Wang Rui did not hide anything from Li Mu, not only disclosed the secret of coke, but also took Li Mu to visit the iron-making furnace under construction.

Li Mu also saw this thing for the first time, and couldn't help but look at it a few more times, Wang Rui thought that he had finally met someone Li Mu didn't understand, and introduced it even harder: "Lord Hou, please see, this cylindrical iron-making furnace, the inner wall is made of more than a foot thick, mixed with clay mixed with salt, after adding salt, this clay can be made more resistant to burning, the outer circle of logs is used for piling and fixing, to prevent dumping, and the outermost layer of wrought iron ring is to ensure that the iron-making furnace will not explode."

Wang Rui told Li Mu that to build such a furnace, even if it is a master, it will take a month to say less, and he can't be rash and greedy. Otherwise, once cracks appear in the salt mud, it will be wasted, and it may also cause danger. If the iron-making furnace explodes, it is not a joke, the molten iron jumps out, and there are casualties everywhere it hits.

Such an iron-making furnace can hold more than 2,000 catties of iron ore. Before ignition, a layer of coke, then a mixture of mineral sand and pulverized coal is spread in the furnace, and after it is spread layer by layer, it is ignited from the bottom and the refining begins.

Next to the iron-making furnace, there is also a huge blower, when making iron, you have to keep sending air to it, this job is not just something that can be done, how much air is sent, how much air is frequent, how much frequency is geometric, depending on the height and color of the flame, all need to be judged by experience.

The iron-making master introduced to Li Mu that after the ore in it is burned and melted into molten iron, it will flow out of the waist hole of the iron-making furnace. This hole is plugged with mud beforehand. Every hour during the day, the mud plug is pierced and the molten iron flows out.

After the molten iron is cleaned, immediately use a fork to pull the mud, plug the hole again, and then continue to blast and smelt, wait for an hour and then open the hole to release the molten iron. And so on until all the mines have melted, and then the slag can be turned off and removed.

Li Mu stood far away, waiting for the next opening in a place where the blazing fire could not be burned. In less than a quarter of an hour, there was an iron-making furnace on the left hand side, and although Li Mu was far away, he could also feel the scorching heat contained in the fiery red molten iron. He watched the molten iron for a moment, and it flowed into a square pond next to it along the stone diversion trough.

Wang Rui told Li Mu that the molten iron that flowed out was pig iron after it was cooled. If you want to use pig iron for smelting, directly in this link, the molten iron is injected into the model, and the cooling can be directly used. But this kind of pig iron is too poor in quality and very brittle, and it is almost not used directly.

Iron tools used in daily life also need to turn pig iron into mature iron.

The pond is made in the same way as the iron-making furnace, but the height is only one and a half feet. A slightly higher brick platform was built with bricks next to it, and the ironsmith and apprentice all stood on the platform to operate it, so as not to overflow the molten iron in this wave.

When the molten iron flows into the pond, the ironmaker quickly sprinkles the prepared fine mud powder evenly on the surface of the molten iron.

"Stir-fry!"

After the master's order, several apprentices violently stirred up with willow sticks and fried the pig iron to mature iron. The willow stick will burn off two or three inches every time it is fried, and it will have to be replaced with a new one when it is fried again.

This method is called the frying method, which can oxidize the silicon, manganese and carbon in pig iron, and reduce the carbon content to the category of steel or wrought iron.

If you do this, you can basically leave the factory. More than ninety percent of the places where Datang produces iron are basically 'wrought iron' products...... Some were cast into various tools, weapons, and armor. Some of them are directly divided into squares in the pond, and after cooling, they are taken out and hammered into rounds, and then sold directly to the blacksmith shop.

This kind of iron is more than enough to make sickles and hoes, but if you want to make blades, it is not enough.

Eventually, less than 10% of the high-quality wrought iron will be used to make 'steel'.

In this era, there is only one way to make steel. That is, when folding and forging, the hay is wrapped outside the wrought iron, the hay is burned, and the grass ash is formed, and then folded and forged, and the charcoal in the grass ash is 'beaten' into the wrought iron, which is outrageously inefficient, so the steel is very difficult to obtain. The blades created in this way are also extremely rare. Every warrior with a sword regards his weapon as his life, because it is not easy to get one.

