白皮书06 · 第11章 · 中文摘要
证据缺口：尚属未知的内容及其解决方式
本章结论：本文中有关RC-1钢厂的每个数字都是在前端工程设计、供应合同和第一炉钢之前作出的估算，因此每个数字都标注了性质和区间。全文列出20项证据缺口，没有一项会推翻核心结论，即接入喀麦隆电网的电弧炉钢厂碳强度将远低于各工艺平均值，但其中几项可能使示意性碳强度变动0.1吨或更多。
本页为本章中文摘要；英文全文附于其后，可展开阅读。
影响碳足迹的缺口。最大的不确定性来自钢厂外购的投入，而非其运行的工艺：实际采购的直接还原铁/热压块铁的碳强度（假设为0.5至0.9吨/吨，影响约±0.07吨），可获得的废钢比例（每10个百分点约±0.09吨），2025年以后的电网排放因子及季节变化（每100克/千瓦时约±0.1吨），以及电弧炉直接排放、少量燃料和六氟化硫及能耗（后者决定一期处于赤道原则阈值的哪一侧）。解决方式为：逐批取得经核查的供应商数据，开展废钢市场调查，取得技术供应商的保证消耗值，并在投产后实测碳平衡。
影响边境调节和认证的缺口。包括欧盟碳边境调节机制对长材的基准值及RC-1炉料的工艺归类、适用于喀麦隆产品的默认值、Steel Climate Standard和LESS的具体阈值，以及喀麦隆是否存在电力属性证书登记系统。
影响绿色铁选项的缺口。喀麦隆矿石能否经济地提质为直接还原级精矿和球团（拟自2027年起与姊妹矿业公司开展冶金试验和研究），天然气储量与供应条件，氢气所需低碳电力的成本与稳定性，以及港口散货装卸能力。
影响适应设计的缺口。克里比短历时降雨强度曲线、厂址热应激统计、雷电密度、克里比海平面预测、钢渣浸出性能和道路主管部门认可，以及有资质的电弧炉粉尘回收商和出口许可。
Cameroon Steel计划在前端工程设计完成后重新发布本文的示意性碳足迹，以供应商保证值和合同数据替换规划值，并在投产后的第一份年度气候报告中以经核查的实测数字取代估算。每次更新都将说明改动内容及原因。
英文全文 5分钟 · 1155词Evidence gaps: what is not yet known, and how it will be resolved
Every number for the RC-1 works in this paper is an estimate made before front-end engineering, before supply contracts and before a single heat. That is unavoidable at this stage, and it is why each figure carries a status and a range. This chapter lists the gaps that matter most for the conclusions, explains why each matters and states how and when it will be closed. None of them overturns the central finding, that an electric-arc works on Cameroon’s grid would sit far below route averages, but several could move the illustrative intensity by a tenth of a tonne or more.
11.1 Gaps that could move the footprint
The largest uncertainties concern the inputs that the works buys rather than the processes it runs: the carbon content of imported iron units, the share of scrap it can secure and the emission factor of the electricity it draws. The tornado analysis in Chapter 4 ranks them; the table below sets out how each will be resolved.
Table 11.1 Evidence gaps affecting the carbon footprint
| # | Gap | Why it matters | How it will be resolved | When |
|---|---|---|---|---|
| 1 | Carbon intensity of the DRI/HBI actually bought (0.5 to 0.9 t/t assumed) | Largest single block of the footprint; ±0.07 t per tonne of product | Supplier-specific, verified data for every cargo; purchasing specification with an intensity ceiling | Phase 1 procurement |
| 2 | Achievable scrap share, domestic and imported | ±0.09 t per tonne for each 10 points of charge | Scrap market survey in Cameroon and the region; import supply contracts; quality tests | Before Phase 1 investment decision |
| 3 | Grid emission factor for 2025 onwards; the harmonised combined-margin factor used by lenders; seasonal variation | ±0.1 t per tonne for each 100 g/kWh | Published Ember data; the IFI harmonised dataset; hourly or monthly utility data; terms of the supply contract | Ongoing; at contract signature |
| 4 | Furnace direct emissions, minor fuels and switchgear SF6, and furnace energy use (0.10 t/t and 450 kWh/t planning values; up to about 490 kWh/t with 30% DRI) | Largest uncertainty in direct emissions; the minor sources decide on which side of the EP4 threshold Phase 1 falls | Technology supplier’s guaranteed consumptions at front-end engineering; measured carbon balance after commissioning | Front-end engineering; first year of operation |
| 5 | Other purchased inputs (ferroalloys, lime, electrodes, refractories) and freight | Needed for a complete product footprint and EPD | Life-cycle inventory at front-end engineering; supplier data | Before first EPD |
| 6 | Construction emissions and land-use change on the site | Not yet quantified | Vegetation and carbon-stock survey in the environmental and social impact assessment; construction plan | Impact assessment |
Source: Cameroon Steel; sensitivities from the WP06 model (Chapter 4).
