The completion of the coking kiln is only the first step of coking, whether it can be smelted qualified, but also depends on the grasp of the furnace temperature and the quality of coking coal.

Not all coal can be used for coking, and bituminous coal is divided into eight types: lean coal, lean coal, coking coal, fertile coal, one-third coking coal, gas-fertile coal, and one-half of the sticky coal. Among them, the most suitable for coking is coking coal and fat coal, lean coal and medium sticky coal can also be improvised.

The remaining four are not very qualified, either the coke produced has a large ash content and high sulfur and phosphorus content, or the coke cannot be refined at all, and it will be broken when touched. Good coke requires black color, large coke blocks, few cracks, uniform porosity, and not easy to break.

If the three conditions of good coke kiln, high-quality coal source and suitable temperature can be met, the coal in the kiln will be burned by the coal in the furnace first, and the gas will be heated to produce gas, and the gas will walk evenly along dozens of ventilation channels in the first layer of coal, and the air coming in from the bottom of the kiln will be heated to a high temperature of nearly 1,000 degrees after being ignited, which is equivalent to dry steaming of coal, also known as dry distillation.

When the coal is dry distilled, it produces gas, and in this way, it spreads upwards layer by layer, and finally distills to the top of the kiln and the coke is smelted.

The coking time of Zhongxing coke kiln is 12 days, the coking rate is about 70%, and the consumption of fuel coal is less than one ton per 100 tons of coking coal.

However, the large amount of gas produced in the coking process cannot be completely burned out, and a large part of it is discharged along the ventilation duct and chimney, which is a great waste.

In addition to being used directly as a gaseous fuel, this gas can also be condensed to form coal tar. At the current level of technology, coal gas cannot be collected directly for the time being, so coal tar has become the main by-product of coking.

Hongtao uses the simplest water-cooled method to collect coal tar, which is to dig a water tank next to the coking kiln, and introduce the gas on the top of the coking kiln into the water tank with a tile pipe, and the water tank is constantly cooled by water from a water truck.

The high-temperature gas in the tile pipe cools down and condenses into coal tar and flows out of a large pool at the end of the trough, where it mixes with the water.

After separation, these oil-water mixed liquids are coal tar, and then through pickling, alkali washing, fractionation and other processes, gasoline, diesel, kerosene, paraffin, asphalt and so on can be extracted.

When Hong Tao was in school, he interned at a coking plant in Qian'an, where private owners still use this primitive coking kiln, which can produce about 30% of the coke.

However, people use active ventilation and condensing tower technology, and the output will be higher. At present, it is obviously very difficult to use an exhaust fan to extract gas condensation, and the oil yield will definitely be low. But as long as the quality of coking coal is good, it is estimated that it will not be much lower, and it should be about 20%.

As mentioned earlier, coal tar and gas are the main by-products of coking kilns, so there should be secondary by-products. That's right, the secondary by-product is that bricks can be burned by the way, especially refractory bricks.

The temperature of the ancient brick kiln is relatively low, with an average of about 700 degrees, but the refractory bricks need to be calcined at a high temperature of about 1000 degrees, and the cost of making a kiln is too high.

It just so happens that the roof of the coking kiln and some ventilation ducts that are not difficult can be covered with bricks, and the temperature of the dry distillation can reach more than 1100 degrees, and the bricks are also fired after more than ten days of high-temperature calcination.

Then someone asked, you can't dismantle the coke kiln for thousands of bricks, right? To ask this is to not read the previous introduction carefully.

The coking kiln itself is not complete, it only has a circle of nearly two meters thick walls and vertical ventilation ducts, and then there is the ignition furnace at the bottom, and the rest of the internal structure, including the kiln roof, chimney and so on, are all built with the coking coal layer by layer.

After the coke is smelted, these temporary structures must be dismantled along with the coke, otherwise the next kiln coke will not be able to be refined. Therefore, the job of burning bricks is to do it if you want to do it, and you have to do it if you don't want to do it, and you can't avoid it.

