Coarse salt purification is one of the key questions for the chemistry experiment in the middle school entrance examination. Li Mu still remembers that when he took the high school entrance examination, there were three questions in total, namely the redox reaction of copper, oxygen production and coarse salt purification. The question he chose was coarse salt purification.

In later generations, no one knew the methods that any junior high school student who passed the chemistry energy mastered in the Tang Dynasty. This should be considered a basic benefit for time travelers. From this, we can conclude that it is still useful for young people to study hard, and maybe one day you will travel through time.

If you learn mathematics, physics and chemistry well, you will not be afraid of traveling all over the world. This sentence really makes sense, especially after traveling through time, talents who study mathematics, physics and chemistry can prosper without a system.

It is normal that even junior high school students in later generations learn mathematics, physics and chemistry knowledge are all basic disciplines formed by the explosion of modern science and the great integration of the world. Even any theorem may be the research results of the life of predecessors. In the times, it is a great change. After traveling through time, it is equivalent to bringing this change forward. How can it not be prosperous?

Rock salt, also known as stone salt. It is a special kind of stone, transparent or translucent, easily broken, and looks a bit like rock sugar and is good partners with chlorides. They were all formed by the evaporation and crystallization of sea water or lake water tens of millions of years ago.

The poison of rock salt comes from its associated chlorides and sulfides.

The first step in preparing fine salt is to get the chloride out of the rock salt. According to the method in the "Basic Operation of Junior High School Chemical Experiment", a qualified filter is made and a set of filter devices are installed. The rock salt is crushed and dissolved in water. Filter out large pieces of impurities such as silt and sand to obtain coarse brine.

The second step is the key point. At different temperatures, the solubility of different substances is different. At 20℃, the solubility of magnesium chloride is greater than the solubility of potassium chloride and sodium chloride. Therefore, by adding an appropriate amount of water to the mixture at room temperature, most of the magnesium chloride can be dissolved in water, so that magnesium chloride can be separated and removed. At 27℃, the solubility of potassium chloride is less than the solubility of sodium chloride. Adding appropriate amount of water to the remaining mixture for the second time can dissolve sodium chloride sodium chloride in water, thereby obtaining crude potassium chloride. The crude potassium chloride is further crystallized and recrystallized to obtain refined potassium chloride, thereby isolating potassium chloride.

The rest is a mixed liquid of sodium chloride and some sulfides.

Then to the third step, calcium carbonate (limestone) and alkali (wood ash) are added to the obtained liquid, and react with the sulfide in the solution, so that the brine can be precipitated to purify and remove the sulfide. The liquid obtained after this step is a pure and non-toxic brine solution.

Finally, when evaporates and crystallizes, the result is fine salt. This used to be a very expensive step, but now with coal as fuel, it is not a problem at all.

Li Mu divided the entire process into three parts and handed it over to the three families. The Changsun family learned to remove chlorides, the Dugu family learned to remove sulfides, and the Yuchi family learned to make a complete set of instruments, including filtration devices, assembly lines, etc. The subtleties required tricks and could not be imitated by thinking about them.

After Li Mu taught the craftsmen of the Yuchi family, it was almost noon. Li Mu did not plan to invite him to dinner, so he took him off without hesitation.

"Mr. Marquis, please wait!" Changsun cried to his own craftsman for a few words and called Li Mu. Li Mu turned around and looked at him and said, "What else does the prince have to do? I have taught you the secret method. I have said that I will not serve food, why is it not over yet? Is it up to me?"

"It's not a matter of food," Changsun cried out. "Marty, it seems that there are some differences. My craftsman just told me that you only seem to have taught half of what he has learned, but you can't make fine salt."

Hearing this, Dugu Xiude and Yuchi Huan also quickly asked their craftsmen. The answers they got were the same as those of Changsun Chong. Their craftsmen had only learned a part of them. The most miserable thing in the Yuchi family was that they simply learned a lot of carpenter work, which had nothing to do with salt making.

The three families suddenly felt like they were deceived.

Li Mu sneered and said, "Didn't I follow your wishes? You three companies ignore my words and have their own thoughts. They say that the company is one, but in fact, they are doing their own calculations and want to cheat the secret method of salt making from me. They plot against me? Just you?"

The three of them were embarrassed, and Changsun rushed over and said, "Marty, we are wrong, but you agreed to the secret method, and Your Majesty also gave the order. I'm afraid you're so perfunctory, right?"

"Where am I perfunctory? I am a person who says one is one, two is two. Once I say it, I will do it. I divide the secret method into two parts and teach you the Zhang Sun family and the Dugu family respectively. I teach you the manufacturing method of the equipment required for salt making to the Yuchi family. Isn't this a teaching?" Li Mu looked at the three of them sarcastically and said, "As long as you work together, fine salt can be made. Or, you really want to know the secret method. Tell each other calmly, and you all know it, so don't ask me."

After saying that, Li Mu made a 'please feel free' gesture, turned around and left.

