.; Ward, C. R.; Wang, P.; Li, T.; Zheng, X.; Seredin, V. V.; Xie, P.; Li, Q. Determination of boron in coal using closed vessel microwave digestion and inductively coupled plasma mass spectrometry (ICPMS). Energy Fuels 2014, 28, 4517−4522. (36) Li, X.; Dai, S.; Zhang, W.; Li, T.; Zheng, X.; Chen, W. Determination of As and Se in coal and coal combustion products using closed vessel microwave digestion and collision/reaction cell technology (CCT) of inductively coupled plasma mass spectrometry (ICP-MS). Int. J. Coal Geol. 2014, 124, 1−4. (37) ASTM. Standard test method for total fluorine in coal and coke by pyrohydrolytic extraction and ion selective electrode or ion chromatograph methods. Standard D5987-96, 2002; ASTM International: West Conshohocken, PA, reapproved 2007. (38) Dai, S.; Hower, J. C.; Ward, C. R.; Guo, W.; Song, H.; O’Keefe, J. M. K.; Xie, P.; Hood, M. M.; Yan, X. Elements and phosphorus minerals in the middle Jurassic inertinite-rich coals of the Muli Coalfield on the Tibetan Plateau. Int. J. Coal Geol. 2015, 144−145, 23−47. (39) ASTM. Standard classification of coals by rank. Standard D38812, 2012; ASTM International: West Conshohocken, PA, reapproved 2007. (40) Ketris, M. P.; Yudovich, Ya.E. Estimations of Clarkes for carbonaceous biolithes: World average for trace element contents in black shales and coals. Int. J. Coal Geol. 2009, 78, 135−148. 10279
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels (41) Dai, S.; Wang, X.; Seredin, V. V.; Hower, J. C.; Ward, C. R.; O’Keefe, J. M. K.; Huang, W.; Li, T.; Li, X.; Liu, H.; Xue, W.; Zhao, L. Petrology, mineralogy, and geochemistry of the Ge-rich coal from the Wulantuga Ge ore deposit, Inner Mongolia, China: New data and genetic implications. Int. J. Coal Geol. 2012, 90−91, 72−99. (42) Grigoriev, N. A. Chemical element distribution in the Upper Continental Crust. UB RAS, Ekaterinburg 2009, 382 (in Russian). (43) Rajabzadeh, M. A.; Ghorbani, Z.; Keshavarzi, B. Chemistry, mineralogy and distribution of selected trace-elements in the Parvadeh coals, Tabas, Iran. Fuel 2016, 174, 216−224. (44) Spears, D. A.; Rice, C. M. An Upper Carboniferous tonstein of volcanic origin. Sedimentology 1973, 20, 281−294. (45) Zielinski, R. A. Element mobility during alteration of silicic ash to kaolinite-a study of tonstein. Sedimentology 1985, 32, 567−579. (46) Dai, S.; Liu, J.; Ward, C. R.; Hower, J. C.; French, D.; Jia, S.; Hood, M. M.; Garrison, T. M. Mineralogical and geochemical compositions of Late Permian coals and host rocks from the Guxu Coalfield, Sichuan Province, China, with emphasis on enrichment of rare metals. Int. J. Coal Geol. 2016, 166, 71−95. (47) Goodarzi, F. Mineralogy, elemental composition and modes of occurrence of elements in Canadian feed-coals. Fuel 2002, 81, 1199− 1213. (48) Dai, S.; Zou, J.; Jiang, Y.; Ward, C. R.; Wang, X.; Li, T.; Xue, W.; Liu, S.; Tian, H.; Sun, X.; Zhou, D. Mineralogical and geochemical compositions of the Pennsylvanian coal in the Adaohai Mine, Daqingshan Coalfield, Inner Mongolia, China: Modes of occurrence and origin of diaspore, gorceixite, and ammonian Illite. Int. J. Coal Geol. 2012, 94, 250−270. (49) Ding, Z.; Zheng, B.; Long, J.; Belkin, H.; Finkelman, R. B.; Chen, C.; Zhou, D.; Zhou, Y. Geological and geochemical characteristics of high Arsenic coals from endemic arsenosis areas in Southwestern Guizhou Province, China. Appl. Geochem. 2001, 16, 1353−1360. (50) Dai, S.; Yan, X.; Ward, C. R.; Hower, J. C.; Zhao, L.; Wang, X.; Zhao, L.; Ren, D.; Finkelman, R. B. Valuable elements in Chinese coals: A review. Int. Geol. Rev. 2016, 1. (51) Saikia, B. K.; Wang, P.; Saikia, A.; Song, H.; Liu, J.; Wei, J.; Gupta, U. N. Mineralogical and elemental analysis of some high-sulfur Indian Paleogene Coals: A statistical approach. Energy Fuels 2015, 29, 1407−1420. (52) Dai, S.; Zhou, Y.; Ren, D.; Wang, X.; Li, D.; Zhao, L. Geochemistry and mineralogy of the Late Permian coals from the Songzao Coalfield, Chongqing, southwestern China. Sci. China, Ser. D: Earth Sci. 2007, 50, 678−688. (53) Dai, S.; Yang, J.; Ward, C. R.; Hower, J. C.; Liu, H.; Garrison, T. M.; French, D.; O’Keefe, J. M. K. Geochemical and mineralogical evidence for a coal-hosted uranium deposit in the Yili Basin, Xinjiang, northwestern China. Ore Geol. Rev. 2015, 70, 1−30. (54) Zhao, L.; Graham, I. T. Origin of the alkali tonsteins from southwest China: Implications for alkaline magmatism associated with the waning stages of the Emeishan Large Igneous Province. Aust. J. Earth Sci. 2016, 63, 123−128. (55) Winchester, J. A.; Floyd, P. A. