The Erlin Department is very luxurious and uses pine charcoal for smelting.

The temperature of pine charcoal is a little different and it consumes more, but it has a huge advantage. It contains very little sulfur and the quality of the iron obtained is very high.

When Shi Tong saw Su You, he started to make gestures: "This furnace was built when the two elders came last time. Now we only need to add air exhaust to blow up the furnace, and the output can still increase!"

Su You didn't care much about this: "Where is the mine?"

Shi Tong also got on the horse: "Guli, follow me."

After turning around a valley, a huge mountain appeared in front of us.

There is no grass on the mountain, only countless potholes and ant-like crowds.

These men were dressed in ragged clothes and carried a large basket on their backs with the straps tied around their foreheads. They carried baskets of ore down the mountain and unloaded them into the baskets on both sides of the horse's back.

Many soldiers from the Erlin Division, armed with whips and steel knives, were patrolling the mountains.

Seeing the unbearable look on Su You's face, Adun Yuanzhen whispered: "They are Qionbu Sichuan people, as well as several surrounding tribes that once rebelled."

Su You nodded: "You have to give people a little hope, otherwise... forget it, let's look at mining."

You can see exposed mine heads everywhere on the mountain, and there are patches of black soil without grass at the bottom of the mountain.

Many pits had been dug very deep and then flooded, so the slaves had to dig new pits in different places.

After looking around, Su You had a rough idea of ​​today's mining methods, so he turned around and returned to the smelting furnace.

This furnace of iron was started three days ago and is now starting to come out.

In addition to the honeycomb-shaped steel at the bottom, there is also a large amount of slag in the upper layer.

The iron material was sent to be re-melted and forged, and the slag was poured into a stockyard behind the mountain.

Su You asked Shi Tong to melt some iron into the graphite crucible he brought, and then cast a short sword.

Comparing the hardness of the dagger made from Meishan iron sand, it was found that the iron materials from the Erlin Department, except for the ones coming out from the bottom, were completely brittle, not much better than glass, and completely unfit for use.

Shi Tong was immediately disappointed: "How...how is this?!"

Adun Yuanzhen said: "Abba has long told the two grandfathers of the Shi family that the iron materials in our Erlin Department are like this. Only the bottom bit is usable when smelting, so we have to buy swords from outside. But we

The copper material is very good!”

Su You felt something in his heart, so he hurried back to the furnace and lay down on the slag to rummage around.

Shi Tong and Atun Yuanzhen hurriedly followed, and saw Su You pulled out a dark brown stone-like thing from the slag, with many small honeycomb-shaped holes on it.

Then I saw Su You hugging the stone and laughing wildly: "Ha? Hahahahaha... I've really seen a ghost..."

Shi Tong was frightened and shook Su You's little body: "Oops, Master, something happened! Master, wake up! Wake up?!"

Su You suddenly came to his senses: "Don't shake, don't shake! Let go quickly... Hahahaha... We have found the treasure in Da Shitou, we have found the treasure in Yuan Zhen! Big treasure..."

This is not an iron mine at all! It is an iron-rich manganese mine! The smelting method of Erlinbu is very similar to the fire enrichment smelting method of later generations. The steel obtained by chance is called ferromanganese, because the manganese content is too low.

As a result, the metal is too brittle and cannot be compared with Meishan iron sand.

Where did the remaining manganese go? It was in the slag. This slag is called manganese-rich slag!

In later generations, the service life of several inter-county roads in Meishan was much shorter than other roads. This was because large trucks of dozens of tons were running on the roads, constantly dumping these lead-zinc ore and manganese-rich slag out.

The administrative villages that Suyou is responsible for often participate in protecting the highways to prevent overloading along the way, and these things are often seen.

Of course, the things obtained by the Erlin Department are of no use now. Only the little bit of iron that was first recovered can be used to make iron tools.

But once the manganese content in steel exceeds 13%, it is called high manganese steel. Its most powerful feature is that it has excellent wear resistance and hardness, and at the same time, the steel can maintain elasticity and toughness.

The reason why this feature is great is that it solves a huge problem of carbon steel. The higher the hardness, the more brittle it is, and the higher the elasticity, the softer it is.

