冶金原理（Metallurgical principle）

1、冶金原理（Metallurgical principle）1., according to the process of extracting metal, it is divided into metallurgy, hydrometallurgy and electro metallurgy.2. the science and principle of applying physical chemistry to study the principles of metallurgical processes is called metallurgy principle.3. the th

2、ermodynamics of metallurgical process is the possibility of studying the metallurgical reaction process and the equilibrium condition of reaction using the principle of chemical thermodynamics.4. metallurgical process dynamics is the study of the rate and mechanism of metallurgical processes using t

3、he principles of chemical kinetics and the principles of matter, heat and kinetic energy transfer.5. metallurgical melt is a specific substance involved in the process of metallurgical reaction. It studies the phase equilibrium structure and physical and chemical properties of melts.6., the Gibbs fr

4、ee energy change of chemical reaction is the basis for judging whether the reaction can be spontaneous under constant temperature and constant pressure.7. the equilibrium constant of a reaction: when a chemical reaction reaches equilibrium at a given temperature, the product of the activity product

5、of the product is the constant of the product of the activity of the reactants.8., the change of pressure quotient or activity quotient is the means to realize the reaction in metallurgy.9. solution is a homogeneous mixing system composed of two or more than two substances.10. Raouls Law: in the sol

6、ution, when the component B XB = 1, its vapor pressure is linearly related to its concentration XB Pb=Pb*xb11. in the whole range of concentration, the solution obeying Raouls law is called an ideal solution.12. Henrys Law: when the concentration of B in the solution is close to that of the 0 dilute

7、 solution, the vapor pressure of the component B is linearly related to its concentration Xb: Pb=Kh (x).Xb13. the solution obeying Henrys law is a dilute solution.14. in the treatment of metallurgical reaction equilibrium constant need to pay attention to certain features of the component activity:

8、in metallurgical process, as the solvent of iron, if the dissolved amount of elements is not high, and the concentration of iron is high, can be regarded as W (Fe) =100% X (Fe) =1, YISHION as a standard substance state: W (Fe) =X (Fe) =1 and R (Fe) =1 activity; therefore iron not including the equil

9、ibrium constant. When the formation of saturated solution is B, the YISHION material is the standard state, aB=1., if the solution belongs to dilute solution, then the concentration can be used instead of activity (Kh is the standard state). The activity of the component in the solution is often cho

10、sen as pure material standard, because its concentration is relatively high.15. when the width property is Gibbs free energy, the partial molar quantity of the component B is called the chemical potential.The Gibbs free energy of 16. solutions is equal to the sum of the partial molar Gibbs free ener

11、gy Gb and its quantity nB product of each component.17. the excess function is the partial molar value of the actual solution when it is assumed to be the partial molar quantity of the ideal solution.18. distribution law: at a certain temperature, component B is dissolved in two immiscible liquid ph

12、ases. When equilibrium, the ratio of component B to activity in two is constant.19. The arrangement of atoms in a crystal is remote. It consists of an ordered array of atoms that occupy the entire crystal volume and exhibit cycles in a three-dimensional direction at a distance.20., two or more than

13、two kinds of metal elements, according to a certain proportion of the formation of new compounds, known as metal compounds.21. the structure of liquid metal refers to the arrangement of atoms or ions in liquid metal, which determines the contrast between atoms.22. the metal melt in general smelting

14、temperature is quasi crystalline structure.23. the structural model of metal melt describes the structure of metal melt and the movement of atoms in a more visual way, including: free volume model, vacancy model and cluster model.24. square root law: at a given temperature, the solubility of diatomi

15、c gases in metals is proportional to the square root of the partial pressure of gas.25. viscosity is the frictional force acting on the unit area between the parallel liquid layers under the unit velocity gradient.26. temperature increase; not only the atomic thermal motion energy increases, the act

16、ivation energy required to supply the particle movement, the specific price increase of the number of quality, but also has the potential to form a viscous flow unit group cluster size decreases, thus reducing the melt viscosity.The excess concentration of the 27. dissolved component on the liquid s

17、urface is called the positive electrode in comparison with the internal concentration of the solution. It reduces the surface tension of the solution. This component is called surfactant.28. when the concentration of the dissolved component appears below the surface, it is relative to the positive a

