Seeing the strange scene in front of them, everyone was stunned.

The sound of tsk came and went.

This place is like an isolated underground world, the huge stone stalactites hang down, very shocking, everyone opens the super strong mine cave, in an instant, everywhere is as bright as day.

Surrounded by rubble, apparently excavated by hand, it seems that this is an ancient mine cave, as they say.

At this time, the old glasses who had not spoken all the way coughed and said softly: "This is impossible!" When pigs fly! ”

This surprised everyone.

"Impossible? What impossible! ”

Director Qin was a little anxious and hurriedly asked.

"I have carefully observed along the way, and it can be basically seen from the traces on the cave wall that this is left by the Western Zhou Dynasty, how could people in that era dig such a deep cave for mining!"

As soon as the words fell, Mr. Du, a geologist, continued: "Not bad! I have noticed that this is a rare metal cave, as far as I know, the smelting of rare metals by human beings is no more than 500 years, if this is a mine cave in the Western Zhou Dynasty, there should indeed be no ...... these ores. ”

Mr. He took two more steps forward, took a deep breath, and became a history teacher......

The bronzes from the Shang and Zhou dynasties to the Warring States period, which symbolize ancient Chinese civilization, can be said to have been created by casting technology.

From the 875-kilogram Simu Wu Fang Ding, the exquisite Zeng Hou Yizun plate and the large Suixian bell group, as well as a large number of ritual vessels, daily utensils, chariots and horses, weapons, production tools, etc., it can be seen that China has mastered the casting technology of comprehensive use of mud casting, separate casting, lost wax method, soldering and brazing, and has been in a leading position in the world in smelting and casting technology.

For a long period of time, our iron and steel smelting technology was once ahead of the world, the beginning of China's smelting of block iron in the 6th century B.C., the evolution of ancient smelting technology before the Spring and Autumn Period, China's smelting technology was in a relatively primitive stage, and the smelting method used at that time was called "block smelting".

At that time, charcoal was used as fuel for ironmaking, and the heat was small, and the furnace body was small and the blower equipment was poor, so the furnace temperature was relatively low and could not reach the smelting temperature of iron, so the iron smelted was a sponge-like solid block, which was called "block ironmaking".

Block iron smelting is more time-consuming, the texture is relatively soft, contains many impurities, and it is forged into wrought iron that can be used. The further development of steel smelting technology has been extended to "block carburized steel".

Excavated artifacts show that China had mastered this earliest steelmaking technology in the late Warring States period at the latest. In the process of forging block iron and wrought iron, people need to continuously and repeatedly heat, and the iron absorbs the carbon in the charcoal, improves the carbon content, and reduces the inclusions to become steel. This steel has a tight structure and uniform carbon content, making it suitable for making weapons and knives.

Further development to the "100 steel" technology. When people make utensils, they consciously increase the number of folding and forging, and a piece of steel often needs to be burned and burned, and repeated many times, or even hundreds of times, so it is called 100 steel. The carbon content of 100 steel is more, the structure is more fine, and the composition is more uniform, so the quality of steel is improved, and it is mainly used to make knives and swords. 8090

The technology of smelting cast iron was earlier than in Europe.

The invention of cast iron appeared in the 5th century BC in China, while in Europe it was as late as the 15th century AD. Since the properties of cast iron were much higher than those of block iron, the true iron age began after the birth of cast iron.

The history of social development shows that the emergence of cast iron is the main sign of the improvement of social productivity and social progress. China's transition from block iron to cast iron invention took only about a century, while the West took a long journey of nearly three thousand years.

The rapid development of iron-making technology in ancient China is unique in the world. Bernard, a famous British historian of science, said that this is the only exception in the history of ironmaking in the world.

Another outstanding pig iron processing technique is frying steel, which was the main method of turning pig iron into steel or wrought iron in ancient China, and was invented around the late Western Han Dynasty. The method is to heat the pig iron into a liquid or semi-liquid state, and constantly stir it to make the carbon and impurities in the pig iron continuously oxidized, so as to obtain steel or wrought iron. The iron smelting sites of the Han Dynasty in Gongxian County, Henan Province and the Han Dynasty iron smelting site in Wafangzhuang in Nanyang provide physical evidence of the application of steel frying technology in the Han Dynasty.

The "Taiping Sutra" written in the Eastern Han Dynasty also said: "If there is an urgency, the engineer will hit the stone, ask for the iron, and smelt it to make water, and then make the good work ten thousand forging, and it will become Moye." ”

"Moyer" is the name of the ancient sword. Although this text is not concise, it is not difficult to see that it describes the process of obtaining pig iron from ore smelting, and then frying and forging from molten pig iron. The steel frying process is easy to operate, the raw materials are easy to obtain, it can be continuously produced on a large scale, the efficiency is high, and the quality of the obtained steel or wrought iron is high, which is of great significance to the steel production and social development in ancient China. A similar technique was invented in Europe until the middle of the eighteenth century by the British.

The steelmaking technology in ancient China was mainly 100 steelmaking. Since Liu Kun of the Western Jin Dynasty wrote the popular poem "What does it mean to make a hundred steels, turn into a soft finger", "a thousand tempers" and "a hundred steels" have become commonly used idioms. Hundred steels began with the block smelting of carburized steel in the early Western Han Dynasty, and then increased the number of forging times to form a finalized processing technology.

By the time of the Eastern Han Dynasty and the Three Kingdoms, the steelmaking process was quite mature.

The above quotation from the "Taiping Sutra" in "Ten Thousand Forging, is to become Mo Evil", is its vivid portrayal. Cao Cao once ordered the engineer to make "a hundred sharp weapons", and Cao Pi's "Classics and Sword Inscriptions" said: "Choose Ziliangjin (referring to iron), order the national worker, refine and refine it, as for the hundred pi". Liu Bei once ordered "Pu Yuan to make 5,000 knives, all of which are chained, and the edge of the blade is engraved with seventy-two pieces".

"Ancient and Modern Notes: Public Opinion" also said: "Emperor Wu has three swords,...... One is a hundred refinements, the second is a green calf, and the third is a leaky scene". This craft has been inherited and developed in later generations. However, there are still certain defects in the technology of frying steel and 100 steelmaking, such as the process of frying steel is complex and not easy to master; 100 steelmaking is labor-intensive and time-consuming.

In addition, in 1981, Chinese scholar Guan Hongye and others studied 513 pieces of iron artifacts unearthed in the Han and Wei dynasties, showing that China had invented ductile iron as early as the Han Dynasty more than 2,000 years ago, far earlier than the developed European countries.

At present, the conclusions made by Chinese scholars have been recognized by the international academic community.

Founded in the Wei, Jin, Southern and Northern Dynasties period, the steel filling technology is an original invention in the history of Chinese metallurgy.

Tao Hongjing said: "Iron and steel is a miscellaneous refining and soft knife and sickle", and Huaiwen, the mother of Qi in the Northern Qi Dynasty, "made an iron knife, and its method burned pig iron to refine the heavy soft collar, and the number of Suzhou became rigid", which is the steel filling technology.

The process of steel filling is roughly as follows: the molten pig iron and wrought iron are combined, and the carbon in the pig iron will diffuse to the wrought iron and tend to be evenly distributed, and some impurities can be removed to become high-quality steel.

Rare refractory metals: including titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, tungsten. The melting point is high, and the melting point of the compounds generated by carbon, nitrogen, silicon, boron, etc. is also high, and the use is more special, such as electronic products, airplanes or aircraft, etc., as for so many rare metal ores here, even the two geologists are confused at this time.

Could it be that people in the Zhou Dynasty already knew how to make electronics or airplanes?