Chapter 143: Steelmaking

The transmigrators' modern fishing boats held undeniable advantages in reconnaissance, protection, speed, and mobility, yet their firepower remained pathetically weak. Had thirty pirate ships descended upon them rather than three, the lone Fishing-1 would likely not have fared so well. The major pirate lords of Fujian and Guangdong each commanded fleets numbering three to four hundred vessels. And across the entirety of Bopu Harbor, the transmigrators' activities and infrastructure had long since expanded beyond the original camp boundaries. More than two hundred transmigrators and commune members now lay scattered across vast, essentially undefended territories.

The conclusion was inescapable: naval upgrades alone would not suffice. Bopu Harbor itself required proper fortification. Staff recommendations poured in—gun emplacements, batch production of cannons at least at the 1800 level, ammunition stockpiles, and the establishment of a coastal patrol fleet. This fleet would primarily consist of steam-sail vessels, thereby conserving the precious overhaul lifespan of the fishing boats. The transmigrators simply could not perform such major maintenance for another five to ten years. Even basic hull painting remained beyond their reach—not for lack of materials, but because they could not replicate the effectiveness of modern anti-rust and anti-fouling marine coatings.

Cannon production fell to the Industrial Department's Mechanical Group, and for the weapon enthusiasts among them, the assignment was pure adrenaline. After frustrating weeks spent crafting trivial hardware—even the mechanical crossbows had been constructed entirely from wood—they would finally get to build real cannons. Energy surged through the workshop. The Mechanical plant's sheds saw an endless stream of artillery enthusiasts, each bearing proposals that varied wildly in ambition. The designs primarily concentrated on three types: a twelve-pounder mountain howitzer, the nimble and versatile Type-92 infantry gun, and the all-purpose mortar. Personal favorites added various functions and improvements to each concept.

Cannon making, of course, demanded massive quantities of steel. The Deng Yingzhou had already delivered two shipments of pig iron ingots and smaller quantities of wrought iron from Guangzhou—fifty tons in all—along with twenty tons of desperately needed coal. This would be roughly sufficient for initial-scale steelmaking.

The transmigrators employed converter steelmaking. In the twenty-first century timespace, small converters had been nationally mandated obsolete industries, slated for elimination. Here, they represented genuinely advanced technology. The headquarters of this nascent industry was established at Bopu Harbor District, chosen because Lingao's steel combine was entirely import-dependent. Ships bringing bulk coal and iron ore could be unloaded and utilized immediately nearby. For now, the steelmaking workshop consisted of nothing more than a large shed supported by brick pillars. A hardened floor held four small converters and a single cupola furnace arranged in a row.

Ji Wusheng, head of metallurgy, had worked as a steelworker in his former life. Though he had never personally operated small-converter equipment, he understood the principles well enough. Since D-Day, he had successfully produced several steel heats, proving that wood charcoal and locally sourced pig iron could indeed yield steel. The drawbacks were considerable, however. The difficulty of controlling material ratios meant that each heat produced steel of essentially random grade. Worse still, the metallurgical process devoured energy at a ferocious rate—the two blast fans required during steelmaking drew so much power that every neighboring facility had to shut down completely.

Based on analyzed pig iron composition, the Metallurgy Group employed converter side-blowing with wrought iron added in calculated proportions. The ratio came to approximately seventy-six percent pig iron, twenty-four percent wrought iron, plus a minimal amount of sand. The sand created acidic slag that absorbed phosphorus from the pig iron.

After discovering local refractory materials, the Metallurgy Group constructed a cupola furnace. This round smelting furnace was not large, but it was far more complex than the converters. The converters required iron liquid heated to 1,380 degrees Celsius—a temperature the cupola would provide. Such heat remained unreachable through ordinary fuels. Before the invention of regenerators, the maximum temperature humans could achieve had been only 1,250 degrees Celsius.

Reaching this threshold required replacing cold blast with hot blast—the principle behind the regenerator. Hot blast had been invented by the Englishman Neilson and first applied at Glasgow ironworks in 1829.

The Metallurgy Group's regenerator operated at roughly an 1850s British level, utilizing cast-iron-pipe hot blast stoves. Cold blast from the main blower was branched to each heating furnace, where it passed through arched cast iron pipes suspended over fires to heat-exchanger pipes on the opposite side, then flowed into the cupola's tuyeres. The entire apparatus was sealed within thick brick and refractory arched heating chambers designed to preserve and reflect maximum heat. Direct-heated blast reached 300 degrees Celsius—hot enough to melt lead. Yet even this temperature failed to satisfy the Metallurgy Group. They added an additional measure: waste gas heating. Ceramic pipes drew exhaust from the top of the cupola, channeling it into the regenerator from above and venting it through a waste outlet at the bottom.

Coal and coke cupolas produced substantial quantities of gas. For centuries, this gas had simply been vented from furnace tops. The flames burning through the night were spectacular, but the practice was severely wasteful and polluting. In 1832, a Baden German ironworks first piped this gas to regenerators for heating. Multiple techniques ultimately raised hot blast temperatures above 500 degrees Celsius.