The dolomite that Hong Tao asked Hu Er to find was the raw material for firing refractory bricks, which was crushed and ground finely mixed with pulverized coal and a small amount of limestone to make bricks to dry, which could be used to build internal temporary structures for coking kilns. Regardless of whether the first furnace of coke can be successfully smelted or not, these bricks will 100% turn into good refractory bricks.

These bricks will be used to build blast furnaces for ironmaking and open-hearth furnaces for steelmaking, and they will not be wasted at all. When the amount of coking increases in the future, you can also change to burn ordinary bricks, whether you use it yourself or sell it, it is money. What can be earned cannot be wasted, and flies are meat even if they are small.

As long as it is a heavy industry, there is nothing that does not pollute, and local coking, iron-making, and steel-making are all industries that pollute water resources.

Coking, in particular, requires a large amount of water from the initial coal washing process to the final coal tar cooling process. This is also an important reason why Hong Tao built Wujin Bank near the water, without the water industry, it is impossible to produce.

"It's a pity that this big lake, fortunately, the water of Jinming Pond does not enter the city, otherwise it will not take a few years, and the water in Kaifeng City will be full of tar smell."

Thinking that a good royal garden was about to be destroyed in his own hands, Hong Tao had no regrets, the only worry was that it was too close to Kaifeng City, and the surface water could go around the city, but the groundwater would have to be polluted after a long time.

But at present, he can't take care of so much, or the same sentence, first to keep the home before talking about environmental protection, the big deal is to survive the difficult period of the past few years and then find a suitable place to build a new factory.

Hu Er's son is really a spirit, Hong Tao painted with his fingers on the ground while talking about him, and when Hong Tao finished speaking, he basically finished painting.

What's even more powerful is that as long as the painting is finished, it is equivalent to understanding and remembering, if there is something unclear, he will stop his fingers, and then let Hu Er ask questions, and then continue to draw after asking all the questions.

And his humble son is not stupid at all, and after he understands everything, he immediately erases the graphics on the ground with his feet, for fear of being seen by others. In fact, it's the same whether you wipe it or not, not to mention other craftsmen who are still confused, even Hong Tao himself can't understand what he paints.

It wasn't just a whole set of blueprints, it was a lot of split structure drawings. His brain circuit is definitely different from others, Hong Tao really has this ability, even if he draws it, he can't correspond to it.

"Why do officials want to build a small kiln, this size can't fit a few loads of charcoal, and it costs a lot, and it can't be drawn left and right."

It's not enough to just understand, Ah Chou still has a personal opinion, but he can only be conveyed by his father, and he stutters seriously when he talks to strangers. The matter of laying the three bricks could not be explained clearly for an hour, and it was difficult for others to listen to him.

"Your ugly child is a baby, don't worry about him, even if you leave, as long as I am here, he will not suffer. As long as the day I make the results, I will play the official family and give you a knighthood for the Hu family. I can't guarantee whether there is food or not, in fact, as long as the craftsmanship is passed on, who is rare for those hundreds of stone grain, is this the truth...... Hey, I don't care if you kneel at every turn, I will break my life when I kneel at such an age, I understand! Hong Tao was already a little red when he looked at it, why didn't he have such a spiritual genius around him?

"Hey...... Ugly get up quickly, if the big officials don't let us kneel, we won't kneel. Blessed are you, boy! Oh, and the officials haven't explained to us clearly what the kiln is used for? There's a problem with my ugly child, and he can't do anything he doesn't understand......"

Hu Er didn't insist, he got up but his son didn't get up, and he stabbed his ankle bone with his elbow vigorously. The father and son have lived together for decades, and there is no need to say a lot of words clearly, and they can know what the other party is thinking with a look and a movement.

"Use a small kiln to test firing first, and save some energy if there is an error. This thing is very picky about charcoal, and whether it is suitable or not has to be tried. "Hong Tao definitely can't say that he hasn't really played with this thing, it's just on paper.

With a roll of his eyes, he attributed the possibility of failure to the quality of the charcoal, and Zhu Bajin, who heard it, grinned. He can hear it, if he succeeds, he is clever, if he fails, he is not good at doing things, and if he is a leader, he doesn't have a good thing!