Chapter 808 - Open-Hearth Steelmaking (Technical Chapter)

Because coal gas served as fuel, steelmaking no longer demanded coke. Even coal unsuitable for coking could be processed through gas generators to provide gaseous fuel. Air and gas mixed to form a combustion flame that reached two-thirds of the chamber's height, sweeping across the surface of the charge. The flame traveled through a long, shallow rectangular chamber lined with refractory materials. To prevent solid particles in the exhaust from settling in the checker brickwork, gases first passed through a slag-settling chamber for precipitation before venting to the chimney. During this exhaust process, the gases transferred part of their heat to the coal gas and air entering through the checker passages—the result being flame temperatures inside the furnace reaching 1,650 degrees Celsius.

Because the Siemens-Martin open-hearth process could smelt large quantities of metal at higher temperatures, it achieved widespread adoption and became the dominant steelmaking technology of the twentieth century.

The inner refractory lining of the Ma'ao open-hearth furnace employed magnesia bricks produced by the bittern factory. The Ma'ao Salt Field's facility extracted magnesium hydroxide from bittern—a byproduct of industrial salt production—then calcined it at high temperatures to produce material for these refractory bricks. A furnace lined with such bricks was classified as a basic furnace.

Early converters and blast furnaces had relied on silicate refractory materials—so-called acid furnaces. Such furnaces could remove manganese, silicon, and carbon from ore and pig iron, but they could not remove phosphorus. This limitation meant steelmaking either required phosphorus-free iron ore or could only produce low-quality steel. Britain's abundant deposits of phosphorus-free ore had conferred considerable advantage during the Industrial Revolution. The emergence of the basic process vastly expanded the utilization of various low-grade ores. Germany's steel industry caught up largely thanks to basic-furnace technology.

Chinese iron ore generally contained phosphorus, rendering most pig iron purchased from Guangdong brittle and high in that element. In the past, when using converters, they had removed phosphorus through slag-making by adding baking soda and limestone. But this process was imperfect, and the resulting steel remained poor in quality.

This time, Ji Wusheng had committed to using the basic process in the open-hearth furnace. Magnesia bricks would also line the blast furnace. However, the acid and basic processes were not a relationship of backward versus advanced—they were distinct technologies. Which to employ depended on the ore and the desired steel. Acid-lined furnaces would therefore be maintained in certain numbers. Ji Wusheng decided the small converters would continue using acid linings.

Within three or four days, the Machinery Sector had assembled a dredger and begun operations at Red Brand Harbor. The Navy provided not only ships and personnel but also dispatched survey boats to conduct hydrographic measurements, marking usable channels and berths with buoys. Meng De immediately had the Port Authority tow stored pontoons to Red Brand to assemble a floating pier for cargo discharge. A fixed pier also went under construction—wooden pilings driven one by one into the muddy sand of the harbor bottom, forming a cargo corridor extending toward the inner anchorage. Temporary flatcar rails and cranes would soon be erected upon it, unloading construction materials from flat-bottomed barges.

Salt Village had been replanned and relocated wholesale to the newly built Ma'ao Commune headquarters—a "new village" constructed on the Bairren Commune model, implementing centralized residential management. Ma'ao Commune was designated a specialized salt-production unit; its entire labor force had been recruited into the salt field. The few local fishermen had been relocated to Bopu Commune, which focused on fishing.

Ma'ao Salt Field served not only as the primary supplier of table salt for Lingao but also as a source of chemical raw materials and a significant revenue stream for the transmigration enterprise. Although its income from private salt sales had steadily declined as a share of total export trade, the revenue remained extremely reliable and stable. Even before and after the Second Counter-Encirclement Campaign, when imports and exports had dropped sharply, their private salt agent on the mainland—Liu Gang—had quietly continued shipping salt from Lingao by the boatload.

They now effectively controlled every salt field in Hainan. Along the Qiongzhou Strait, Qiongzhou Prefecture contained multiple historically established coastal salt fields. But these remained in the same derelict state as old Ma'ao had been—workers fled, production abandoned, facilities and methods extremely backward, output dismally low. They required consolidation and technical upgrading, work that could not be accomplished overnight. Ma'ao Salt Field therefore remained the primary source for now.

Given the foreseeable seawater pollution problem, some Elders advocated immediately developing Yinggehai or salt fields along the Guangdong coast, reserving Ma'ao salt for industrial use only. But Ji Tuisi dismissed the urgency.

"In the original timeline, the Bohai Bay coast remained a major sea-salt production region despite industrial pollution far worse than our modest steel company generates. The Bohai Rim industrial belt—heavy chemicals, steel, machinery—all high-pollution industries." Ji Tuisi shrugged. "At worst, we can source special-supply salt for the Elders from Leizhou in the future. They're just worried about ingesting high-iron salt."

