Chapter 175: Precious Slag

The second forest department is very luxurious, and pine charcoal is used for smelting.

The temperature of the pine charcoal is a little worse and the consumption is more, but there is a huge benefit, the sulfur content is very small, and the quality of the iron obtained is very high.

Shi Tong saw Su You and began to compare: "This furnace was built last time the second elder came, and now you only need to add air exhaust and blast, and the output can go up!" ”

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

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

Turning a valley, a huge mountain appeared in front of me.

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

The men, dressed in rags, carried a large basket on their backs, with a strap on their foreheads, and carried a basket of ore down the hill and unloaded it into the baskets on either side of the horse.

Many soldiers of the Second Forest Department, armed with leather whips and steel knives, patrolled the mountains.

Seeing that Su You's face was unbearable, Ah Ho Yuanzhen said in a low voice: "They are from Qiongbu Chuan, and there are several tribes around them that have rebelled. ”

Su You nodded: "You have to give people a little hope, otherwise...... Forget this, let's take a look at mining. ”

Exposed mine heads can be seen everywhere on the mountain, and there are patches of black soil without grass growing at the bottom of the mountain.

Many of the holes had been dug deep and then flooded, and the slaves had to dig them again in different places.

After looking around, Su You had a rough idea of today's mining methods, and turned the horse's head back to the edge of the smelter.

This furnace of iron, which was boiled three days ago, is now starting to be baked.

In addition to the honeycomb steel at the bottom, there is a large amount of slag on the upper layer.

The iron was sent for re-forging, and the slag was dumped in a stockyard behind the mountain.

Su You dissolved some of the iron in the graphite crucible that Shi General had brought, and then cast a short sword.

The short sword made of Meishan iron sand was compared with its hardness, and it was found that the iron material of the Erlin Department, except for the one that came out at the bottom, was brittle and messy, and it was not much better than glass, and it was completely unusable.

Shi Tong was immediately disappointed: "What...... How so?! ”

Ah Ho Yuanzhen said: "Abba has already told the two grandfathers of the Shi family that this is the iron material of our Erlin Department, and only the bottom point of the refined things can be used, so we have to buy swords from outside." But our copper is good! ”

Su You's heart moved, and he hurriedly ran back to the refining furnace and rummaged on the slag.

Shi Tong and Ah Ho Yuanzhen hurriedly followed, but saw Su You turn out a black-brown stone-like thing from the slag, and there were many small honeycomb holes on it.

Then I saw Su You holding the stone and laughing wildly: "Huh? Hahahaha...... What the hell......"

Shi Tong was frightened, shaking Su You's small body: "Ouch, Master has hit an evil spirit!" Master, wake up! Are you awake?! ”

Su You suddenly came to his senses: "Don't shake, don't shake!" You let it go...... Hahahaha...... We have found the treasure of the big stone, and we have found the treasure of Yuanzhen! Big baby, ......"

It's not an iron ore mine at all! Rather, an iron-rich manganese ore! The smelting method of the second forest department is very similar to the fire enrichment refining method of later generations, and the steel obtained by chance is called ferromanganese, because the manganese content is too low, resulting in too much brittleness of the metal, and Meishan iron sand can not be compared.

Where did the rest of the manganese go? It's just inside the slag, and this slag is called manganese-rich slag!

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

The administrative village in charge of Su You is often involved in protecting the highway and catching overloading along the way, and it is not uncommon to see these things.

The things that the second forest department has obtained by refining themselves are of course of no use now. Only the little bit of iron that was first restored could be used to make iron.

But once the manganese content in the steel exceeds 13%, it is called high manganese steel, and its most powerful feature is that the wear resistance and hardness are excellent, and the steel can also maintain elasticity and toughness.

This property is powerful because it solves a huge problem of carbon steel – the harder it is, the more brittle it is, and the more elastic it is, the softer it is.

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

At the same time, when heated to a light orange color, it becomes very soft and easy to process in a variety of ways.

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

Su You said to Ah Ho Yuanzhen: "Yuanzhen, let people pull all these things to the windmill mill, and let your sister prepare Dali iron and asbestos lining; Big stone, you find some coal to coke, let's smelt a furnace and try it, and see if it's the treasure I said! Let's go back and talk to the general and Mr. Fan! ”

Ah Ho Chizun and Mr. Fan were also shocked when they heard it, the unusable iron material in the mine pit in the back mountain turned out to be a treasure?

Over the decades, I haven't gotten much good iron, and that kind of slag is piling up!

There is no doubt about the importance of good steel, and under such a great temptation, Mr. Fan decided to put all the craftsmen into a windmill mill, three shifts, and strive to build the wind mill quickly.

Shitong and Suyou devoted themselves to the construction of the crucible smelting furnace, and also used water glass to cast sand boxes and seal them into the gas chamber for hardening.

After that, it was scrap, mixed melting, and after a few attempts, Su oil got a metal.

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

The manganese content of this thing is about 15 to 30 percent, and after getting this, Su You can almost conclude that this mine in the Erlin Department is a proper manganese ore!

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

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

The so-called "no manganese, no steel" refers to this.

Of course, relying on a small manganese mine in Jianzhou to make Dasong Iron and Steel better than Dali Xixia Japan, it is undoubtedly a fool's dream.

However, Shijia Workshop can study the characteristics of ore veins, conduct ore sampling, conduct preliminary tests, determine the metal content of 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 workshop ironware.

Three days later, the crucible furnace was built, and everyone was immediately put into melt testing.

Li Lianzhu and Shi Tong were responsible for smelting, and Su You was responsible for test statistics and calculations.

The test materials include Dali iron, return material, low-manganese steel smelted at the bottom of the furnace, as well as mirror iron and manganese-rich slag.

There are still a large number of impurities in many materials, but through the weight of raw materials, the weight of finished products, and the ratio of each material, we can bring in the upper and lower limits of the known mirror iron manganese content and manganese-rich slag manganese content, and list a series of equations to obtain the approximate formula ratio range.

……

The furnace is very small, it can only melt ten catties of materials at a time, and it can melt four pots at the same time, pure test equipment.

The furnace is constantly burning, and a pot of molten steel with different proportions is baked, and the test data is getting closer and closer to the ideal.

Shi Tong has been sleepless for two nights, but he is not tired at all, his eyes are getting brighter and brighter, and he is excited.

The sand mold is very simple, that is, rows of shallow grooves, all of which are in the shape of long knife strips, and the tail grooves are connected.

A new pot of molten steel melted again, and Shi Tong took out a small crucible and poured molten steel onto the sand mold in the oven.

After that, the casting is taken out, the tail connection is chopped off, and while the knife strip is still in a red and soft state, it is sent to the plate rolling machine to go back and forth twice, and after fine-tuning and straightening on the anvil by hand, it is directly water quenched.

The second forest department couldn't be pickled, so Shi Tong took a hammer to knock off the oxide layer, and then chopped it down with a short knife.

With a "dang" sound, the spark splashed out, and this time the knife strip only left a small mang.

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

Su You and Tie were both indifferent, because the two babies had already been tormented by the test data.

This is still when Su You knows the ratio of high manganese steel, and the tolerance of manganese steel itself is also high, so it can be done so quickly, just like that, the experimental data is also full of two books!