The 95km2 Hawiah exploration licence is located in the south-west of the Arabian Shield on the 120km Wadi Bidah Volcanogenic Mineral belt. The Wadi Bidah belt is almost three times as long as the Bisha belt in Eritrea (see Nevsun) and is almost unique among the world’s volcanogenic massive sulphide (VMS) belts in that it remains, to all intents and purposes, unexplored.
Exhibit 6: Hawiah location
|
|
Source: KEFI Gold and Copper
|
Maiden resource estimate and PEA
KEFI announced a maiden mineral resource at Hawiah on 19 August 2020.
Exhibit 7: Hawiah* maiden mineral resource estimate
Material type |
Category |
Tonnage (kt) |
Cu (%) |
Zn (%) |
Au (g/t) |
Ag (g/t) |
Cu (kt) |
Zn (kt) |
Au (koz) |
Ag (oz) |
Oxide, open pit |
Inferred |
0.1 |
0.1 |
0.03 |
1.7 |
3.9 |
0.1 |
0.04 |
7 |
16 |
Transition, underground |
Inferred |
2.0 |
1.1 |
0.8 |
0.7 |
12.0 |
21 |
16 |
45 |
763 |
Fresh, underground |
Inferred |
17.2 |
0.9 |
0.8 |
0.5 |
10.1 |
147 |
141 |
297 |
5,595 |
Total |
Inferred |
19.3 |
0.9 |
0.8 |
0.6 |
10.3 |
168 |
157 |
349 |
6,373 |
Source: Edison Investment Research, KEFI Gold and Copper. Note: *KEFI 34% beneficial interest; reported in accordance with the Australasian Code for the Reporting of Exploration Targets, Mineral Resources and Ore Reserves, The JORC Code (2012).
At prevailing metals prices (US$9,180/t Cu, US$2,837/t Zn, US$1,778/oz Au and US$25.86/oz Ag), the resource contains total metal to a value of US$2.8bn, or the equivalent of 302kt of contained copper or 1.6Moz of contained gold.
The entire deposit comprises three separate zones (see Exhibit 8), which may be summarised as follows:
■
The ‘Camp Lode’: previously 1,200m long, but with the strike length now doubled relative to the 2020 mineral resource estimate and the total plunging strike extended by 670m down plunge to 1,200m, with an average true width of c 7m and confirmed to a depth of 590m below surface (cf 300m previously).
■
The ‘Crossroads Lode’: 1,000m long, with an average true width of c 5m and now confirmed to a vertical depth of 380m below surface (cf 170m previously).
■
The ‘Crossroads Extension Lode’: 800m long, but mineralisation now extended by an additional 110m and confirmed to a depth of 350m below surface at an average true width of c 5m.
In its most recent (third) phase of exploration, KEFI has confirmed that the Hawiah mineralisation remains open at depth, that the VMS style of mineralisation is continuously present directly beneath 4.5km (cf 4.0km previously) of gossanous ridgeline and that it is the source of an extensive and exceptionally strong geophysical anomaly. The massive sulphides intersected in its drill programme are reported to reflect a dominantly pyritic stratiform body containing a variable polymetallic blend of copper, zinc, gold and silver. Nevertheless, there remains considerable blue-sky potential at Hawiah. To date, the orebody has only been drilled to a vertical limit of 590m, but continues to remain open at depth. The down-dip continuation of the Camp Lode is of particular interest in this respect, where drilling results have reported grade and thickness increasing significantly with depth. Two of the deepest holes drilled (HWD_005 and HWD_059) have registered grades of 1.27% copper over a true width of 9m and 1.55% copper over a true width of 8.7m, respectively, and, if intersected in line with expectations, would extend mineralisation to a depth of c 800m and may indicate that resources are nearing the source (vent) of the VMS, where higher grade and thicker massive sulphides and stockwork-style mineralisation may typically be found. Geochemical analysis and volcaniclastic textures within the lodes have also indicated increasing proximity with depth to a potential primary feeder source.