Iron and steel could still be smelted without regenerators, but production efficiency simply could not compare. According to British calculations, early regenerators that raised blast temperatures to just 300 degrees Celsius tripled iron output per unit of fuel compared to cold blast.

High-temperature hot blast, however, damaged cupola tuyeres and required protection. The transmigrators' technical capabilities proved sufficient to overcome this challenge. They easily replicated the Scottish tuyere invented by Condie at Scottish ironworks: a wrought-iron coiled tube fitted into a cast-iron conical tube, with both ends extending beyond the cone's base. Water entered through one extending pipe, spiraled around to the narrow end of the tuyere, circulated through the coil, and exited through the opposite extending pipe.

With this cupola operational, the Metallurgy Group successfully produced steel in several small-scale heats. The next step was coking.

The transmigrators had initially relied on charcoal, but coke remained the ideal fuel. The significance of coal coking extended far beyond providing high-quality fuel for iron and steel production—coking by-products were crucial feedstocks for the chemical industry. For this reason, they had brought complete coal coking equipment with them through the crossing. Beyond coke itself, the by-products could yield more than twenty important chemicals: gasoline, diesel, asphalt, phenol, toluene, crude benzene, sulfuric acid, various solvent oils, lubricants, and paraffin. Once the coal coking enterprise went operational, the transmigrators' chemical capabilities would make a qualitative leap.

Like all complete industrial systems, however, installation proved extremely difficult. Despite training from the manufacturer, abundant drawings and manuals, and specialized equipment, progress in amateur hands remained painfully slow. The system demanded continuous operation—it could not simply stop and start at will. A single batch required more than one hundred tons of coal, while the transmigrators' total coal reserves amounted to just twenty tons. The Metallurgy Group had no choice but to rely on simpler indigenous coking methods.

Indigenous coking could be accomplished through many methods. The simplest was open-pile coking—two to four tons of coal heaped in a semicircle on the ground, three to four meters in diameter at the base, covered with straw for ignition and left to cook for four to five days. Yields reached only fifty percent. This method had been widely used during the Great Leap era, causing severe waste and pollution. The transmigrators could ignore environmental concerns, but coal tar was far too valuable as chemical feedstock to squander.

Luo Duo discovered an improved method in the computer archives: Kailuan-style round-furnace coking. Kailuan furnaces came in three sizes with batch capacities ranging from fifty-five to two hundred sixty tons. The fifty-five-ton furnace offered the best cost efficiency and suited the transmigrators' limited coal supplies during this early stage.

Construction materials were straightforward: besides some sheet-iron components, the furnace required only brick and fire brick. The entire coking process took approximately twelve days and achieved yields of seventy-five percent. This furnace design could utilize the gas generated during coking for heating while also recovering some coal tar. Water-cooled and recovered tar was collected in clay jars for future use as chemical feedstock.

At last, both coke and pig iron stood ready. Ji Wusheng assembled the steelworkers—transmigrators who had only recently converted to metallurgical work. They donned asbestos suits and gloves, specialized caps, and photochromic goggles. Ji Wusheng reminded them of the critical points: wind volume adjustments must be gradual with no sudden changes; iron liquid poured into the furnace must never exceed the tuyere level or it would block them; and the volume of iron liquid per pour must never exceed one-sixth of the converter chamber's capacity.

Both blowers started simultaneously. One fed air into the cupola, gradually raising its temperature above 1,300 degrees Celsius until the pig iron ingots melted completely. Ji Wusheng directed the workers to add 0.4 percent baking soda for desulfurization. Meanwhile, the converter underwent preheating—the entire vessel needed to reach 1,000 degrees Celsius to reduce temperature loss when the iron liquid entered.

When the optical pyrometer showed the cupola's iron liquid reaching 1,380 degrees Celsius, the molten metal was poured into the converter for blowing. Blower pressure was maintained between 0.07 and 0.12 atmospheres. The iron liquid continued to heat under the high-temperature hot blast as Ji Wusheng watched the furnace flames intently. Iron sparks burst continuously while flame color progressed from red-yellow to yellow-white to white to brilliant white—each shift indicating steadily rising temperature within the furnace.

Blowing continued for approximately ten minutes. Star-shaped carbon sparks intensified; brilliant white flames lengthened from their initial shortness. Carbon combustion was reaching its peak.

When Ji Wusheng observed the flames shortening again and the carbon sparks beginning to thin, he knew the residual carbon was approaching steel content. He rocked the furnace once or twice using the tilting levers, checking for any sudden burst of additional carbon sparks. Seeing none, he ordered the wind shut off.

The workers moved quickly through the remaining steps—removing furnace lids and blast pipes, skimming and clearing the slag, and finally pouring the molten steel into molds. The mold sand was composed of ninety percent yellow sand, five percent clay, and five percent white mud. After casting came steel ingots. Whether the result was high, medium, or low carbon steel, Ji Wusheng could not yet control. Each heat would require testing to determine what grade of steel they had produced.

(End of Chapter)