The Yanzheng investigation team over there is still being formed, but Zhu Yijun's mind is no longer there, his mind is now focused on the War Bureau, because Chen Ju came to report that Zhu Yijun made his trial production of the wrought iron cannon successful.

After so many years of doing this, there are finally practical results, which makes Zhu Yijun excited.

Coming down from the dragon book case, Zhu Yijun glanced at Chen Ju and found that his honest eunuch was really hard. Not only is his face tired, but he also has a lot of calluses on his hands, and it seems that he is also working with it, which is not easy.

"The slave maid lives up to His Majesty's trust, and the wrought iron cannon is completed!" Chen Ju knelt on the ground and wept loudly.

For so many years, the eunuch of the same generation as him, Xu De is in charge of the inner factory, and he is naturally infinite in light, but he is constantly investing money on his side, but there is no output, and the pressure on Chen Ju is so great.

Zhu Yijun looked at Chen Ju and scolded with a smile: "Get up, what do you look like when you cry." ”

"I remember your merits, and if the wrought iron cannon I built this time satisfies me, I will reward you well." Saying that, Zhu Yijun kicked Chen Ju again and said, "Take me to have a look, don't embarrass me here!" ”

Zhu Yijun smiled very happily, and Zhang Whale next to him looked at Chen Ju with a smile.

Although there was a smile on his face, the urgency in Zhang Whale's heart was strengthened again, he originally thought that this Chen Ju was inconspicuous and not a threat, but looking at the current posture, this is going to be a big deal!

Obviously, Chen Ju's hard work for so many years has not been in vain, just look at the emperor's attitude towards Chen Ju.

Although Zhu Yijun really wanted to go and see it now, it was not so easy for him to get out of the palace.

The smelter of the War Bureau is in Huangzhuang, Zhu Yijun's trip this time is a light car, and Yu Dayou, the left guard of Longwu, personally led people to escort him, and the team of more than 1,000 people seemed to drive to Huangzhuang.

Yu Dayou is even older, and when Zhu Yijun saw him, he knew that the old general's days were numbered.

When the group came to Huangzhuang, martial law had already been imposed here, and the guards were also replaced by people from Longwu Zuowei, and there were Jinyi guards and Dongchang fans everywhere. Zhu Yijun got off the imperial chariot, and the group entered the imperial village.

On the northwest side of Huangzhuang, several blast furnaces are particularly obvious, and at a glance you can see that they are the places where iron is smelted.

"Your Majesty, the open-hearth steelmaking method you asked the slave to study still hasn't succeeded, and now it's still the Dajian furnace." Chen Ju said with some shame.

Zhu Yijun nodded, he also knew that this thing was not so easy to make, so let's learn it slowly!

Chen Ju said that the Dajian furnace, which is a kind of iron-smelting furnace unique to the Ming Dynasty, is basically similar to the blast furnace of later generations. Looking up, Zhu Yijun found that the height of this Great Jian Furnace was more than four meters.

Seeing Zhu Yijun staring at the Dajian furnace, Chen Ju explained on the side: "Emperor, each furnace of the Dajian furnace can smelt 2,000 catties of iron sand, and it can produce iron in half an hour, and it can produce about 600 catties of iron." ”

Zhu Yijun was stunned, this output is not low!

This is different from what I thought, I thought that the ironmaking of Daming was underdeveloped, but this is very developed! Even if you need more, you can directly build more of this kind of big furnace, and the output will naturally come up when the number is enough.

"What about wrought iron and steel?" Zhu Yijun turned his head to look at Chen Ju and asked again.

"Wrought iron needs to be made from five refining of pig iron, and steel needs to be refined nine times." Seeing Zhu Yijun asking, Chen Ju hurriedly said: "It's just that this kind of Dajian furnace costs a lot, if you open the road to refine every day, after three months, this furnace will not work." ”

It's not that the technology can't work, it's the lack of money!

Zhu Yijun also understood that if you want to build a large-scale steel plant, you need a lot of money. In this era, the transportation of ore was also inconvenient, and coke was used for refining, and coal was not possible.

Fuel is also an issue that needs to be solved, and Zhu Yijun also knows that there are two main distribution areas of coking coal in China, one in Shanxi and the other in Guizhou.

With the current transportation conditions, don't think about transporting coal from Guizhou, it's not realistic at all.

It is also unrealistic for Shanxi coal to be shipped out, for example, it is convenient and fast to go to Shanxi and Shaanxi for refining. Zhu Yijun pondered for a while and felt that Shanxi and Shaanxi were still not good, and the most suitable place was Liaodong.

There are ports, convenient transportation, coal, rich mountain and forest resources, iron ore, large land area, no people, these conditions combined, absolutely suitable for the heavy industry base of the Ming Dynasty. It seems that the pacification of Liaodong needs to be put on the agenda as soon as possible!

After walking forward for a while, Zhu Yijun saw another stove, which was much shorter than the Dajian furnace. Zhu Yijun pointed to the road and asked, "What does this stove do?" ”

"Back to the emperor, this stove is fried wrought iron, pig iron comes out of the Dajian furnace, and it is fried here, and after frying, the pig iron becomes mature iron." Chen Ju hurriedly explained.

Zhu Yijun nodded, he now has a general understanding of Daming's iron-smelting technology, and he can be regarded as having a good idea, glancing at Chen Ju, Zhu Yijun said: "Take me to see the wrought iron cannon!" ”

Chen Ju hurriedly led the way in front, and not far away, Zhu Yijun saw a row of ten sports cars.

The wheels of a sports car are similar to those of a horse-drawn carriage, with handles on both sides that can be pushed by two people. There is a hook in front, and it is obviously able to be walked by horse. On top of the gun carriage, there is a cannon, which looks more than a meter long, with a large belly, which looks a little funny.

"You're not going to blow up, are you?" Zhu Yijun looked at Chen Ju and asked.

Compared with the copper cannon, the biggest problem of the cast iron cannon is the explosion of the bore, and the Ming Dynasty has long studied the cast iron cannon, after all, iron is much cheaper than copper. The skilled craftsmen of the Ming Dynasty also came up with a cast iron cannon, but it was too easy to blow up.

"Back to the emperor, no!" Chen Ju said with a smile on the side.

Zhu Yijun had mentioned the matter of granular gunpowder before, but it turned out that there was already a Ming Dynasty, and people's requirements were quite high, Zhu Yijun watched the process of making gunpowder, and he was shocked and speechless.

Each material uses five catties of nitrate, one catty of yellow, and one catty of eggplant ash. The above nitrate, yellow, ash a total of seven catties, divided into three troughs, fixed grinding 5,500 degrees, out of the trough.

Three catties of each medicine, one catty of good soju, into mud, still in the trough, and then grind hundreds of times, out of the trough. Mix into grains, such as the size of yellow rice or mung bean, and it must be burned in the palm of a person's hand without feeling hot.

This kind of gunpowder, Zhu Yijun has also seen, it is really a good thing, if the process is strictly required, Daming's firearm is really powerful. Now looking at the wrought iron cannon in front of him, Zhu Yijun's heart is even more excited.

"Yes, Emperor!" Chen Ju agreed, and hurriedly greeted the person next to him.

The men did not dare to hesitate, carried over the box, and began to take the shells from it, all of which were solid iron ball shells. The cannonballs were quickly stuffed in, and then they stood aside with torches.

Zhu Yijun is also very excited, he has been a human being for two lives, and it is the first time he has seen a cannon.