The Iron Age is a hurdle that no civilization can get around. Pen, fun, pavilion www. biquge。 For this reason, Sun Yi specially asked Wang Erniu to convene the doctors of the Leiyun Hall to discuss this issue.

More than 20 people gathered in the shade under the catalpa tree and formed a large circle. Many people wore the Tai Chi Yin Yang Fish badge made of tin on their chests, which was a sign of the official doctor's fame.

A conspicuous exception is the little pomegranate, she doesn't even have a doctor, she doesn't even have a colloquial title, and the little girl herself doesn't know what the purpose of the first brother calling her to come.

Sun Yi briefly introduced the background:

If ironwood wants to have a raft propelled by water jets, it is better to have iron screws;

If you want to have iron screws, you have to have good quality iron, even steel.

In order to have high-quality iron, there are two necessary conditions: one is high-quality iron ore raw materials, and the other is an iron-making furnace that can reach a temperature of 1500 degrees.

The quality of iron ore in China is generally low, and in order to solve the problem of raw materials, Sun Yi proposed a detour: large-scale electrolysis of ordinary cast iron to obtain electrolytic pure iron.

All the doctors glanced at the little pomegranate in unison.

The scale of electrolytic iron that Little Pomegranate takes care of is currently a clay pot, and Sun Yi's goal is to build hundreds of clay pots.

The key to the technology of electrolytic iron is the electrolytic solution, at present, ironwood can be used to react with iron with mixed water to obtain iron sulfate and iron chloride electrolyte, and the waste liquid in the scrapped iron can battery is just the electrolyte of electrolytic iron.

Theoretically, the electrolytic iron solution is not consumed with the electrolysis process. In the electrolytic tank, the iron ions in the electrolyte are continuously precipitated under the action of voltage to become pure iron, and the iron electrode will be continuously corroded to replenish the iron ions in the electrolyte.

The only drawback of this solution is that it requires a lot of electricity, and the production of pure iron will be very expensive. But in the end, the problem of the availability of high-quality raw materials was solved.

The pure iron obtained by electrolysis is the shape of iron powder or small iron sheets, and there are two ways to turn the pure iron particles into iron blocks, one is to heat the pure iron to about 1100 to 1200 degrees, and forge it when the pure iron turns red and soft, and the other is to honestly raise the temperature to the melting point of pure iron, that is, 1500 degrees, and the pure iron melts into molten iron and cools it into iron.

Sun Yi chose the second option.

In the first scheme, when the pure iron is heated to red and soft, it is still difficult to ensure that the pure iron is not mixed with minerals such as sulfur and phosphorus in charcoal or coal during the heating process, and the loss of pure iron sparks in the forging process cannot afford the loss of iron and wood.

The second option raised the temperature to 1,500 degrees, and there was no other way to make coal into coke than the current fuel of the Ming Dynasty. At present, ironwood does not even have coal, and the sulfur and phosphorus impurities in coal will also reduce the quality of electrolytic pure iron, so Sun Yi decided not to use the fuel of the Ming Dynasty.

Sun Yi's plan is to use electricity!

The temperature of the arc can reach 3600 degrees Celsius, and the melting point of pure iron is only 1500 degrees.

Sun Yi's scheme is very simple, using pure iron particles as one electrode and other materials as the other electrode, when the two electrodes are close to each other, an arc is generated to melt the pure iron, and the whole process is very clean and will not introduce new impurities.

The question is that with such a high temperature, what is used to hold pure iron particles?

Due to the melting and endothermic melting of pure iron, the temperature of the entire process is fixed at 1500 degrees. It's like melting ice over a furnace fire, and as long as the ice doesn't melt, the temperature of the ice-water mixture is clamped to the melting point of the ice, which is 0 degrees.

Gold is fired at 1000°C, stone turns to lime at 1100°C, porcelain melts between 1500°C and 1600°C, none of these materials work.

Pure sand, i.e. silica, has a melting point of 2300 °C and graphite has a melting point of 3600 °C.

Everyone's eyes looked at several pottery-burning kiln handles.

A kiln handle said: "Graphite is not difficult to find. The dolls who had just learned to write practiced with graphite, and the mother-in-law of the poor family used graphite to draw their eyebrows. Graphite has no other use, and the graphite dug out of the coal kiln is piled aside. If you go to the place where the graphite is produced, you will have to pull as much as you want if you don't give money, and the coal kiln shopkeeper will have to thank us. We can try to grind graphite into powder and sand mixed together to make the shape of a jar, and then put it in a pottery kiln to fire it. ”

One of the benefits of graphite crucible is that its basic component is carbon, and a part of the carbon will seep into the process of melting pure iron into molten iron, and the carbon content in the pure molten iron can be controlled to obtain steel directly.

The shortcomings of Sun Yi's graphite crucible electric furnace scheme are also obvious, one is that the scale cannot be very large, and the other is that it will consume a lot of electricity.

In order to solve the bottleneck of electricity, Sun Yi decided to upgrade the existing iron can battery.

The first is to replace the iron electrodes in the iron can battery with a metal zinc electrode. Zinc is more active than iron, and the voltage of the battery can be increased by 0 . 3 volts to 1 volt. Copper sulphate is still used as the battery solution, but a copper rod is used as the other electrode. The entire chemical reaction turns into zinc and replaces copper. The high-purity electrolytic copper precipitated on the copper rod can also be further used as a high-quality pure copper raw material.

The second is to change the shape of the battery, use a large crockpot as the battery container, add enough copper sulfate solution, and place zinc block electrodes and copper rod electrodes in the solution, sacrificing the flexibility of the battery to improve the capacity of the battery.

This required Ironwood's caravans to go out and purchase large quantities of copper sulphate and zinc metal.

Copper sulfate, also known as blue alum, was sold in pharmacies as traditional Chinese medicine after decoction and purification in the Ming Dynasty. Copper-producing places generally produce coarse blue alum, and Shaanxi produces coarse blue alum.

The metal zinc was called lead in the Ming Dynasty. Because the ignition point and boiling point of zinc are very low, "Tiangong Kaiwu" records that metal zinc "flies away as smoke when it enters the fire, like lead and is violent, so the name is called "Japanese lead". ”

In the Ming Dynasty, the main use of lead was to mix copper to make brass to reduce costs, and all copper coins minted in the Ming Dynasty were mixed with metal zinc. When the Ming court minted money, it was seven points of copper and three points of lead, and the fake money minted by private individuals could account for half of the lead in order to be cheap. In addition to being used as a mixture for smelting brass, there was no other use for it, and the general copper shops were in stock, and the price was not expensive, and it was not a controlled commodity that was prohibited from being exported to the grassland in the Ming Dynasty.

In order to make the water jet raft, Sun Yi used a carpenter of ironwood. In order to make small iron screws that improve the performance of the waterjet engine, Sun Yi used a group of craftsmen who liked to work on batteries, such as blacksmiths, potters, caravans, and small pomegranates.

But Sun Yi thinks all the effort is worth it.

Faced with such a large project where various craftsmen worked together, Wang Erniu stood up, "Master, I'll coordinate this matter." ”