A Study on the Stability Fields of Arc Plasma in the HPSR Process

Abstract

One of the major challenges for Europe’s future steel production will be minimizing the inherent process emissions in the production of crude steel based on iron ores. In this case, mainly the reduction of CO2 emissions is a focus. One promising process to overcome these problems is the hydrogen plasma smelting reduction (HPSR) process. This process has been studied for several years already at the Chair of Ferrous Metallurgy at Montanuniversitaet Leoben. The work presented focused on the stability of plasma arcs in the DC transferred arc system of the HPSR process. The stable operating plasma arc is of utmost importance for the future development of the process. The major objective is the definition of the most favorable conditions for this kind of arc. Therefore, tests were conducted to define fields of a stable operating plasma arc for multiple gas compositions and process variables. For several gas compositions of argon, nitrogen, argon/nitrogen, argon/hydrogen and nitrogen/hydrogen, fields of stability were measured and defined. Besides, the major influencing parameters and trends for the fields of stability were evaluated and are shown in this work.

A New Methodological Approach on the Characterization of Optimal Charging Rates at the Hydrogen Plasma Smelting Reduction Process Part 2: Results

“…The system components, the procedure description, and the evaluation method have already been explained in detail in other publications [12,13] and are only briefly mentioned here.…”

A New Methodological Approach to the Characterization of Optimal Charging Rates at the Hydrogen Plasma Smelting Reduction Process Part 1: Method

“…The facilities have been described multiple times in previous works. In the most recent article about arc stability fields, all facilities were described in detail [ 23 ]. Nevertheless, the equipment and the flowsheet of the process are summarized in Table 1 and Figure 4 .…”

“…Further additional information must be collected for this scale-up, and many further analyses must be performed to find systems that allow for a comparison between the development steps. A fundamental study on the arc’s stability has already been carried out [ 23 ]. In addition to the arc’s stability, the rate of ore-charging and the connected kinetic parameters are some of the most critical issues to be investigated.…”

The Materials Science behind Sustainable Metals and Alloys

“…Some process pathways (liquid or solid reduction), feedstock types and dispersion (pellets, lump, fines) and reactor types (shaft, fluidized bed) are shown in Figure 86. 334−336 If, however, in the course of sustainable metallurgy, fundamentally new reduction processes have to be developed anyway, which then do not work with fossil reducing agents but with sustainable reducing agents such as hydrogen, ammonia, or renewable carbon carriers, the types of ores used in these novel process variants can then also be considered as an additional variable set An important example in this direction is reducing plasmametallurgy, 143,145,254,337,338 in which untreated ores can be used directly. A second example is the use of fluidized bed reactors for powdered fine ores, which also do not require any upstream sinter compaction.…”

“…Ellingham Richardson diagram showing the Gibbs free energy for several metal oxides together with Gibbs free energy lines for hydrogen and the H + radical, ,, present (among many other ionized species) in a hydrogen-containing plasma . Other versions of Ellingham diagrams with several types of higher-order plasma-related hydrogen radicals have been published in refs , , , and − (see also Figure ).…”