中国钢铁行业要实现碳达峰、碳中和，有两个核心问题需要关注，即粗钢产出总量控制与三类钢铁制造流程（高炉—转炉长流程、全废钢电炉流程和氢还原—电炉流程）的交替演变。当前，中国钢铁工业应该借助“双碳”的大背景，引导废钢资源尽可能流向电炉流程，进而逐步调整中国钢铁行业的铁素资源结构、产品结构和流程结构的布局。
粗钢产出总量控制

Carbon emissions in the steel industry are strongly correlated with crude steel output. For China's steel industry to achieve carbon peaking and carbon neutrality, it is essential to first adjust the industrial structure at a macro level. This involves continuously and moderately reducing total output, phasing out outdated capacity, avoiding further increases in crude steel production, and refraining from large-scale exports of low value-added steel products. Instead, the industry should pursue a high-quality, low-volume development path. The following specific measures can be taken:

First, guide the steel industry to shift from scale expansion to improving energy efficiency and upgrading product quality; study the reasonable demand for steel and total volume control issues centered on structural adjustment and industrial upgrading, so as to regulate the total output of steel.

Based on a comprehensive analysis of data changes in China's steel industry since the new century—including annual crude steel production, average daily crude steel output on a monthly basis over the past two years, end-of-month rebar prices, direct steel exports, and indirect exports of steel products (see figures)—it is preliminarily concluded that China's current crude steel production generally exhibits a state of oversupply. The steel industry has entered a phase of fluctuating decline in volume, though the duration and extent of this downward fluctuation require further observation. The following section will predict and explore the future trends of China's crude steel production.

To scientifically predict China's future crude steel production, this study refers to the (referring to environmental load, population size, per capita, and unit environmental load) model prediction method and optimizes the modeling on this basis. It links crude steel production with economic development level, population size, energy consumption, and energy consumption structure, thereby conducting a predictive analysis of China's annual crude steel demand from year to year. This study establishes three development scenarios—high production, medium production, and low production—by adjusting growth rates and population growth rates, constructing a national crude steel production prediction model (the model calculation results are shown in the table).

Analysis of the calculation results reveals the following: First, China's steel production will show a decreasing trend in the future. Under the high-production scenario, the country's crude steel output is expected to decline from ** billion tons in ** to ** billion tons in **, a drop of **%; under the medium-production scenario, crude steel production is projected to fall to ** billion tons in **, a decrease of **%; under the low-production scenario, crude steel output is estimated to drop to ** billion tons in **, a reduction of **%. Second, China's per capita apparent steel consumption will exhibit a downward trend in the future. Since China's steel industry primarily serves domestic demand, the forecast for future crude steel production assumes a balance in steel imports and exports. Under the high-production scenario, the per capita apparent steel consumption in China is about ** kg in **, decreasing to ** kg in **; under the medium-production scenario, it is approximately ** kg in **, falling to ** kg in **; under the low-production scenario, it is around ** kg in **, dropping to ** kg in **.

Secondly, we will further advance the supply-side structural reform in the steel industry. During the process of group restructuring, outdated production capacities, equipment, processes, products, and enterprises that fail to meet national environmental emission standards, energy consumption limits, and product quality standards will be phased out. Projects aimed at expanding steel production capacity under any name or in any form are strictly prohibited. For steel smelting projects that are genuinely necessary for renovation, the capacity replacement measures must be strictly implemented, and oversight of capacity replacement must be strengthened.

Third, continuously optimize the import and export policies for steel products. Continue to encourage the import of primary steel products such as billets, ingots, and semi-finished goods; adhere to a domestic demand-oriented approach, avoiding the export of large quantities of low-value-added steel products, coke, and billets as a solution to overcapacity, and fully utilize economic and taxation measures to control the export volume of primary products like steel (billets) and coke; strictly restrict the export of high-energy-consuming and low-value-added products; encourage the indirect export of processed high-end finished goods or electromechanical products.

