The ancients once classified substances according to their certain properties and attempted to trace their origins and their changing laws. In the 4th century BC or earlier, China proposed the theory of Yin and Yang and the Five Elements, which believed that all things are composed of gold, wood, water, and fire.

, is composed of the five basic substances of earth, while the five elements are formed by the interaction of yin and yang. This statement is a simple materialist view of nature, using the concept of "yin and yang" to explain the two opposites and mutual growth and decline in nature

It is believed that the interaction between the two is the source of changes in all natural phenomena. This theory is one of the theoretical foundations of Chinese alchemy.

In the 4th century BC, Greece also proposed the four-element theory of fire, wind, earth, and water, which was similar to the Five Elements theory, and the ancient atomic theory. These simple elemental ideas were the germination of the theory of material structure and its changes. Later it appeared in China

In the Qin and Han Dynasties in the 2nd century BC, alchemy became quite popular. It was spread to Arab countries in the 7th century AD, and merged with ancient Greek philosophy to form Arab alchemy. Arab alchemy was introduced to Europe in the Middle Ages.

, formed European alchemy, and later gradually evolved into modern chemistry.

The guiding ideology of alchemy is the belief that substances can be transformed, and they try to artificially synthesize gold and silver in alchemy furnaces or cultivate the elixir of immortality. They purposefully mix and smelt various substances and conduct experiments. This involves studying the transformation of substances.

Various types of utensils, such as sublimators, distillers, mortars, etc., have also been created, and various experimental methods have been created, such as grinding, mixing, dissolving, cleaning, burning, melting, sublimation, sealing, etc.

At the same time, the properties of various substances were further classified and studied, especially the properties of mutual reactions. These laid the foundation for the emergence of modern chemistry. Many instruments and methods have been improved and are still used in today's chemical experiments. Alchemy

During the experiment, scientists invented gunpowder, discovered several elements, made certain alloys, and prepared and purified many compounds. We are still using these achievements today.

The renaissance of chemistry

Beginning in the 16th century, European industrial production boomed, promoting the creation and development of medicinal chemistry and metallurgical chemistry, turning alchemy into daily life and practical applications, and then paying more attention to the study of chemical changes of matter itself. After the scientific concept of elements was established, through

Precision experimental research on combustion phenomena established scientific oxidation theory and the law of conservation of mass, and subsequently established the law of constant proportion, the law of multiple proportions and the law of combined quantities, laying the foundation for the further scientific development of chemistry.

At the beginning of the 19th century, modern atomic theory was established, which highlighted the mass of atoms of various elements as its most basic characteristic. The introduction of the concept of quantity was a major difference from ancient atomic theory. Modern atomic theory made it possible at that time

The chemical knowledge and theories have been reasonably explained and become a unified theory to explain chemical phenomena. The molecular hypothesis was put forward and the atomic and molecular theory was established, which laid the foundation for the study of material structure. After Mendeleev discovered the periodic law of elements, not only

A system of inorganic chemistry was initially formed, and together with the atomic and molecular theory, a chemical theoretical system was formed.

Through the analysis of minerals, many new elements were discovered, and with the experimental verification of the atomic and molecular theory, the classic chemical analysis methods also had their own systems. The synthesis of oxalic acid and urea, the emergence of the concept of atomic valence, the six rings of benzene

The establishment of theories such as structure and carbon-valence bond tetrahedron, the splitting of tartaric acid into optical isomers, and the discovery of molecular asymmetry, etc., led to the establishment of organic chemical structure theory, allowing people to have a deeper understanding of the nature of molecules.

And laid the foundation of organic chemistry.

In the second half of the 19th century, after thermodynamics and other physical theories were introduced into chemistry, they not only clarified the concepts of chemical equilibrium and reaction rate, but also made it possible to quantitatively judge the direction and conditions of substance transformation in chemical reactions. Solution theory and ionization theory were successively established.

, the theoretical basis of electrochemistry and chemical kinetics. The birth of physical chemistry raised chemistry to a new level theoretically.

