证据缺口：尚不了解的情况及其解决方式

11.1 Gaps about the grid and power

The most important technical unknown for Phase 1 is the short-circuit strength of the electricity network at the plant’s 225 kV connection point. It determines how much flicker the arc furnace will cause and therefore the size and type of compensator needed (Chapter 5). It can only be established once the zone’s 225 kV line and substation are commissioned and modelled with the transmission operator. A related gap is the firm capacity that the zone line will reserve for the plant at each stage, beyond the published design values of 100 MW at first and 330 to 400 MW later [S25].

The second gap is the plant’s actual electricity consumption. RC-1 plans on a benchmark value of 450 kWh per tonne for the furnace, within 347 to 500 [S03]; this paper adds an upper planning value of about 490 kWh with 30% DRI or HBI in the charge, which adds about 13 GWh a year to Phase 1 and about four minutes to each heat (Chapter 5). The technology supplier’s guaranteed values and the transformer rating will replace these benchmarks in front-end engineering, and with them settle whether one furnace delivers the nameplate of 0.3 Mtpa or the expected sustained output of 270,000 to 300,000 t.

11.2 Gaps about iron units

No survey of Cameroon’s scrap arising has been published since the 2007 study, whose data date from 2006 [S13]. The estimate in this paper that about 0.1 Mt of scrap is collected each year is a derived order of magnitude (Annex A); RC-1 plans on only about 30,000 t a year of domestic scrap for the plant, within 0 to 60,000 t [S03]. A national scrap survey, ideally with the industry associations and the customs authority, would establish the volume, the grades and the collection chain.

Prices and contract terms for imported HBI and scrap over the life of Phase 1 are not known. They depend on markets in which DR-grade feed is forecast to tighten [S17], and, with the price of imported billets, they set the spread on which the melt shop’s case rests (White paper 04, Chapter 8). Binding offers from at least two suppliers per iron unit will be sought before the Phase 1 investment decision.

11.3 Gaps about ore and ironmaking

The DR-grade concentrate that would feed a Kribi direct-reduction module has been produced only in testwork [S19]. Pilot-scale production from a defined ore body, with pellet strength and reducibility tests, is needed. No concentrator or pellet plant for DR-grade product is in any published plan [S36, S81]. The location, ownership and timing of such a plant are open.

The remaining reserves of Cameroon’s producing gas field are not public, and the main undeveloped resource has no investment decision [S35]. Gas taxation for industrial users and the price at which gas could be contracted for a direct-reduction module’s life are also unknown. An independent reserve audit and negotiations with the national oil company would close these gaps before Gate 4.

11.4 Gaps about the site, climate and products

No measured atmospheric corrosivity classification under ISO 9223 has been published for Kribi [S100]. The humidity and coastal setting suggest the upper categories, but a year of on-site exposure tests is needed to classify the site properly, both for the plant’s own structures and for customer guidance.

The national rebar standard NC 236 is reported in the press but its full text was not consulted for this paper [S26, S27]. Before Phase 1, Cameroon Steel will obtain the standard from ANOR and map its requirements against BS 4449 and ASTM A615 in the mill’s design specifications.

11.5 Gaps about technology costs

This paper deliberately gives no investment amounts for Cameroon Steel’s plant, and the public benchmarks it uses come from other regions and other years. No public, recent cost data were found for Chinese-supplied bar and wire-rod mills in Africa, for African direct-reduction modules or for pellet plants of the size that a Kribi DR module would need. Those costs will be established by competitive vendor quotations during front-end engineering and reviewed by an independent engineer before each gate, rather than inferred from benchmarks.

Source: Cameroon Steel. Target dates are Cameroon Steel’s planning targets, tied to the RC-1 schedule (edition 10 October 2026); dates for public bodies and other parties are proposals, not their commitments.

11.6 How the gaps will be closed and reported

Cameroon Steel intends to close the Gate 1 gaps during front-end engineering and the impact assessment, which RC-1 targets for 2027 to 2028, with the certificate in the fourth quarter of 2028 [S03], and to update this paper when the results are available. Where a gap is closed by a third party (the transmission operator, the national oil company, the mining company or the standards agency), the update will cite that party’s published document. Where a gap remains open at a gate, the gate’s decision will be "hold" for the dependent step, as Chapter 10 describes.

Three principles govern the updates. First, measured data replace benchmarks as soon as they exist, and the status chip on each figure changes accordingly. Second, a derived value is always shown with its inputs, so that readers can recompute it when an input changes. Third, nothing that cannot be sourced is printed: where this paper says that a value is not known, it is because no reliable public source was found.