Exploration Update on Zimbabwe Projects

RNS Number : 5148E
Premier African Minerals Limited
10 February 2015
 



Premier African Minerals Limited / Ticker: PREM / Index: AIM / Sector: Mining

 

10 February 2015

 

Premier African Minerals Limited

("Premier" or the "Company")

Exploration Update on Zimbabwe Projects

 

Premier African Minerals Limited, the AIM-traded, multi-commodity natural resource company with mineral projects located in Southern and Western Africa, provides an update on exploration activities at certain of its projects in Zimbabwe, namely the RHA Tungsten Project ("RHA"), the Zulu Lithium, and Tantalum Project ("Zulu") and the Globe Graphite Project ("Globe").

 

Highlights

·     Encouraging surface trenching results on the open pit at RHA

·     New assays of Zulu drill cores returned enhanced lithium grades

·     Reconnaissance sampling revealed tantalum mineralisation at Zulu pegmatite

·     Trenching at Globe returned graphitic carbon grades with possible poly-metallic upside

George Roach, CEO, commented:

"The positive results from the open pit trenching programme at RHA both confirms the geological model and offers the prospect of additional high grade mineralisation within the pit envelope. With the prospect of resultant benefits in grade, stripping ratio and operating costs, together with confirmation that at this time RHA remains on track for plant delivery and commissioning in May 2015, risk continues to reduce and confidence in the project continues to improve.

Re-evaluation of previous exploration activity at the Zulu pegmatite is most encouraging and Premier will move its development focus onto this project immediately after RHA is cash generative. Similarly, Globe, whilst offering good graphitic carbon opportunity will benefit from the potential poly-metallic mineralisation that in the context of other graphite developments is essential if this is to develop further."

RHA Tungsten Project

Surface trenching totalling 184m of the open pit at RHA was conducted in 2013 primarily to identify lode structures on surface previously identified at depth in drilling campaigns, see Table 1. The lode structures have been identified together with additional extensive vein structures. Despite the fact that tungsten mineralisation at or near surface is usually weathered and depleted, a sampling campaign in November and December 2014 parallel to the strike of the veins and perpendicular to the strike of the host rocks has yielded encouraging results including the highest WO3 grade so far of 9% in a 20cm wide vein, with many other veins ranging between 0.50% WO3 and 2.24% WO3, see Table 2.  In several cases the adjacent host rocks which occasionally show minor thin quartz veining were also mineralised. The best grade so far reached 0.31% WO3 over 0.70m. All samples were prepared by Peacock & Simpson; Harare (drying, crushing, pulverizing and splitting) and submitted to SGS Minerals Services Pty Ltd, Johannesburg for chemical analysis.

When all results have been received, we anticipate updating our resource model. It should also be noted that the additional mineralised veins now identified and not previously encountered at depth are within the proposed open pit and had not previously been included in our resource estimates.

In November 2014 channel sampling of the underground workings was started. In January 2015 the programme was completed and a total of 90 samples were taken on Levels 859, 865 and some sublevels. This sampling programme was carried out in order to confirm the reliability of historic channel samples taken by Falconbridge in the 1970s. The historic database comprises 1,272 samples and the 90 samples taken by Premier represent approximately 7% thereof. The results of the first 18 randomly chosen samples have arrived and they confirm by and large the historic grades, particularly given the very spotty nature of wolframite mineralisation at RHA. Whereas Falconbridge used a hammer and chisel to take their samples, Premier has used a compressed air driven twin cutting machine which allows taking clearly defined samples. The initial results are given in Table 3.

Table 1: Details of trenching programme

Trench

Length (m)

Direction

Elevation start (m)

Elevation

end (m)

TRE-01

15.00

N150°

925.50

927.70

TRE-02

21.00

N150°

926.20

933.40

TRE-03

64.00

N150°

928.00

944.30

TRE-04

42.00

N162°

928.70

941.50

TRE-05

42.00

N188°

928.40

942.90

Total

184.00




 

Table 2: WO3 grades of veins and host rocks in RHA trenches TRE-01 to TRE-05, only values over 0.03% WO3 are reported.

