|
О сайте:
|
chinachemicalgroup.com
With the rapid development of industry, a larger and larger range of Chemicals are invented and widely used in the production like Fluorine Chemicals.
Fluorine is an univalent poisonous gaseous halogen, it is pale yellow-green and it is the most chemically reactive and electronegative of all the elements. Fluorine readily forms compounds with most other elements, even with the noble gases krypton, xenon and radon. It is so reactive that glass, metals, and even water, as well as other substances, burn with a bright flame in a jet of fluorine gas.
In aqueous solution, fluorine commonly occurs as the fluoride ion F-. Fluorides are compounds that combine fluoride with some positively charged counterpart.
Atomic fluorine and molecular fluorine are used for plasma etching in semiconductor manufacturing, flat panel display production and MEMs fabrication. Fluorine is indirectly used in the production of low friction plastics such as teflon and in halons such as freon, in the production of uranium. Fluorochlorohydrocarbons are used extensively in air conditioning and in refrigeration. Fluorides are often added to toothpaste and, somewhat controversially, to municipal water supplies to prevent dental cavities. Fore more information visit our page on mineral water.
Small amounts of fluorine are naturally present in water, air, plants and animals. As a result humans are exposed to fluorine through food and drinking water and by breathing air. Fluorine can be found in any kind of food in relatively small quantities. Large quantities of fluorine can be found in tea and shellfish. Fluorine is essential for the maintenance of solidity of our bones. Fluorine can also protect us from dental decay, if it is applied through toothpaste twice a day. If fluorine is absorbed too frequently, it can cause teeth decay, osteoporosis and harm to kidneys, bones, nerves and muscles. Fluorine gas is released in the industries. This gas is very dangerous, as it can cause death at very high concentrations. At low concentrations it causes eye and nose irritations.
When fluorine from the air ends up in water it will settle into the sediment. When it ends up in soils, fluorine will become strongly attached to soil particles. In the environment fluorine cannot be destroyed; it can only change form. Fluorine that is located in soils may accumulate in plants. The amount of uptake by plants depends upon the type of plant and the type of soil and the amount and type of fluorine found in the soil. With plants that are sensitive for fluorine exposure even low concentrations of fluorine can cause leave damage and a decline in growth. Too much fluoride, wheater taken in form the soil by roots, or asdorbed from the atmosphere by the leaves, retards the growth of plants and reduces crop yields. Those more affected are corns and apricots.
Animals that eat fluorine-containing plants may accumulate large amounts of fluorine in their bodies. Fluorine primarily accumulates in bones. Consequently, animals that are exposed to high concentrations of fluorine suffer from dental decay and bone degradation. Too much fluorine can also cause the uptake of food from the paunch to decline and it can disturb the development of claws. Finally, it can cause low birth-weights.
Just like Fluorine Chemicals Lithium Chemicals are also commonly used. Lithium is the first of the alkalis in the periodic table. In nature it’s found like a mixture of the isotopes Li6 and Li7. It's the lightest solid metal, and is soft, silvery-white, with a low melting point and reactive. Many of its physical and chemical properties are more similar to those of the alkaline earth metals than to those of its own group. Between the most significant properties of lithium we find its high specific heat (calorific capacity), the huge temperature interval in the liquid state, high termic conductivity, low viscosity and very low density. Metallic lithium is soluble in short chain aliphatic amines, like etilamine. It's insoluble in hydrocarbons.
Lithium takes part in a huge number of reactions, with organic reactants as well as with inorganic reactants. It reacts with oxygen to form monoxide and peroxide. It’s the only alkaline metal that reacts with nitrogen at ambient temperature to produce a black nitrure. It reacts easily with hydrogen at almost 500oC (930oF) to form lithium hydride. Metallic lithium’s reaction with water is extremely vigorous. Lithium reacts directly with the carbon to produce the carbure. It binds easily with halogens and forms halogenures with light emission. Although it doesn’t react with parafinic hydrocarbons, it experiments addition reactions with alquenes substituted by arile and diene groups. It also reacts with acetylenic compounds, forming lithium acetylures, which are important in vitamin A synthesis.
The main lithium compound is the lithium hydroxide. It's a white powder; the manufactured material is monohydrate lithium hydroxide. The carbonate can be used in the pottery industry and in medicine as an antidepressant. The bromine and the lithium chloride both form concentrated brine, which have the property of absorbing the humidity in a wide interval of temperature; these brines are used in the manufactured air conditioning systems.
The main industrial use of lithium is in lithium stearatum form, as lubricant grease's thickener. Other important applications of lithium compounds are in pottery, specifically in porcelain glaze; as an additive to extend the life and performance of alkaline storage batteries and in autogenous welding and brass welding.
Except for the kinds metioned above, there are other chemicals especially for Electronic Grade Chemicals like Alumina Chemicals.
|