Production safety is Ji Situi's biggest headache. Accidents in chemical plants are no different than those in ordinary companies: worker casualties are not counted, equipment will be damaged, and the dire consequences of chemical leaks are even more difficult to predict. These former farmers have little regard for dangerous goods.
His attitude was really too much for him - he conducted several production safety educations and scolded a few guys who didn't wear protective clothing as required.
A few unlucky guys stood dejectedly and were scolded by him for a full half hour. Considering the high weather conditions, standing next to the stove with full protection was indeed torture. Fiberglass trousers, rubber aprons, and long arms
Gloves and high boots are both airtight, and even if you don't work near the stove for a few minutes, you will be sweating profusely.
"Do you want to be like him?!" Ji Sidui took out a medical atlas - he got it from a big book. The photos in it were all of patients with chemical burns.
However, the effect of the photo was so horrific that it had the opposite effect. Several indigenous workers came to beg him and said they no longer wanted to do this work. Ji Sixui was so angry that he became angry.
After some consolation, making wishes, and threatening to send him to the labor camp to taste the legendary Fu Youdi's whip if he didn't work, he finally calmed down the people in the sulfuric acid workshop, and production returned to normal. Only then did Ji Sidui get out.
I came and rushed to the caustic soda workshop. Outside the workshop, there were already piles of large and small water tanks, as well as a large amount of salt. Bingfeng was leading people to install the equipment.
"We have salt, tap water and water tanks. Since the project is not finished yet, let's prepare saturated salt water first," said Bai Yu, who volunteered to bring students to help. Although he became a teacher, he was also a chemistry enthusiast.
"This salt is not good." Xu Yingjie shook his head, "Coarse salt! There are too many impurities."
The principle of electrolyzing salt to make caustic soda is very simple. It directly electrolyzes saturated salt water and decomposes sodium hydroxide, which is the so-called caustic soda. It can also decompose chlorine and hydrogen. However, the salt sent from Yanchang Village has not been
Refined coarse salt contains not only sodium salts, but also various impurities such as potassium salts, magnesium salts, and sulfates. The impurities will affect the decomposition efficiency during production and damage precious electrodes.
Therefore, before electrolysis, the coarse salt must be processed and refined first to remove impurities and turn it into a pure saturated solution of sodium chloride before it can be put into production. Modern time and space have an industrial system with a highly developed division of labor, and the caustic soda industry can completely purchase refined sodium chloride solutions.
Sodium chloride finished products. Here, everything has to be done by yourself. The more backward and primitive the industry is, the more things you need to support yourself.
Ji Situi first analyzed the salt delivered. The salt in Yanchang Village was of high quality and contained very little sulfate, which has the greatest impact on electrolysis. This was good news for him: removing sulfate is an industrial practice.
Use barium chloride - he doesn't have this stuff, and barium chloride is a highly toxic chemical. Even if it can be synthesized, he doesn't want to make it. As for calcium salt, the content of magnesium salt is not high, so it is an ideal industrial salt.
He asked people to pour baskets of coarse salt into the sedimentation tank, and after adding water until it was saturated, Bai Yu, who was responsible for refining the electrolyte, brought soda ash and caustic soda, and added them in proportion according to the tested brine composition.
After the calcium salt and magnesium salt react chemically with it, calcium chloride and magnesium hydroxide are precipitated. The above clear liquid is the saturated sodium chloride solution used for electrolysis. Because caustic soda and soda ash have been added, it is necessary to
Neutralize with a small amount of dilute hydrochloric acid.
Electrolysis of salt during production is a continuous process, and saturated sodium chloride solution must be continuously replenished into the electrolytic tank. Therefore, the refining of salt water is continuously carried out throughout the electrolysis process.
The intermittent refining method using one cylinder per cylinder is easy to operate and has simple equipment, but it is too labor-intensive and consumes too much manpower. Generally, continuous refining is used in industry. Although Ji Situi's method is an indigenous method,
We decided to automate production as much as possible.
Based on his own conditions - with tap water supply - Ji Sidui decided to use continuous operation in the salting stage during formal production. Water flows from the bottom of a special salting tank, through the salt layer in the tank, and from the upper part of the tank.
The outlet overflows. Salt is added intermittently by manpower to maintain a certain salt layer. The brine produced is saturated brine, which is introduced from the salt tank to the sedimentation tank for neutralization treatment.
In order to reduce labor intensity, the position of the brine tank is made into a ladder shape, one is higher than the other, so that the position difference and the siphon principle can be used to transport brine. From low to high, they are the salt tank - the sedimentation tank - the neutralization tank.
Finally, the saturated sodium chloride solution flowing out of the neutralization tank is fed into the heating tank.
This system is simpler than those used in industry and does not require any mechanical assistance. A small amount of manpower is enough.
"To make caustic soda, you actually need to add caustic soda!" said Bai Yu, who led students to handle the salt water.
Xu Yingjie said: "These are two different things. You are making refined brine, but it is completely different from making caustic soda."
