1. The univalent and bivalent metal elements are malleable and malleable. They are one of the best conductors of heat and electricity, and the only metal that can be produced in large quantities naturally. They also exist in various ores (such as chalcopyrite, chalcocite, bornite and malachite) and can be used in industry, engineering technology and technology in the form of metal and brass, bronze and other alloys. Such as: Tongshan (a copper-producing mountain); Copper flower (copper sheet); Copper gold (copper); Copper powder (copper sheet. A golden powder alloy made by melting copper and other metals, which can be used as a pigment); Tongling (copper mountain); Copper drops (copper scrap. Medicinal); Copper smell (copper smell)
2. Copper [object]. Such as: copper balls (small balls cast with copper); Copper teeth (the hook on the crossbow string is called a tooth, and the copper is called a copper tooth); Copper tile (copper tile); The history of copper (missing bronze figures on copper cans); Copper seal (a seal cast of copper. Also known as "bronze seal"); Bronze soldiers (bronze weapons); Tongdi (a man made of copper). That is, "bronze man". Or "golden man"); Copper washing (copper toilet utensils); Copper column (copper column); Copper lotus (copper candlestick. Shaped like a lotus leaf); Copper incense burner (lion-shaped incense burner made of copper); Copper muddy (copper armillary sphere. Also known as "bronze musical instrument"); Bronze nose (nose buckle hole made of copper on ancient official seal)
3. Money made of copper. Also used to refer to money in general.
4. figurative reality. Such as: bronze Guo (describing the wall as solid as copper casting); Copper (iron wall) is the female wall on the city); Copper building (gorgeous and solid building); The iron wall of Tongshan (metaphor for the perseverance and integrity of Fengjie); Bronze head and forehead (figuratively speaking, people are very brave and tough)
5. Powerful. Such as: Tong Doudou (for an experienced old prostitute)
Element name: copper
Elemental symbol: copper
Atomic weight of element: 63.55
Element type: metal element
Number of protons: 29
Neutron number: 35
Atomic number: 29
Period: 3
Number of families: IB
Electron shell distribution: 2-8- 18- 1
Discovered by: year of discovery:
Discovery process:
Copper was discovered in ancient times.
Element description:
A metal with purple luster, with a density of 8.92g/cm3. Melting point1083.4 0.2℃, boiling point 2567℃. Common valences are+1 and +2 (trivalent copper only occurs in a few unstable compounds). The ionization energy is 7.726 electron volts. Copper is one of the earliest metals discovered by human beings and one of the best pure metals. It is slightly hard, extremely tough and wear-resistant. It also has good ductility. Good thermal and electrical conductivity. Copper and some of its alloys have good corrosion resistance and are stable in dry air. But in humid air, a layer of green basic copper carbonate [Cu2(OH)2CO3] can be formed on its surface, which is called patina. Soluble in nitric acid and hot concentrated sulfuric acid, slightly soluble in hydrochloric acid. Easy to be corroded by alkali.
Element source:
Chalcopyrite, chalcopyrite, chalcopyrite and malachite are important copper ores in nature. After the sulfide ore is calcined, it is fused with a small amount of silicon dioxide and coke to obtain coarse copper smelting, which is then reduced to copper foam, and finally copper is obtained by electrolytic refining. A new method of extracting copper is being studied. The underground low-grade ore is crushed by atomic energy, leached in situ with dilute sulfuric acid, and then the leaching solution is pumped to the surface to precipitate copper on iron filings.
Element usage:
Copper is a non-ferrous metal closely related to human beings, which is widely used in electric power, light industry, machinery manufacturing, construction industry, national defense industry and other fields. It is second only to aluminum in the consumption of non-ferrous metal materials in China.
Copper is widely used in electrical and electronic industries, accounting for more than half of the total consumption. Used for winding various cables and wires, motors and transformers, switches and printed circuit boards.
In the manufacture of machinery and transport vehicles, it is used to manufacture industrial valves and accessories, instruments, sliding bearings, molds, heat exchangers and pumps.
It is widely used in the chemical industry to manufacture vacuum tanks, distillation tanks, brewing tanks, etc.
In the national defense industry, it is used to make bullets, shells, gun parts and so on. For every 1 10,000 rounds of ammunition, 13- 14 tons of copper is needed.
In the construction industry, it is used as various pipes, fittings and decorative devices.
