How to smelt metal in ancient times?

Satisfied answer ぅ Sakura Wing1Grade 6 2010-11In early civilized countries and regions, China used copper, iron and other metals relatively late. However, due to China's invention and innovation in smelting and casting technology, China's metallurgical industry soon came from behind and jumped to the forefront of the world, laying a solid material foundation for China's highly developed ancient civilization. From here, we can see a typical example. Technological progress drives the development of production and further promotes the progress of social civilization. Egypt entered the Bronze Age around 5000 BC and the Iron Age around 1000 BC. Mesopotamia began to use natural copper around 7000 BC, entered the bronze age around 4000 BC and entered the iron age around 1200 BC. The Aegean region began to enter the Bronze Age around 3300 BC and the Iron Age around 1000 BC. India entered the Bronze Age around 2500 BC and the Iron Age around 800 BC. China entered the Bronze Age around 1500 BC and the Iron Age around 500 BC. One of the most prominent features in China's metallurgical history is that casting technology occupies an important position, so that casting not only exists as a molding process, but also becomes an integral part of smelting process, reaching the point where "smelting" and "casting" are inseparable. Therefore, it is often called smelting and casting in ancient literature, which has a far-reaching impact on China culture. Common words such as "model", "scope", "edification" and "submission" all come from smelting and casting technology. This metallurgical tradition, which is inseparable from smelting and casting, is incomparable to other countries and regions in the ancient world. 1. Bronze smelting is considered as a symbol of ancient civilization in China. Bronzes from Shang and Zhou Dynasties to Warring States Period, in a sense, can be said to be created by casting technology. Although China started smelting bronze about 1000 years later than the West, it came from behind and soon surpassed the West in smelting level. From Simuwu Fang Ding, which weighs 875 kilograms, exquisite Zunpan in Ceng Houyi, and large chimes in Suixian, to a large number of ritual vessels, daily utensils, chariots and horses, weapons, production tools, etc., it can be seen that China had mastered the casting technology of comprehensive utilization of clay casting, separate casting, lost wax method, tin welding and brazing at that time, and was in a leading position in the world in smelting and casting technology. And "Examination of Gong Ji" records: "Gold has six qi. Its gold and tin are divided into six parts, which is called the Qi of Zhong Ding. Its gold and tin are divided into five parts, that is, the axe Jin Qi. Its gold and tin are divided into one, that is, the gas of Geji. One-third of its Suk Kim, it is called the gas of big blade. Its gold and tin are the second, that is, slaying the arrows. Half gold and half tin can be called mirror, which is the earliest empirical scientific summary of alloy ratio in the world. It shows that at that time, China had realized the relationship between alloy composition and properties and uses of bronze, and had controlled the ratio of copper to tin quantitatively, so as to obtain bronze alloys with different properties and suitable for different uses. "Flower King Gongji" also records: "Where gold is cast, Suk Kim will do it, followed by yellow and white; Yellow and white gas is exhausted, followed by blue and white; The blue and white gas is exhausted, followed by the green gas, and then it can be cast. " This shows that the knowledge of judging whether bronze is smelted to purity according to the color of flame was mastered at that time, which is the origin of flame identification method in chemistry later. This is the origin of the idiom "Perfect Kung Fu". Another important achievement of copper smelting is wet copper smelting, also known as bile copper method. This is a method discovered by alchemists to smelt copper by using the substitution reaction of iron to copper ions. Its technological process is to dissolve copper sulfate or copper carbonate (formerly known as Zeng Qing, bile alum, stone gall, etc.). ) make bile water in water, and then throw the iron into the solution. Because iron is chemically more active than copper, iron ions will replace copper. This is the earliest hydrometallurgy in the world, and this method has been used in large-scale copper smelting production in Song Dynasty. 2. Although China started smelting massive iron with cast iron as late as 6th century BC, which was about 900 years later than that in the west, the technology of smelting cast iron was 2000 years earlier than that in Europe. The invention of cast iron in China appeared in the 5th century BC, while in Europe it was as late as15th century. Because the performance of cast iron is much higher than that of block iron, the real iron age began after the birth of cast iron. The history of social development shows that the appearance of cast iron is the main symbol of social productivity improvement and social progress. It took China only about a century to invent cast iron, while it took the West nearly 3000 years. China's ancient ironmaking technology developed so rapidly that it was 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. Because pig iron has high carbon content, although it is hard and brittle, it is not resistant to impact and is easy to be destroyed. In order to improve the performance of pig iron, China invented a series of pig iron processing technologies in ancient times. Among them, the first is the softening of cast iron, which existed during the Warring States Period. This technology can be divided into two categories: one is to decarbonize pig iron in oxidizing atmosphere to make it become white-core ductile iron; One is to graphitize pig iron in neutral or weakly oxidizing atmosphere to make it into black core ductile iron. In the west, the production technology of white-core ductile iron was first described by the French in 1722, and black-core ductile iron appeared in the United States in 183 1 year. In the Han Dynasty, there was a new breakthrough in the softening of cast iron, and a production process of decarburization of cast iron was