In the last Khitan rebellion in Hebei, Sun Wanrong's rebels captured Jizhou and killed tens of thousands of military and civilian officials. However, it has little impact on Xingzhou, because it is still hundreds of miles away.

Now that the rebellion has been put down, the people's spring seeds have all been planted and seedlings have grown, and they are busy with spring ploughing.

Wu Yanzhi had already seen their busy scene on the way here. His main task was to increase steel production.

Iron production in the Tang Dynasty was mainly in Hebei, accounting for more than seventy percent of the country. There is a large iron ore vein here, trending north-south. It mainly spans three states from north to south: Xingzhou, Xiangzhou, and Xiangzhou, that is, the line of Xingtai, Handan, and Cixian, spanning hundreds of miles.

……

Shahe County, Xingzhou, morning.

There is a metallurgical superintendent who regulates the mining and smelting industry in the area.

"Lord Qiqi, the mining farms under the jurisdiction of this county, last year, a total of more than 3.1 million catties of iron. The public mine produced 2.5 million catties of iron; The private mine is more than 60 million catties, and the tax is more than 120,000 catties. Wang Jin, the supervisor of Shahe Metallurgical Prison, reported.

Wu Yanzhi knew that the management of Hebei's iron industry was similar to copper, gold and silver.

Several of the larger farms are also state-owned, while the rest are privately owned. At the same time, the management of the mining and smelting of metal ores at that time was relatively loose. Only in places where the output is relatively large, will a metallurgical supervisor be set up to manage and collect taxes, but in fact, it is mainly to collect taxes, not to mention management.

For counties that have not set up metallurgical supervisors, all metals such as gold, silver, copper, and iron are mined by the people themselves, and they do not have to pay even 20% of the tax.

"Do you use charcoal for the smelting of iron?" Wu Yanzhi asked.

"Returning to the prince, there are those who use charcoal, and there are those who burn charcoal (coal). Although it costs less to use charcoal, the iron produced is not very good and becomes brittle. It still needs to be refined. ”

Wu Yanyi listened, this is of course, the coal used must have too high sulfur content, which caused this phenomenon.

To make good steel, you have to use coke. So he said, "Is there a place around here where coal is produced?" ”

"Of course, there are four in this county, and there are even more in nearby counties. It is the charcoal, which is also divided into two kinds, one has very little smoke and dust, and it is very easy to burn. The other type will scorch and the smoke will be very large. ”

"Let's go, you take us to see it! To make good steel, this charcoal must be used, and it must be smelted again. Wu Yanzhi said as he walked.

The people next to him didn't understand either, but Judge Jiang Shipeng knew that his lord never said something that he was not sure of.

So Wu Yanzhi took Yao Kuan, Yufei, Jiang Shipeng, Lu Hong, Gu Zhiwen and others, under the leadership of metallurgical supervisor Wang Jin and others, and rushed to the nearby coal quarry.

A group of people rode horses, and the distance of more than ten miles actually arrived in an instant. Wu Yan saw that this was an open-pit coal quarry, and more than a dozen people were busy.

He thought to himself, but unfortunately the current population is not large, and industrialization has not yet started, otherwise such a large open-pit coal mine would have earned a lot of money a year.

Because his cost is much lower than the cost of underground coal mine (underground) mining. And there is no danger of gas explosion, and the safety is much higher.

"Lord Qiqi, the mining farm here has only been excavated for more than ten days this year. In winter, it is covered with heavy snow, the weather is too cold, and the sales volume is not large, so it is not mined! Wang Jin said.

Wu Yanzhi and the others dismounted and looked around.

"Lord Wang, the charcoal here will stick together when burned! There are also a few houses with stoves, so I'll take a look at them later! Wang Jin said.

A dozen people worked, and there was a woman cooking.

The men, as well as some of the children, were astonished when they saw the sudden arrival of many officials and officials.

Several officials were doing their work of explaining to them.

The woman who was cooking was washing rice outside the door.

"The lady of the Bai family, this is the king of Donglai, see it soon!" A county guard said.

The lady of the Bai family in her 30s has naturally never seen such a big official, even a county official, and it is rare to see it once a year.

She was so frightened that she hurriedly knelt down and kowtowed: "Concubine to see the prince!" ”

Next to her was a little boy of four or five years old, with a runny nose and dirty. He leaned timidly behind her mother, staring at them stupidly.

"Ladies are exempt! Let's just look at the stove! Come, little friend, I'll give you something! Wu Yanzhi took out two silver coins and handed them to the child.

The kid went but didn't dare to pick it up!

"Catch it! This is the king's reward! Rare! Jiang Shipeng said on the side, and he motioned for the woman to take it quickly.

So the woman motioned for her youngest son to take the coin, and then thanked him again.

Wu Yanzhi then under her leadership carefully inspected the coal burning in the stove in the house and the stove in the stove house.

I found that this was really coking coal, and it seemed to look good, and I felt that it should be high-quality coking coal. Under such conditions, there is no laboratory equipment, and it is impossible to judge.

Anyway, the steel I want to smelt is not a special steel, it is mainly used to make weapons and armor, and the impact is not great.

"This charcoal can be used, but a coke oven must be built first."

"Coke oven?"

The crowd didn't know what it was.

Wu Yanzhi saw that everyone was very confused, so he roughly explained: "It is to build several large closed furnaces, put this charcoal in it and burn it first, and then use it to make iron!" ”

As soon as he said this, the people around him roughly understood what he meant.

As mentioned earlier, a friend has reported that the cement kiln here has been built and can be used for trial production. This time, Wu Yanzhi brought a number of skilled hands in firing cement.

"Let's go and see the cement kiln first, and then we will burn the refractory bricks and build the coke oven. At the same time, converters for steelmaking should be built at the same time. Wu Yanzhi said.

……

Let's talk about the role of coking and charcoal first.

As we all know, the main ingredient of this coal is charcoal, which is the same as charcoal.

However, it took hundreds of millions of years for this coal to become it. In addition to charcoal, it also contains many other substances that are not needed or harmful for steelmaking, such as sulfur, tar, and so on.

This thing has to be removed by coking, otherwise they are very harmful to iron or steel.

So how do you coke? Coking refers to the process in which coking coal is heated to about 1000°C (high-temperature dry distillation) under the condition of isolated air, and coke is produced by thermal decomposition and coking.

Metallurgical coke has high carbon content, high porosity and high strength (especially high temperature strength).

Coke is an important fuel and reducing agent for blast furnace ironmaking, and it is also the proppant (supporting iron ore) of the entire blast furnace column.

In other words, carbon is not only a fuel, but also a reducing agent, which can reduce the oxygen (O) in iron ore to carbon monoxide (CO) and carbon dioxide (CO2) and evaporate it.

It should be mentioned here that in fact, this coke is used in ironmaking. Modern steelmaking is the re-smelting of molten iron, which only needs to control the amount of oxygen blown in, and does not need to add any fuel, mainly relying on its own chemical reaction.

(The temperature of molten iron in a closed furnace can be increased by more than 200 degrees Celsius by its own chemical reaction.) Oxygen is then blown in, and the excess charcoal is reduced and removed, and the steel is smelted. Please Baidu "throw the book network" Thank you for your support!