The following is the proportion of copper consumption in all industries to total copper consumption: the proportion of copper consumption in all industries to total consumption
Electronic (including communication) 48%
Construction 24%
General engineering 12%
Traffic 7%
Other 9%
Application of copper properties ※
Electrical conductivity: 64%, corrosion resistance: 23%, structural strength: 12%, decoration: 1%.
Element auxiliary data:
The largest natural copper obtained in nature weighs 420 tons. In ancient times, people found natural copper, cut it down with a stone axe and hammered it into objects. So bronzes squeezed into the ranks of stone tools and gradually replaced them, ending the Neolithic Age in human history.
In China, the Xia Dynasty began to use red copper, that is, natural copper, 4000 years ago. It is characterized by a forging hammer. 1957 and 1959, nearly 20 bronzes were unearthed at Huangniangtai site in Wuwei, Gansu. Through analysis, the copper content in bronzes is as high as 99.63% ~ 99.87%, which belongs to pure copper.
Of course, the output of natural copper is scarce after all. The development of production urges people to find ways to obtain copper from copper mines. The total content of copper in the earth's crust is not large, not exceeding 0.0 1%, but copper-bearing minerals are common, and most of them have various bright colors, which attract people's attention. For example, bright green malachite CuCO3. Cu(OH)2, dark blue cerulete 2CuCO3. Cu(OH)2, etc. These minerals are burned in air to obtain copper oxide, and then reduced with carbon to obtain metallic copper.
1933, malachite weighing 1 8.8kg, charcoal block with diameter exceeding1inch, general helmet for smelting copper with pottery and cinder weighing 210.8kg were found in the excavation of Yin Ruins in Anyang County, Henan Province, showing the process of China ancient working people obtaining copper from copper mines more than 3,000 years ago.
But things made of copper smelting are too soft, easy to bend and soon dull. Then it was found that tin and copper were mixed to make copper-tin alloy bronze. The melting and manufacturing of bronze devices are much easier and more difficult than pure copper (if the hardness of tin is set at 5, the hardness of copper is 30, while the hardness of bronze is 100 ~ 150). Historically, this period was called the Bronze Age.
China's book Zhou Li Kao Gong Ji during the Warring States Period summarized the experience of smelting bronze and described the different proportions of copper and tin used in bronze casting of different objects: "Gold has six qi (prescription). Its gold (copper) and tin are six points in one, that is, the gas of Zhong Ding; Its gold and tin are divided into one, that is, the axe Jin Qi; Its gold and tin are divided into one, that is, the gas of Geji; Two-thirds of its gold and tin are in one place, which is called the gas of the big blade; Its gold and tin are in the second place, that is, cutting and killing arrows (arrows) together; Suk Kim is half, called a mirror (mirror) (using a mirror to gather light to make a fire). " This shows that more than 3000 years ago, the working people in our country have realized that different bronzes have different requirements for performance, and the proportion of metal components used to cast bronzes should also be different.
Because bronze is hard and easy to melt, it can be well cast and formed, and it is stable in the air, even in the Iron Age after the Bronze Age, it has not lost its use value. For example, around 280 BC, the bronze sun god stood in Rhodes Harbor on Rhodes Island in the Aegean Sea of Europe, with a height of 46 meters, which was higher than an adult's finger.
The working people in ancient China first used natural copper compounds to smelt copper by wet method, which is the origin of wet technology and an invention in the history of world chemistry. This method is expressed by modern chemical formula:
Copper sulfate+iron = ferrous sulfate+copper
According to western legend, the ancient Mediterranean island of Cyprus was a place where copper was produced, hence its Latin name CUPRUM and its element symbol Cu. Both COPPER in English and CUIVRE in Latin come from this place.
Copper has unique electrical conductivity, which cannot be replaced by aluminum. In today's era of the development of electronic industry and household appliances, this ancient metal has regained its youth. Copper conductor is being widely used. From the perspective of foreign products, the copper wire required for the electronic and electrical accessories of an ordinary family car is as long as 1 km, and the rails of French high-speed trains use 10 ton of copper per km, which accounts for 2% of the total weight of Boeing 747-200 aircraft.
Application of 1. in electrical industry
Power transmission ※
A large amount of copper with high conductivity is needed in power transmission, which is mainly used in power cables, buses, transformers, switches, plug-ins and connectors.