Trench

From  (m)

To (m)

Int. (m)

Sample type

WO3 (%)

WO3 kg/t

TRE-01

3.00

3.20

0.20

vein

1.02

10.20

TRE-01

4.20

4.30

0.10

vein

0.15

1.50

TRE-01

8.10

8.20

0.10

vein

0.28

2.80

TRE-01

8.80

9.00

0.20

vein

0.04

0.40

TRE-02

13.20

14.40

1.20

host rock

0.04

0.40

TRE-02

15.50

15.60

0.10

vein

1.13

11.30

TRE-03

6.10

7.00

0.90

host rock

0.05

0.50

TRE-03

14.40

14.50

0.10

vein

1.76

17.60

TRE-03

17.80

18.80

1.00

host rock

0.50

5.00

TRE-03

18.80

19.00

0.20

vein

2.16

21.60

TRE-03

21.40

21.60

0.20

vein

9.04

90.40

TRE-03

23.70

24.00

0.30

vein

1.88

18.80

TRE-03

54.90

55.00

0.10

vein

0.30

3.00

TRE-03

57.80

58.10

0.30

vein

0.03

0.30

TRE-03

59.60

60.20

0.60

host rock

0.03

0.30

TRE-03

67.20

67.30

0.10

vein

0.37

3.70

TRE-03

67.30

68.60

1.30

host rock

0.04

0.40

TRE-03

70.10

70.50

0.40

host rock

0.05

0.50

TRE-03

75.10

75.30

0.20

vein

0.03

0.30

TRE-04

23.90

24.20

0.30

host rock

0.04

0.40

TRE-04

24.20

24.30

0.10

vein

0.23

2.30

TRE-04

38.70

38.90

0.20

vein

0.10

1.00

TRE-04

40.70

41.00

0.30

vein

0.30

3.00

TRE-04

46.40

46.50

0.10

vein

0.06

0.60

TRE-05

3.10

3.40

0.30

vein

0.25

2.50

TRE-05

7.50

7.90

0.40

vein

1.02

10.20

TRE-05

22.80

23.40

0.60

vein

0.09

0.90

TRE-05

25.60

25.80

0.20

vein

0.05

0.50

TRE-05

27.00

27.70

0.70

host rock

0.04

0.40

TRE-05

27.70

28.00

0.30

vein

0.18

1.80

TRE-05

28.00

28.50

0.50

host rock

0.03

0.30

TRE-05

34.40

34.50

0.10

vein

0.04

0.40

TRE-05

60.40

60.50

0.10

vein

0.67

6.70

TRE-05

60.50

61.20

0.70

host rock

0.31

3.10

TRE-05

73.60

73.80

0.20

vein

1.37

13.70

TRE-05

75.10

75.30

0.20

vein

0.13

1.30

TRE-05

75.70

75.90

0.20

vein

0.15

1.50

 

Table 3: Comparison between historic 1970s WO3 grades by Falconbridge and Premier in 2015

Sample n°

Station

Channel sample length (m)

historic WO3 (%)

2015 WO3 (%)

K  0801

865 L peg 138 E

0.95

0.20

0.25

K  0802

865 L peg 137 W

1.00

1.15

0.56

K  0803

865 L peg 137 W

1.20

0.65

1.51

K  0804

865 L peg 138 E

1.30

0.03

0.74

K  0805

865 L peg 138 E

1.40

0.01

0.20

K  0806

865 L peg 138 E

0.40

0.15

0.07

K  0807

865 L peg 138 E

1.00

0.04

0.11

K  0808

865 L peg 145 E

1.05

0.11

<0.03

K  0809

865 L peg 145 E

0.90

0.12

0.20

K  0811

865 L peg 146 E

1.40

0.07

0.05

K  0812

865 L peg 139 W

1.15

0.65

0.96

K  0813

865 L peg 139 W

1.20

0.60

<0.03

K  0814

865 L peg 139 W

1.35

0.08

<0.03

K  0815

RSE No 6 Sub LEV W

1.00

0.50

0.11

K  0816

RSE No 6 Sub LEV W

0.70

0.40

<0.03

K  0817

RSE No 6 Sub LEV W

1.15

0.20

0.09

K  0818

RSE No 6 Sub LEV W

0.70

0.70

0.05

 

Zulu Lithium and Tantalum Project

Older drill core samples from late 2011, see Table 4, with known low, medium and high grade lithium mineralisation have been re-submitted to SGS, Johannesburg for an ICP-OES/ICP-MS multi-element scan using a different digestion method than in the past. This now applied total digestion method has returned Li2O grades which are on average 15% higher than in earlier assays. The highest encountered grade is 1.74% Li2O over 1m compared to 1.57% Li2O over 1m in the past, see Table 5. The higher lithium grades may positively influence the overall economics of the Zulu Project.

