The steel-filling method is used to make steel, which requires a lot of tempering and a lot of manpower, so it is mainly used as a weapon, not for other purposes.

In addition, almost all iron tools are made of iron, and there are 13 kinds of armor in the Tang Dynasty, among which Mingguang armor, Guangyao armor, fine Lin armor, Shanwen armor, black hammer armor and chain mail are all iron armor, made of iron.

Of course, this is wrought iron, which is very soft and easy to process into armor.

As mentioned earlier, the so-called wrought iron is to re-smelt the molten iron to reduce all the carbon in it (using the oxygen in the oxygen to reduce it to carbon dioxide CO2), of course, the ancients did not understand this technology, they did not know how to stop.

If that charcoal happens to retain a certain proportion (0.02%-2.11%), it can be turned into steel. Of course, this ensures an even flow of molten iron. Otherwise, the carbon content of the steel will not be uniform, and some places may be pig iron, and some places will become mature iron.

Wu Yanzhi didn't want to tell them about oxygen or anything, but he just said that with this converter, the temperature inside could be controlled, and quicklime could be added to increase the temperature of the molten iron, and at a certain temperature, the molten iron would become steel.

Here we would like to introduce the converter steelmaking method.

The oxidizing agent used in this steelmaking process is oxygen. Air is blown into molten pig iron to oxidize impurities such as sulfur, silicon, manganese, carbon, phosphorus, etc. During the oxidation process, a large amount of heat is released (1% silicon can raise the temperature of pig iron by 200 degrees Celsius), which can bring a sufficiently high temperature in the furnace.

Therefore, converter steelmaking does not require additional fuel. Converter steelmaking is carried out in a converter. The shape of the converter is like a pear, the inner wall has refractory bricks, and there are many small holes (air outlets) on the side of the furnace, and compressed air blows into the furnace from these small holes, which is also called a side blowing converter.

At the beginning, the converter is at a level, liquid pig iron at 1300 degrees Celsius is injected inward, a certain amount of quicklime is added, and then air is blown in and the converter is turned to make it stand upright. At this time, the violent reaction on the surface of the liquid pig iron causes the oxidation of iron, silicon and manganese (FeO, SiO2, MnO,) to form slag, and the convection of the molten steel and slag is used to make the reaction spread throughout the furnace.

After a few minutes, when only a small amount of silicon and manganese remains in the molten steel, the carbon begins to oxidize, producing carbon monoxide (exothermic) that causes the molten steel to boil violently. A huge flame appeared at the furnace mouth due to the combustion of spilled carbon monoxide. Finally, phosphorus also undergoes oxidation and further forms ferrous phosphate.

Ferrous phosphate reacts with quicklime to form stable calcium phosphate and calcium sulfide, which together become slag. When the phosphorus is gradually reduced by sulfur, the flame recedes, and the brown steam of ferric oxide appears at the furnace mouth, it indicates that the steel has been smelted.

……

Those people were confused, but we were a little skeptical when we heard that this small furnace was making steel for a while.

This is a thousand-fold increase in efficiency compared to the steel filling method!

"You won't understand this steelmaking method if I talk too much, but you'll know when the time comes! Let's build this stove first.

Judge Jiang has already prepared the steel materials for making the shell of the steelmaking furnace, and I think it has basically taken shape, so after the refractory bricks are burned, the furnace will be built, and then the mouth will be sealed. Wu Yanzhi said.

Of course, his stove is not big, he calculated it, it is just about 6,000 catties of molten iron.

Although the 6,000 catties are very small, you must know that the pig iron output of Da Zhou at this time is not only about 10 million catties.

Just this small furnace, to operate normally, there is no problem at all with the production of 100,000 catties a day. Because of that furnace of molten iron, a few minutes is fine, plus other miscellaneous time, it takes less than an hour to smelt a furnace of steel!

Although the furnace itself is very troublesome, it also requires some technology, the cost is also high, and the management is also difficult, but after a long time, I will get used to it. According to his plan, a total of three steel smelting furnaces will be built in Xingzhou and two nearby states.

In the future, it is necessary to gradually increase the amount of pig iron mined here and promote the use of iron tools.

You know, even iron tools are high-end materials now. Because iron tools are high-grade materials, the development of industry and agriculture is greatly restricted, and the agricultural development of the Pearl River Delta has great problems.

Of course, the manpower to mine iron ore is a problem, but Wu Yanzhi has already thought about it, and in the future, he will have to use prisoners!

As for the source of this captive, of course, there is only war, and it must be won!

However, there are many things that you can't control by yourself. Although he is now a minister, or a minister of two ministries, his power is really limited.

In feudal society, big things had to be approved by the emperor.

……

The county seat of Shahe is on the edge of the Shahe River, a tributary of the Zhanghe River. The river is not very wide, there is not much water, and the water surface is shallow.

Wu Yanzhi and the others, along the river, rode to Qiyang Village.

There are several large state-owned mining farms here. Wu Yan studied it when he was in school, and knew that it was mainly a contact metasomatic skarn iron ore deposit, also known as Handxing-style magnetite.

The magnetite here is of high grade, with a grade of 50%.

In fact, at that time, the price of iron was very high, the main transportation was convenient, and 20% also had great mining value, which is different from our commercial grade now, and now iron is not valuable.

Xingzhou, Zhaozhou, and Xiangzhou were the most convenient areas for iron production at that time, and the first was high grade; second, the reserves are very large; Third, it is convenient to transport.

Of course, in the southern Hezhou (Ma'anshan), there are also huge iron mines that can be mined, and the transportation is relatively convenient.

"Lord Wang, there are more than 5,000 people in this stope!" Wang Jin pointed to the boundless shed and introduced.

Wu Yanzhi looked at it, this mining field was indeed very large, stretching for several miles.

Their mining method, which is open-pit mining, uses the most primitive manual stripping method. It is to first use an iron chisel to chisel out a small groove, and then use a large iron wedge with a sledgehammer to dig the mountain.

This method of digging rocks can still be seen in a few places in the south, but of course it is very rare. In the 80s of the last century, it was still common in rural and mountainous areas, when stone houses were built.

He turned around for a long time and saw that it was all manual, what line of output? This iron ore is so hard, even if you use the fire method, you can't mine much iron!

Gunpowder must be used! If gunpowder is used, this output will definitely increase by dozens of times!

It seems that a supporting gunpowder factory was also set up here to produce gunpowder for use in mines.

It doesn't cost much to build a gunpowder factory, anyway, it's up to you. So he said to Jiang Shipeng: "Judge Jiang, you immediately send a disc to Sun Heng, put the matter of establishing a gunpowder factory here on the record with Shangfangjian, and at the same time report it to Fengge Luantai, and explain the necessity of establishing a gunpowder factory, they will not fail to approve it." ”

"Yes! Lord Wang, if you use gunpowder to mine iron ore, there will be no problem with the annual iron output of 100 million catties! Jiang Shipeng said.

"Speaking of which, 100 million catties is not too much!" Wu Yanzhi said lightly.

"100 million catties is not much? In the past, millions of catties were enough? Wang Jin said.

He's never seen any gunpowder! Please Baidu "Throw Book Network" Thank you for your support!