The first blast furnace was finally completed after round-the-clock labor. The drying process ran for twenty-four hours. After drying and cooling, workers began laying the refractory-brick lining inside the furnace, followed by another round of drying.

The purpose of drying was to remove moisture from within the furnace. Moisture would lower the hearth temperature, causing the bottom to freeze and blocking iron discharge. It would also shorten the furnace's lifespan and cause wall cracks.

The second drying was more critical. In effect, from the second drying onward, the blast furnace would never go cold again but proceed directly to charging and continuous production. This meant the second drying had to wait until refined ore powder arrived from Sanya. As for coke, a considerable stockpile had accumulated at Bopu, shipped to Ma'ao, crushed into twenty-millimeter granules, and loaded into storage bins.

Thanks to the efforts of the Elders in Sanya, on February 10 the Dajing finally delivered the first shipload of refined iron-ore powder. Subsequently, two Navy supply ships made additional runs, each bringing back a cargo of open-hearth ore and blast-furnace ore. Wang Luobin guaranteed that as long as shipping capacity held, current stockpiles could sustain two to three shiploads per week—one hundred fifty to two hundred fifty tons per voyage. This rate would ensure continuous blast-furnace and open-hearth production.

After discussion with Wu De, Ji Wusheng concluded that the official ignition of the blast furnace and open-hearth should be scheduled for late February. This would allow Lingao to stockpile a buffer quantity of refined ore in case Sanya's supply was interrupted.

"We need at least one week's production requirement of ore and coke in reserve," Ji Wusheng explained. "If sea transport is severed or Tiandu encounters problems, we can keep the furnaces running without blowing down. And power coal—the steelworks needs its own dedicated reserve, with earmarked funds that can't be lumped into the Fuel Department's general accounts. Power coal requires at least seven days' reserve, and gasification coal counts toward that quota."

Lingao Steel Company was a steel enterprise that had to import both coke and iron ore—a high degree of external dependency. Coking coal came from Jiazi Coal Mine in Qiongshan; iron ore from Sanya; power coal from Guangdong and Hongji in Vietnam. For a steel company heavily reliant on steam-engine power, power coal was lifeblood. Without it, even the blowers couldn't run. No machinery could operate. Steelmaking was out of the question.

"Is one week enough?" Wu De's brow furrowed with concern. Apart from Jiazi Coal Mine, which was fairly reliable, the other sources—Sanya on the far side of Hainan, Hongji across the Gulf of Tonkin, and mines in mainland Guangdong—all existed in uncertain states. Sanya was the most dependable, but if something serious happened there—a major accident or an enemy raid—a week probably wouldn't suffice to restore normal operations.

Ji Wusheng shook his head. "Probably not. But I understand the current predicament, especially regarding power coal. I hear the shortfall is severe."

"More than severe." Wu De quietly informed Ji Wusheng that the entire Lingao power-coal reserve, converted to standard coal, amounted to only nine days' supply.

"That little?" Ji Wusheng was shocked. At one point, after developing Nanbao Coal Mine and Jiazi Coal Mine, power-coal reserves had reached thirty days of standard coal. "Hasn't the coal-shipping route from Guangdong been restored?"

"Just restored. Volumes haven't picked up yet," Wu De replied.

Coal supply from Guangdong had been largely severed since before the Chengmai Campaign. Only Leizhou coal, being close and easy to transport, continued flowing steadily to Lingao via the Leizhou Station's operations. Other mainland sources had been completely cut off. And the finest Hongji anthracite arrived only intermittently and unreliably.

"You should know, we're also shipping power coal to Sanya every week now, and their appetite grows constantly." Wu De's hair had thinned since he became Director of the Planning Commission, and worry lines had appeared between his brows. "Maintaining nine days of reserves—I'm already thanking heaven for that."

He had been mulling plans to occupy Hongji. The lure of that massive open-pit anthracite mine was too powerful to ignore. Lingao's industrial system desperately needed easily mined, high-quality anthracite.

Currently, Hongji coal came through the Vietnam Trade Company operated by the Leizhou Station. The company purchased coal through local agents—shipping sugar out, bringing rice and coal back. But this trade had never achieved significant scale.

"Chang Shide told me the exchange rate for Vietnam trade is very favorable to us, but the trade goods we can supply are limited in both quantity and variety," Ji Wusheng said. "He says Vietnam has enormous demand for hardware goods and great need for military equipment. North and South are fighting almost every day—on a massive scale."

Wu De considered the situation: Lingao's products suffered from one fundamental constraint—limited production capacity. And capacity was tied to machinery shortages, which in turn stemmed from insufficient steel. Once they achieved a breakthrough in steel, everything else would follow.

(End of Chapter)