What are the uses of sodium, magnesium, aluminum, potassium, manganese, barium and mercury?

Pure metallic sodium is of little use in industry, but sodium compounds can be used in medicine, agriculture and photographic equipment. Sodium chloride is salt. Liquid sodium is sometimes used to cool nuclear reactors (sodium-potassium alloy is liquid at room temperature, which is the thermal conductor of nuclear reactors and plays the role of transferring the heat generated by the reactors to steam turbines. Molten metal sodium can be used as a heat exchanger in value-added reactors. In the past, sodium metal was mainly used to make antiknock agent for automobile gasoline, but it has been decreasing day by day because it will pollute the environment. Sodium metal is also used to prepare titanium and potassium, and to produce sodium hydroxide, sodium amino, sodium cyanide, etc.

reductant

It is often used as a reducing agent to replace metals such as titanium, zirconium, uranium and beryllium. It is mainly used for manufacturing light metal alloy, nodular cast iron, scientific instrument desulfurizer dehydrogenation and Grignard reagent, and also can be used for manufacturing fireworks, flash powder, magnesium salt, etc. Its structural characteristics are similar to those of aluminum. As a light metal, it has many uses and can be used as an alloy material for aircraft and missiles. However, magnesium is flammable at the ignition point of gasoline, which limits its application.

Daily use

Gymnasts often apply magnesium powder to increase friction. (MgCO3) Medical use: treating magnesium deficiency and spasm. Sports use: inject a few hours before strenuous exercise or after strenuous exercise to make up for the loss of magnesium.

danger

If the injection speed is too fast, it will cause fever and general discomfort. Magnesium can react with most nonmetals and acids; Magnesium hydride can be directly synthesized by hydrogen under high pressure; Magnesium can react with halogenated hydrocarbon or halogenated aromatic hydrocarbon to synthesize Grignard reagent, which is widely used in organic synthesis. Magnesium has an obvious tendency to form coordination compounds. Magnesium is an important material in aviation industry, and magnesium alloy is used to manufacture aircraft fuselage and engine parts. Magnesium is also used to make photographic and optical instruments; Magnesium and its alloys are also widely used in unstructured applications. As a strong reducing agent, magnesium is also used to produce titanium, zirconium, beryllium, uranium and hafnium. The strength of pure magnesium is small, but magnesium alloy is a good lightweight structural material, which is widely used in aerospace technology, aviation, automobiles, instrumentation and other industrial sectors. A supersonic plane contains about 5% magnesium alloy, and a missile generally consumes 100 ~ 200 kg of magnesium alloy. Magnesium is the main component of other alloys (especially aluminum alloys), and its combination with other elements can strengthen the heat treatment of aluminum alloys. Magnesium is used as nodulizer for nodular cast iron; However, some metals (such as titanium and zirconium) use magnesium as reducing agent in production; Magnesium is an indispensable component of incendiary bombs and flares; Magnesium powder is an essential raw material for festival fireworks; Magnesium is the structural material or packaging material of nuclear industry; Magnesium fertilizer can promote the absorption and utilization of phosphorus by plants, while the growth of plants lacking magnesium tends to stagnate. As a basic material, magnesium plays an important role in people's lives.

Application of magnesium in other fields

Magnesium is one of the lightest structural metal materials, which has the advantages of high specific strength and stiffness, good damping and machinability, and easy recycling. Magnesium alloys are used in automobile industry both inside and outside the national magnesium structure diagram to reduce weight, save energy, reduce pollution and improve the environment. The fuel consumption of automobiles in developed countries will eventually reach the goal of 3L. Magnesium for automobiles in Europe accounts for 65,438+04% of the total consumption of magnesium, and it is expected to increase at a rate of 65,438+05-20% in the future, reaching 200,000 tons in 2005. China's Dongfeng, Chang 'an and other automobiles have begun to use magnesium alloys. Soon, Chongqing, Chengdu and other places will become the R&D, application and production bases of magnesium alloys for automobiles in China. Compared with plastics, magnesium alloys have the advantages of light weight, high specific strength, good vibration damping, good thermal fatigue performance, difficult aging, good thermal conductivity, strong electromagnetic shielding ability, excellent die casting process performance and easy recycling. It is a new generation of high-performance structural materials to replace steel, aluminum alloy and engineering plastics. In order to adapt to the development trend of high integration, thinness and miniaturization of electronic and communication devices, magnesium alloys are ideal materials for product casings of transportation, electronic information, communication, computers, audio-visual equipment, portable tools, motors, forestry, textiles and nuclear power equipment. Developed countries attach great importance to the development and application of magnesium alloys, especially in the application of portable electronic products such as automobile parts and notebook computers, which is growing at a rate of 20% every year, which is very eye-catching and the development trend is amazing. As an electrical appliance city, Qingdao has invested 26.5438+0 million yuan and 350 million yuan to manufacture mobile phone casings, digital cameras, portable computers, palmtop computer casings and advanced audio-visual equipment casings, with an annual output of 65.4380+0.6 million magnesium molecular structure castings. The first magnesium alloy development and application industrialization base will be settled in Qingdao. Magnesium is the main alloying element in aluminum alloy, and the global annual demand is about 6.5438+0.5 million tons. In 2000, the output of aluminum alloy in China was 2.9 million tons, with magnesium as the alloying element, and the annual demand was about 654.38+0.065.438+0.000 million tons. With the increasing demand for high-strength and low-sulfur steel in automobile industry, petroleum, natural gas pipelines, offshore drilling platforms, bridge construction and other fields, in recent years, steel mills such as Angang, Baosteel, WISCO, Benxi Steel, Baotou Steel, Panzhihua Steel and Shougang have all used magnesium powder for deep desulfurization to obtain high-quality steel, and achieved good results. Magnesium powder has a potential steel desulfurization market. In addition, magnesium powder is also used to manufacture chemical products, medicines, fireworks, signals, signal flares and other materials, metal reducing agents, paints and coatings, welding wires and nodular cast iron nodulizer. As one of the effective methods to prevent metal corrosion, magnesium sacrificial anode can be widely used in subway pipelines, oil pipelines, storage tanks, offshore facilities, equipment, civil and other fields. Magnesium alloy profiles and pipes are used as bicycle frames, wheelchairs, rehabilitation and medical devices. Modern warfare requires the army to have the ability to quickly deploy sports at a long distance, and requires lightweight weapons and equipment. A large number of light metal materials will be used for hand-held weapons, armored combat vehicles, transport vehicles and aviation guidance weapons. Lightweight is an important direction to improve the combat performance of weapons and equipment. The light weight of magnesium determines that magnesium alloy is an essential structural material for the production of spacecraft, military aircraft, missiles, highly mobile chariots and ships. Therefore, the modernization of national defense needs to vigorously develop the application scope of magnesium alloys.

