Hi everyone
I have 3 different ilmenite ores (nominally FeTiO3) with largely similar chemical and mineralogical compositions. I must emphasise that these are naturally occurring materials, and not synthesised or purified analytically. The chemical and mineralogical analyses were done by credible laboratories. These materials are smelted in an electric furnace to produce alloy and slag. One would expect that the electrical energy consumption would be similar when processing these materials, but they are not.
Our investigation has led us to believe that the enthalpy of formation (ΔHf) of the materials may somehow be different. We therefore want to determine the ΔHf of each material experimentally.
What methods can we use to do this? We have considered DSC and drop calorimetry. These techniques are somewhat indirect. Is there a direct way to determine the ΔHf?
The absolute accuracy of the methods is not my primary concern. I need to detect confidently whether there is a significant difference between the ΔHf of the different materials, so that I can test my hypothesis that the energy consumption differences observed in the plant are due to ΔHf differences.
Thanks for the help
Johan
I suggest as reference: O. Kubaschewski, C.B. Alcock, P.J. Spencer, "Materials Thermochemistry", 6th ed., Pergamon Press, 1993.
I don't think there is a more direct way for measuring the enthalpy of formation than calorimetry. There is exciting work by a group of prof.A.Navrotsky about measuring the surface energy of the nanoparticles by calorimetry: "Size-Driven Structural and Thermodynamic Complexity in Iron Oxides". Most of the results are measured by solution calorimetry (oxide melt or acid). These results are precise enough to be able to measure additional energy of the nanoparticles due to surface energy compared to the same amount of the bulk material. However, these experiments require experts and a lot of specialized instruments.
In your case maybe you can measure with DSC the difference between different ilmenite ores by placing the same amount of two minerals in reference crucible and sample crucible. Usually, it is measured with empty reference crucible (or with some reference material like quartz), but you are interested in differences of two samples of ilmenite ores not absolute values. In your case, if the difference between different ores is measurable, you should see the difference in the DSC signal between the reference sample (ilmenite ore #1) and sample crucible (ilmenite ore #2).
Dear T. Ivas
Thank you very much for the valuable information. I found Prof. Navrotsky on ResearchGate, and will contact her. I will look into your recommendations on using DSC. I certainly sounds like it could give us the results we need.
All the best
Johan
The starting point of thermodynamic logic is: 1) opposing perpetual motion. 2) The irreversibility of dynamics. Let's look at how to get Carnot efficiency = 1-T1/T2.
1.1 There are many kinds of type 2 perpetual motors, each of which is a natural phenomenon.
A) Machine A: against the irreversibility of thermodynamics (diffusion, heat conduction, friction, etc) - dynamics;
B) Machine B: Utilizing the Difference of Carnot Efficiency (Reversible Thermodynamics) - Thermodynamics
1.2 A and B belong to different disciplines. There is a parallel relationship between them and there is no logical mutual inevitability.
1.3. Logic of the Second Law of Thermodynamics:
Experience induction, deny that A machine==> B machine can not be manufactured==> All material Kano efficiency: 1-T1/T2.
1.4 The logic of the second law of thermodynamics violates the physical logic that A and B cannot be inferred from each other.
1.5 The second law of thermodynamics elevates the "irreversibility", which is in fact only a kinetic experience.
📷 Detailed discussion can be found in the following figure.
1. The second law of thermodynamics loses the ability of quantitative prediction.
2. Data processing method of law 2 of thermodynamics violates scientific discipline: modifying experimental data to satisfy theory
See the picture for details.
3. The second law of thermodynamics can only be called science if it reaches the same quantitative prediction ability as Newton's second law, otherwise it is pseudoscience.
4.Unfortunately, all the charts of enthalpy and entropy are organized in this way.
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