In the process of wire and cable transmission, electric energy is wasted due to resistance heating. From the point of view of energy saving and economy, the standard of "optimal cable section" is being popularized all over the world. In the past, the popular standard only determined the minimum allowable size of the cable from the perspective of reducing the one-time installation investment, in order to minimize the cross section of the cable and avoid dangerous overheating under the rated current required by the design. The cable laid according to this standard, although the installation cost is low; However, in the process of long-term use, the energy consumption of the resistor is relatively large. The "best cable section" standard comprehensively considers two factors: one-time installation cost and power consumption, and appropriately enlarges the cable size to achieve the purpose of energy saving and the best comprehensive economic benefits. According to the new standard, the cable section is often more than twice as large as the old standard, and about 50% energy saving effect can be obtained.
In the past, due to the shortage of steel in China, considering that the proportion of aluminum is only 30% of that of copper, aluminum was used to replace copper in overhead high-voltage transmission lines, hoping to reduce the weight. At present, considering environmental protection, underground cables will be laid on overhead transmission lines. In this case, compared with copper, aluminum is dwarfed by its poor conductivity and large cable size.
The same primary circuit is replaced by an energy-saving and efficient copper winding transformer! Japanese aluminum winding transformer is also a wise choice.
Automobile manufacturing ※
Copper alloy has high conductivity and high strength, and is widely used in motor manufacturing. The main copper parts are stator, rotor and shaft head. In a large motor, the winding needs to be cooled by water or hydrogen, which is called double water internal cooling or hydrogen cooling motor and needs a long hollow conductor.
Motor is a big user of electric energy, accounting for about 60% of the total power supply. The accumulated electricity fee of a motor is very high, which generally reaches the original cost of the motor within the first 5 00 hours, which is equivalent to 4 ~ 16 times of the cost in one year and 200 times of the cost during the whole working life. A small increase in motor efficiency can not only save energy; But also can obtain remarkable economic benefits. The development and application of high-efficiency motor is a hot topic in the world today. Because the energy consumption inside the motor mainly comes from the resistance loss of the winding; Therefore, increasing the cross-sectional area of copper wire is the key measure to develop high-efficiency motor. Compared with traditional motors, the usage of copper windings in some high-efficiency motors pioneered in recent years has increased by 25 ~ 100%. At present, the US Department of Energy is funding a development project to produce motor rotors by casting copper.
Communication cable ※
Since 1980s, due to the advantages of large carrying capacity, optical cable has been replacing copper cable in communication trunk lines, and it has been rapidly popularized and applied. However, a lot of copper is still needed to convert electric energy into light energy and input lines to users. With the development of communication, people rely more and more on communication, and the demand for optical cable and copper wire will also increase.
Residential circuit ※
In recent years, with the improvement of people's living standards and the rapid popularization of household appliances, the electricity load of residents has increased rapidly. As shown in Figure 6.6, the electricity consumption of residents in 1987 was 26.96 billion kWh (l kWh = 1 kWh), and after 10, it soared to131100 million kWh, an increase of 3.2 times. Nevertheless, there is still a big gap compared with developed countries. For example, in 1995, the per capita electricity consumption of the United States was 14.6 times that of China, and that of Japan was 8.6 times that of China. In the future, China residents' electricity consumption will still develop greatly. It is predicted that from 1996 to 2005, it will increase by 1.4 times.
2. Application in electronic industry
Electronic industry is a new industry. In the process of its vigorous development, new products and new application fields of steel are constantly developed. At present, its application has developed from electric vacuum devices and printed circuits to microelectronics and semiconductor integrated circuits.
Electric vacuum device ※
Electric vacuum devices are mainly high-frequency and ultra-high-frequency emission tubes, waveguides, magnetrons and so on. They need high-purity oxygen-free copper and dispersion-strengthened oxygen-free copper.
Printed circuit ※
Copper printed circuit, with copper foil as the surface, stuck on the plastic board as a support; Print the circuit wiring diagram on the copper plate by photography; Excess parts are removed by etching, leaving interconnected circuits. Then punch holes in the connection between the printed circuit board and the outside, insert the terminals of discrete components or other components, and weld them on this port, thus assembling a complete circuit. If immersion plating is used, all joints can be welded at one time. In this way, for those occasions that need fine layout of circuits, such as radios, televisions, computers, etc. The use of printed circuits can save a lot of labor for wiring and fixing circuits; So it is widely used and needs to consume a lot of copper foil. In addition, various copper-based solders with low price, low melting point and good fluidity are needed in the connection of circuits.