* Aluminum alloy is light in weight and high in strength, so it is widely used in making airplanes, cars and rockets. * Because aluminum has good electrical and thermal conductivity, it can be used as extra-high voltage cable material. High purity aluminum has better performance. * Aluminum can be easily reduced at high temperature, and can be used to smelt high melting point metals. (This method of smelting metal is called "aluminothermic method") * Aluminum is rich in resources and can be made into aluminum foil for packaging. * Aluminum is a metal and can be recycled, but the recovery rate is not high. * Aluminum has excellent corrosion resistance (especially oxidation resistance, because its oxide alumina increases the corrosion resistance and heat resistance of aluminum), good appearance and reasonable price, and is the first choice for computer chassis. In recent fifty years, aluminum has become one of the most widely used metals in the world. In addition to the above, in the construction industry, aluminum is widely used because of its stability in air and excellent appearance after anodic treatment; Aluminum alloy materials are also widely used in aviation and national defense military departments; In power transmission, aluminum cables reinforced with high-strength steel wires are often used; Container transportation, daily necessities, household appliances and mechanical equipment all need a lot of aluminum.

Used to make potassium-sodium alloy; Used as reducing agent in organic synthesis; It is also used to make photovoltaic cells. Potassium compounds are widely used in industry: potassium salts can be used to make fertilizers and soaps. Potassium plays an important role in the growth and development of animals and plants, and is one of the three major nutrient elements for plant growth.

The most important use of manganese is to make alloy manganese steel. The temper of manganese steel is very strange and interesting: if 2.5-3.5% manganese is added to the steel, the low manganese steel will be as brittle as glass, and it will break when knocked. However, if more than 13% manganese is added to make high manganese steel, it will become hard and tough. When high manganese steel is heated to light orange, it becomes very soft and easy to process. In addition, it has no magnetism and will not be attracted by magnets. Nowadays, manganese steel is widely used to manufacture buckets of steel mills, ball bearings, bulldozers and excavators, as well as iron-manganese-manganese rails and bridges. The roof of the audience hall of Shanghai New Cultural Square adopts a novel grid structure, which is welded by thousands of manganese steel pipes. The fan-shaped hall is 76 meters long and 138 meters wide, without a pillar in the middle. Because manganese steel is used as structural material, it is very strong, and the materials used are less than other steels, with an average of only 45 kilograms of manganese steel per square meter of roof. 1973 Xingjian Shanghai Gymnasium (accommodating 18000 people) also uses manganese steel as the structural material of the grid roof. Militarily, high manganese steel is used to make helmets, tank armor and penetrators. When refining manganese steel, soft tin ore containing 60-70% manganese and iron ore are mixed together for smelting.

Used to make barium salt, alloy, fireworks, etc. It is also an excellent deoxidizer for refining copper. Barium, strontium, calcium and magnesium are all alkaline earth metals, and they are also the elements with more contents in the earth's crust. However, the content of barium and strontium in the crust is still less than that of calcium and magnesium. In addition, their compounds are not as widely used as those of calcium and magnesium. Therefore, their compounds were recognized later than those of calcium and magnesium, but David also separated barium and strontium from calcium and magnesium by electrolysis. Used for barium meal

Inorganic compounds of mercury, such as mercury nitrate (Hg(NO3)2), mercury chloride (HgCl2), calomel (HgCl), mercury bromide (HgBr2), mercury arsenate (HgAsO4), mercury sulfide (HgS), mercury sulfate (HgSO4), mercury oxide (HgO) and mercury cyanide (Hg (Hg). Some of them are also used as drugs, and oral administration, excessive inhalation of dust and skin coating can cause poisoning. In addition, mercury fulminate (Hg(ONC)2. 1/2H2O) is used to manufacture detonators, etc.