Chapter 1313 - The Special Blast Furnace
Ultimately, the plan they decided on was to use a blast furnace to smelt ferrosilicon, then a converter to smelt silicon steel.
Ji Wusheng looked at the various plans on his desk and stretched. Through the window, he could see the towering flames of Ma'ao No. 1 and No. 2 blast furnaces in the distance—using these two large furnaces to smelt ferrosilicon would be somewhat wasteful. For this purpose, the Planning Commission had specifically approved a project to build another small blast furnace at Ma'ao Steel Company specifically for smelting ferrosilicon.
The "Special" blast furnace was currently in its second bake-out. Compared to the 125 cubic meter capacity of Ma'ao No. 1 and No. 2, the Special furnace was miniature—only 30 cubic meters. However, being right next to the others, it could fully utilize their hot exhaust gases, especially from the specially constructed large hot-blast stove.
These favorable conditions allowed the Special blast furnace to easily boost its smelting temperature to sufficient levels. Smelting ferrosilicon required temperatures exceeding 1800°C and continuously blowing hot air above 500°C into the furnace body. This was a difficult condition for ordinary small blast furnaces to achieve, but posed no problem for the Ma'ao blast furnace cluster with its specially constructed large hot-blast stoves.
Now they only needed to wait for the bake-out to complete before trial-smelting the first heat of ferrosilicon. The raw materials prepared for smelting had all been delivered: quartz sand, pig iron, coke... Just waiting for the furnace to open operations before experimental smelting could begin.
The telephone on his desk suddenly rang. He picked up the receiver—it was the duty supervisor at the Special blast furnace front calling to report that the intermittent-blast coke bake-out had finished. They were now loading fresh coke and beginning continuous uninterrupted blast operations.
"Very good. Continue operating according to the work schedule," Ji Wusheng ordered. Prior to this, bake-out work had already continued for 48 hours. He looked at the schedule—the first formal charging would begin approximately 4 hours later. He decided to get some sleep first: once the furnace opened for operations, he would probably have to keep watch at the furnace front for 24 consecutive hours.
Ji Wusheng woke punctually one hour before furnace opening. He washed his face, changed into work clothes, and found several apprentice technicians he had personally trained already waiting respectfully outside his office.
The apprentice technicians were young men with some educational foundation whom he had personally selected from among the Ma'ao Complex's steelworkers. They were currently being trained as duty supervisors and would eventually take on more important work.
But many promising seedlings had been lost to frequent accidents. The transmigrator technicians were well aware of the dangers of furnace-front work and generally tried to avoid personally performing dangerous tasks. When they did participate, they took precautions. But the natives of this timeline, who had just encountered the monster of modern industry, had no intuitive understanding whatsoever. Quite a few didn't live to see the day Ji Wusheng acknowledged them—they had already turned to ash and become elements in the steel.
"Let's go." Ji Wusheng checked each person's work equipment and said simply. They boarded the commuter train operating within the steel complex and headed toward the blast furnaces.
The Ma'ao Steel Complex had begun to take shape. Though to Ji Wusheng's eyes this complex was quite shabby, by this timeline's standards it was already at science fiction levels. Just the rails on the ground, the overhead trusses and pipes, and the forest of chimneys were enough to make any native entering the factory area for the first time think they had entered some "demon realm."
Ji Wusheng got off at the "station" in front of No. 2 blast furnace—he wanted to first inspect this new furnace that had been in production for less than a year.
No. 2 blast furnace was tapping iron. Accompanied by repeated alarm bells, flames over a meter long shot out from the tap hole, the heat oppressive. Beneath the blast furnace, firelight dazzled the eyes. Inside the furnace, molten iron churned and jumped, radiating a searing glow. The iron was poured out, splashing in all directions. The boiling furnace was like a "mountain of flames," spewing hot fire. The molten iron inside was like rolling magma, occasionally spraying sparks all around.
Inside the production workshop, workers constantly stirred the glowing red-hot molten iron. Their soaking-wet clothes clung tightly to their backs. Standing before the blast furnace, five meters away from that giant maw spewing red flames, waves of heat continuously pressed down. Accompanied by occasional sprays of steel sparks, the surrounding air itself seemed to twist. The blast furnace's outline had long been swallowed by the red-hot flames. Even the steelworkers nearby, rising and falling as they worked the stirring rods, seemed as if they might at any moment be sucked into that great mouth.
Such a magnificent scene would move even a transmigrator, but for Ji Wusheng it was routine. This blast furnace's capacity was less than one-quarter of the one he had worked at in the old timeline.
The naturalized workers worked every day in front of blast furnaces at temperatures exceeding 1600°C. The workshop temperature reached 55°C. Working 12-hour shifts in day and night rotation, they spent half their time at the high-temperature furnace front. For safety, they wore Lingao-produced protective goggles, safety helmets, large gloves, thick long socks, and other protective equipment. They also had to wear thick canvas long-sleeved protective suits—each several times thicker than ordinary summer clothing. Everyone's face was blackened by soot and smoke.