In the meantime, drilling below the Central Zone (the 1,700m long area between the Crossroads and Camp lodes) has intersected mineralisation down to a depth of 580m (cf 80m previously) and confirmed its resource potential, as indicated by a strong induced polarisation (IP) anomaly. Finally, massive sulphides are reported to have been intersected in a drill hole 150m to the north of the Hawiah ridgeline, confirming that the mineralised horizon continues at depth even beyond the northern surface exposure in the ‘Crossroads extension area’.
Exhibit 8: Hawiah project drilling and exploration
|
|
Source: KEFI Gold and Copper
|
Similar potential exists in the upper levels of the deposit, where the gossan portion of the mineralised zone is challenging to drill by virtue of the weathering patterns and the numerous cavity zones encountered. However, the French geological survey, Bureau de Recherches Géologique et Minières (BRGM), drilled these gossans in the 1980s, as a result of which it delineated a resource of 1.2Mt at a grade of 6.4g/t, containing 254koz gold, and management confirms that this oxidised portion of the deposit, which has demonstrated high levels of gold mineralisation, will also be further investigated.
Based on published literature, KEFI management believes that the Hawiah deposit is analogous to (albeit already bigger than) the Al Masane polymetallic VMS mine, which was the first mine in Saudi Arabia to export copper and zinc concentrates and has reported resources of 10.0Mt at grades of 1.1% copper, 4.8% zinc, 1.1g/t gold and 36g/t silver, and a similar metal composition and structural and geological settings. Note that the discovery of the stockwork zone that fed the structure now being drilled could also represent a potentially much larger bulk-mineable target analogous to the Jabal Sayid mine operated by Barrick to the north of Hawiah.
The resource reported by KEFI in Exhibit 7 is the equivalent of 19.3Mt at a grade of 1.57% copper equivalent or 2.51g/t gold equivalent, such that each tonne of ore contains US$144 (cf US$119 previously) worth of combined metals at spot prices (see Exhibit 9).
On 22 September 2020, KEFI announced the results of a preliminary economic assessment (PEA) at Hawiah. The PEA was conducted by the KEFI planning team, supported by internationally recognised specialists, including SRK, and included technical analysis, high-level assessments and trade-off studies to establish the likely key components of the mine’s potential development. Among other things, these included:
■
Underground mining using long-hole open stoping, using rib and sill pillars for support.
■
Processing via two-stage flotation to produce separate copper and zinc concentrates, with a cyanide leach circuit to allow for the production of gold doré from the zinc concentrate and tailings stream.
■
Tailings storage and required infrastructure.
The full details of KEFI’s PEA announcement may be found here. It was also the subject of Edison’s report entitled Rose gold, published on 30 September 2020, and readers are directed towards this report for more details on Edison’s approach to calculating a value for Hawiah and its assumptions in doing so. A brief comparison of the major differences between KEFI’s and Edison’s assumptions is as follows:
Exhibit 9: Comparison of KEFI and Edison assumptions regarding Hawiah cf spot prices
|
KEFI assumption |
Edison assumption |
Spot prices |
Metals prices |
|
|
|
Copper price (US$/t) |
6,603 |
*6,410 |
9,180 |
Zinc price (US$/t) |
2,315 |
*2,315 |
2,837 |
Gold price (US$/oz) |
1,956 |
*1,524 |
1,778 |
Silver price (US$/oz) |
27.50 |
*24.99 |
25.86 |
|
|
|
|
Other |
|
|
|
Sustaining capital expenditure |
US$46m |
Seven years at US$8m pa = US$56m |
N/A |
Source: KEFI Gold and Copper, Edison Investment Research. Note: *Long-term real prices.
Readers should note that Edison has revised its long-term prices of gold and silver very fractionally higher relative to our last note, to reflect the passage of time and inflation – that is to say, our real gold price assumption is now US$1,524/oz in 2021 money terms (cf US$1,494/oz in 2020 money terms previously), while our silver price is US$24.99/oz (cf US$24.53/oz previously).
