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Chapter 286 Alchemy and Smokeless Propellant

Absorbent cotton has better dressing and hygienic effects than ordinary cotton. The principle is obviously because some of the oil and protein components in ordinary cotton are not required for dressing materials.

Grease and protein are easily decomposed and utilized by bacteria, and become the "culture medium and nutrient solution" for cultivating bacteria and viruses. Therefore, medical cotton should be degreased and deproteinized as much as possible, leaving purer cellulose.

However, the cotton requirements for making nitrocellulose are obviously different from those for medical cotton.

Some of the ingredients that are removed from medical cotton are needed when making nitrocellulose.If you take it off too clean, it will cause the reaction to fail.

Therefore, when Fang Yizhi came up with medical absorbent cotton, Shen Shuren was grateful for this invention, but also had more hidden worries, thinking that the research and development of nitrocellulose had temporarily fallen into a wrong path.

Fortunately, Fang Yizhi knew him too well, just by looking at the changes in his expression, he knew what he was depressed about. Originally, Fang Yizhi wanted to make a fool of himself, so now he directly confessed:
"My dear brother is very knowledgeable. Don't you know that medical cotton and nitrated cotton have different requirements for raw materials?"

When Shen Shuren heard the words, he couldn't help being overjoyed, and had a bit of anticipation: "Why did you say 'also'? That means you already knew it? Mr. Song also knew it? Could it be that you have produced both kinds of cotton?"

Only then did Fang Yizhi show a smug expression: "That's natural, and it's not difficult. When dealing with absorbent cotton, maybe too much lime-alkaline surface was used, and the things that came out did lack a lot of useful ingredients.

But since we know the truth, and also know that the scholars of the Hongmao Yi people have used this idea to create gun cotton, we can try and modify it repeatedly. Can we still figure it out for a few months? "

Shen Shuren finally felt a little awe-inspiring: This Fang Yi is very wise, he was instructed by himself, did he realize that he can understand the basic principles of acid-base balance, and have a glimpse of the chemical common sense of acid-base balance.

Even if there is no breakthrough in the research and development of new gunpowder this time, it will definitely be of great help to the development of chemistry in this era based on this experience alone.

He still couldn't wait to ask: "So... You finally tried it out, which kind of pretreated cotton is suitable for acidification? Then how did you do the experiment, did you come up with the kind of cotton made with saltpeter? strong acid?"

Fang Yizhi didn't speak, just smiled at Song Yingxing next to him, and first showed Shen Shuren a little of the mysterious finished product.

It was some grey-yellow powder, slightly darker in color, but definitely not burnt black, not quite what Shen Shuren imagined.

It may also be that Shen Shuren did not learn chemistry well in his previous life, or he had seen the primer powder removed from the bullets of modern guns in his previous life, and knew that they were all black, so he mistakenly thought that nitrocellulose was also black.

In fact, nitrocellulose is grayish-yellow, which is not exactly the same color as the primer of modern bullets. Modern primers are also mixed with some other ingredients.

On the other hand, in the early production of nitrocellulose, if black appeared, it was generally because the reaction was too violent, the control of heat and heat dissipation was not good, the temperature rose and carbonized, and impurities were mixed in.

The nitrocellulose displayed by Fang Yizhi at this moment is obviously not pure, and with the level of technology in the late Ming Dynasty, it is impossible to make too pure.

Shen Shuren held it in his hand and carefully observed it, but he couldn't tell if it was true or not, so he had to ask someone to take some of it and put it into the bullet for test shooting.

Fang Yizhi was also prepared, and immediately asked someone to bring a revolver produced by the Daye Military Factory, as well as a breech-loaded short-barreled double-barreled gun, and then demonstrated it on the spot. The powder in the gun was changed from black gunpowder to this kind of grey-yellow powder, and finally it was handed over to a guard next to Shen Shuren to shoot a test shot.

Shen Shuren watched the whole process with full attention, until the moment when he fired at the end, under a few roars that were slightly different from black powder, some white smoke drifted away, but it was definitely much smaller than the smoke of black powder.