Bai Yu said: "Fortunately, we also brought a lot of chemical products, otherwise without them as a 'lead', wouldn't it be impossible to start work?"
"It's not that serious." Ji Si retreated and said while paying attention to the reaction in the tank. "It will only damage the electrodes. It is not impossible to just physically refine sodium chloride. But it requires a lot of investment, and it has to be directly transformed.
Salt industry equipment in Yanchang Village begins."
"The salt industry equipment in Yanchang Village has been improved a lot."
"The renovation project carried out by Wang Gong was mainly aimed at increasing production. The windmill he built was used to lift the brine and dry it, shortening the concentration time of the brine." Ji Sidui visited the Yanchang Village several times because of business relationships.
"When it comes to refining, it's impossible without a boiler." Ji Sixui continued, "The Planning Commission originally said that we would build a refined salt plant in Bopu. As soon as our caustic soda plant is put into operation, this project must be launched.
"
"The construction of the chemical industry is booming!" Xu Yingjie said with emotion.
"It's the turn of the chemical industry. Think about it: pesticides, fertilizers, explosives, and medicine. Once these four magic weapons come out, they won't dominate the world!" Bai Yu said with great interest.
"It's still a long way off, don't even think about becoming fat in one bite." Ji Situi said, "There are still many supporting facilities and equipment needed in the chemical industry. Practical problems in production must be solved slowly. Let's talk about the first batch of sulfuric acid plants.
The sulfuric acid produced has a very high impurity content, which is very dangerous in certain chemical productions. But to improve the purity, many conditions must be met."
He compared it, "This is like a puzzle piece. After making three acids and two bases, we have just found the four corners of the puzzle and saw hope, but it will take a long time to actually piece together the complete pattern."
time."
Xu Yingjie commented: "This is like someone trying to use glycerol made by saponification method to mix nitroglycerin. The theory is correct, but in fact it will kill you."
The entire brine reaction and precipitation process lasted 24 hours. Ji Sidui took people to the lime kiln. Quicklime was already prepared here. Based on the data in the process manual, he calculated how much chlorine would be produced in 72 hours of continuous production.
How much hydrated lime is needed to absorb it? Weigh a sufficient amount of quicklime, and then slowly spray water on it to make it digest slowly. After the digestion is completed, let the workers sift the slaked lime, and then put it in a basket and transport it to the caustic soda workshop.
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Ji Situi asked Xu Yingjie to measure the moisture content of slaked lime. It was about 3%. This ratio was a little too high, so he asked people to pile the slaked lime in a shed and store it for a few days. There was still some quicklime in the slaked lime to allow the moisture to escape.
Continue to digest the lime so that the moisture content will drop below the appropriate 1% after a few days.
After everything was ready, a large amount of white sediment had been deposited in the brine refining tank the next day. The above clarified liquid was extracted and the test results showed that it met the requirements of electrolysis. Baiyu used the siphon principle to purify the clarified sodium chloride
The saturated solution was pumped to the heating tank, and Ji Sidui set up firewood under the heating tank to heat the brine to 70°C. The purpose of heating is to remove carbon dioxide from it.
The white sediment in the sedimentation tank is collected, the main components of which are calcium chloride and magnesium hydroxide. Both are useful chemicals and cannot be easily discarded. Especially calcium chloride, pharmaceutical factories can use it to make
Calcium chloride injections and tablets can treat various diseases caused by low calcium. In industry, it can be used as a commonly used desiccant, antifreeze in the construction industry, as a refrigerant for refrigeration equipment, to deink waste paper... and finally...
Can be used to order tofu.
Ji Situi used their different solubility in water to separate them - calcium chloride is easily soluble, while magnesium hydroxide is insoluble in water. Add water to dissolve the calcium chloride and then pour it out for separate disposal. The insoluble part
It is magnesium hydroxide. Although magnesium hydroxide is not so versatile, as an alkali salt, it can replace caustic soda and lime as a neutralizing agent for acidic wastewater; it can be used as an oil additive to play anti-corrosion and desulfurization effects;
It is an insulation material and acts as a building flame retardant. It is also an excellent desulfurizer, which is exactly what is needed in the exhaust duct of Ji Situi's sulfuric acid workshop, which can effectively purify polluted gases in the acid making process.
The heated sodium chloride is easily pumped into the electrolytic tank and filled up. Ji Sidui pulled the switch, and the entire electrolysis process started automatically. He wore a set of anti-electricity labor protection clothing and anti-electricity rubber-soled shoes.
I used a test pen to measure the surroundings of the electrolytic tank and the floor of the workshop - there was no leakage of electricity.
The electrolyte began to flow out of the outlet. The color was clear and no terrible black liquid came out. He waited silently for five minutes to calculate whether the flow of electrolyte was normal. Finally, he measured the temperature and voltage in the tank.
―Everything is normal. Whether the temperature and voltage are normal determines the electrolysis efficiency in the tank.
"Is the caustic soda solution that came out?" Bai Yu asked.