Integrated circuit ※
The core of microelectronics technology is integrated circuit. Integrated circuit refers to a miniaturized circuit which takes semiconductor crystal material as the substrate (chip) and integrates the components and interconnection lines of the circuit on the inside, surface or substrate by special technology. This microcircuit is thousands of times smaller in size and weight than the most compact discrete component circuit. Its appearance caused great changes in computers and became the basis of modern information technology? D shell concave howl? 3. Who is it? hey
Lead frame ※
In order to protect the normal operation of integrated circuits or hybrid circuits, it is necessary to package them; When packaging, a large number of connectors in the circuit are led out of the sealing body. These leads are required to have certain strength and form the supporting skeleton of integrated packaging circuits, which is called lead frame. In actual production, for high-speed mass production, the lead frame is usually stamped on the metal strip continuously in a specific arrangement. Frame materials account for 1/3 ~ L/4 of the total cost of integrated circuits, which is very large; Therefore, there must be low cost.
Copper alloy has low price, high strength, electrical and thermal conductivity, excellent machinability, needle weldability and corrosion resistance. Its properties can be controlled in a wide range by alloying, which can better meet the performance requirements of lead frames and has become an important material of lead frames. At present, steel is the most widely used material in microelectronic devices.
3. Application in energy and petrochemical industry
Energy industry ※
Both firepower and atomic power generation rely on steam to do work. The steam circuit is as follows:
The steam generated in the boiler-steam pushes the turbine to do work-the steam after doing work is sent to the condenser-cooled into water-and returned to the boiler to become steam again.
At the same time, the main condenser consists of tube plate and condenser tube. Because steels have good thermal conductivity and can resist water corrosion, they are made of pot brass, aluminum brass or white copper. According to the data, 5 tons of condenser tubes are needed for every 10,000 kilowatts installed capacity. A 600,000 kW power plant needs 3 00 tons of condenser tubes.
The use of solar energy also uses a lot of copper pipes. For example, the swimming pool of a hotel near London, England, is equipped with a solar water heater, which can keep the water temperature at 18 ~ 24℃ in summer. Solar water heaters contain 784 pounds (3.56 kilograms) of copper tubes.
Petrochemical industry ※
Copper and many copper alloys have good corrosion resistance in aqueous solution, hydrochloric acid and other non-oxidizing acids and organic acids (such as acetic acid, citric acid, fatty acid, lactic acid, oxalic acid, etc.). ), all kinds of alkali and non-oxidizing organic compounds except ammonia (such as oils, phenols, alcohols, etc.). ); Therefore, in the petrochemical industry, a large number of containers, piping systems, filters, pumps and valves are used to manufacture corrosive media. It also uses its thermal conductivity to manufacture various evaporators, heat exchangers and condensers. Because of its good plasticity, copper is especially suitable for manufacturing heat exchangers and cross-woven copper tubes with complex structures in modern chemical industry. In addition, bronze production tools are used in oil refineries; The original circuit will not burst into sparks when it is impacted, which can prevent the occurrence of fire.
Marine industry ※
The ocean accounts for more than 70% of the earth's surface area, and people pay more and more attention to the rational development and utilization of marine resources. Seawater contains chloride ions that are easy to cause corrosion, and many engineering metal materials such as steel, aluminum and even stainless steel are not resistant to seawater corrosion. In addition, marine dirt will be formed on the surfaces of these materials and non-metallic materials such as wood and glass. Copper is outstanding, not only resistant to seawater corrosion; Moreover, copper ions dissolved in water have bactericidal effect and can prevent marine organisms from fouling. Therefore, copper and copper alloys are very important materials in marine industry and have been widely used in seawater desalination plants, offshore oil and gas platforms and other coastal and submarine facilities. For example, pipeline systems, pumps and valves used in seawater desalination, and equipment used on oil production and gas production platforms, including bolts, drilling days, anti-pollution bags, pump valves and pipeline systems used in splash areas and underwater. The next section will introduce the application of copper and copper alloys in ships.
