3623 Premature ageing of a blast furnace taphole clay containing resole resin and liquid pitch as binder

Authors

  • Andrie M Garbers-Craig University of Pretoria
  • Dr. Izak Cameron Centre for Pyrometallurgy, Department of Materials Science and Metallurgical Engineering, University of Pretoria; currently with Elkem Silicon Product Development, Kristiansand, Norway https://orcid.org/0000-0002-6065-3690
  • Dr. Shatish Ramjee Centre for Pyrometallurgy, Department of Materials Science and Metallurgical Engineering, University of Pretoria https://orcid.org/0000-0003-0104-207X

DOI:

https://doi.org/10.17159/

Abstract

The cause of reduction in workability and increased ageing of a blast furnace taphole clay was examined. The investigated taphole clay contained 60 mass% alumina, with phenol-formaldehyde resole resin and liquid pitch as the binder system. The workability and Marshall extrusion pressure of as-manufactured clay samples were evaluated to identify the extent of ageing of the clay. The wettability of all the raw materials was investigated to confirm compatibility between the dry raw materials and both the resin and liquid pitch, while the dry raw materials were analysed using XRF, XRD and SEM-EDS. The characterisation of the resin and liquid pitch, as well as the analysis of their interaction, was performed using viscosity measurements, Fourier-transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Analyses confirmed a chemical interaction between the resole resin and liquid pitch, where the chemical structure of the resole resin changed when mixed with pitch, preventing the typical curing behaviour of the resin. After ageing of the resin and liquid pitch mixtures, the resin prematurely cross-linked, causing the curing process to move to lower temperatures, i.e., an earlier onset of curing. The premature cross-linking of the resole resin was likely due to secondary amines present in the liquid pitch that acted as a catalyst for the resin curing process. This reduction in curing temperature after ageing was confirmed by an increase in binder viscosity, which was the primary cause of the reduced workability, increased ageing and increasing Marshall extrusion pressure of the taphole clay. 

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Author Biographies

  • Andrie M Garbers-Craig, University of Pretoria

    Dept Materials Science & Metallurgical Engineering

    Prof

  • Dr. Izak Cameron, Centre for Pyrometallurgy, Department of Materials Science and Metallurgical Engineering, University of Pretoria; currently with Elkem Silicon Product Development, Kristiansand, Norway

    Izak Cameron is a research and development scientist at Elkem Silicon Products, specializing in the use of microsilica and other constituents in refractory materials. He earned his MEng and PhD at the University of Pretoria, focusing on taphole clay materials, particularly the replacement of pitch as a binder with more environmentally friendly alternatives.

  • Dr. Shatish Ramjee, Centre for Pyrometallurgy, Department of Materials Science and Metallurgical Engineering, University of Pretoria

    Shatish Ramjee is a senior lecturer in the School of Engineering, contributing to both the  Department of Materials Science and Metallurgical Engineering and the Department of Chemical Engineering at the University of Pretoria.

Published

2026-01-19

Issue

Section

Papers of General Interest