Recent reconnaissance sampling of the eluvial cover along the 5km long Zulu pegmatite has revealed the presence of discrete tantalite grains in the eluvium along the eastern side of the pegmatite. The maximum grade found in the eluvium so far is 98 ppm Ta2O5. Outcrop samples taken in the extreme south and north of the pegmatite body returned Ta2O5 grades of 297ppm and 280ppm respectively.

The Zulu pegmatite is characterised by an extensive 5km long lithium mineralisation consisting of petalite in the south, spodumene in the north and ubiquitous lepidolite, as well as a locally strong tantalum mineralisation. The most eastern parts of the pegmatite could also host a caesium mineralisation in the form of pollucite, a white mineral which is easily overlooked as it strongly resembles quartz. The highest grade encountered so far is 195 ppm Cs2O in an outcrop sample.   Pollucite as a source of caesium is mined only in Manitoba, Canada and at the Bikita Mine in Zimbabwe. 

Table 4: Diamond drillholes drilled in 2011 on Zulu

BH_ID

Easting

Northing

Dip

Azimuth

End of hole (EOH)

DD 1

751165

7782428

-50°

271°

524m

DD 1a

751165

7782460

-50°

305°

275m

DD 2a

751239

7782640

-50°

296°

373m

DD 3

751255

7782801

-50°

293°

300m

DD 4

751314

7782980

-50°

293°

344m

DD 5

751406

7782981

-50°

347°

420m





Total:

2236m

 

Table 5: Comparison between historic (2012) and recent (2015) Li2O grades

Sample

Drillhole

From / to (m)

Length (m)

Li2O historic (%)

Li2O

new (%)

2416

Zulu DD 1a

224.38 - 225.38

1.00

0.69

0.87

2417

Zulu DD 1a

225.38 - 226.38

1.00

0.51

0.71

2425

Zulu DD 1a

233.38 - 234.38

1.00

1.51

1.58

2430

Zulu DD 1a

238.38 - 239.38

1.00

1.57

1.74

2454

Zulu DD 1a

87.18 - 88.18

1.00

0.10

0.07

2457

Zulu DD 1a

91.92 - 92.92

1.00

0.40

0.64

2458

Zulu DD 1a

92.92 - 93.92

1.00

0.75

0.90

2459

Zulu DD 1a

93.94 - 94.38

1.00

0.46

0.67

2460

Zulu DD 1a

94.38 - 95.38

1.00

0.58

0.74

2461

Zulu DD 1a

95.38 - 96.38

1.00

0.79

1.24

2462

Zulu DD 1a

96.38 - 97.38

1.00

0.56

0.66

2465

Zulu DD 2a

316.38 - 316.58

0.20

0.02

0.01

2477

Zulu DD 2a

329.38 - 331.00

1.62

0.07

0.04

2489

Zulu DD 2a

343.78 - 344.78

1.00

0.00

0.00

2490

Zulu DD 2a

344.78 - 345.70

0.92

0.01

0.00

2495

Zulu DD 1a

152.18 - 154.38

2.20

0.58

0.39

2496

Zulu DD 1a

156.40 - 159.00

2.60

0.26

0.16

 

Globe Graphite Project

Results of a 28m long reconnaissance trench (GLO-TRE 01) excavated and sampled in October 2014 returned encouraging results. Within a 21.4m long section of the trench, four mineralised zones were encountered. The graphitic carbon grades of these zones were 6.40m @ 10.14%, 2.70m @ 7.94 %, 1.50m @ 9.24% and 1.40m @ 8.20%, see Table 6. At Globe the shear zone hosted graphite mineralisation is known over a strike length of at least 450m. It consists of four or more parallel graphite rich zones in gneisses.

Multi-element assays were conducted on all trench samples as similar structures on a neighbouring property show a distinctive poly-metallic mineralisation. Over almost the whole length, the trench returned anomalous copper and zinc grades, with maxima of 434 ppm Cu and 428 ppm Zn. It also showed anomalous silver grades with a maximum of 11 ppm and a singular tungsten peak of 137 ppm which would not be expected in this type of geological environment.  This anomaly could point to a deeper seated shear zone hosted poly-metallic mineralisation.

