Chapter 111: Failed Guncotton

Phew… finally, something of milestone significance has been completed. Xiao Bailang flicked the newly made ceramic vat, and the clear, ringing sound was louder than the bells of heaven. The brothers from the industrial department, who had been eating and sleeping at the kiln for over a dozen days, shed tears—it wasn’t easy. After numerous failures in shaping, drying, glazing, and controlling the firing temperature, they had finally achieved success. Now, they had the basic set of tools for large-scale pickling of seafood, making soy sauce, and producing light chemical products. The future of flush toilets was also in sight.

“The days when our Transmigrator Nation could not produce its own ceramic vats and was completely dependent on the people of the Ming Dynasty are gone forever!” Xiao Bailang declared with a powerful voice by the side of the ceramic vat, striking a pose. Unfortunately, Dingding wasn’t there to capture it on camera.

Although the principle of a ceramic vat is simple, this type of large-diameter, relatively thin-walled pottery is the most difficult to make. The transmigrators had previously made small-caliber ceramic pipes and vats, but they had no experience with such large sizes. In the end, the industrial department consulted countless materials and even brought in all the craftsmen in Lingao who knew how to fire pottery. Only then did they complete the firing of the ceramic vat. This was no simple task. According to the assisting potters, only the kilns near Qiongshan County in the entire Qiongzhou Prefecture had such capabilities. They were also very surprised that it could be successfully trial-produced.

The industrialized basic pottery workshop now had preliminary production capacity. The brick and tile factory itself had all the conditions for making and firing, and a temperature of 800 degrees Celsius was sufficient.

With these large and small vats and pots, the chemical group could finally begin their great process of primitive chemical engineering. Among all the chemical products most urgently needed by the transmigrators, sulfuric acid and nitric acid were the most widely used, especially nitric acid, which was needed in the manufacture of most explosives and pyrotechnics, from the transmigrator’s divine tool, guncotton, to the most dangerous explosives.

To make nitric acid, one must have nitrates. Before the advent of the synthetic ammonia industry, nitric acid could only be made from nitrates. China’s natural nitrate ore deposits are in Sichuan and the northwest, completely absent in the south. They had to rely on collecting niter-rich soil to refine niter. This was a dirty and inefficient job. If it weren’t for the timely shipment of a large amount of saltpeter from the Guangzhou advance station, the chemical department would have been reduced to digging up toilets and pigsties everywhere.

With enough saltpeter—all intended for smuggled export from Guangdong, of very good quality—and a large stock of black powder on hand, all the saltpeter could be used to produce nitric acid.

How to make nitric acid? Almost every transmigrator enthusiast had read “The Mysterious Island” and knew that nitric acid could be made from sulfuric acid. To have nitric acid, one must have sulfuric acid.

Ji Situi thought for a moment. Modern industrial production of sulfuric acid generally comes from three different sources: as a byproduct of the coal coking industry, from sulfur and saltpeter, and from pyrite. The three methods each have their pros and cons, as well as their own primitive process flows, but for the transmigrators at this stage, none were viable—they lacked the raw materials. Fortunately, Guangzhou had already procured some copperas. Although this process had a very small yield, the process was extremely simple and could be done with the laboratory equipment they had on hand.

Extracting oil of vitriol from copperas was the most traditional and simplest method of producing sulfuric acid. The ancients also used oil of vitriol on a small scale, mostly in the field of metal processing. In the late Ming Dynasty, thanks to the introduction of technology from Western missionaries, some people had already produced nitric acid and aqua regia, but the creators apparently did not realize the specific uses of these substances. If given more time, they might have ushered in a new era of Chinese chemistry, but the slave-owner regime, eager to “establish a great unified state,” soon put an end to this possibility.

The dry distillation of copperas had an extremely low yield, producing only about 10% sulfuric acid from the raw material, but it was better than nothing and served as a temporary substitute. This distillation method was highly polluting and somewhat dangerous. The chemical group chose a spot in the Bopu heavy industrial zone with a suitable wind direction and built a factory. They began distillation using the dry distillation method. All participating personnel were issued chemical factory labor protection clothing and masks. A few days later, they had 20 kilograms of concentrated sulfuric acid.

With concentrated sulfuric acid, they could make nitric acid. Using the distillation method again, they added saltpeter to the sulfuric acid and then slowly heated it, using the volatility of nitric acid to obtain concentrated nitric acid. This process released a large amount of heat. The ice blocks made by the Fengcheng Maru’s cold storage were put to proper use for the first time—a mixture of ice and water was used to condense the nitric acid in the retort.

With nitric acid, guncotton, that divine tool of transmigrators, was immediately proposed. Guncotton not only had a greater explosive power than black powder but was also a good propellant.

After the experimental plan was approved, Li Di began to trial-produce smokeless powder—guncotton—for the army. Logically, this was a matter for the chemical group, but the chemical group was skeptical about their ability to produce guncotton. Li Di from the Navy suddenly stopped working on steam engines and volunteered to take on the task of making guncotton—on the condition that once guncotton was mass-produced, the Navy would have priority supply.

He first got a few ceramic vats and the acids and alkalis needed for one production run, along with 15 kilograms of cotton. The caustic soda came from stock and had to be approved by the Planning Committee. Fortunately, explosives were a matter of national importance, and the Planning Committee readily approved it.

