Shi Yiwen didn't know if others could make such bricks, but an inconspicuous refractory brick made him realize that industry has never been so simple.

The industry starts from scratch and often has to overcome many difficulties.

With the problem of refractory bricks solved, the iron plant was finally put into operation, and truckloads of selected iron ore were pushed to the top of the furnace through the ramp of the material and then poured into the furnace, into which the iron ore, coke and lime were poured.

When the blast furnace spewed out scorching smoke, Zhao Shizhen looked at some lime scattered on the ramp and asked with some puzzlement.

"Zhiyuan, why do you still use lime for this iron smelting?"

"In ironmaking, the reduced iron becomes liquid at high temperatures, and the particles of silica with a high melting point are mixed in the molten iron. In order to remove this impurity, limestone is used as a flux, which decomposes into calcium oxide and carbon dioxide at high temperatures. Calcium oxide reacts with silica at high temperature to form calcium silicate with a lower melting point than the molten iron temperature, while liquid calcium silicate is less dense than molten iron and is not miscible with molten iron, so it floats on molten iron. When the slag outlet on the blast furnace is opened, the liquid calcium silicate flows out first and solidifies into blast furnace slag. ”

When answering this question casually, seeing Zhao Shizhen's confused appearance, Shi Yiwen reacted at this time, what silica, calcium oxide, and carbon dioxide are tantamount to heavenly books for him, so he quickly changed the topic and said.

"I have other uses for those slags."

That kind of blast furnace slag can be crushed and formulated into cement, which is very important to Shi Yiwen, especially the fire plant that is being built by the Lugou River near the Lugou Bridge. While he was concentrating on the ironworks and researching the refractory bricks, the ironworks that produced muskets in the capital did not stop, and in order to use the water power, Shi Yiwen built the factory on the banks of the Lugou (Yongding River), where the construction needed some cement.

Under the impetus of the hydraulic bellows, the flames of the blast furnace are gushing, and it takes a day and a night to smelt a furnace of iron.

"Hurry up, send it to the furnace ......"

The mixing furnace is a foot away next to the blast furnace, and the so-called molten iron car is actually an inverted bell, with several layers of refractory bricks inside, which can hold 1 ton of molten iron. In order to transport the molten iron, Shi Yiwen deliberately dismantled more than ten meters of steel rails from the factory in the space and laid it between the mixing furnace and the blast furnace, after the workers pushed the molten iron cart to the mixing furnace and poured the molten iron into the mixing furnace, the workers began to stir the molten iron with iron rods under the guidance of Shi Yiwen.

This is another time and space, in 1783, the Englishman Henry Curt invented the churning method, which is mainly to stir molten pig iron on the hearth bed of a reverberatory furnace. Stirring with an iron rod to burn and remove the carbon in the pig iron, so that the carbon content meets the composition requirements of wrought iron, and stirring in the furnace is its characteristic. That's why it's called the stirring method. Since molten pig iron is not in direct contact with coal. Therefore, the sulfur content in the coal does not depend on the material of the finished product.

The disadvantage of the mixing method is that sand and gravel are used at the bottom of the mixing furnace. The silica in the sand and gravel is combined with iron oxide, and it is easy to form slag that is too acidic to absorb the phosphorus contained in pig iron refined from ordinary phosphate-containing iron ore. The need to repair the sand layer corroded by acid slag can reduce the production of the ironmaking furnace, resulting in considerable losses. And now Shi Yiwen has switched to refractory bricks to replace the sand layer, which fundamentally solves this problem.

Because there was no rolling mill, the iron that was smelted could not be taken out and rolled into rounds, plates, profiles, and shaped by a rolling mill in a red-hot state, as the British in another time and space did. But it can be cast into iron slabs, although it needs to be further forged to become usable slats, but even so, when hundreds of iron slabs have cooled, looking at the floor slabs, Zhao Shizhen has long been stunned.

"This, so that wrought iron is refined?"

"Yes, the output of a furnace is a little small, less than 4,000 catties of wrought iron a day, but for now, it is almost enough."

4,000 pounds of wrought iron can make at least 500 flintlock guns.

"It seems a little bit more."

Just when this thought popped up in Shi Yiwen's heart, Zhao Shizhen counted it there.

"Now the factory smelts 1,000 catties of iron, almost 1,500 catties of coke, and counting labor, the price of iron in our factory is ......."

Suddenly, Zhao Shizhi's eyes widened, looking at Shi Yiwen, and then at the surrounding iron works, thinking about their incomprehension and even cynicism about the construction of new blast furnaces here in the past two months. I couldn't help but say.

"I'm afraid that in less than half a year, Zunhua Iron Factory will only be left with Zhiyuan, your iron price is too cheap, others have to sell ten taels of thousands of catties, at most only two taels of profit, put aside you This is the capital, this furnace of iron is nearly 20,000 catties, and the iron quality is far from being comparable to other factories, since then ......"

Shaking his head and sighing, Zhao Shizhen looked at the surrounding iron works again.

"Zunhua Iron Works can only be surnamed Shi!"

Belch...... Shi Yiwen really didn't expect this, originally he just wanted to smelt some iron. Now that he was reminded by Zhao Shizhen, he realized that there was indeed such a possibility.

Compared with the traditional iron-making method, the new blast furnace has higher output, lower cost and better quality, even if there is no price war, just relying on quality can put other ironworks in Zunhua into a desperate situation.

"This ...... Shiji, this is also an accident. ”

Accidentally.

Of course, this is not an accident, and the emergence of any new technology can be fatal to the side that uses the old technology. All this is inevitable, and there is nothing Shi Yiwen can do about it.

"Zhiyuan, what are you going to do next?"

Facing Zhao Shizhen's question, Shi Yiwen was silent for a moment, and then said.

"Naturally, if you build another blast furnace, the output of this furnace will be less than 40,000 catties a day, and if you build another one, 70,000 catties of iron, it is almost the output of Quanzunhua, since it is a backward output......"

After a pause, looking at the dumbfounded Zhao Shizhen, Shi Yiwen smiled.

"After all, ore and fuel are limited, rather than let them waste so much, it is better to leave us to produce better output!"

A few days later, when Shi Yiwen handed over the factory to Zhao Jisheng and left Zunhua, he looked back at the iron factory again, this can be called a primitive factory, perhaps the first factory he established in this era, as for Nanjing, it was just a small fight......