Li Zhi looked at the vat of alum oil and nodded. Cao Shoudao took out a scrap iron stick from the room www.biquge.info and put it into the green alum oil. After a while, tiny bubbles popped up from the iron rod, and the colorless alum oil turned light green.

Li Zhi knew that this was the reaction of dilute sulfuric acid and iron to produce ferrous sulfate and hydrogen. Of course, there is also a large amount of sulfurous acid in this alum oil. However, sulfurous acid is not stable, as long as it is left for a period of time, sulfurous acid will be oxidized to sulfuric acid.

With sulfuric acid, Li Zhi was able to make nitric acid, Li Zhi was happy in his heart, and said: "Daochang Cao, how much silver will you sell me for this set of technology?" ”

Cao Shoudao said: "Uncle, my set of things looks simple, but in fact, the effect is not small, not an inch of green alum is wasted, and not a trace of green alum oil is leaked." This is a skill passed down from the ancestors, if the uncle wants to buy it, I will sell it to the uncle for a hundred taels. ”

Li Zhi blinked, and secretly said that this Taoist priest was really good at trading. In the past, the equipment for refining mercury was sold to himself for 100 taels, and the technology of alum oil was 100 taels. Li Zhi licked his lips and said at a counteroffer: "Dao Chief, this equipment looks far less complicated than the set of mercury, how can it be sold for a hundred taels?" ”

Cao Shoudao stroked his beard and groaned, and said for a long time: "Eighty taels!" Eighty taels were sold to the uncle. It can't be less, and if it's less, I'll be sorry for the teacher. ”

Li Zhi smiled and killed Cao Shoudao for a few more words, but Cao Shoudao bit eighty taels and didn't let go. Speaking of which, Cao Shoudao helped Li Zhi solve the source of sulfuric acid, and the credit is not small. Li Zhi had no choice but to pay eighty taels to this Taoist and buy his technique.

Cao Shoudao got the silver, so he handed over the set of jars and jars to Li Zhi's guards. Everyone took Cao Shoudao back to the General Soldier's Mansion, Cao Shoudao instructed Li Zhi's guards in the backyard of the General Soldier's Mansion, built a small earthen stove, and taught the guards how to use it and precautions.

Li Zhi stood aside and listened for a while, only to realize that there are many famous names here. There are several points on how to heat the crucible, and if there is no one to guide you to figure it out on your own, I am afraid it will take several months and burn out countless raw materials and equipment to find out.

These eighty taels of silver are not too tricky.

Li Zhi's personal guards finished learning Cao Shoudao's techniques, operated them several times on the spot, and confirmed that they had learned it, and then Cao Shoudao left the General Military Mansion with a whisk of dust.

With dilute sulfuric acid, Li Zhi is about to start making concentrated sulfuric acid. Nitric acid can only be made from concentrated sulfuric acid when concentrated sulfuric acid is obtained.

It is also quite difficult to make concentrated sulfuric acid from dilute sulfuric acid. Because sulfuric acid cannot be purified by simple distillation. To purify sulfuric acid by distillation, it must be distilled under vacuum pressure. Vacuum distillation requires vacuum pumps or similar equipment, which is simply not available to Li Zhi now.

However, Li Zhi played with sulfuric acid before crossing over. At that time, the government controlled the concentration of sulfuric acid and did not allow stores to sell concentrated sulfuric acid, and only 70 percent of the sulfuric acid was sold. At that time, in order to purify sulfuric acid, Li Zhi studied many methods, and finally found that the simplest and easiest purification method was electrolysis of dilute sulfuric acid.

The so-called electrolysis of dilute sulfuric acid is actually the electrification of dilute sulfuric acid. When the sulphuric acid solution is electrified, the water in it is electrolyzed into hydrogen and oxygen, and the sulphuric acid is preserved. After being energized for a long time, dilute sulfuric acid becomes a high concentration of concentrated sulfuric acid.

Li Zhi had already made a simple generator before, and this time the generator came in handy.

However, to decompose the water in dilute sulfuric acid, a high-power generator is required. This kind of power cannot be achieved by manpower, and the generator needs to be rotated by a steam engine. This time, Li Zhi made a large copper coil, and the copper wires were all insulated with a thick layer of tree paint, driven by a steam engine, and placed in two large magnets.

Li Zhi found a few graphite crucibles for steelmaking, and cut two pieces of graphite from them to make electrodes. The two electrodes are connected to the two poles of the generator and placed in a dilute sulfuric acid solution.

As soon as the steam engine starts, the coil is driven by the steam engine to rotate at high speed in the magnetic field, generating electricity. The power of this steam engine is still quite large, and the current generated is not small. As soon as the two graphite electrodes are placed in the dilute sulfuric acid solution, the solution seems to boil, and large bubbles continue to emerge.

After half an hour, a porcelain basin of dilute sulfuric acid the size of a basin was electrolyzed into a small half basin of viscous liquid.

Li Zhi took a small wooden stick and plunged it into the viscous liquid, and the small wooden stick was corroded into charcoal in an instant. Obviously, this is the concentrated sulfuric acid that Li Zhi needs.

Concentrated sulfuric acid is considered to be done.

After the concentrated sulfuric acid is made, it is also necessary to make nitric acid from concentrated sulfuric acid, so that nitric acid can finally be used to make new gunpowder.

With sulfuric acid, making nitric acid is easy to say. As long as saltpeter and concentrated sulfuric acid are slightly heated together, nitric acid gas can be obtained. When nitric acid gas is passed through cold water, nitric acid dissolves into the water, gradually forming a high concentration of nitric acid solution.

However, Li Zhi had never made nitric acid before crossing, and only knew the principle and equation of the reaction. The first time saltpeter and concentrated sulphuric acid were heated in a closed crucible, the result was a pot of viscous liquid. Li Zhi was stunned at that time, and the nitric acid should not be viscous.

As a result, the platoon commander of the personal guard named Zhang Yu, who was doing chores for Li Zhi next to him, said: "Uncle, I'm afraid that the fire is too fierce and the sulfuric acid has been burned into water vapor." This sticky pot is probably still sulfuric acid. ”

Li Zhi reacted at this time, and the dark passage must have been boiling before the sulfuric acid and saltpeter had time to react.

Li Zhi didn't expect that the platoon commander of the personal guard who was doing miscellaneous work for himself would be so smart, and he would figure out what sulfuric acid was so suddenly, and he thought faster than himself.

"How do you know it's sulfuric acid? Do you know what sulfuric acid is? ”

The platoon commander of the personal guard said calmly: "Hasn't Uncle been talking to Daoist Cao about sulfuric acid, sulfuric acid." Sulfuric acid is this sticky alum oil, and I understand it! ”

Li Zhi looked at this smart guard platoon commander at that time, and secretly said that this Zhang Yu is so clever that he can be of great use. However, it was not used in the preparation of this new type of gunpowder. The preparation of this new type of gunpowder Li Zhi is still ready to be kept secret, this Zhang Yu is so smart, he can see it when he looks at it, Li Zhi can't keep it secret.

Li Zhi waved his hand and said, "Zhang Yu, you go back to the barracks, I don't need you today." You call that slow-headed Xiao Yuke and ask him to give me a hand. ”

Zhang Yu was stunned, and he didn't know why his uncle didn't let him do chores. He also wanted to take the opportunity to get acquainted with his uncle, so that he could get a greater chance of effectiveness in the future, but he didn't expect the opportunity to be lost all of a sudden. Did you say the wrong thing yourself?

Zhang Yu hurriedly agreed, walked down with some disappointment, and called another guard platoon commander over.