Because both caustic soda and nitric acid were corrosive, Li Di put on the chemical-use gloves and apron he had borrowed from Ji Situi.

Guncotton requires very pure degreased cotton. General explosives factories purchase ready-made products, but the transmigrators could only rely on their own manual production.

First was to process the cotton: tear it apart, pick out visible impurities such as small stones and dead leaves. Wash the cotton with water until the runoff is clear. Place the cotton in a ceramic pot, add water just enough to cover it, then add 2%-5% of the water’s weight in caustic soda. Cover and bring to a boil, then simmer for 10 minutes. Cool, rinse with a large amount of water, rubbing for about 10 minutes. Place the washed cotton on clean paper to dry in the sun outside. Then pour the remaining alkaline water into the waste alkali bucket. Begin to prepare the mixed acid for esterification by mixing concentrated nitric acid and concentrated sulfuric acid in a 6:4 ratio. Although it was the dry season in Lingao, the air humidity was still a bit high. The mixed acid had cooled, but the cotton had not yet dried. It seemed that a dryer would be needed in the future. The Eighth Route Army’s military industry used a heated kang for drying, which could be learned.

Li Di placed more than half of the dried cotton into the mixed acid, pressed it down, stirred it, covered it, and looked at his watch. After 10 minutes, he took it out, set it aside, and then put the remaining cotton in. After finishing, he mixed the two batches together.

He poured the waste acid into the waste acid bucket and continued with the stabilization process. It took a full 6 hours to finally produce the first batch of guncotton, but it was still wet. He only dared to air-dry it, and had to spread it out as much as possible, otherwise, there would be trouble.

By evening, he finally had dry guncotton, 16 kilograms of it. Time to take it to the artillery group for testing! They were now practically a weapons research institute.

These days, explosions could be heard from the Bopu shooting range every day, and one could often see Lin Shenhe, Bai Yu, and others, covered in green smoke and with blackened faces, gasping for breath by the river.

Li Di came to the shooting range with the newly made guncotton. Suddenly, he heard a loud bang and saw half of a cannon barrel flying in the air, which gave him a big scare. After a while, he saw Lin Shenhe climbing out of a trench, covered in black soot, nodding repeatedly at the few people who crawled out after him, saying:

“The lifespan of our cannon barrels is even better than we thought.”

Li Di quickly ran over, handed him the guncotton, and said, “This is the guncotton I just made. Please have the artillery group test it. Be careful, the power of this stuff is no match for black powder!!!”

But Lin Shenhe looked puzzled and asked, “Is this strong cotton or weak cotton?”

“Strong cotton?” Li Di was bewildered.

“My god, brother, you don’t even know this and you’re making guncotton?” Lin Shenhe was shocked. “Guncotton with different nitrogen content has completely different properties.”

“I think it should be weak cotton,” Bai Yu said. Although he specialized in weapon manufacturing, he also knew a little about pyrotechnics. “With primitive nitric acid and primitive esterification, it’s difficult to produce guncotton with high nitrogen content.”

“Let’s give it a try,” Li Di said, now a little less confident.

Half an hour later, Lin Shenhe, with a blackened face and a strong smell of gunpowder, found Li Di and said irritably, “That guncotton you made is good for making paint or glue.”

“I made it exactly according to the book!” Li Di shouted. “Standard laboratory procedure.”

“The problem is, it can’t be detonated at all.”

“Probably not enough nitrogen,” Bai Yu said.

“Another victim of Jules Verne’s poison.”

Jules Verne made the process of making guncotton sound very simple, but in reality, it is not easy to make in a simple environment. Especially during the esterification process, it is necessary to accurately control many factors such as the composition of the nitrating agent, reaction temperature, and reaction time to control important indicators such as nitrogen content and viscosity.

Just how difficult was it? The transmigrators’ technical database contained many booklets and books on primitive explosive manufacturing methods, even including primitive methods for making saltpeter and RDX, but there was nothing on guncotton, which shows that guncotton is not an easy thing to make.

Industrially, guncotton is divided into several grades based on nitrogen content: No. 1 strong cotton, No. 2 strong cotton, No. 3 weak cotton, blasting gelatin cotton, collodion cotton, varnish cotton, celluloid cotton, etc. The guncotton made by primitive methods can at most reach the level of celluloid cotton.

“What a waste of so much nitric acid and caustic soda,” Li Di was very annoyed. Chemical products were already in short supply.

“If it can reach the level of celluloid cotton, it would be good to use as a propellant, although a bit poor,” Lin Shenhe thought for a moment. “Wu Yunduo said in his memoirs that when they reloaded bullets back then, they used either black powder or bought scrapped movie film to use celluloid as a propellant.”

“How about we try it as a propellant?”

“It can’t be used like this. It needs to be processed into powder and then pressed firmly,” Bai Yu shook his head. “Let’s store it for now. We’ll mass-produce it later when we have the equipment. We should still ask the chemical department to produce mercury fulminate as soon as possible. Those rifles are no good without it.”

[Note: It is impossible to make qualified guncotton using Li Di’s method. In a laboratory environment, with various analytical grade reagents, it is not a problem to make celluloid cotton. However, the formal production of guncotton is much more complex. In addition to the difficulty of controlling the nitrogen content, the process of removing acid from the cotton is not as simple as washing with water. In the early days, guncotton caused frequent accidents due to incomplete removal of free acid and was completely abandoned by the military.]