And once the blade has a gap, it is basically in a state of scrapping. That's why craftsmen who can repair blades are so popular. Chu Dali was able to get orders from the Ministry of War, not all of them relied on Li Mu's care, but they really had real skills.

Li Mu watched from the side for a while, and then he knew it in his heart. The technical level of the Tang Dynasty is still very limited.

"I don't want to come in vain today," Li Mu showed his arms and sleeves after visiting, and said: "Recently, I have developed a method, teach it to you, find a few trustworthy skilled blacksmiths, and arrange an anvil to come." ”

Wang Rui couldn't help but be overjoyed, as far as he knew, what Li Mu shot had never disappointed. This is an iron factory, anvils are everywhere, Wang Rui hurriedly ordered someone to clean one out, and arranged for someone to surround the surroundings with a straw curtain.

Wang Rui found three generations of domestic servants who had worked for the Wang family to help Li Mu and learn his craft. He thought that Li Mu was going to do it himself, but Li Mu didn't, he just moved his mouth. In front of outsiders, it is impossible for Li Mu to use the functions of the system.

Li Mu first asked a blacksmith to put the unforged wrought iron pieces into the iron-making furnace, and there was also a small worker next to him who was pulling the bellows to heat.

About two minutes later, Li Mu instructed another blacksmith to clamp one end of a piece of pig iron with large tongs and place it diagonally in the mouth of the furnace, and at the same time ordered the small worker to intensify the air blast so that the temperature of the furnace would continue to rise.

Before the tea was served, the pig iron began to melt at the end of the furnace, and the molten iron continued to drip down. At this time, Li Mucai took the big iron tongs from the blacksmith's hand, clamped the end of the pig iron outside the furnace, and began to move left and right, so that the molten iron was evenly poured on the wrought iron below, and made a demonstration for them.

Because the melting point of wrought iron is higher than that of pig iron, although it was put in first, it was only burned red and showed no signs of melting.

At the same time, Li Mu's other hand kept turning the wrought iron sheet so that it could be evenly poured with molten iron on both sides. After pouring it twice, he clamped the wrought iron to the anvil next to the furnace and let the blacksmith forge it with a sledgehammer.

If two blacksmiths repeatedly beat it thousands of times, they were surprised to find that the pig iron wrought iron had become one and turned into steel! Although this is also very cumbersome, it is much easier than the original grass ash folding and forging!

Wang Rui trembled with excitement, with this method, the speed of forging blades in his ironworks would be ten times that of the original. What is the concept of tenfold? This means that if Li Mu does not pass on this secret method to others, Jiangnan Iron and Steel Plant will be the only place in Datang that can quickly mass-produce blades, and the benefits will not only be money. The imperial court and the military department will rely on it very much, and the Jiangnan Iron and Steel Plant will become irreplaceable!

Langya Wang's right to speak will gradually increase. The family will rise in his hands!

Wang Rui is now completely convinced, he finally believes that there are people in this world who are born to know, and his awe of Li Mu has risen to the top, and he does not dare to have the slightest contempt!

Seeing Wang Rui's excited appearance, Li Mu was somewhat speechless. That's it, excited? This is just a steel-filling method, and he has more than one way to build weapons.

In the system, although it is not clear that there are several ways to forge blades, in the process of forging different blades, these basic means will be revealed. In addition to the steel filling method, there are also metal composite processes such as steel cladding, steel clamping, and steel embedding. Different steels are combined to produce steels with different metal properties.

For example, clad steel is made of relatively soft steel, such as mild steel or wrought iron, to forge the basic shape of the knife, and then wrap one side of the knife with a sheet of high-carbon steel and forge it into a blade. This method is relatively simple, but there are some limitations, first of all, it is difficult to produce a double edge, so this method is not used when forging a sword. In addition, Baotou Steel is hard steel clad soft steel, if it is over-polished when grinding, the soft steel inside leaks out, the knife can be scrapped, and the blade made is relatively wear-resistant.

The opposite process of cladding steel is called steel clamping, which is made of hard high-carbon steel and soft steel on both sides. The advantage of this process is that it can be made into a double-edged sword, and there is no need to be careful with polishing, and the production is relatively simple. However, there is another problem, the steel consumed by the steel clamping process is much more than the steel cladding process, and there is no advantage in the cost.

