Technically it's a graph between Gibbs free energy of the reaction of metal/metal-oxides Vs temperature. It tells about the stability of compounds/elements at different temperature. In metallurgy it tells about whether and how is the metal oxides is reducible by other elements/compounds. So as in irRead more
Technically it’s a graph between Gibbs free energy of the reaction of metal/metal-oxides Vs temperature.
It tells about the stability of compounds/elements at different temperature.
In metallurgy it tells about whether and how is the metal oxides is reducible by other elements/compounds. So as in iron and steel industry, where reduction of iron-oxide to iron and oxidation of metal impurities to their oxides is checked and managed to get required properties in iron.
Ellingham plotted the experimentally determined variations of delta(G°) with T for the oxidation and sulfidation of a series of metals and found that the equation of delta(G°) , in spite of the terms involving In (T) , T^2, and T^(-1), the relationship approximated to straight lines over ranges of tRead more
Ellingham plotted the experimentally determined variations of delta(G°) with T for the oxidation and sulfidation of a series of metals and found that the equation of delta(G°) , in spite of the terms
involving In (T) , T^2, and T^(-1), the relationship approximated to straight lines over ranges of temperature in which no change of state occurred. The relations could thus be expressed by means of the simple equation:
delta(G°) = A + BT
The main application of Ellingham diagrams is that it helps to select the best reducing agent for various ores in the extraction process, purification and grade setting for steel manufacturing.
As according to the Ellingham diagram, lower metal oxide and upper metal are stable.
what is Ellingham diagram? It is graphical representation of DelG° ( y axis) and temperature in X axis. what it tells about? Basically, it tells about relative stability of oxides. That means, if you have SiO2 and CaO2 at same temperature how can you say which one is stable? This information we canRead more
what is Ellingham diagram?
It is graphical representation of DelG° ( y axis) and temperature in X axis. what it tells about? Basically, it tells about relative stability of oxides. That means, if you have SiO2 and CaO2 at same temperature how can you say which one is stable? This information we can get from this diagram. Obviously our next question is how it link with iron and steel making? we know that naturally iron occurs in oxide form – the main ores of iron are hematite and magnenite. Before going to further details let’s define iron making and steel making. Iron making is defined as removal oxygen from ore and steel making is defined as selective oxidation of impurities to remove those impurities. Our next question is how to remove oxygen from ore? Yes, here the application of Ellingham diagram comes into picture. let’s understand from simple examples. We know that large negative free energy compound is most stable compare to other compounds. From the diagram one can understand that CaO is most stable oxide compare to other oxides. That means let’s say you have SiO2 if you Ca to the system Ca will remove oxygen from SiO2 and form CaO. The reverse does not work. Because it increases the free energy. Similarly in iron making, we are using carbon as reducing element to remove oxygen from iron ore. Carbon positioned below the Fe line above some temperature ( just see the diagram). That carbon is used based on Ellingham diagram. let’s come to steel making. In this process you have to remove impurities without loss of iron. That means you need to avoid Fe oxidation. how to do that? So here it comes the application of Ellingham diagram.
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Technically it's a graph between Gibbs free energy of the reaction of metal/metal-oxides Vs temperature. It tells about the stability of compounds/elements at different temperature. In metallurgy it tells about whether and how is the metal oxides is reducible by other elements/compounds. So as in irRead more
Technically it’s a graph between Gibbs free energy of the reaction of metal/metal-oxides Vs temperature.
See lessIt tells about the stability of compounds/elements at different temperature.
In metallurgy it tells about whether and how is the metal oxides is reducible by other elements/compounds. So as in iron and steel industry, where reduction of iron-oxide to iron and oxidation of metal impurities to their oxides is checked and managed to get required properties in iron.
Ellingham plotted the experimentally determined variations of delta(G°) with T for the oxidation and sulfidation of a series of metals and found that the equation of delta(G°) , in spite of the terms involving In (T) , T^2, and T^(-1), the relationship approximated to straight lines over ranges of tRead more
Ellingham plotted the experimentally determined variations of delta(G°) with T for the oxidation and sulfidation of a series of metals and found that the equation of delta(G°) , in spite of the terms
involving In (T) , T^2, and T^(-1), the relationship approximated to straight lines over ranges of temperature in which no change of state occurred. The relations could thus be expressed by means of the simple equation:
delta(G°) = A + BT
The main application of Ellingham diagrams is that it helps to select the best reducing agent for various ores in the extraction process, purification and grade setting for steel manufacturing.
See lessAs according to the Ellingham diagram, lower metal oxide and upper metal are stable.
what is Ellingham diagram? It is graphical representation of DelG° ( y axis) and temperature in X axis. what it tells about? Basically, it tells about relative stability of oxides. That means, if you have SiO2 and CaO2 at same temperature how can you say which one is stable? This information we canRead more
what is Ellingham diagram?
See lessIt is graphical representation of DelG° ( y axis) and temperature in X axis. what it tells about? Basically, it tells about relative stability of oxides. That means, if you have SiO2 and CaO2 at same temperature how can you say which one is stable? This information we can get from this diagram. Obviously our next question is how it link with iron and steel making? we know that naturally iron occurs in oxide form – the main ores of iron are hematite and magnenite. Before going to further details let’s define iron making and steel making. Iron making is defined as removal oxygen from ore and steel making is defined as selective oxidation of impurities to remove those impurities. Our next question is how to remove oxygen from ore? Yes, here the application of Ellingham diagram comes into picture. let’s understand from simple examples. We know that large negative free energy compound is most stable compare to other compounds. From the diagram one can understand that CaO is most stable oxide compare to other oxides. That means let’s say you have SiO2 if you Ca to the system Ca will remove oxygen from SiO2 and form CaO. The reverse does not work. Because it increases the free energy. Similarly in iron making, we are using carbon as reducing element to remove oxygen from iron ore. Carbon positioned below the Fe line above some temperature ( just see the diagram). That carbon is used based on Ellingham diagram. let’s come to steel making. In this process you have to remove impurities without loss of iron. That means you need to avoid Fe oxidation. how to do that? So here it comes the application of Ellingham diagram.