When it comes to sulfuric acid, many people think it is a modern chemical product, but in fact it has been produced in ancient times.

The "Yellow Emperor Jiuding Divine Alchemy Sutra" compiled by the Tang Dynasty in China contains the "Method of extracting gold from gallstones" by the alchemist Hu Gangzi (also known as Hu Gangzi) in the late Eastern Han Dynasty (AD 25-220).

"Essence method". The so-called "stone gall" refers to the pentahydrate crystal of copper sulfate (CuSO4.5H2O), which is still called "gall vitriol" in our country because it is blue, just like gall. "Refining stone gallbladder to extract the essence"

"Method" is to distill bile alum to produce sulfuric acid. Because the pentahydrate crystal of copper sulfate decomposes when heated, it generates copper oxide (CuO), sulfur trioxide (SO3) and water. Sulfur trioxide dissolves in water to form sulfuric acid, which is used

Modern chemical equations represent:

CuSO4.5H2O→CuO+SO3+5H2O

SO3+H2O→H2SO4

The original text of this paragraph is as follows: "Make two square-headed furnaces with earth mounds, two feet apart. Make a hole in the middle of the fine clay on the outside and inside. Make a hole on the side to make the fine clay fumigated and dry. Open the furnace and burn copper.

Plate, make it set, that is, dense mud; burn stone gallbladder with charcoal in a furnace to make smoke, use objects to fan it, and all the essence will be poured into the copper plate. Put the fire in the furnace until it cools down, then open it for use. Add ten thousand medicines, and the medicine

"All gods". The "earth" here means "adobe"; "fine mud between" means sealing the gap with fine clay; "fine fumigation" means slowly heating; "smoke" refers to the combination of sulfur trioxide and water vapor

The generated mist gas; using a "copper plate" is obviously to prevent dilute sulfuric acid from corroding the receiver.

This means that around the 2nd century AD, our country had created the "earth chamber method" to produce sulfuric acid. However, this method has not been promoted in our country.

In the 13th century, the German Catholic priest Albertus Magnus (1193-1280) in Europe mentioned in his writings the distillation of green vitriol to produce sulfuric acid. Green vitriol is a heptahydrate crystal of ferrous sulfate (FeSO4.7H2O), which is green in color.

It got its name. The chemical process of distilling green vitriol to produce sulfuric acid is the same as distilling bile vitriol. Therefore, Europeans called sulfuric acid green vitriol oil in the Middle Ages.

According to the writings of the 10th-century Persian alchemist al-Rhazes (845-930) translated by Europeans, it was also mentioned in the distillation of green vitriol to produce sulfuric acid.

In the late Middle Ages, European capitalist production relations gradually grew based on the development of productivity within the feudal system. By the 18th century, European manual workshops had transitioned to large-scale machine production, and sulfuric acid was needed to promote all aspects of society.

In 1736, the Englishman Ward (Joshua 1685-1761) established the "Great Vitriol Works" (Great Vitriol Works) in Twickenham on the Thames River in England and began to produce sulfuric acid on a large scale.

Ward was a charlatan. He was convicted of trying to sneak into the British Parliament in 1717. He fled to France. In 1733, he was pardoned and returned to England. He engaged in manufacturing saltpeter and porcelain and practicing medicine in Twickenham. He believed that Glauber's salt

(Glauber's Salts) has extraordinary effects in medicine, so I wanted to make it. Glauber's salt refers to sodium sulfate. It was invented by the 17th-century German chemist Glauber (Johann Rudolph 1604-1670) near Vienna, Austria in 1625.

Found in mineral water. He distilled mineral water and obtained its decahydrate crystal (Na2SO4.10H2O). He first used it as a laxative and realized that it could be produced by the action of salt and sulfuric acid, and was a by-product of producing hydrochloric acid.

In order to prepare Glauber's salt, Ward made sulfuric acid. He made sulfuric acid by burning a mixture of sulfur and saltpeter. This method was first created by the Dutch inventor Drebbel (Cornelius 1572～1633). French pharmacist List

Lemery (Nicolas 1645-1715) mentioned this method in his works published from 1675 to 1690, which involves burning a mixture of sulfur and saltpeter in a large inverted funnel. Therefore, this method is also called the bell jar method.

