Looking at these gray-haired people, the youngest is probably close to fifty, and the older one is over sixty.

"Everyone, get up quickly. Since you worship me as your master and learn the method of refining gunpowder, I also want to make it clear to you that my master, Lou Guan Dao Xiaoyaozi, founded the Longmen Sect. I am the second generation disciple of the Longmen Sect, and also

The current leader, you worship me as your teacher. From now on, you will be the third generation disciple of Louguan Longmen Sect. From now on, you will concentrate on learning the method of refining gunpowder.

In fact, this kind of gunpowder can be penetrated by just a little bit, so it is nothing unusual to pierce the layer of paper.

All gunpowder is mainly saltpeter and sulfur, supplemented by charcoal.

The nature of nitrate is to the yin level, and the nature of sulfur is to the yang level. The two divine objects of yin and yang meet in a seamless space."

Huaiyu didn't intend to hide anything from these ten disciples. To be honest, it was better not to appear in the world in the first place. Now that he has appeared in the world, he must hand it over completely. Otherwise, even a great emperor like Li Shimin would probably not be able to sleep peacefully.

The common man is not guilty, but he is guilty of carrying the jade.

The ten old men all remembered it very seriously.

The prince once summoned them and asked them to learn the method of gunpowder, but he also asked them not to reveal even a single word of the secret recipe of gunpowder. They were not allowed to record it in writing, and they were not allowed to tell anyone.

"In fact, the stability and power of gunpowder are related to the purity of its extraction. Especially the saltpeter. Making saltpeter is also called boiling saltpeter..."

"Charcoal, fir charcoal is the best, but ordinary plant ash is much worse..."

Huaiyu had no reservations about the professor. After teaching the basics, he started the experimental class directly.

There were ready-made saltpeter, sulfur, charcoal, etc. Huaiyu checked the saltpeter and found that the saltpeter was gross saltpeter and needed to be purified.

"First manually pick out the impurities in the saltpetre, and then put it into an iron pot. For one pound of saltpeter, we add half a pound of water. It can cook fifty pounds of saltpetre at a time. Heat it to boil. After two seconds, add a small amount.

Cold water, stop when it boils again."

One teaches with heart, and ten learns with heart.

"Look, after the second boiling, most of the impurities are floating on the surface. Let's pick up these impurities.

At this time, please note that we need to add a small amount of fish bladder glue to the surface. This will increase the surface viscosity of the solution, making it easier to remove impurities. Repeat this operation several times until all impurities are removed, and then let it sit.

After the solution is clarified, put it into a ceramic jar and let it cool down and crystallize naturally."

The old men studied extremely seriously.

There are many ways to refine gunpowder, and the ones Huaiyu knew were relatively simple.

The crystallized hair salt contains crystal water and needs to be dehydrated again.

"We put the crystallized saltpeter into a large iron pot and heat it to evaporate the water. The crystallized saltpeter in a molten state will evaporate quickly. You have to immediately use an iron spoon to put the saltpeter on an iron plate or stone slab.

Then let it cool down naturally again to obtain anhydrous nitrate."

After cooling, the refined saltpeter becomes lumpy. At this time, it is broken into pieces with a copper hammer. Finally, it is pressed into fine powder with a roller and filtered with a sieve to make the particle size consistent.

The crushed fire salt needs to be dried again to reduce the moisture content, but it cannot be heated directly by fire. A fire wall type drying chamber must be used. The partition wall is heated by fire outdoors. The saltpeter is spread on the drying plate and sent to the drying room. In a specific

It is dried at a certain temperature for three or four hours. After drying, it is screened with a specific sieve, and then it can be prepared.

"If we make more firearms in the future and require a large amount of saltpeter, we will have to find natural saltpeter holes to increase the supply of saltpeter. Otherwise, it will be difficult to make gunpowder without saltpeter..."

On the first day, Wu Huaiyu basically taught everything he could.

Huaiyu has also explained the key to the next preparation of the medicine. They can just slowly figure out the preparation by themselves.

The old men felt as if their heads were going to explode, but they didn't expect that this master didn't hide anything and taught him all at once.

It was both exciting and a little doubtful.

"The secret method has been taught to you. Next, you can work in groups of two or three, or refine and prepare it individually. As long as you can master the method proficiently, you can develop it and apply it to weapons.

Gunpowder is the foundation, but purification is more important. Although the preparation ratio is also important, the purity will affect the ratio and effect."

Huaiyu left the island in a small boat, and the ten old men stayed on the island, where they wanted to digest the knowledge they had just learned, and also conduct experiments and explore the formula.

No one is allowed to board the island, let alone have contact with them.

Every day, several Shenji Battalion soldiers rowed their food to the shore, and then came back directly. They could not pick it up until the Shenji Battalion soldiers left.

The meals delivered, the lunch boxes collected, etc. must be returned to the designated personnel for inspection.

Huaiyu rowed the boat back to the shore and found that Xu Jizu, a second-pole man, had already bought fishing nets from Chang'an City on horseback. He was netting fish in the water with some Qianqi soldiers. There were also many Qianqi soldiers who took off their clothes and were swimming in the mud in the water.

Dig lotus roots.

"Erlang, we have caught a lot of fish and shrimps in the net, and also dug out a lot of lotus roots. We have fish, shrimps and lotus vegetables tonight. It's great!"
Chapter completed!