Graphite: melting point, properties and application
Graphite refers to minerals that differmultifunctionality in practical use. It is usually accepted to associate it with coloring substances, but this does not limit its possibilities. At the same time, one can not speak of the universality of the use of this material, since its layered structure also determines the scope of application. And this is not to mention the need to create special processing conditions. The fact is that the melting point of graphite in degrees Celsius can reach 2800 ° C, which requires the use of special capacities for the production of the final product.
Properties of graphite
Among the main operational qualities of thismineral, heat conduction, ability to act as a conductor of electric current and soft structure, which, however, does not always go in plus to graphite products. As for the thermal conductivity, it can reach 2400 W / (m * K) or more. This indicator depends on the structure and density of the material. It is important to note that graphite, whose melting point ranged from 2500 to 3000 ° C, has a softer structure. This may be beneficial for further disclosure of the wire mineral properties, but thermal treatment dramatically reduces physical strength characteristics. As a result, graphite can be as effective as metal in electrical conductivity processes, but because of its fragility it will not be suitable for use in conditions of severe mechanical operation.
Also, the mineral is characterized by reactivity incontacts with reactive substances, among which salts and alkali metals. True, this depends on the conditions in which graphite is found. A melting point of about 2800 ° C (at which the mineral interacts with oxygen) can lead to its combustion before the formation of carbon dioxide.
The temperature spectrum at which it is possible to obtainmelting of graphite is very diverse. Much depends, for example, on the final tasks of this operation. The temperature range also determines the external conditions, and the characteristics of the composition of a particular mineral, and the use of additional means of impact on graphite during heat treatment. The melting point at which graphite ready for use can be obtained varies from 2,600 to 3,800 ° C. Calculation on the Kelvin scale is also practiced. In this case it already reaches 4000 ° K, but this value can also increase depending on the pressure index. Usually, graphite is melted at a pressure of 105 - 130 bar.
Need for heat treatmentis due to the fact that enterprises tend to modify the performance of the material in order to create more efficient products. Less commonly used methods to bring the mineral to boil, but they also improve certain properties of the structure. The question of what is the melting point and the boiling point of graphite, often involves specifying the same range - from 3800 to 4200 ° C. The lower threshold determines the melting state, and the upper one determines the boiling point of the material. Again, depending on the characteristics of the graphite and its variety, the conditions of thermal action in terms of obtaining the desired state of the mineral - boiling or melting - can converge.
Technologies for obtaining
Virtually all graphite products before the finaluse are subject to processing operations. The method of production is determined by a variety of graphite material. As a rule, the difference in methods is due precisely to the temperature effect. Thus, by heating the pitch and coke mixture, Acson's graphite is obtained. The melting and boiling points in this case will be 2800 and 4200 ° C, respectively. The thermomechanical technique of processing the coke mixture provides for the effect with the same heating parameters - the difference is only in the application of carbide-forming components. The pyrolysis method is a low indicator of the temperature treatment. In this case, natural graphite is modified from gaseous hydrocarbons in a vacuum at 1500 ° C. At the same time, cooling methods for processing base mixtures for graphite production are also common. These technologies include blast furnace, in the process of which the cooling of the cast iron masses is slow.
Application of graphite
The properties of graphite, as already noted, allowedhe can find wide application in various fields. It is used in the manufacture of electrodes, pencils, protective equipment, reference measuring materials and even as a lubricant. The thermal qualities of the mineral determined its usefulness in the structure of the furnace facilities. For example, lining plates and melting crucibles are made of graphite. But here too much depends on the specific variety in which graphite is presented. The melting point of some types of material, 2600 ° C, for example, does not allow their use in industrial heat treatment chambers. But electrochemical properties allow using most graphite products as elements of the conductor infrastructure.
Graphite materials can be considered asFlexible basis for use in different industries. The qualities of electrical and thermal conductivity, although they are adjacent to physical fragility and modest indicators of mechanical reliability, but open up wide opportunities for highly specialized application of the mineral. In terms of industrial processing standards, the melting point of graphite in degrees, which is an average of 2800 ° C, is not critical. To organize the process of melting or boiling the material can even afford small enterprises engaged in the manufacture of electrochemical fittings. Another thing is that the production of finished graphite products requires not only thermal processing.