Table 6: Results for graphitic carbon, copper, zinc, silver and tungsten in trench GLO-TRE 01

SampleID

From_m

To_m

width (m)

Graphitic carbon (%)

Cu (ppm)

Zn (ppm)

Ag (ppm)

W (ppm)

K 0101

0.00

3.00

3.00

NA*

130

47

1

21

K 0102

3.00

6.60

3.60

NA*

49

100

<1

18

K 0103

6.60

9.30

2.70

7.94

235

62

3

23

K 0104

9.30

9.90

0.60

NA*

73

42

8

13

K 0105

9.90

11.40

1.50

9.24

73

34

4

13

K 0106

11.40

14.20

2.80

NA*

142

99

11

9

K 0107

14.20

15.60

1.40

8.20

226

121

6

10

K 0108

15.60

17.60

2.00

NA*

114

428

4

6

K 0109

17.60

19.60

2.00

NA*

116

262

3

4

K 0110

19.60

21.60

2.00

NA*

133

66

6

6

K 0111

21.60

23.60

2.00

9.01

152

<10

5

15

K 0112

23.60

25.60

2.00

8.61

137

26

4

6

K 0113

25.60

28.00

2.40

12.50

434

141

4

137

NA* =  not analysed








 

All assays were conducted by SGS Minerals Services Pty Ltd, Johannesburg. The RHA trench and underground samples were analyzed by XRF after borate fusion (SGS code XRF79V). This batch contained 10% of certified reference material consisting of blanks and standards. Due to the small number of samples and the reconnaissance nature of the other sampling programmes, no blanks or standards were inserted into the other batches.

The graphitic carbon, i.e. graphite, was determined by LECO (SGS code CSA05V). The multi-element scans (50 elements) were done by sodium peroxide fusion with ICP-MS + ICP-OES finish (SGS code ICM90A).

Qualified Person

Wolfgang Hampel, Exploration Manager of Premier African Minerals Limited, has reviewed and approved this release and the attachments thereto that are available for download from the Premier website. Mr Hampel has 24 years' experience in the African, American, European and Asian exploration and mining industry and holds a Diploma in Economic Geology (Dipl.-Geol.) from the Technical University of Munich.  He is a registered European Geologist (EurGeol), n° 1261, with the European Federation of Geologists.

Enquiries

Pamela Hueston

 

Premier African Minerals Limited

 

Tel: +44 (0) 755 778 3855

 

Michael Cornish / Roland Cornish

Beaumont Cornish Limited

(Nominated Adviser)

Tel: +44 (0) 207 628 3396

Jerry Keen/ Edward Mansfield

Shore Capital Stockbrokers Limited

Tel: +44 (0) 207 408 4090

Tim Blythe/ Halimah Hussain

Blytheweigh

Tel: +44 (0) 207 138 3204

 

 

Notes

Premier African Minerals Limited (AIM: PREM) is a multi-commodity exploration and development company focused in Southern and Western Africa. The Company has a diverse portfolio of multi-commodity projects which includes tungsten, rare earth elements, gold, lithium and tantalum in Zimbabwe and Togo, which span from brownfield projects with near-term production potential to grass-roots exploration. The Company holds 2m shares in Circum Minerals Limited (Circum), the owners of the Danakil Potash Project. At present those shares are valued at US$2.5m based on the latest price at which Circum has accepted subscriptions.

 

Glossary of Technical Terms

"WO3" is tungsten trioxide.

"Cs2O" is dicaesium oxide

"Ta2O5" is ditantalum pentoxide

"Li2O" is dilithium oxide

"Zn" is the symbol for zinc

"Ag" is the symbol for silver

"Cu" is the symbol for copper

"W" is the symbol for tungsten

"ICP-OES" is inductively coupled plasma optical emission spectrometry

"ICP-MS" is inductively coupled plasma mass spectrometry

"XRF" is X-ray fluorescence

"LECO" is a trademark, an acronym of the original name, Laboratory Equipment Corporation

"Lode Structure" a grouping of veins in close proximity to allow combined economic extraction 

ENDS


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