18、dsorption of negative adsorption. It can keep the surface tension of the solvent unchanged or increase. This component is called non surface active substance.29. slag is a component of molten oxide formed by metallurgical process.30. slag can be classified as follows: the reduction smelting of ore o

19、r concentrate as raw material, crude metal at the same time, the slag is not reduced and the solvent added to the slag, known as smelting slag or reducing slag. Refining crude metal; the slag consisting of elemental oxide is called refining slag or oxidizing slag. Some useful ingredients in the raw

20、material are enriched in the slag, so that the slag which is recovered to the next process is called enrichment slag. The role of slag,But the use of pre prepared slag slag material called synthetic slag.31. the slag in smelting process is an oxide which can not be reduced by reduction furnace. Oxid

21、ation formation of oxide during smelting. In order to meet the requirements of smelting, the flux and refractory oxide of the refractory are added, and a small amount of sulfide and CaF2 and other halides are formed, in which a small amount of metal particles are entrained.32. in the process of meta

22、l smelting slag respectively in the separation or absorption of impurities, the removal of impurities in crude metal metal products harmful to the properties of metal oxides and metal refining enrichment useful role, and can protect the metal from the environment and reduce the heat loss of metal co

23、ntamination.The storage of 33. slag is controlled by controlling the chemical composition, temperature and physicochemical properties of the slag.34., the physical and chemical properties of slag are related to the structure.The 35. phase diagram is the phase equilibrium relation between the composi

24、tion of the condensed phase system and the temperature.36. molecular structure hypothesis and ion structure theory.37. molecular structure hypothesis four points: (1) slag is regarded as an ideal solution for various molecular particles. Molecules are simple compounds or oxides. There is a balance r

25、elationship between them. Only free oxides have the ability to react chemically.38.P178Oxides of 39.3 types of slag: 1. Acidic oxides: SiO2, P2O5, V2O5, Fe2O3., basic oxides CaO, MgO, FeO, MnO, V2O3, Al2O3, TiO3, Cr2O3.40. in production practice, the ratio of the mass fraction of the main alkaline o

26、xide in the slag to the acidic oxide content is defined as the basicity of the slag.41., the ability of slag to contain or dissolve harmful substances is called the capacity of slag.42., the solid slag completely changes into homogeneous liquid phase, or the liquid slag begins to precipitate the tem

27、perature of the ancient phase when cooling.43. the material that can reduce the melting point of slag when added is called flux.44.CaF2 plays an important role in adjusting viscosity.45. at present, under the condition of smelting, alkaline slag has less viscosity than acid slag.46. basic slag cooli

28、ng can pull into Cathy, section is glassy, and because the solidification temperature range is wide, so called card or the stability of slag slag.47. when the temperature is low, the melting temperature (melting point) is also lower.48. the temperature has little influence on the surface tension of

29、slag.49. slag components which affect the interfacial tension can be divided into two categories: (1) insoluble or slightly dissolved slag components in molten metal, such as SiO2, CaO, Al2O3, etc., do not cause significant changes in G2. (2) energy distribution in slag and liquid metal between the

30、components, such as FeO, FeS, MnO and CaL2 of G2 decreased greatly because of non metal elements in these fractions can enter the metal, the interface structure of molten metal and slag to reduce the phase step asymmetry of the particles on the surface of stress field. Especially in the metal in liq

31、uid oxygen on G2 reduce the decisive.50. metal liquid elements that affect interfacial tension. (1) the elements such as C, W, Mo, Ni and so on do not change into the slag phase, but have no effect on G2. (2) the elements that can form oxides into the slag, such as Si, P, Cr and Mn, can reduce G2 be

32、cause they can form chromium ions, which are called surface active components in slag. (3) elements with strong surface activity, such as O and S, reduce G2, and the effect is very strong. Although their concentration is very low, but their role is very large, far more than the role of acidic oxides

33、.51., the greater the decomposition pressure, the greater the delta rGm theta, the more easily decomposed compounds, and its stability is less.There are two ways to decompose compounds when they desire to be in a certain state. (1) reduce the partial pressure of gas B AB. (2) increasing the system t

34、emperature Pb (AB).53. the temperature that heats up to Pb (AB) =Pb is the temperature at which AB (s) starts at B (g) and continues, and is called the temperature at which the decomposition of the compound begins.54. when the compound is heated, the decomposition pressure reaches the total pressure