In addition, it can help desulfurization and deoxidation, improve the performance of sulfur-containing steel, and reduce the generation of bubbles, so high manganese steel can usually be cast by sand casting.

At the same time, if it is heated to light orange, it can become very soft and can be easily processed in various ways.

The only flaw is that the quality will be affected after remelting.

Su You said to Atun Yuanzhen: "Yuanzhen, have people take all these things to the windmill, and ask your sister to prepare Dali iron materials and asbestos linings; for the big rocks, you can find some coal for coking, and we will melt it.

Try it and see if it’s the treasure I mentioned! Let’s go back and talk to the General and Mr. Fan in detail!”

Atun Chizun and Mr. Fan were shocked when they heard that the unusable iron material in the back mountain mine turned out to be a treasure?

Over the past few decades, not much good iron has been obtained, and mountains of slag have piled up!

There is no doubt about the importance of good steel. Under such a huge temptation, Mr. Fan made an immediate decision and all the craftsmen devoted themselves to a windmill mill, working in three shifts, striving to build the windmill quickly.

Shi Tong and Su You devoted themselves to the construction of a small crucible smelting furnace. They also had to cast a sand box with water glass and seal it in an air chamber for hardening.

Then there was the scrapping and mixing. After several attempts, Su You obtained a metal.

This thing can be distinguished by the naked eye, and the cross section is as bright as a mirror, so it is called mirror iron.

The manganese content of this thing is about 15 to 30%. After obtaining this, Su You can almost conclude that the Erlinbu mine is a proper manganese ore!

With mirror iron, theoretically there is the foundation of the steel industry. This is an important raw material for adjusting the manganese content in molten iron and desulfurizing and deoxidizing.

With it, the requirements for iron ore can be reduced a lot, which is even more important for the Song Dynasty where the grade of ore is not high.

The so-called "no steel without manganese" refers to this.

Of course, it is undoubtedly a fool's dream to hope that Song Dynasty Iron and Steel can surpass Dali Xixia Japan based on a small manganese mine in Jisizhou.

However, the Shijia Workshop can study the characteristics of the veins, conduct ore sampling, conduct preliminary tests, determine the metal content of the ore, finalize the process flow, improve the process formula, gain valuable experience, and accumulate technology.

By the way, there is no problem in improving the quality of the ironware in the workshop.

Three days later, the crucible furnace equipment was completed, and everyone immediately started the smelting test.

Li Shuanzhu and Shi Tong were in charge of smelting, and Su You was in charge of experimental statistics and calculations.

The test materials include marble iron, recycled materials, low manganese steel smelted from the bottom of the furnace, mirror iron, and manganese-rich slag.

There are still a lot of impurities in many materials. However, you can use the weight of raw materials, the weight of finished products, and the ratio of each material to bring in the known upper and lower limits of the mirror iron and manganese content and the manganese content of manganese-rich slag, and list a series of equations.

, get the approximate formula proportion range.

…

The furnace is very small and can only melt about ten kilograms of material at a time. It can melt four pots at the same time. It is purely a test equipment.

The fire continues, pots of molten steel with different proportions are released, and the test data is getting closer and closer to the ideal.

Shi Tong has been awake for two nights, but he is not tired at all. His eyes are getting brighter and brighter, with an expression of excitement.

The sand mold is very simple, just rows of shallow grooves, all in the shape of long knife strips, with thin grooves connected at the end.

A new pot of molten steel was melted. Shitong took out a small crucible and poured the molten steel onto the sand mold in the oven.

After that, take out the casting, chop off the tail joint, and send the blade to the bending machine for two rounds while the blade is still in a red and soft state. After fine-tuning and straightening by hand on the anvil, it is directly quenched with water.

Erlinbu couldn't pickle it, so Shi Tong used a hammer to knock off the oxide layer, and then chopped it off with a short knife.

With a "dang" sound, sparks flew out, and this time the knife blade only left a small awn.

Shi Tong suddenly fell to the ground: "Master... it's done, it's really done..."

Su You and Shuan Shu both looked indifferent, because the two children had already been tortured to death by the test data and were numb.
Chapter completed!