4. Application in transportation industry
Ship ※
Many copper alloys, such as aluminum bronze, manganese bronze, aluminum brass, gun copper (tin-zinc bronze), Bai Gang and nickel-copper alloy (Monel alloy), have become standard materials for shipbuilding. Generally, copper and copper alloys account for 2 ~ 3% of the weight of warships and merchant ships.
The propellers of warships and most large merchant ships are made of aluminum bronze or brass. Each propeller of this big ship weighs 20 ~ 25 tons. The propellers of the aircraft carriers Queen Elizabeth and Queen Mary each weigh 3 5 tons. The heavy stern shaft of large ships often uses "Admiral" gun copper, and the conical bolts of rudder and propeller also use the same material. Steel and copper alloys are also widely used in engines and boiler rooms. The world's first nuclear-powered merchant ship used 30 tons of copper condenser tubes. Recently, aluminum brass tubes have been used as large heating coils for oil tanks. There are 12 such oil storage tanks on the 65438+ million-ton ship, and the corresponding heating system is quite large. The electrical equipment on the ship is also very complicated, and the engine, motor and communication system almost all rely on copper and copper alloys. The cabins of large and small ships are usually decorated with steel and copper alloys. Even for wooden boats, it is best to use alloy steel (usually silicon bronze) screws and nails to fix the wood structure. This kind of screw can be mass-produced by rolling.
In order to prevent the hull from being polluted by marine life and affect navigation, copper plating was often used for protection in the past. Now it is usually solved by brushing copper-containing paint.
In World War II, in order to prevent German magnetic mines from attacking ships, an anti-magnetic mine device was developed. A copper belt is tied around the steel hull to neutralize the ship's magnetic field and make the mine unable to detonate. Starting from 1944, all allied ships, about 18000 ships, have been protected by this degaussing device. Some large capital ships need a lot of copper for this purpose. For example, one of them uses copper wire, which is 28 miles long and weighs about 30 tons.
Automobile ※
The amount of copper for automobiles is 10 ~ 2i kg/ vehicle, which varies with the type and size of automobiles, accounting for about 6 ~ 9% of the automobile weight. Copper and copper alloys are mainly used in radiators, brake system pipelines, hydraulic devices, gears, bearings, brake friction plates, power distribution and power systems, washers and various joints, fittings and decorations. Among them, the radiator is the one with large amount of steel. Modern pipe belt radiator is welded with brass belt and bent into heat sink with thin copper belt.
In recent years, many improvements have been made to copper radiator to further improve its performance and enhance its competitiveness compared with aluminum radiator. In terms of materials, adding trace elements to copper can improve its strength and softening point without losing its thermal conductivity, thus reducing the thickness of thin strip and saving steel consumption; In the manufacturing process, the copper tube is welded by high frequency or laser, and the radiator core is assembled by steel brazing instead of soft welding which is easy to be polluted by lead. The results of these efforts are shown in Table 6.2. Compared with brazed aluminum radiator, under the same heat dissipation conditions, that is, the pressure drop of air and coolant, the new copper radiator is lighter and smaller. Coupled with the good corrosion resistance and long service life of steel, the advantages of copper radiator are more obvious.
Railway ※
Railway electrification needs a lot of copper and copper alloys. Overhead lines need more than 2 tons of special-shaped copper wire per kilometer. In order to improve its strength, a small amount of copper (about 1%) or silver (about%%) is often added. In addition, the motor, rectifier, control, braking, electrical and signal systems on the train all depend on copper and copper alloys.
Airplane. ※
Aircraft navigation is also inseparable from copper. For example, wiring, hydraulic, cooling and pneumatic systems in airplanes all need copper, aluminum bronze pipes are used for bearing seats and landing gear bearings, diamagnetic steel alloys are used for navigators, and many instruments use copper elastic components.
5. Application in machinery and metallurgical industry
Mechanical engineering ※
Almost all machines have copper parts. In addition to a large number of steel used in motors, circuits, hydraulic systems, pneumatic systems and control systems, a wide variety of transmission parts and fixed parts made of brass and bronze, such as gears, worm wheels, worms, coupling parts, fasteners, torsion parts, screws and nuts, can be seen everywhere. Bearings or bushings made of wear-resistant copper alloys are used for almost all parts that move relatively. In particular, the cylinder liners and slide plates of 10,000-ton large-scale extruders and forging presses are almost all made of bronze, and the weight of castings can reach several tons. Many elastic elements are made of silicon bronze and tin bronze. Welding tools, die casting molds and so on are inseparable from copper alloys, and so on.