11.2 Gaps that affect carbon border exposure and certification
Table 11.2 Evidence gaps affecting market and certification outcomes
| # | Gap | Why it matters | How it will be resolved | When |
|---|---|---|---|---|
| 7 | CBAM benchmark values for long products and their route classification for RC-1’s charge | Sets the free-allocation adjustment for EU-bound tonnes | Review of the annexes to the CBAM implementing regulations; legal advice | Before any EU sale |
| 8 | CBAM default values that would apply to Cameroonian products | Determines the cost of unverified data for buyers | Review of the default-value annex by CN code | Before any EU sale |
| 9 | Numeric thresholds of the Steel Climate Standard and LESS classes; design of the EU low-carbon steel label | Certification targets and buyer requirements | Monitoring of standard-setters’ publications | Ongoing |
| 10 | Existence of an electricity attribute-certificate registry in Cameroon | Credibility of any market-based Scope 2 claim | Engagement with the regulator and the utility | Before a market-based claim |
Source: Cameroon Steel.
11.3 Gaps that affect the green-iron option
Table 11.3 Evidence gaps for the reserve direct-reduction module
| # | Gap | Why it matters | How it will be resolved | When |
|---|---|---|---|---|
| 11 | Whether Cameroonian ore can be upgraded economically to DR-grade concentrate and pellets | Decides whether a domestic module would use local or imported feed | Metallurgical testwork, concentrate and pelletising study with the sister mining company | Studies from 2027 |
| 12 | Gas reserves and supply terms for a direct-reduction module | A module needs about 9 to 10 PJ a year per Mt of DRI | Reserve audit; negotiation with gas producers | Before any module decision |
| 13 | Cost and firmness of low-carbon electricity for hydrogen | Hydrogen-based iron needs power at about US$35 to US$40/MWh to compete on published estimates | Power supply studies; new hydro or firming options | Long term |
| 14 | Port bulk handling for pellets and HBI | Required for imports of pellets or exports of HBI | Engagement with the port and the mineral terminal | With the module decision |
Source: Cameroon Steel; requirements from Chapter 6.
11.4 Gaps that affect adaptation design
Table 11.4 Evidence gaps for climate adaptation
| # | Gap | Why it matters | How it will be resolved | When |
|---|---|---|---|---|
| 15 | Short-duration rainfall intensities (intensity-duration-frequency curves) for Kribi | Sizing of roof drainage, channels and retention | National meteorological service data; site station from the start of construction | Design |
| 16 | Site heat-stress statistics (wet-bulb globe temperature) | Heat-stress plan; equipment ratings | Site measurements; reanalysis calibrated to the station | Design and first year |
| 17 | Lightning flash density | Lightning protection design | Satellite lightning climatology; site records | Design |
| 18 | Kribi-specific sea-level projections | Design of any coastal infrastructure | IPCC AR6 regional projections tool | Before any coastal works |
| 19 | Slag leaching behaviour and local acceptance for road use | Outlet for about 45,000 t a year in Phase 1 | Standard leaching and stability tests; road-authority approval | Before commissioning |
| 20 | Access to a licensed EAF dust recycler and export permits | Avoiding a hazardous-waste liability | Recycler contract; Basel Convention procedure | Before commissioning |
Source: Cameroon Steel.
11.5 How the gaps will be closed and reported
The gaps fall into three groups. The first, supplier, contract and study data (gaps 1, 2, 4, 5, 7, 8, 11, 12, 13 and 20), closes as the project moves through front-end engineering, procurement and the ore and gas studies; each new data point will replace a planning value in the RC-1 reference configuration, with its source and date. The second, site and environmental data (gaps 6, 15, 16, 17 and 19), closes through the environmental and social impact assessment and the site weather station. The third, external developments (gaps 3, 9, 10, 14 and 18), closes as institutions, the port and the grid publish or build; Cameroon Steel will update its figures when they do. Each of the twenty gaps sits in exactly one group.
The annexes that follow set out the method and assumptions in full (Annex A), define the technical terms used (Annex B), list every source (Annex C) and print the values behind every figure (Annex D).
引用本章
Cameroon Steel（2026）。喀麦隆低碳钢铁：碳强度有望降至全球平均的三分之一左右（中文摘要版）。白皮书06，第11章：证据缺口：尚属未知的内容及其解决方式。CS-WP-06。https://www.cameroon-steel.com/zh/library/lower-carbon-steel/evidence-gaps/
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