The steel embedding technology is a technology that combines the advantages of both. It is based on mild steel as the skeleton, and then grooved where the blade is needed, and then the high-carbon steel is embedded in it, compared with clad steel, in the case of the same blade performance, the time of embedding steel is shorter, more suitable for mass production, and can be forged at will to double edge, and there is no worry about grinding. Compared with clamping steel, it consumes less high-carbon steel and saves more materials.

But this kind of technology, the process is complicated, and it is not something that a casual blacksmith can do. Li Mu didn't plan to send Jiangnan Iron and Steel Plant to the throne of the first place in Datang, so he didn't expose the technology of pressing the bottom of the box at all, and the current situation, the steel filling method was enough to deal with.

Because the melting point of wrought iron is higher than that of pig iron, although it was put in first, it was only burned red and showed no signs of melting.

At the same time, Li Mu's other hand kept turning the wrought iron sheet so that it could be evenly poured with molten iron on both sides. After pouring it twice, he clamped the wrought iron to the anvil next to the furnace and let the blacksmith forge it with a sledgehammer.

If two blacksmiths repeatedly beat it thousands of times, they were surprised to find that the pig iron wrought iron had become one and turned into steel! Although this is also very cumbersome, it is much easier than the original grass ash folding and forging!

Wang Rui trembled with excitement, with this method, the speed of forging blades in his ironworks would be ten times that of the original. What is the concept of tenfold? This means that if Li Mu does not pass on this secret method to others, Jiangnan Iron and Steel Plant will be the only place in Datang that can quickly mass-produce blades, and the benefits will not only be money. The imperial court and the military department will rely on it very much, and the Jiangnan Iron and Steel Plant will become irreplaceable!

Langya Wang's right to speak will gradually increase. The family will rise in his hands!

Wang Rui is now completely convinced, he finally believes that there are people in this world who are born to know, and his awe of Li Mu has risen to the top, and he does not dare to have the slightest contempt!

Seeing Wang Rui's excited appearance, Li Mu was somewhat speechless. That's it, excited? This is just a steel-filling method, and he has more than one way to build weapons.

In the system, although it is not clear that there are several ways to forge blades, in the process of forging different blades, these basic means will be revealed. In addition to the steel filling method, there are also metal composite processes such as steel cladding, steel clamping, and steel embedding. Different steels are combined to produce steels with different metal properties.

For example, clad steel is made of relatively soft steel, such as mild steel or wrought iron, to forge the basic shape of the knife, and then wrap one side of the knife with a sheet of high-carbon steel and forge it into a blade. This method is relatively simple, but there are some limitations, first of all, it is difficult to produce a double edge, so this method is not used when forging a sword. In addition, Baotou Steel is hard steel clad soft steel, if it is over-polished when grinding, the soft steel inside leaks out, the knife can be scrapped, and the blade made is relatively wear-resistant.

The opposite process of cladding steel is called steel clamping, which is made of hard high-carbon steel and soft steel on both sides. The advantage of this process is that it can be made into a double-edged sword, and there is no need to be careful with polishing, and the production is relatively simple. However, there is another problem, the steel consumed by the steel clamping process is much more than the steel cladding process, and there is no advantage in the cost.

The steel embedding technology is a technology that combines the advantages of both. It is based on mild steel as the skeleton, and then grooved where the blade is needed, and then the high-carbon steel is embedded in it, compared with clad steel, in the case of the same blade performance, the time of embedding steel is shorter, more suitable for mass production, and can be forged at will to double edge, and there is no worry about grinding. Compared with clamping steel, it consumes less high-carbon steel and saves more materials.

But this kind of technology, the process is complicated, and it is not something that a casual blacksmith can do. Li Mu didn't plan to send Jiangnan Iron and Steel Plant to the throne of the first place in Datang, so he didn't expose the technology of pressing the bottom of the box at all, and the current situation, the steel filling method was enough to deal with. Because the melting point of wrought iron is higher than that of pig iron, although it was put in first, it was only burned red and showed no signs of melting.

At the same time, Li Mu's other hand kept turning the wrought iron sheet so that it could be evenly poured with molten iron on both sides. After pouring it twice, he clamped the wrought iron to the anvil next to the furnace and let the blacksmith forge it with a sledgehammer.