But all this full-body protection could only fend off spraying iron sparks. One slip and the sparks would fly out—a lump of red-hot iron bursting out was just like a bullet. Hit a person and it could be fatal. At Lingao's level of medical care, furnace-front injuries couldn't be treated.
Ji Wusheng felt sweat beads already sliding down his forehead. The blast furnace workshop's average annual temperature was over 40°C; in summer's hottest times it reached over 60°C.
The tap hole was sealed again. Furnace Master Zhao Youcai held a temperature gun with both hands and quickly approached the furnace to test the molten iron temperature inside. If the temperature was too high, he had to add charge to the furnace; if too low, he had to tell the blower room to increase the blast. At this moment, beads of sweat poured from under his safety helmet, and his protective suit was completely soaked through.
Zhao Youcai had come from Guangdong—he wasn't a refugee but had crossed the sea to immigrate on his own initiative. He had originally been an iron-smelting craftsman in Shaoguan. When business had turned bad recently, he heard that Lingao needed large numbers of iron-smelting craftsmen and came to seek work. After entering the steel plant, he was assigned to No. 1 blast furnace as a furnace-front worker.
He had been an iron-smelting craftsman at local iron kilns in the Shaoguan area for over ten years, accumulating rich experience—he could judge rough temperatures just by looking at the fire or smoke. Craftsmen and iron workers from a forge background mostly had such accumulated experience, but this experience had neither standards nor specific numbers. After coming to Lingao and receiving systematic training and furnace-front practice, his experience was systematically and theoretically organized—and he was an eager learner who had attended the steel plant's training classes and become a key worker. His sensitivity to temperature quickly came to Ji Wusheng's attention. After serving as his "apprentice technician" for a period, Zhao Youcai had become furnace master of No. 2 blast furnace.
"Chief—" Zhao Youcai saw Ji Wusheng and hurried over to greet him.
Ji Wusheng waved a hand. "How's it going?"
"Second tap of this shift. Everything normal. Today's conversion rate is quite good—I think we can exceed 1." A proud smile appeared on Zhao Youcai's face.
"Well done." Ji Wusheng nodded. "First hand over your current work to the duty foreman, then we'll go to the Special blast furnace."
Zhao Youcai went to complete the handover. Ji Wusheng looked around at production conditions near the blast furnace. Currently the two blast furnaces and one open-hearth furnace were operating fairly smoothly. Though limited by furnace body materials, the intervals between minor, medium, and major repairs were somewhat short—at least continuous production was maintained, more or less satisfying the current industrial sector's demand for steel.
However, too little specialty steel and too few rolled sections remained his main problems. Though steel production quantities were considerable, the rolling mill's production capacity was far from meeting current demands. No matter which enterprise used it, they couldn't directly use iron ingots or steel ingots.
After solving silicon steel, he definitely had to find a way to domestically produce some rolling mill equipment and expand rolling mill production scale. Ji Wusheng calculated.
In front of the Special blast furnace, the workers participating in the trial smelting had already assembled. After the bake-out work ended, workers were cleaning slag and incompletely burned coke ash from the furnace chamber. Ji Wusheng watched their operations and asked the duty foreman:
"How's the furnace chamber?"
"Everything normal. No damage found."
Ji Wusheng walked to the material bunker. The raw materials prepared for this trial smelting were already ready: coke, quickite, pre-treated rod-shaped pig iron, and evenly crushed quartz sand.
Ji Wusheng knew that aside from the coke, the quicklite, quartz sand, and pig iron had all been tested for composition at the Heavy Industry Central Laboratory and prepared according to optimal ratios. This pig iron was specifically purchased from Guangdong and had been reprocessed for desulfurization and dephosphorization.
They weren't using pig iron produced in-house because the Tiandu iron ore naturally contained higher manganese content, so the pig iron smelted by Ma'ao's blast furnaces also contained more manganese.
For smelting silicon steel and ferrosilicon, manganese content needed to be below 0.35%—excessively high manganese would affect the silicon steel sheet's magnetic properties. Not only that, silicon steel also required impurities to be as few as possible, especially low carbon, low sulfur, and low nitrogen. So in preparing ferrosilicon, harmful element content had to be controlled from the first step. This would help improve the finished product rate when using the converter to smelt steel next.
Ji Wusheng immediately ordered: "Begin charging! Prepare to open the furnace!"
Workers began loading coke into the furnace chamber while starting to blow hot air into the furnace. As the amount of coke loaded increased and blasting duration extended, the furnace bottom began to glow red. The flames in the furnace chamber gradually changed from red to white, finally becoming an intense white flame brightness. Even standing on the observation platform, Ji Wusheng could feel the intense heat radiation. Workers began adding quickite at a 3-4% ratio while adding coke, filling up to two-thirds of the furnace chamber.
(End of Chapter)