In its PEA, KEFI considers a ‘base case’ scenario in which the mine operates at a throughput rate of 2.0Mtpa for seven years and an ‘extended’ scenario in which it operates for a further 10 years ‘at the average grade of the Camp Lode below the 1070m RL elevation’. On the basis of these assumptions, the updated financial outcomes generated by Edison from its model compare with those generated by KEFI as shown in Exhibit 10. In addition, we have also shown equivalent outcomes in the event that the current spot prices of metals (see Exhibit 9) prevail over the entire course of Hawiah’s mine life in real terms:
Exhibit 10: KEFI versus Edison financial model outcomes
Extended mine life scenario |
Scenario |
Base case scenario |
KEFI |
Edison |
Edison |
Edison |
Model |
KEFI |
Edison |
Edison |
Edison |
KEFI |
KEFI |
Edison |
Spot |
Assumptions |
KEFI |
KEFI |
Edison |
Spot |
|
2.0 |
2.0 |
2.0 |
Ore processing rate (Mtpa) |
2.0 |
2.0 |
2.0 |
2.0 |
|
17 |
17 |
17 |
Life of mine (years) |
7 |
7 |
7 |
7 |
|
78 |
78 |
78 |
Average annual operating costs (US$m) |
79 |
78 |
78 |
78 |
|
155.5 |
142.6 |
194.3 |
Average annual revenue (US$m) |
153 |
155.5 |
142.6 |
194.3 |
|
86 |
86 |
86 |
Average annual all-in sustaining costs (US$m) |
85 |
86 |
86 |
86 |
|
69.5 |
56.6 |
108.3 |
Annual steady-state net pre-tax free cash flow (US$m) |
67 |
69.5 |
56.6 |
108.3 |
*362 |
*311.3 |
166.1 |
497.6 |
Post-tax NPV (US$m) |
*96 |
*99.8 |
28.3 |
229.5 |
28 |
26.6 |
21.5 |
41.2 |
Post-tax IRR (%) |
22 |
20 |
13.7 |
37.0 |
|
222 |
222 |
222 |
Pre-production capital expenditure (US$m) |
222 |
222 |
222 |
222 |
123.1 |
105.9 |
56.5 |
169.2 |
34% KEFI share of post-tax NPV (US$m) |
32.6 |
33.9 |
9.6 |
78.0 |
5.72 |
4.92 |
2.62 |
7.86 |
Ditto (US cents per share) |
1.51 |
1.58 |
0.45 |
3.62 |
4.03 |
3.46 |
1.85 |
5.54 |
Ditto (pence per share) |
1.07 |
1.11 |
0.32 |
2.55 |
Source: Edison Investment Research, KEFI Gold and Copper. Note: *NPV calculation conducted at an 8% discount rate; otherwise, all other NPV’s conducted at a 10% discount rate.
Several features of these outcomes are noteworthy:
■
The similarity between the outputs of the KEFI model and the Edison model using KEFI assumptions for the ‘base case’ scenario, which confers confidence upon Edison’s financial model relative to KEFI’s.
■
For the ‘extended mine life’ scenario, the difference between the net present value (NPV) of the KEFI model and the Edison model using KEFI assumptions is 14.0% (US$311.3m cf US$362m), which we regard as being an acceptable variance within the context of a PEA in which the operating and capital cost estimates are made to a ±50% level of accuracy.
■
The sharp increases in the values attained using spot prices compared with long-term prices.
In consequence and owing to the tabular and continuous nature of the mineralisation, KEFI anticipates that Hawiah can be advanced to a development decision quickly and at relatively low cost. In particular, if the resource can be expanded to make the ‘extended mine life scenario’ a reality, then KEFI expects that 75% of the project funding could be eligible for debt finance, thereby increasing the project’s (leveraged) post-tax internal rate of return (IRR) to in excess of 50%.