In this data sheet we present a typical quantitative determination of the phase content as well as of process critical parameters for the production of direct reduced iron (DRI).
Direct reduced iron (DRI), also called sponge iron, is produced by the reduction of iron ore (in the form of lumps, pellets or fines) with a reducing gas (primarily hydrogen or carbon monoxide) produced from natural gas or coal. In order to achieve maximum efficiency of the production process, a number of parameters need to be monitored, such as metallic iron content (Femet), metallization (Metn), total carbon content (Ctot) and the mineralogical phase content.
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Direct reduced iron (DRI), also called sponge iron, is produced by the reduction of iron ore (in the form of lumps, pellets or fines) with a reducing gas (primarily hydrogen or carbon monoxide) produced from natural gas or coal. In order to achieve maximum efficiency of the production process, a number of parameters need to be monitored, such as metallic iron content (Femet), metallization (Metn), total carbon content (Ctot) and the mineralogical phase content.
X-ray diffraction (XRD) is a fast and precise analytical tool for rapid process control of DRI. The Metals edition of Aeris is the first benchtop X-ray diffractometer that is designed for process control in iron and steel production environments. In this data sheet we present a typical quantitative determination of the phase content as well as of process- critical parameters for the production of direct reduced iron (DRI).
In order to show the capabilities of the Aeris Metals edition, several samples from different stages of the DRI production were analyzed. The presented data were measured using cobalt radiation, which is especially suited for iron-containing sample materials, as it produces high-resolution data.
Measurement time per sample was 5 minutes, followed by automatic data processing and reporting of the relevant process parameters.
Quality control of direct reduced iron is possible by using modern X-ray diffraction (XRD) methods. Process-critical parameters that cannot be accessed by conventional chemical analyses are calculated from the mineralogical phase content. Crucial process parameters such as the metallic iron content (Femet), metallization (Metn) and the total carbon content (Ctot) can all be derived from a single 5 minute measurement.
In addition, XRD can also characterize the overall mineralogical contents in a DRI sample, which provides further important information about the reduction process. The Metals edition of Aeris is a perfect tool to optimize the iron and steel making process.
Figure 1 and 2 show typical examples of a DRI analysis using XRD in combination with an automatic Rietveld refinement. The full mineralogical content is determined by providing quantitative information about the metallic iron-contributing phases (α-iron Fe, cohenite Fe3C) as well as iron oxide phases (magnetite Fe3O4, hematite Fe2O3, wuestite FeO) and various silicatic phases (pyroxenes, olivines, etc.). From these phase contents the process- critical parameters Femet, Fetot, Metn, and the Ctot are directly calculated as part of the automated analysis. When compared to independent reference data from wet-chemical analysis and carbon analyzers the data obtained from XRD show a very good agreement over a wide range of values.
Figure 1. Quantitative Rietveld refinement of direct reduced iron
This clearly shows the power and benefit of XRD for production and quality control of DRI as all of the critical process parameters can be derived from the same 5 minute measurement. The analysis is fully automated, including the measurement, data evaluation and reporting of the derived phase contents and process parameters. This routine can be integrated in fully automated environments including automated sample preparation, measurements, analysis, and reporting of results. In addition the same type of analysis can also be applied to screen the iron ores used as input for the reduction process.
Figure 2. Comparison of Femet, Fetot, Metn, and Ctot obtained by XRD to independently determined reference values
The presented results show the capability of the Metals edition of Aeris as a fast and precise analysis tool to determine process-critical parameters such as metallic iron (Femet), total iron (Fetot), metallization (Metn) and the total carbon (Ctot) content within minutes. The mineralogical phase composition of direct reduced iron provides information about the efficiency of the reduction process which will ultimately improve raw material mixture optimization. The Metals edition of Aeris is perfectly suited for process control in the iron and steel industry.