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chem. Geol. 1977, 20, 325−343. (56) Finkelman, R. B. Modes of occurrence of environmentally sensitive trace elements in coal. In Environmental Aspects of Trace Elements in Coal; Swaine, D. J., Goodarzi, F., Eds.; Kluwer Academic Publishing: Dordrecht, 1995; pp 24−50. (57) Dai, S.; Zhang, W.; Seredin, V. V.; Ward, C. R.; Hower, J. C.; Wang, X.; Li, X.; Song, W.; Zhao, L.; Kang, H.; Zheng, L.; Zhou, D. Factors controlling geochemical and mineralogical compositions of coals preserved within marine carbonate successions: A case study from the Heshan Coalfield, southern China. Int. J. Coal Geol. 2013, 109−110, 77−100. (58) China National Administration of Coal Geology. Sedimentary Environments and Coal Accumulation of Late Permian Coal Formation in Western Guizhou, Southern Sichuan and Eastern Yunnan, China;
Chongqing University Press: Chongqing, China, 1996; pp 1−275 (in Chinese with an English abstract). (59) Zhang, Y. The Sedimentary Environment and Coal Accumulation of the Late Permian Coals in Southern Sichuan, China; Guizhou Science and Technology Press: Guiyang, Guizhou, 1993; pp 204 (in Chinese with an English abstract). (60) Chi, Q.; Yan, M. Handbook of Elemental Abundance for Applied Geochemistry; Geological Publishing House: Beijing, China, 2007; pp 1−148 (in Chinese with an English abstract). (61) Vinogradov, A. P. Average concentrations of chemical elements in the main types of igneous rocks of the earth crust. Geochem. 1962, 7, 555−571 (in Russian). (62) Glick, D. C.; Davis, A. Variability in the inorganic element content of U.S. coals including results of cluster analysis. Org. Geochem. 1987, 11, 331−342. (63) Saikia, B. K.; Ward, C. R.; Oliveira, M. L.; Hower, J. C.; Baruah, B. P.; Braga, M.; Silva, L. F. Geochemistry and nano-mineralogy of two medium-sulfur northeast Indian coals. Int. J. Coal Geol. 2014, 121, 26− 34. (64) Saikia, B. K.; Saikia, A.; Choudhury, R.; Xie, P.; Liu, J.; Das, T.; Dekaboruah, H. P. Elemental geochemistry and mineralogy of coals and associated coal mine overburden from Makum coalfield (Northeast India). Environ. Earth Sci. 2016, 75 (8), 1−21. (65) Tian, C.; Zhang, J.; Zhao, Y.; Gupta, R. Understanding of mineralogy and residence of trace elements in coals via a novel method combining low temperature ashing and float-sink technique. Int. J. Coal Geol. 2014, 131, 162−171. (66) Dai, S.; Zeng, R.; Sun, Y. Enrichment of arsenic, antimony, mercury, and thallium in a Late Permian anthracite from Xingren, Guizhou, Southwest China. Int. J. Coal Geol. 2006, 66, 217−226. (67) Dai, S.; Jiang, Y.; Ward, C. R.; Gu, L.; Seredin, V. V.; Liu, H.; Zhou, D.; Wang, X.; Sun, Y.; Zou, J.; Ren, D. Mineralogical and geochemical compositions of the coal in the Guanbanwusu Mine, Inner Mongolia, China: further evidence for the existence of an Al (Ga and REE) ore deposit in the Jungar Coalfield. Int. J. Coal Geol. 2012, 98, 10−40. (68) Dai, S.; Li, D.; Chou, C.-L.; Zhao, L.; Zhang, Y.; Ren, D.; Ma, Y.; Sun, Y. Mineralogy and geochemistry of boehmite-rich coals: New insights from the Haerwusu Surface Mine, Jungar Coalfield, Inner Mongolia, China. Int. J. Coal Geol. 2008, 74, 185−202. (69) Dai, S.; Ren, D.; Chou, C.