The three of them were blushing and were ashamed. They had already said this, and if they provoked Li Mu, they would definitely turn against each other. The three of them left in disappointment. As for how they discussed, Li Mu would ignore it. If they really exchanged secret techniques with each other and got the complete one, they would do whatever they wanted. Originally, Li Mu would have to hand over the complete one to them, and doing this was to disgust them.

The three left the Zhulu Marquis' Mansion and did not rush to go home, but came to the Duke of Zhao's Mansion. They could not make up the decision about what happened today, and they had to be the head of the Guanlong nobles, Changsun Wuji.

After hearing the whole story, Changsun Wuji's face darkened. He looked at Changsun, sighed, and said, "Chong'er, you are very disappointed to be a father."

Changsun was sweating profusely in cold sweat and bowed, "Father, the child knows his mistake."

"Where are you wrong?"

"This..." Changsun Chong didn't know how to answer, and his head lowered.

Changsun Wuji said, "Li Mu is a good man. Yuan Tiangang said that he is a reincarnation of an immortal and a person with the wisdom of the past. How can he deceive him? If you have the ability to make him unable to find it, it is your ability to enter the jar. But if you don't have this ability, you should be honest and don't be clever."

Although Changsun Wuji was scolding Changsun Chong, Dugu Xiude and Yuchi Huan listened and seemed to be scolding themselves, and they were all very embarrassed. Dugu Xiude, relying on his generation to be with Changsun Wuji, interrupted: "Auxiliary Machine, now is not the time to scold children. You can make a decision. What should we do now?"

Changsun Wuji sighed again and said, "What else can be done? According to the regulations set by Li Mu, build a yard along the river in the suburbs. While picking salt, it is time to make salt, and strive to complete it within March and start selling it after the New Year."

"Auxiliary machine, what I'm talking about is the salt making method..."

Changsun Wuji interrupted Dugu Xiude and said, "Brother Dugu, it is useless to say too much about this. Who do you think the three families will be willing to hand over the secret method you have learned?"

Dugu Xiude was asked in one sentence.

Although the three families are all Guanlong nobles, Guanlong nobles are originally a loose alliance. Everyone has their own thoughts due to the situation, interests, etc.

Now the three families have learned part of the salt-making method. Who is willing to take it out? I took it out, what if you don’t take it out? I haven’t tried it, who knows the true or false? If I took it out, what you took it out is fake, wouldn’t I be thrown out? Even if there is a contract as a guarantee, in the face of huge interests, if anyone can’t protect it, then someone will risk the ancestral grave explosion and tear up the contract, it is not impossible to do it.

When Changsun Wuji saw Dugu Xiude, he said, "For the sake of our current plan, let's do our own job. Just follow the part you learned, and first test whether Li Mu's salt making method is easy to use, and then talk about other things!"

The three of them nodded, and there was no other way to do this in this situation.

Just as they were discussing, the whole Chang'an City became lively.

The people of Chang'an City are already accustomed to obtaining information through the Tang Dynasty Daily. People who are illiterate will also surround the "newspaper" on the streets and alleys to hear him talk about the latest news in the newspaper.

There is also a newspaper reader at Xishikou. When he got the Tang Daily today, he suddenly found that there were two newspapers today.

Usually, there are only one picture, and rarely two. So far, there are several times, either when Li Mu was arrested, to counterattack the Shandong gentry and publish one picture, or when introducing the four algorithms, in the days, special things happen.

There was one more picture today, why? He went over the first picture and looked directly at the second picture, and his eyes widened.

Many of the vendors in the West City were illiterate and came to him to read newspapers every day. When he saw him from afar, he asked what was the big deal.

"Marquis Zhulu has paid for it!"

"What?" / "What?"

The newspaper reader waved the newspaper in his hand and said, "Look, there are puzzles and maps here. You can guess the location of the treasure by finding clues. Go and buy newspapers. You can guess the questions that you can read illiterately, and read pictures that you can't read. If you are too late, the treasure will be gone!" After that, the newspaper reader ran away. He just saw that a place where the clues were hidden was in the West Market, and he was afraid that others would take it first.

"What baby?" / "What are you giving?"

When everyone was headless, the owner of a cloth shop next to him ordered the newspaper. When he heard the newspaper's call, he hurriedly picked up the newspaper to read. When everyone saw it, they gathered and blocked the door.

"Shopkeeper, tell me what kind of treasure is there? Don't run away. If you don't explain clearly, we can't let you go out!"

"Oh!" The shopkeeper stomped his feet in a hurry and cursed: "Zhi Mom, you guys! Okay, let me tell you that the baby is money, at least ten cents! Whoever finds it first will belong to whom!"

"Tianguan? Then what else to do? Look for it!"

Some people were also more rational and shouted, "Don't listen to the wind and rain, can it be true!"

"I see you are from another place! I'll ask who Zhulu Hou is first. I'm too lazy to tell you, let's go buy newspapers... Well, there's a newspaper seller over there! The newspaper seller, stop!!!"
Chapter completed!