Next Article in Journal
The Use of Univariate and Multivariate Analyses in the Geochemical Exploration, Ravanj Lead Mine, Delijan, Iran
Previous Article in Journal
Effects of Dolomite on Mineral Compositions and Metallurgical Properties of Chromium-Bearing Vanadium–Titanium Magnetite Sinter
Article Menu
Issue 11 (November) cover image

Export Article

Open AccessArticle
Minerals 2017, 7(11), 211; https://doi.org/10.3390/min7110211

Effect of Heating Rate on Pyrolysis Behavior and Kinetic Characteristics of Siderite

College of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China
*
Authors to whom correspondence should be addressed.
Received: 10 October 2017 / Revised: 29 October 2017 / Accepted: 1 November 2017 / Published: 3 November 2017
Full-Text   |   PDF [7885 KB, uploaded 3 November 2017]   |  

Abstract

The pyrolysis characteristics of siderite at different heating rates under the neutral atmosphere were investigated using various tools, including comprehensive thermal analyzer, tube furnace, X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive spectrometry (EDS) and vibrating specimen magnetometer (VSM) measurements. The reaction of siderite pyrolysis followed the one-step reaction under the neutral atmosphere: FeCO3 → Fe3O4 + CO2 + CO. As the increasing of heating rate, the start and end pyrolysis temperatures and temperate where maximum weight loss rate occurred increased, while the total mass loss were essentially the same. Increasing heating rate within a certain range was in favor of shortening the time of each reaction stage, and the maximum conversion rate could be reached with a short time. The most probable mechanism function for non-isothermal pyrolysis of siderite at different heating rates was A1/2 reaction model (nucleation and growth reaction). With increasing heating rate, the corresponding activation energies and the pre-exponential factors increased, from 446.13 to 505.19 kJ∙mol−1, and from 6.67 × 10−18 to 2.40 × 10−21, respectively. All siderite was transformed into magnetite with a porous structure after pyrolysis, and some micro-cracks were formed into the particles. The magnetization intensity and specific susceptibility increased significantly, which created favorable conditions for the further effective concentration of iron ore. View Full-Text
Keywords: siderite; neutral atmosphere; heating rate; pyrolysis; mechanism siderite; neutral atmosphere; heating rate; pyrolysis; mechanism
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zhang, X.; Han, Y.; Li, Y.; Sun, Y. Effect of Heating Rate on Pyrolysis Behavior and Kinetic Characteristics of Siderite. Minerals 2017, 7, 211.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Minerals EISSN 2075-163X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top