-L.; Li, S.; Jiang, Y. Mineralogy and geochemistry of the No. 6 coal (Pennsylvanian) in the Junger coalfield, Ordos Basin, China. Int. J. Coal Geol. 2006, 66, 253−270. (70) Seredin, V. V.; Dai, S. Coal deposits as potential alternative sources for lanthanides and yttrium. Int. J. Coal Geol. 2012, 94, 67−93. (71) Dai, S.; Graham, I. T.; Ward, C. R. A review of anomalous rare earth elements and yttrium in coal. Int. J. Coal Geol. 2016, 159, 82−95. (72) Taylor, S. R.; McLennan, S. M. The Continental Crust: Its composition and evolution; Blackwell: London, 1985; p 312. (73) Zhao, L.; Dai, S.; Graham, I. T.; Li, X.; Liu, H.; Song, X.; Hower, J. C.; Zhou, Y. Cryptic sediment-hosted critical element mineralization from eastern Yunnan Province, southwestern China: Mineralogy, geochemistry, relationship to Emeishan alkaline magmatism and possible origin. Ore Geol. Rev. 2017, 80, 116−140. (74) Dai, S.; Liu, J.; Ward, C. R.; Hower, J. C.; Xie, P.; Jiang, Y.; Hood, M. M.; O’Keefe, J. M. K.; Song, H. Petrological, geochemical, and mineralogical compositions of the low-Ge coals from the Shengli Coalfield, China: A comparative study with Ge-rich coals and a formation model for coal-hosted Ge ore deposit. Ore Geol. Rev. 2015, 71, 318−349. (75) Emsbo, P.; McLaughlin, P. I.; Breit, G. N.; du Bray, E. A.; Koenig, A. E. Rare earth elements in sedimentary phosphate deposits: Solution to the global REE crisis? Gondwana Res. 2015, 27 (2), 776− 785. (76) Mardon, S. M.; Hower, J. C. Impact of coal properties on coal combustion byproduct quality: Examples from a Kentucky power plant. Int. J. Coal Geol. 2004, 59, 153−169. (77) Seredin, V. V.; Kremenetskii, A. A.; Trach, G. N.; Tomson, I. N. New data on the REY hydrothermal ores with extraordinarily high 10280
DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
Article
Energy & Fuels concentrations of rare earth elements. Dokl. Earth Sci. 2009, 425, 403− 408. (78) Dai, S.; Zhou, Y.; Zhang, M.; Wang, X.; Wang, J.; Song, X.; Jiang, Y.; Luo, Y.; Song, Z.; Yang, Z.; Ren, D. A new type of Nb(Ta)Zr(Hf)-REE-Ga polymetallic deposit in the late Permian coal-bearing strata, eastern Yunnan, southwestern China: Possible economic significance and genetic implications. Int. J. Coal Geol. 2010, 83, 55− 63. (79) Seredin, V. V.; Dai, S.; Sun, Y.; Chekryzhov, I. Y. Coal deposits as promising sources of rare metals for alternative power and energyefficient technologies. Appl. Geochem. 2013, 31, 1−11. (80) Dai, S.; Chou, C.-L.; Yue, M.; Luo, K.; Ren, D. Mineralogy and geochemistry of a Late Permian coal in the Dafang Coalfield, Guizhou, China: influence from siliceous and iron-rich calcic hydrothermal fluids. Int. J. Coal Geol. 2005, 61, 241−258. (81) Hower, J. C.; Dai, S. Petrology and chemistry of sized Pennsylvania anthracite, with emphasis on the distribution of rare earth elements. Fuel 2016, 185, 305−315. (82) Hower, J. C.; Eble, C. F.; Dai, S.; Belkin, H. E. Distribution of rare earth elements in eastern Kentucky coals: Indicators of multiple modes of enrichment? Int. J. Coal Geol. 2016, 160−161, 73−81. (83) Dai, S.; Xie, P.; Jia, S.; Ward, C. R.; Hower, J. C.; Yan, X.; French, D. Enrichment of U-Re-V-Cr-Se and rare earth elements in the Late Permian coals of the Moxinpo Coalfield, Chongqing, China: Genetic implications from geochemical and mineralogical data. Ore Geol. Rev. 2017, 80, 1−17. (84) Ward, C. R. Analysis, origin and significance of mineral matter in coal: An updated review. Int. J. Coal Geol. 2016, 165, 1−27. (85) Dai, S.; Tian, L.; Chou, C.-L.; Zhou, Y.; Zhang, M.; Zhao, L.; Wang, J.; Yang, Z.; Cao, H.; Ren, D. Mineralogical and compositional characteristics of Late Permian coals from an area of high lung cancer rate in Xuanwei, Yunnan, China: Occurrence and origin of quartz and chamosite. Int. J. Coal Geol. 2008, 76, 318−327. (86) Dai, S.; Chou, C.-L. Occurrence and origin of minerals in a chamosite-bearing coal of Late Permian age, Zhaotong, Yunnan, China. Am. Mineral. 2007, 92, 1253−1261. (87) Tian, L.; Dai, S.; Wang, J.; Huang, Y.; Ho, S.; Zhou, Y.; Lucas, D.; Koshland, C. P. Nanoquartz in Late Permian C1 coal and the high incidence of female lung cancer in the Pearl River Origin area: a retrospective cohort study. BMC Public Health 2008, 8, 398. (88) Creelman, R. A.; Ward, C. R.; Schumacher, G.; Juniper, L. Relation between coal mineral matter and deposit mineralogy in pulverized fuel furnaces. Energy Fuels 2013, 27, 5714−5724.
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DOI: 10.1021/acs.energyfuels.6b02248 Energy Fuels 2016, 30, 10268−10281
