Pulverized coal injection

Over the past half-century, since blast furnace coal injection technology was first put into industrial-scale, large‑area application, domestic steel production capacity has continued to expand, and key technologies for pulverized‑coal injection have steadily advanced and matured. As a result, market demand has grown steadily. In recent years, with the gradual depletion of China’s high‑quality coking‑coal resources, the role of blast furnace coal injection in the steelmaking process has become increasingly prominent, playing an ever more critical part in reducing smelting costs across the industry. Indeed, the very origins of blast furnace coal injection as a metallurgical tool predetermined this trend: (1) substituting pulverized coal for a portion of metallurgical coke lowers the coke‑to‑iron ratio and cuts pig iron production costs; (2) it helps regulate the furnace’s thermal regime and ensures stable operation; (3) the injected coal powder gasifies and burns just upstream of the tuyeres, reducing the theoretical combustion temperature; to maintain the theoretical combustion temperature, supplemental heat must be supplied, thereby creating favorable conditions for higher blast pressures and oxygen‑enriched air blowing; and (4) replacing part of the coke with pulverized coal not only reduces investment in coking facilities—allowing fewer coke ovens to be built and curbing air pollution associated with coking—but also significantly eases the tight supply‑demand balance of coking coal.

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喷吹煤

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Over the past half-century since blast furnace coal injection was first put into industrial use on a large scale, domestic steel production capacity has continued to expand, and key technologies for pulverized‑coal injection have steadily advanced and matured. As a result, market demand has grown steadily. In recent years, with China’s coking‑coal resources becoming increasingly scarce, the role of blast furnace coal injection in the steelmaking process has become ever more prominent, playing an increasingly vital part in reducing smelting costs across the industry. Indeed, the very origins of blast furnace coal injection as a metallurgical fuel predetermined this trend: (1) substituting pulverized coal for a portion of metallurgical coke lowers the coke‑to‑iron ratio and cuts pig iron production costs; (2) it helps regulate the furnace’s thermal regime and ensures stable operation; (3) the injected coal powder gasifies and burns before reaching the tuyeres, thereby reducing the theoretical combustion temperature; to maintain the desired hearth temperature, supplemental heat must be supplied, which in turn creates favorable conditions for higher blast pressures and oxygen‑enriched blowing; (4) replacing part of the coke with pulverized coal not only reduces capital investment in coking plants—allowing fewer coke ovens to be built and curbing air pollution associated with coking—but also significantly eases the tight supply‑demand balance of coking coal.