Ward may have learned this method while living in St. Germain, near Paris, while on the run from prison to France.

Ward's equipment for making sulfuric acid is a spherical wide-mouth glass bottle with a capacity of 40-50 gallons (British capacity unit, 1 gallon = 4.546L). During operation, a small amount of water is placed in the bottle and a small stoneware jar is placed on the jar.

Place an iron plate with a mixture of sulfur and saltpeter in it. Use a small red-hot shovel to ignite the mixture and plug the mouth of the bottle tightly with a cork. After a period of time, repeat the installation until the desired concentration of sulfuric acid is reached.

Due to the harmful smoke produced during production and environmental pollution, Ward's sulfuric acid manufacturing workshop was opposed by local residents. In 1740, it was moved to Richmond in northern England and obtained a British patent in 1749. In order to

He kept his manufacturing secret, employing Welsh workers who did not speak English. However, he told his friend Page, John, the secret, which was made public after his death in 1763. But at that time the glassblower

How such large-capacity glassware was made is a mystery.

Ward's sulfuric acid works used about 100 spherical wide-mouth glass bottles, which brought the price of sulfuric acid down to 2 shillings and 6 pence per pound (British currency unit). This was equivalent to the previous price per ounce, 1 pound was equal to 16

ounces, which means that the price of sulfuric acid dropped to 1/16 of the original price.

However, Ward's equipment and operating methods for making sulfuric acid were soon replaced by the lead chamber method created by another Englishman, Roebuck (John 1718-1794).

Roebuck was a doctor of medicine and a doctor. He was elected as a member of the Royal Society in 1764. He lived in the British industrial city of Birmingham in the 1840s, practiced medicine in private, founded an ironworks, and also ran a jewelry business.

In 1746, he and his partner Garbett (Samuel 1717-1805) were recycling gold and silver, which required sulfuric acid to dissolve impurities. From chemistry textbooks, they learned that lead can resist the corrosion of sulfuric acid.

So wood was used to make a frame and lead plates were used as walls to create a cubic lead chamber with 6 feet (British length unit, 1 foot = 0.3048m) on each side. During the operation, sulfur and saltpeter were placed in an iron spoon and ignited.

Put it into an iron plate in the lead chamber, so that the generated sulfur oxide gas is absorbed by the water sprayed on the wall of the lead chamber in advance to form sulfuric acid, and continuously add sulfur and saltpeter. Take out the acid about every four weeks and put it in again.

Heat and concentrate in a glass container.

By 1749, Roebuck founded the "Prestonpans Vitriol Co." in Prestonpans, Scotland, built larger and more lead chambers, and hired 50 workers, working day and night shifts.

Operation, the production of sulfuric acid ranged from pounds to tons, not only for use in Britain, but also as far away as continental Europe.

In order to keep the secret of production technology, Robke also built a high wall around his factory and required every worker to swear an oath of confidentiality. However, under the temptation of money, the high wall was destroyed and the oath was abandoned. Bewdley's one

A wealthy chemical manufacturer named Skey Samuel bribed a worker to learn about the structure and operation of a lead chamber, and built a 10-foot cubic lead chamber to manufacture sulfuric acid. Then, in London or

Lead chambers were also built in some other places and in some places in France. Lead chambers were built larger and larger, and the number was increasing. In 1805, a sulfuric acid manufacturing plant on Burnt Island in the United Kingdom had 360 lead chambers.

Each lead chamber has a volume of 192 cubic feet. Chaptal (Jean Antoine Claude 1756-1832), a professor of chemistry at the University of Montpellier in France and a wealthy industrialist, proposed that the largest lead chamber should be 25 feet on each side and 15 feet high.

feet was appropriate, but he once built a large lead chamber 80 feet long, 40 feet wide and 50 feet high, which collapsed after 18 months of use.