Moreover, the flame of open flame is also smaller than that of black powder, and the muzzle flame of the gun is much shorter and faster, and the flame can be seen, but it is definitely not the way that black powder sprays fire directly.

All this shows that the new charge is much stronger than black powder in terms of deflagration rate and gas expansion rate, so that it can deflagrate so fully and completely in an instant.

Obviously, as a new type of propellant, this grey-yellow powder is very qualified.There is still a small amount of smoke remaining, which should be due to insufficient purity, poor control during the reaction, and impurities mixed in by carbonization.

These problems are not big, and it is acceptable to give it a few months or even a year and a half to slowly optimize and improve, or even continuously learn from experience in actual combat use, and make feedback and changes while using it.

Shen Shuren was just curious: where did Fang Yizhi and the others get the concentrated nitric acid?

Adding nitric acid to cotton is a step that everyone on earth knows, but nitric acid itself was not easy to do in ancient times.

……

A quarter of an hour later, in the laboratory of the Gunpowder Bureau, everything finally came to light and the mystery was revealed.

And Shen Shuren also had to admire that the ancients were actually good at chemical practice, what was lacking was only a systematic theoretical summary.

While showing him a bunch of experimental equipment, Fang Yizhi threw him an ancient book in a showy manner.

"This is the notebook of Tang Dynasty genius doctor Sun Simiao. It can be regarded as a remnant of Qianjin Fang. It mainly records Sun Simiao's verification of the actual medicinal value of a part of the minerals that Ge Hong used to make elixirs in the Eastern Jin Dynasty.

This was found by Mr. Song. At the beginning, you mentioned that a new kind of acid should be made from saltpeter and other strong acids. After Mr. Song tried it for a while, he suspected that the acid used by the Hongyi people you said was saltpeter and green acid. The product of the alum oil reaction.

Green vitriol oil was recorded by Ge Hong in the Eastern Jin Dynasty, but he didn't say how to make green vitriol oil, how to get it, only said that there is such a thing, which is hard to come by.

Tang Sun Simiao went a step further and wrote in the prescription notes in the medical books that green vitriol was calcined, adding some other vitriol to absorb the essence of the burning, and green vitriol oil could be obtained, so Mr. Song and I explored according to this idea.

At the beginning, I tried dozens of times, but I couldn’t figure it out, and I couldn’t do it. Later, I found that there seemed to be ancient and modern records of "green vitriol" and "green bile vitriol". There are many differences in cognition, so I found many sources. Green vitriol, and minerals similar to green vitriol, were calcined and compared with their products, and only then did we know where the misunderstanding between Sun Simiao and Ge Hong was——

Green vitriol and green bile vitriol in the world should not be just one kind of thing. Some green vitriol fumes can be obtained after being calcined, but some can’t be burned at all, or the poisonous gas that is burned out is only similar to the smell of ordinary sulfur burning. , and can not burn out green vitriol fumes.After trial and error, we found a green vitriol that can be used—I also decided to distinguish green vitriol from green bile vitriol and record it.Green vitriol and bile vitriol should be completely different things, some bile vitriol is green, but it is mixed with impurities. "

After hearing Fang Yizhi's analysis, Shen Shuren was really in awe.

Rao had studied middle school chemistry in his previous life, and it took him a while to confirm Fang Yizhi's discoveries one by one in his mind.

The green vitriol and green bile vitriol mentioned by people in the Ming Dynasty should have ferrous sulfate and copper sulfate with impurities-pure copper sulfate crystals should be water blue, which is known to those who have studied chemistry in junior high school, but natural Copper sulfate is easy to mix with impurities, especially yellow impurities such as natural sulfur. It is normal for yellow and blue to turn green after mixing.

So much so that in the Tang, Song and Ming dynasties, the ancients did not know that ferrous sulfate and copper sulfate containing sulfur impurities were not the same thing.When those alchemists burned green alum and gallbladder alum, the products they burned were different every time, and they couldn't explain it themselves.

