Kalahari Mn Field - Wessels Type Ore

Location - South Africa

Age (of portore) - 2250 Ma

Original size - 50.0 million tonnes of Mn

References

Gutzmer, J., and Beukes, N.J., 1995, Fault-controlled metasomatic alteration of Early Proterozoic Sedimentary Manganese Ores in the Kalahari manganese field, South Africa: Economic Geology, v. 90, p. 823-844.

Chetty, D., 2008, A geometallurgical evaluation of the ores of the northern Kalahari Manganese Deposit, South Africa. PhD Dissertation, University of Johannesburg (Unpublished)

major elements - trace elements - rare-earth elements - REE normalized - isotopes -mineralogy

Major Elements (% oxide)

 

 

 

%

%

%

%

%

%

%

%

%

%

%

MnO

Fe2O3tot

SiO2

Al2O3

CaO

MgO

K2O

Na2O

TiO2

P2O5

LOI

 Average

 Oxide
71.9
13.3
3.0
0.2
5.3
0.5
0.0
0.0
0.1
0.1
1.9
NC-1b-33
hausmannite
91.2
1.33
0.12
0.32
0.04
0.04
0.02
0
0.07
0.02
-0.11
NC-1b-32
hausmannite-braunite
87.8
5.46
0.4
0.08
0.37
0.15
0.02
0.01
0.03
0.09
-0.02
NC-1b-26
hausmannite-braunite
85.2
6.33
0.12
0
0.19
0.26
0
0
0.05
0
-1.26
NC-1b-16
bixbyite-hausmannite
81.9
9.01
0.72
0.13
0.91
0.53
0.01
0
0.09
0.03
0.56
NC-1b-21
hausmannite
81.6
11.08
0.27
0.04
0.19
0.74
0
0
0.07
0.13
-1.84
NC-1b-20
hausmannite
78.5
12.97
0.21
0.25
1.75
1.13
0
0
0.08
0.14
1.01
NC-1b-27
hausmannite-braunite
78.5
12.17
1.95
0.04
2.04
0.09
0.01
0
0.06
0.03
-0.47
NC-1b-17
hausmannite
78.1
11.72
0.8
0.56
1.88
1.53
0.02
0.04
0.05
0.05
1.59
NC-la-8
braunite-marokite-hausmannite-manganite
76.4
6.38
0.85
0
8.01
0.29
0
0
0.08
0.03
4.84
NC-la-4
braunite 
72.4
11.55
9.79
0.1
4.44
0.1
0.01
0.02
0.09
0
1.91
NC-la-5
hausmannite-braunite
71.1
13.90
3.8
0.05
3.57
0.13
0.01
0.04
0.06
0.02
0.53
NC-la-14
hausmannite
68.8
24.59
0.52
0.14
1.7
1.18
0
0
0.07
0.02
4.57
NC-1b-31
braunite 
67.7
13.65
10.9
0.79
4.65
0.16
0.03
0.03
0.06
0.06
0.43
NC-la-10
braunite-calcite
66.5
12.73
4.71
0.24
7.2
0.02
0.01
0.02
0.06
0.04
1.25
NC-la-6
braunite-marokite-hausmannite-manganite
65.5
12.05
0.78
0.03
9.84
0.26
0.01
0
0.05
0.03
2.43
NC-1b-28
braunite 
63.9
13.77
11
0.58
4.69
0.94
0.03
0.05
0.08
0.04
0.68
NC-la-7
braunite-marokite-hausmannite-manganite
63.1
9.06
0.84
0
20.2
0.38
0
0
0.02
0.05
0.57
NC-la-11
braunite-calcite
63.1
12.91
7.74
0.03
12.4
0.35
0.04
0.03
0.06
0.06
7.35
NC-1a-14
hausmannite
62.6
32.89
0.69
0.23
0.49
0.25
0.12
0
0.07
0.07
-1.88
NC-la-13
bixbyite-hausmannite
61.5
28.31
0.83
0.03
2.42
0.51
0.01
0.03
0.08
0.04
3.02
NC-la-12
bixbyite-hausmannite
45.4
18.16
5.7
0.18
25
0.73
0.02
0.05
0.04
0.7
14.4
                         
                         

 

Trace elements

 

 

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

ppm

 
As
Ba
Cd
Co
Cr
Cu
Mo
Nb
Ni
Pb
Rb
Sc
Sr
Th
U
V
Y
Zn
Zr

 Average
20.2
2317
nr
13
154
259
36
25
106
86
bd
bd
1139
bd
bd
bd
bd
383
bd
NC-1b-33
24
136
3
55
286
6
30
29
221
4
88
NC-1b-32
4
1,829
3
54
288
19
24
78
141
32
162
NC-1b-26
4
1,373
3
14
288
13
29
72
31
23
21
NC-1b-16
36
bd
6
59
266
32
24
96
38
7
1,310
NC-1b-21
22
bd
3
18
271
24
30
69
59
3
324
NC-1b-20
29
bd
3
55
274
29
23
77
59
12
576
NC-1b-27
20
bd
5
48
260
19
22
57
29
1.5
64
NC-1b-17
bd
bd
9
87
256
20
26
89
102
11
3,590
NC-la-8
bd
1,421
58
1,188
268
254
25
494
320
2,640
556
NC-la-4
34
bd
6
120
247
33
26
119
121
75
45
NC-la-5
bd
3,043
3
13
261
9
32
57
60
415
11
NC-la-14
bd
2,849
15
58
250
15
26
71
38
397
165
NC-1b-31
101
bd
12
162
258
37
22
99
53
5
33
NC-la-10
bd
7,186
9
5
275
7
23
41
24
8,970
20
NC-la-6
bd
20,128
9
34
277
13
22
61
130
4,860
401
NC-1b-28
107
21
3
143
231
26
24
83
14
9
23
NC-la-7
bd
2,782
55
297
247
42
20
163
71
1,930
273
NC-la-11
bd
bd-4
9
242
217
51
23
133
52
208
39
NC-1a-14
bd
bd
8
332
278
72
32
186
120
21
102
NC-la-13
bd
7,840
24
104
276
32
26
104
39
3,990
182
NC-la-12
bd
bd
31
<8
174
12
19
40
74
314
66

nr = not reported; bd = below detection

Rare-earth elements

not reported

Mineral distribution (weight %) by rietveld refinement

 

Mineral

 Least-altered ore Partially-altered ore Advanced alteration
braunite
31.9
1.6
16.5
kutnahorite
28.9
4.3
hausmannite
11.7
28.6
42.2
calcite
9.41
16.1
1.83
dolomite
6.85
2.97
jacobsite
4.80
2.12
1.11
hematite
3.96
4.16
7.38
lizardite
1.52
2.54
rhodochrosite
trace
barite
1.19
3.64
braunite II
34.9
11.0
bixbyite
1.45
10.4
brucite
1.20
andradite
1.41
clinochlore
1.47
manganite
1.68
neltnerite
1.43

a blank indicates no x-ray peak found