Section 13 Copper smelting

After knowing the basic principles, the smelting of metals is actually not mysterious.

For example, if you want to smelt cuprous oxide-based cuprite, then you only need to add carbon to replace the oxygen in cuprous oxide. Of course, in the inverse requires a very high temperature to displace the oxygen atom from the stable molecular structure.

High temperature is the second element in metal smelting in addition to carbon.

The principle is simple and there is no mystery about it, but the fact that the heat has stumped countless scientists and engineers from ancient times to the present day. Even on Earth, which is considered to be scientifically advanced, how to achieve enough high temperatures is still a huge problem.

Of course, the ancients were entangled in how to make the temperature reach the level of melting bronze and steel, while the modern people are entangled in how to produce the high temperature like the sun, how to increase the core temperature, how to increase the duration of the high temperature, and how to make the high temperature controllable......

…… Around temperature, countless global problems plague mankind and hinder the progress of human beings.

What bothered Chen Zheng's progress was also something that was extremely simple in the eyes of modern people, but extremely difficult for Chen Zheng in an alien planet - how to use charcoal to reach a high temperature of more than 1,200 degrees.

The melting temperature of copper is as high as more than 1300 degrees, and the melting temperature of iron is more than 1500 degrees.

The melting temperature of the alloy is much lower than that of the element, for example, bronze is only 900 to 1000 degrees, although the melting point of bronze varies according to the formula, but it is generally lower than 1000 degrees Celsius.

If memory serves, the melting temperature of cuprous oxide should be around 1200 degrees, which is much higher than that of ordinary bronze.

The combustion temperature of ordinary coal is about 900 degrees, and the combustion temperature of high-quality lignite in civil boilers is only 1000 degrees. Anthracite coal in steel mills can be burned at temperatures of 1,700 to 1,900 degrees with the help of blowers, while blast furnaces using coke can reach high temperatures of 2,300 degrees.

It can be seen that even in the modern era of advanced technology, it is difficult for ordinary civilian temperatures to exceed 1000 degrees, and this is still in the case of using coal as fuel.

As for the burning temperature of charcoal, it is even lower, only 700 degrees, and in the case of "advanced" mud furnace and blast equipment (bellows), the burning temperature of charcoal can barely reach 1000 degrees.

In the Central Plains, there are few records of the use of "coal" in ancient times, and charcoal was often used even for smelting metals.

Bronze is smelted at a very low temperature, and it can be melted even when charcoal is used. This is not the case with iron, where even the first cast iron (mainly composed of iron, carbon, and silicon) has a melting point of more than 1,200 degrees.

Don't look at this gap of only more than 200 degrees, this more than 200 degrees is the gap between the Iron Age and the Bronze Age. It took thousands of years for human civilization to cross the 200-degree bottleneck.

Comparing the above, it is not difficult to find out why ancient times first experienced the "Bronze Age" and then the "Black Iron Age".

The difficulty of smelting cuprous oxide with a melting point of 1200 degrees is self-evident with a mere amount of charcoal. However, for Chen Zheng, he is different from the ancient people who crossed the river by feeling the stones, since he has the wisdom of his predecessors, all he has to do is bend down to pick it up.

Compared with the simple and crude carbonization pool, what Chen Zheng has to do next is an important step that human civilization has taken - smelting blast furnaces.

To be precise, it is actually a small blast furnace similar to the period of earth-based steelmaking.

Of course, since there is no high-quality anthracite, Chen Zheng still needs to make some structural adjustments if it is replaced by charcoal.

The most important part of these adjustments, which can be said to account for more than 50% of the total amount of work, is the blower equipment and heat recovery system.

That's right, in order to reach higher temperatures with charcoal, Chen Zheng needed a more complex system.

The first thing to do is the design work.

Spreading out a piece of air-dried bark, Chen Zheng used a thin strip of charcoal to write and draw on the uneven paper.

The blower system is naturally a blower, and to put it bluntly, it is a large manpower bellows. As far as the bellows themselves are concerned, the difficulty is not high, but how to provide power and how to achieve a large enough air supply is the biggest problem.

But fortunately, Chen Zheng doesn't need to smelt many copper ores, even if he carries back a few boxes, a blast system several times that of an ordinary bellows can be done.

As for the power problem, it is naturally not the laborious mode of pushing and pulling back and forth by the human arm. Chen Zheng designed a drivetrain similar to an old-fashioned train, which could convert the force of the downward pedal into circular motion. Then the rudimentary belt system drives the entire bellows cycle back and forth.

The design of the bellows is also a "double-acting piston bellows" that can enter the air regardless of pushing and pulling, and can continuously blow air.

The heat recovery system is more than a high-end one, which is nothing more than mixing the hot exhaust gases with the fresh air blowing in from the bellows and sending them back into the furnace.

In this way, on the one hand, the inlet air temperature is increased, which is conducive to increasing the temperature of the furnace core, and on the other hand, the oxygen and carbon monoxide in the exhaust gas can also re-enter the furnace for secondary reaction, which greatly improves the reaction efficiency.

However, how to design this exhaust gas recovery system, how to solve the air tightness, and how to use the power of the bellows to fully mix the exhaust gas and air...... These are the biggest design difficulties in the whole project.

When these difficulties are overcome one by one, Chen Zheng will be able to obtain a part of the copper that is not very pure. As for how to remove impurities from these copper products...... That's another bigger problem.

After more than an hour of gesturing on the bark paper, Chen Zheng finally stopped his pen satisfied. The imaginary difficulties were solved by Chen Zheng one by one during this time, and when he put down the slender carbon bar, he was still quite complacent in his heart.

Indeed, it was a good feeling to be able to solve a problem that had been bothering him for a long time with a few small changes in engineering. But soon, the pride in Chen Zheng's heart turned into bitterness.

After planning for a long time, he realized that there was one most important part that he had forgotten to calculate, and that was ...... Weather!

In such cold weather, how is he going to hit mud bricks? How to slip the sewing?

Even if the ground is roasted and the snow water is melted to bring out the mud, how will it be dried after it is beaten into mud bricks? Before the mud embryo dries, it will be frozen and cracked!

In the same way, even if everything goes well, Chen Zheng built a small blast furnace, but how to solve the sealing problem!? Slit with a good sludge? Before the mud dries, the wall will be frozen and cracked!!

“…… Looks like there's a lot to do......"

Chen Zheng shook his head helplessly.

Talking about it and putting it on paper and pen and paper is really much more simplified than what you actually have to do.

However, there will always be a way to overcome these difficulties, but the plan will have to be adjusted a little.

Before building a small blast furnace, Chen Zheng also needed to build a drying room.

"It needs to be expanded a little more......"

Chen Zheng looked at the carbonization pool with curling green smoke and muttered to himself.