Metallurgical equipment ※
Metallurgical industry is a big consumer of electric energy and is called "electric tiger". In the construction of metallurgical plants, it is usually necessary to have a huge power transmission and distribution system and power operation equipment that relies on copper. In addition, in pyrometallurgy, continuous casting technology has occupied a dominant position, and the key components of crystallizer are mostly copper alloys with high strength and high thermal conductivity, such as chromium copper and silver copper. In electro-metallurgy, the water-cooled crucibles of vacuum arc furnace and electroslag furnace are all made of steel pipes, and all kinds of induction coils for induction heating are made of copper pipes or special-shaped copper pipes, and the inside is water-cooled.
Alloy additive ※
Copper is an important additive element in alloys such as steel and aluminum. Adding a small amount of copper (0.2 ~ 0.5%) to low-alloy structural steel can improve the strength and atmospheric and marine corrosion resistance of steel. Adding copper to corrosion-resistant cast iron and stainless steel can further improve their corrosion resistance. High-nickel alloy containing about 30% copper is a famous monel alloy with high strength and corrosion resistance, which is widely used in nuclear industry.
Many high-strength aluminum alloys contain copper. Through quenching-aging heat treatment, dispersed fine particles are precipitated in the alloy, and the strength is significantly improved, which is called age hardening aluminum alloy. Among them, hard aluminum or hard aluminum is famous, which is an aluminum alloy containing copper, manganese and magnesium, and is an important structural material for manufacturing aircraft and rockets.
6. Application in light industry
Light industrial products are closely related to people's lives, and there are many kinds and varieties. Because steel has good comprehensive properties, it can be seen everywhere. Here are a few examples:
Air conditioner and refrigerator ※
The temperature control function of air conditioner and freezer is mainly realized by evaporation and condensation of copper tube of heat exchanger. The size and heat transfer performance of heat transfer tubes largely determine the efficiency and miniaturization of the whole air conditioning and refrigeration device. All these machines use special-shaped copper tubes with high thermal conductivity. Based on the excellent machinability of steel, a radiator tube with high fin and inner groove has been developed recently, which can be used to manufacture heat exchangers in air conditioners, freezers, chemicals and waste heat collection devices. The total thermal conductivity of the new heat exchanger can be increased to 2-3 times that of ordinary tubes and 1.2- 1.3 times that of ordinary low fin tubes. Used in China, it can save 40%.
Watch and clock. ※
Clocks, timepieces and devices with clockwork mechanisms are now produced, and most of the working parts are made of "clock brass". The alloy contains 1.5-2% lead, which has good machinability and is suitable for mass production. For example, gears are cut from long extruded brass bars, flat wheels are stamped from strips of corresponding thickness, and carved clock faces, screws and joints are made of brass or other copper alloys. A large number of cheap watches are cannon copper (tin-zinc bronze) or nickel-plated silver (white copper). Some famous big clocks are made of steel and copper alloys. The hour hand of the British "Big Ben" is made of solid cannon copper rod, and the minute hand is made of 14 foot long copper tube.
A modern watch factory, with copper alloy as the main material, can produce 1 10,000 to 30,000 watches every day with low cost.
Papermaking ※
In a society with ever-changing information, the consumption of paper is very large. The surface of paper looks simple, but the paper-making process is very complicated, requiring many steps and many machines, including coolers, evaporators, beaters, paper machines and so on. Many parts, such as various heat exchange tubes, rollers, impact rods, semi-fluid pumps, screens, etc., are mostly made of steel alloys.
For example, at present, fourdrinier machine is used to spray the prepared pulp onto the fast-moving fine mesh (40-60 mesh). Mesh cloth is woven from brass and phosphor bronze wires, and its width is very large, generally more than 20 feet (6 meters), and it is required to be completely straight. The mesh cloth moves on a series of small brass or copper rollers, and when it passes with the pulp sprayed on it, the water is sucked out from below. The screen vibrates at the same time, bonding the small fibers in the pulp together. The mesh size of a large paper machine is very large, which can reach 26 feet 8 inches (8. 1 m) wide and 65,438+000 feet (3 0. 5 meters) long. Wet pulp not only contains water, but also contains chemicals used in papermaking process, which is very corrosive. In order to ensure the quality of paper, the requirements for mesh materials are very strict, not only with high strength and elasticity; In addition, copper alloys are fully capable of resisting pulp corrosion.