formed. All kinds of low, medium and high carbon steels could be directly produced from pig iron after heat treatment. Since then, China has become an advanced steel producer in the world. With the development of transportation and trade between China and foreign countries, its products are also shipped to neighboring countries and Central Asia, West Asia and Arabia. Another outstanding pig iron processing technology is steel explosion, which was the main method to change pig iron into steel or wrought iron in ancient China, and was invented in the late Western Han Dynasty. Its method is to heat pig iron into liquid or semi-liquid and stir it constantly, so that carbon and impurities in pig iron are oxidized continuously, thus obtaining steel or wrought iron. Iron smelting sites in Tieshenggou, Gongxian County, Henan Province and Wafangzhuang, Nanyang provided physical evidence for the application of steel blasting technology in Han Dynasty. The Taiping Jing written in the Eastern Han Dynasty also said: "If you are in a hurry, you will make the craftsman hit the stone, seek the iron inside it, and burn it to make water. If you let good workers forge it, it will become Mo Ye. " "Mo Ye" is the name of the ancient sword. Although this passage is abbreviated, it is not difficult to see that it describes the technological process of obtaining pig iron from ore smelting and then frying it into finished products. The steel frying process is simple in operation and easy to obtain raw materials, and can be continuously produced on a large scale and efficiently. The obtained steel or wrought iron is of high quality, which is of great significance to the ancient steel production and social development in China. It was not until the middle of the eighteenth century that the British in Europe invented similar technology. China's ancient steelmaking technology was mainly "Baigang". Since Liu Kun in the Western Jin Dynasty wrote that well-known poem, "Why should it be tempered into steel and turned into a soft finger?" "A hundred tempering makes steel" and "A hundred tempering makes steel" have become common idioms. Hundreds of steelmaking began with a large number of carburized steel smelting in the early years of the Western Han Dynasty, and then the forging times were continuously increased, forming a set of processing technology. By the Eastern Han Dynasty and the Three Kingdoms, the steelmaking process was quite mature. Quoting "Mo Xie" in Taiping Jing is a vivid portrayal. Cao Cao once ordered engineers to make "hundreds of sharp weapons", and Cao Pi's Dian Lun Ming Jian said: "Choose good gold (iron) and order other countries to work hard and refine it. As for the hundred swords. " Liu Bei once ordered that "Puyuan made five thousand knives, all of which were connected in series, and the cutting edge was engraved with seventy-two guillotines". Notes on Ancient and Modern Costume also said: "Wu Dadi has three swords, one is a hundred trials, the other is a young calf, and the third is a lack of scenery." This technology has been continuously inherited and developed in later generations. In addition, 198 1 year, China scholar Guan Hongye and others studied 5 13 pieces of ironware unearthed during the Han and Wei Dynasties, which showed that China had invented ductile iron in the Han Dynasty more than two thousand years ago, much earlier than the developed countries in Europe. At present, the research conclusions of China scholars have been recognized by international academic circles. Founding in Wei, Jin, Southern and Northern Dynasties, pouring steel technology is an original invention in the metallurgical history of China. Tao Hongjing said, "The sickle is made of mixed iron and steel", and the mother of the Northern Qi Dynasty heard that, "The cast iron knife is hardened after several nights by burning pig iron essence with a soft collar", that is, casting technology. The process of steel casting is roughly as follows: when molten pig iron is mixed with wrought iron, the carbon in pig iron will diffuse into wrought iron and tend to be evenly distributed, and some impurities can be removed to form high-quality steel. After the Song Dynasty, the pouring technology of steel was continuously improved, reducing the times of pouring and refining, and even refining once. Shen Kuo said in Volume III of Meng Qian's Notes: "The so-called iron forgers in the world use soft iron to bend plates, which are made of pig iron trapped in them, sealed with mud and forged, which is called' Tuangang', also known as' pouring steel'", and said that "the second and third smelting makes pig iron self-cooked, but it is still soft iron", which reflects the reduction of pouring times. Among them, the purpose of bending soft iron is to increase the contact surface between raw and cooked iron, improve the casting efficiency and promote the more uniform distribution of carbon; Mud sealing can promote slagging, remove impurities and play a protective role. In the Ming Dynasty, the technology of pouring steel was further developed. According to the record in Volume XIV of Tiangong Wu Kai, the flexible iron was changed into thin and cooked iron sheet, which further increased the contact surface of raw and cooked iron, accelerated the process of "raw and cooked iron was mixed and steel was refined", and the mud seal was also changed into grass and mud mixed seal. Casting steel, also known as "smearing steel" and "Suzhou Steel", is still very popular from Qing Dynasty to modern times. Before the invention of crucible steelmaking, pouring steel was the most advanced steelmaking technology. In addition to copper and iron, metals smelted and used in ancient China include gold, silver, mercury, lead, tin and zinc, among which zinc smelting was first invented by China. In pre-Qin bronzes, China has added zinc as an associated ore to copper alloys. From the Han Dynasty to the Yuan Dynasty, zinc oxide "calamine" was consciously added to the copper melting furnace to produce copper alloy brass with zinc as the main alloying element. Zinc was extracted from calamine on a large scale in the Ming Dynasty. Since16th century, zinc from China has been introduced into Europe. Zinc smelting didn't start in Europe until17th century, and the zinc smelting process also originated in China.