From Ge Hong, a great alchemist in the Eastern Jin Dynasty, to Sun Simiao, a genius doctor in Tang Dynasty, they all recorded the calcining of these alums, but they didn't know that they were burning several different things.

Of course, ferrous sulfate can be calcined to produce sulfur trioxide gas, and then absorbed by a special process, sulfuric acid can be obtained, which is the "green vitriol oil" recorded in ancient books.

With sulfuric acid, it is easy to produce nitric acid. Take sulfuric acid and saltpeter or other nitrates to react directly. It is best to produce sulfate precipitation, so that the rest is nitric acid.

The specific process is somewhat complicated, but after all, it is a technology that the ancients have mastered, so there is nothing to repeat. The most critical step is to produce sulfuric acid out of nothing in an environment without strong acid.

Shen Shuren was originally limited by his thinking, because the modern industrialized large-scale production of sulfuric acid basically burns sulfur dioxide directly with sulfur, and then adds a certain catalyst to further oxidize it to sulfur trioxide, and then absorbs it.This is very efficient, and the raw materials used are cheap, and sulfur is everywhere.

Even in modern industry, in order to control the excessive emission of sulfur dioxide, many factories with sulfur-containing waste gas directly add catalysts in the waste gas treatment process to oxidize it into sulfur trioxide and then absorb it into sulfuric acid.Sulfuric acid is directly the product of environmental protection waste gas treatment, and it is so cheap that it is unnecessary.

But Shen Shuren traveled back to the end of the Ming Dynasty, and he couldn't simply come up with the operation of "further catalytically oxidizing sulfur dioxide gas into sulfur trioxide", so he couldn't think of how to industrially produce hexavalent sulfur and sulfuric acid.

Unexpectedly, Fang Yizhi and Song Yingxing didn't think about "industrialized mass production" at all. He chose to directly calcinate sulfur trioxide gas from the hexavalent sulfate readily available in nature, and then absorb it into sulfuric acid.

The advantage of this is that you no longer have to worry about how to catalyze the reaction of tetravalent sulfur into hexavalent sulfur. The sulfur in sulfate itself is hexavalent.

The disadvantage is that it puts forward very high requirements on the production raw materials - if industrialized large-scale production is used, it is required to directly produce sulfuric acid with sulfur or even sulfur-containing waste gas, which is extremely cheap.Now they are looking for ferrous sulfate minerals, and the raw materials are not known how many times more expensive.

It is impossible to count on the small output of ferrous sulfate calcination to supply large-scale propellant for musketeers.At most, it can only supply the elite troops of the most direct lineage, or personal guards.

Shen Shuren briefly asked about the cost of this sulfuric acid, and it was indeed very expensive, more than ten times more expensive than burning sulfur directly.In other words, the cost of sulfide used is at least ten times more expensive than the sulfur used in black powder.

In terms of the cost of using nitrate, it is at least several times more expensive than the saltpeter used in black gunpowder. Anyway, because of the complicated reaction process in the middle, the rate of nitrate participating in the reaction is relatively low, and every reaction has losses.

On the whole, the current manufacturing cost of this nitrocellulose smokeless gunpowder is about eight to ten times that of black gunpowder!
In the future, if it is possible to directly use sulfur-containing waste gas or sulfur to burn sulfuric acid, and improve the utilization rate of nitrate, then the cost can be reduced to one-third or even one-fourth under the current state.In that case, the production cost is still two to three times that of black powder.

"It doesn't matter, although it is a bit expensive, it is a good thing to be able to make things first. Craftsmanship and cost reduction can be found slowly. This batch of gunpowder should be used by my guards first.

At present, all of them will be used by the revolver team. After all, the revolver is the most precise and has the highest requirements for the control of propellant residue and leakage. In the future, if there are cheaper ones, they will be used by the long gun team. "

Shen Shuren quickly thought of how to deploy this new type of propellant.

(End of this chapter)