三类典型钢铁制造流程交替演变

From a process perspective, under the "dual carbon" framework, the steel industry will gradually evolve into three typical types of steel manufacturing processes in the future:

The first is the large-scale blast furnace—basic oxygen furnace—high-grade sheet, thick plate, and medium-thick plate process. The blast furnace—basic oxygen furnace long process is inevitably set to gradually reduce production, yet it will still maintain a certain proportion within the process structure. It will progressively transition to primarily producing flat products, especially high-end sheet, thick plate, and medium-thick plate in large quantities, mainly located near coastal deep-water ports and large mining areas. From the perspective of implementing the "dual carbon" strategy, particularly considering the increasing domestic scrap steel resources, producing bulk construction materials like rebar and wire rods through the long process is unfavorable for achieving the "dual carbon" goals.

The second approach is the scrap steel-green electricity-electric furnace-long products (urban peripheral steel plants) process. The full scrap steel electric furnace process will initiate a transformation in the production process of long products for construction, gradually replacing the small and medium-sized blast furnace-converter process used to produce bulk products such as rebar and wire rods. Located around urban areas, these plants are "urban steel mills" centered on the "two chains and one flow (supply chain, service chain, and production manufacturing process)" system.

The third approach involves the hydrogen reduction-electric furnace process for producing thin plates, medium-thick plates, seamless pipes, and special steel (with hydrogen sources including gray hydrogen, green hydrogen, etc.). These methods are still in the active exploration and development phase. A comprehensive analysis should be conducted in stages to assess their economic viability and the market adaptability of the products. Careful selection and prudent investment are essential.

The alternating evolution of these three types of steel manufacturing processes will be closely related to the output and flow of China's future scrap steel resources. Currently, scrap steel can be categorized into self-generated scrap from steel mills, downstream industrial processing scrap, and social depreciation scrap. Based on the predicted results of China's future crude steel production as shown in the table, different methods—such as the conversion coefficient method and the steel product life cycle method—are applied to various types of scrap steel to construct a predictive model for scrap steel resources. This model is used to scientifically estimate the annual scrap steel resources in China from [specific years] (the estimation results are presented in the table below).

From this, it can be observed that: First, China will have an ample total supply of scrap steel resources in the future. According to the forecast results, under various scenarios, before [year], the annual growth rate of China's scrap steel resources will be relatively slow. By [year], the scrap steel resource volume will mostly remain at around [X] billion tons, an increase of [Y] billion tons compared to [base year], representing a growth of approximately [Z]%. Around [year], the scrap steel resource recovery will enter a peak plateau period, with the peak volume expected to reach about [A] billion tons per year, an increase of roughly [B] billion tons compared to [base year]. Between [year] and [year], China's scrap steel resources will show a declining trend but will generally remain above [C] billion tons per year. By then, domestic steel resources and self-produced iron ore will largely meet the demand for crude steel production, significantly reducing dependence on imported iron ore. Second, depreciation scrap steel dominates. Under various scenarios, depreciation scrap steel accounts for the largest proportion among the three types of scrap steel resources. Currently, depreciation scrap steel makes up about [D]% of the total scrap steel resources, and this figure is expected to rise to around [E]% by [year]. After [year], it will further increase to over [F]%. Third, the volume of scrap steel resources will increase year by year. Between [year] and [year], China's scrap steel resources will experience two rapid growth phases, entering a peak plateau period for scrap steel resource recovery around [year]. Afterward, it will decline gradually, though the decrease will be modest.

Guide the flow of scrap steel resources in a reasonable manner. In recent years, China's steel industry has consumed approximately 220 million tons of scrap steel annually, with the comprehensive scrap ratio exceeding 20% for five consecutive years. However, the consumption of scrap steel in the blast furnace–basic oxygen furnace (BF-BOF) long process accounts for about 90%, while the short process only accounts for about 10%. The proportion of scrap steel consumption in the long process relative to the total scrap consumption in the steel industry has increased from 70% in 2015 to 90%, whereas the proportion for the short process has declined from 30% in 2015 to 10%. It can be said that the majority of newly added scrap steel resources in recent years have flowed to long-process enterprises, which is actually unfavorable for the green and low-carbon transformation of the entire industry in the future.

To quantitatively analyze the contribution of different scrap ratios to carbon reduction in the long process, a calculation model for carbon emissions in the long process under various scrap ratios was constructed. Two scenarios were set: ensuring unchanged converter steel output and ensuring unchanged hot metal input. Based on material balance and heat balance, the changes in total carbon dioxide emissions and emission intensity of the steel production process corresponding to different converter scrap ratios (%, %, %, %) were analyzed (see table).