35、 system, compound intense decomposition, especially if the water is heated to the vapor pressure is equal to the external pressure boiling, then the decomposition temperature of compounds called boiling temperature.55., three reduction methods; 1 indirect reduction method using combustible gas as co

36、mbustible gas; 2. direct reduction method using solid C as reductant; 3. metal reduction method using metal such as si.Al as reducing agent.Thermodynamic conditions for the reduction of 56. oxides; a given temperature must be greater than the starting reduction temperature.57. at 818 degrees Celsius

37、 hydrogen and carbon monoxide reduction has the same ability; less than 818 degrees Celsius, reducing power capacity of carbon monoxide is less than hydrogen; at 818 degrees Celsius, carbon monoxide. Less than hydrogen.58., three hundred page examples59., the amount of heat released by a unit molar

38、mass reactant (charge) in a thermal reduction reaction is characterized by heat release from a heat reduction, known as the unit charge effectSixtyIn order to make the metal heat reduction proceed smoothly without external heating, the heat effect of unit charge should be more than 2300KJ.kg-1., but

39、 the refractory oxide Q should be higher than this.61. when the heating effect of the furnace is small and the reaction can not be carried out normally, it is necessary to add readily reducible oxide to the burden or to make the reaction in an external heat source, such as in an electric furnace. Bu

40、t if the reaction is too exothermic and the charge is overheated, a large amount of material will splash out. This should be accompanied by an inert substance which does not react with the reducing agent.62. in blast furnace, the content of Si in pig iron is mainly controlled by temperature and basi

41、city of slag.63. main factors of slag desulphurization: (1) temperature (2), basicity of slag (3), composition of metal melt (4) hearth oxygen potential.64. the oxidizing agents used in oxidizing smelting are oxygen, air, oxygen gas, and iron ore.65. the elements above the FeO oxygen line are virtua

42、lly non oxidizing.66.P342 exampleThe role of the partition constant of the 67. element oxidation: the degree to which the element is oxidized.The 68. distribution constant is when the element is oxidized, from the metal phase to the slag phase. The state of a store (or formation) changes.69. reducin

43、g the temperature (increasing K), increasing the oxidation energy of slag and reducing rMnO (reducing alkalinity) can lead to the oxidation of manganese in molten steel.70., decreasing the temperature (increasing K), increasing the activity of FeO (Fe2+ and O2-) in slag and decreasing rsiO2 (increas

44、ing basicity) can strengthen the oxidation of Si.71., the removal of P is essentially the use of oxidizing agents to oxidize P in liquid iron to P2O5 and then to form a stable compound compound with an additive P that reduces its activity coefficient and is present in the slag.72., the thermodynamic

45、 conditions of removing P: (1) high iron oxide, high basicity, namely P slag with large capacity, is formed in time, which is a necessary condition for strengthening P removal. (2) the P removal reaction is highly exothermic (rHm theta = - 384KJ - mol-1) elevated temperature K value decreased (CPO4

46、theta 3- also decreases), so low temperature is conducive to removal of P. (3) the existence of some elements (C, O) that can remove phosphorus and activity coefficients in metal solutions.73. influencing factors: (1) composition of slag (2) composition of metal (3) temperature;74. precipitation deo

47、xidation: an oxide formed by adding oxygen to the molten steel and forming an element of stable oxide with oxygen. It can be expelled by buoyancy of itself or by convection of molten steel. Diffusion deoxidation: using molten slag with low iron oxide content to treat molten steel, the oxygen in molt

48、en steel is continuously reduced by diffusion slag. Vacuum deoxidation: PCO reduces the balance of s with molten steel by vacuum, thus reducing the W (CO) and W (I) content of molten steel.75. deoxygenation constant: used to measure the deoxidizing power of an element76.P40077.P4011. heterogeneous r

49、eaction process and steps(1) the reaction convection diffusion to the reaction interface; (2) reactant adsorption in the reaction interface; (3) the chemical reaction in the reaction interface; (4) the reaction product of the reaction interface liberation; (5) the reaction products leave the reactio

50、n interface phase diffusion.The 2. reaction is a grade A for the reactant, and the B is B, and the index is n=a+b+. The total series of reactions, referred to as series.3. if the reaction order is equal to the sum of the number of reactants in the reaction, the series is a positive integer, then the reaction formula of this kind of reaction can represent the reaction mechanis