Printing ※
In printing, copper plates are used for photographic plate making. The polished copper plate was sensitized with emulsion and photographed. The exposed copper plate needs to be heated to harden the glue. In order to avoid heating softening, copper often contains a small amount of silver or arsenic to increase the softening temperature. Then, the plate is etched to form a printed surface with a pattern of concave and convex dots.
On the automatic typesetting machine, brass font blocks are arranged to make plates, which is another important use of copper in printing. Font blocks are usually made of lead-containing brass, sometimes copper or bronze.
Brewing wine. ※
Copper plays an important role in world beer brewing. Copper is often used as the inner village of malt barrels and fermenters. In some famous wineries, there are more than a dozen such vats with a capacity of more than 20,000 gallons. In the fermenter, steel pipes are often used to cool down in order to cool down. It is also used to heat beer by introducing steam into steel pipes, and to transport liquor through steel pipes.
When distilling whisky and other spirits, steel distillers are usually used. Whisky malt liquor needs to be distilled twice, and two large copper distillation pots are needed.
Medicine ※
In the pharmaceutical industry, all kinds of steaming, boiling and vacuumizing instruments are made of pure copper. Zinc-white copper is widely used in medical devices. Copper alloy is also a common material for spectacle frames.
7. Copper for building and art
Piping system ※
Compared with galvanized steel pipes and plastic pipes, steel pipes have many advantages, such as beautiful and durable appearance, convenient installation, safety, fire prevention, health care and so on, and have obviously superior cost performance. In residential and public buildings, automatic sprinkler systems for water supply, heating, gas supply and fire prevention are increasingly favored by people and become the first choice material at present. In developed countries, copper water supply system has accounted for a large proportion. Manhattan Building, the sixth tallest building in the world in new york, USA, only uses 60,000-foot (L km) copper pipes to unify the water system. In Europe, the consumption of steel pipes for drinking water is very large. The average consumption of steel pipes for drinking water in Britain is 1.6 kg per person per year, and that in Japan is 0.2 kg. Because galvanized steel pipes are easy to rust, many countries prohibit their use. Hong Kong banned it as early as 1996 65438+ 10, and Shanghai began to implement it in May. It is imperative to popularize the use of copper pipe system in residential construction in China.
House decoration ※
In Europe, building roofs and eaves with steel plates is a tradition. Nordic countries even use it as a wall decoration. Copper has good atmospheric corrosion resistance, durability and recyclability. It has good processability, can be easily made into complex shapes, and has beautiful colors. So it is very suitable for house decoration. It has a long history of application on the roofs of churches and other ancient buildings, and it still exudes attractive brilliance. Moreover, it is used more and more in modern large-scale buildings, even in the construction of apartments and houses. For example, in London, the Commonwealth Parliament Building, which represents modern British architectural art, has a complex steel roof and weighs about 25 tons. 1966 crystal palace sports center, 60 tons of corrugated steel roof, etc. According to statistics, the copper plate used as the roof consumes 0.8 kg per person per year in Germany and 0.2 kg in the United States.
In addition, interior decoration, such as door handles, locks, shutters, bars, lamps, wall decoration and kitchen accessories. , not only durable, disinfection and hygiene, but also elegant and atmospheric decoration, deeply loved by people.
Statues and handicrafts ※
No metal in the world can be widely used to make all kinds of handicrafts like steel, and it lasts for a long time. In today's urban construction, cast copper alloy is widely used in various memorials, casting bells, Baoding, statues, Buddha statues, antique products and so on. Modern musical instruments, such as flutes, are made of white steel, while saxophones are made of brass. All kinds of exquisite works of art, cheap gold-plated, imitation gold and imitation silver jewelry also need to use copper alloys with various components.
Built in 1996, Hong Kong Tiantan Giant Buddha is made of tin, zinc and lead bronze, with a height of 26 meters and a weight of 206 tons. Guanyin Buddha in Nanhai, Putuo Mountain, Zhejiang Province, built in 1997, is 20 meters high and weighs 70 tons. This is the world's first giant bronze statue made of imitation gold. Later, an 88-meter-high bronze statue of Muni Buddha was built in Wuxi. Hainan Island, Jiuhua Mountain, Japan and India are building taller Buddha statues.