From this, it can be seen that: firstly, scrap steel itself is an energy-carrying resource. Whether in the long process or the short process, using scrap steel to produce steel can significantly reduce the carbon emission intensity of the steel production process.

Secondly, excessively increasing the scrap ratio in the converter requires some necessary measures, such as scrap preheating and the addition of heating agents (carbonaceous or siliceous).

Third, under the mode of maintaining unchanged hot metal input, excessive scrap addition for production organization is essentially a disguised form of output increase. This also serves as an invisible driving force for the current long-process consumption of scrap resources, leading to persistently high scrap prices and increased production costs for electric arc furnace processes. Although this mode reduces the CO₂ emission intensity per ton of steel in long-process production, the total carbon emissions of enterprises are actually increasing.

Fourth, organizing production under the model of ensuring unchanged steel output from the converter and increasing the scrap ratio will inevitably require reducing production in the iron-making process. This approach is beneficial for the company's carbon reduction efforts and should be moderately encouraged under the premise of not affecting product quality.

Fifth, high scrap ratio smelting is conducive to reducing carbon dioxide emission intensity. However, socially sourced scrap steel purchased by enterprises often contains higher levels of impurity elements such as chromium, nickel, copper, phosphorus, and sulfur. Excessive use of such scrap steel during converter smelting can significantly compromise molten steel quality. Therefore, in high scrap ratio smelting—especially when producing high-grade steel grades—greater emphasis must be placed on the meticulous classification of scrap to ensure its quality and consistency before charging. On the other hand, the scrap ratio should be moderately controlled. Based on practical production experience at a steel plant, when smelting high-grade steel grades under current scrap conditions (with externally sourced scrap accounting for over %), the scrap ratio should be maintained within %%. This approach should represent the future development direction of the blast furnace-converter long process route.

Overall, China's steel industry should leverage the broader context of "dual carbon" goals to channel scrap steel resources towards electric furnace processes as much as possible. This will gradually adjust the structure of iron resources, product mix, and process layout within the sector. For instance, starting now, using a full-scrap electric furnace process to produce construction steel could serve as an entry point to gradually replace small and medium blast furnace–converter processes for the same purpose, while still meeting quality requirements. Meanwhile, existing large blast furnace–converter processes should continue using iron ore as the primary raw material, increasingly focusing on high-volume, high-efficiency production of high-end products.

On this basis, a process structure calculation model was constructed by comprehensively considering the scrap ratios of each process. Taking the low production scenario as an example (see table):

In the year, China's steel industry was still dominated by the blast furnace–converter long process, but its proportion had declined. Taking the low production scenario as an example, the share of the blast furnace–converter long process decreased from .% in the year to .% in the year, a drop of approximately . percentage points. The proportion of the electric arc furnace short process steadily increased year by year, and by , China's electric arc furnace short process could rise to around .%. The hydrogen reduction–electric furnace process, affected by technological maturity and market adaptability, was in the early stages of development before , with a relatively low share of about .%.

In the coming years, the proportion of the full scrap electric furnace process (%) is expected to surpass that of the blast furnace—basic oxygen furnace long process (%), becoming the primary production method in the steel industry.

By the year, the proportion of blast furnace–basic oxygen furnace long processes in China's steel industry will further decrease, while the share of short processes will increase. Under a low production scenario, the long process will gradually adjust to .%, the share of scrap-based electric arc furnace short processes will rise to .%, and the hydrogen reduction–electric arc furnace process is expected to grow to .%.

Although the development ratio of the three main processes will continue to evolve, under the condition of growing scrap steel resources, the path of developing the electric arc furnace (EAF) short process (including the direct reduced iron–EAF process) is undoubtedly correct. It is essential to consistently maintain strategic thinking, considering the phased characteristics of the steel industry's development, and to focus on the scrap steel industry and strategic research related to the scrap–EAF process from multiple perspectives, dynamically and continuously (with particular emphasis on the refined classification and grading of scrap steel, as well as product development and cost control research based on this). Continuous reflection and adjustment of understanding are necessary to align with strategic development goals and the realities of China's steel industry, truly promoting high-quality development in the sector, adapting to the "dual carbon" development direction, and ensuring it aligns with the overall national strategic deployment.

Author｜Yin Ruiyu, Shangguan Fangqin

Editor: Li Xinrui

Review Liu Jiajun

Planning by Chen Xiaoli