In order to reduce the cost of sulfuric acid production, some manufacturers are gradually replacing sulfur with pyrite or chalcopyrite and other sulfur-containing minerals. Some manufacturers are also constantly improving production equipment, such as spraying water vapor into the lead chamber instead of spraying water into the lead chamber.

The walls were sprayed with water, and a separate furnace was installed to burn sulfur or other sulfur-containing minerals instead of burning in the lead chamber. In this way, the production of sulfuric acid gradually changed from intermittent to continuous, which greatly increased the output of sulfuric acid. By 1878, the annual production of sulfuric acid in Europe

The output has reached millions of tons.

For a period of time, sulfuric acid manufacturers believed that the purpose of adding saltpeter when burning sulfur in the process of making sulfuric acid was to generate oxygen to oxidize sulfur dioxide into sulfur trioxide, so they no longer supplied air to the lead chamber. In 1806, Desormes, Charles Bernard, France (1777)

~1862) and Clement Nicolas (1779~1841), two chemists, observed that the mixed gas of sulfur dioxide and nitrogen dioxide was passed into the lead chamber to form white crystals, and the white crystals were treated with water to form sulfuric acid and re-formed.

Nitric oxide gas is released, so it is determined that sulfur dioxide is not directly oxidized by oxygen in the lead chamber, but forms an intermediate product with nitrogen oxide. The entire process of forming sulfuric acid is a cyclic process. This has caused research by many chemists.

After many studies by many people, it has been determined that sulfur dioxide, nitric oxide, oxygen and water in the lead chamber form nitros sulfuric acid (ONOSO2H), which then reacts with water to form sulfuric acid and release nitrogen oxides, which can be used

The following chemical equation represents:

2NO+O2→2NO2

2SO2+3NO2+H2O→2ONOSO2OH+NO

2ONOSO2OH+H2O→2H2SO4+NO+NO2

In other words, nitrogen oxide is actually the catalyst for oxygen to oxidize SO2 to SO3.

Therefore, the amount of expensive saltpeter was reduced in the lead chamber method to produce sulfuric acid, and the amount of air supply was increased, reducing the cost again. By the beginning of the 20th century, saltpeter was basically no longer used, and ammonia was used, because ammonia in the presence of catalysts such as platinum,

It can react with oxygen in the air to form nitrogen oxides. This reaction is:

4NH3+5O2→4NO+6H2O

Since nitrogen oxides can be used repeatedly, the problem of how to recycle these nitrogen oxides arises. The famous French chemist Gay-Lussac (Joseph Louis 1778-1850) proposed in 1827 to set up a tower behind the lead chamber.

It is filled with coke, and the gas released in the lead chamber is introduced from the bottom of the tower. After rising, it encounters the sulfuric acid flowing from the lead chamber to the top of the tower and is dissolved and absorbed. However, the nitrogen oxides cannot be completely absorbed.

Because nitric oxide is not easily soluble in sulfuric acid and does not react chemically, while nitrogen dioxide is not easily soluble in concentrated sulfuric acid and can only be dissolved in dilute sulfuric acid. It is necessary to release the nitrogen oxides again so that they can return to the original state.

To be used in the lead chamber, the acid that absorbs nitrogen oxides was initially diluted with water, which would dilute the generated sulfuric acid and make it uneconomical to concentrate again. Therefore, the tower designed by Gay-Lussac has not yet been put into practical use.

.The tower was later named the Gay-Lussac Tower.

In 1859, Glover (John 1817-1902), a British pipeline worker, proposed to set up a tower between the sulfur-burning furnace and the lead chamber to make the high-temperature sulfur dioxide gas flow upward and reach the top of the tower from the Lussac Tower.

The nitrogen-containing sulfuric acid was sent to heat and release the nitrogen oxides into the lead chamber. This not only fully recovered the nitrogen oxides, but also released the nitrogen oxides absorbed in the Gay-Lussac Tower.

came out. This tower was later named Glover's Tower and was quickly used in actual production. An ordinary worker perfected the design of a famous chemist and became famous in the manufacture of sulfuric acid.

Since then, sulfuric acid manufacturers have made a series of improvements to the lead chamber.
To be continued...