Contraction in layers of particles of selected limestones as a result of thermal decomposition

1 Sample of a layer of limestone particles in the thermal-analysis apparatus: 1 – limestone particles, 2 – vessel, 3 – lifting device, 4 – cylindrical shaft, 5 – heating coil made using Kanthal APM, 6 – support ring, 7 – thermocouples, 8 – hot junction of thermocouples, 9 - furnace thermocouple, 10 – locking, 11 – level indicator, 12 – seal. The flow of heated air and carbon dioxide (45 % vol.) into the layer is indicated by an arrow

2 Specimen plots of temperature for calcination of a layer of particles of the Carboniferous limestone: 1 – plot of temperature above the vessel base, 2 – plot of temperature at midlayer depth, 3 – plot of
temperature immediately below the upper surface of the layer (initial mass of layer m0 = 1214.97 g, loss on ignition 43.5 %)

3 Changes in temperature and sample mass
during calcination for 420 particles of Carboniferous
limestone: 1 – sample mass, 2 – temperature at the geometrical centre of the sample, 3 – furnace temperature

4 Contraction crack in thermally decomposed
particle of the Jurassic limestone from the Bukowa deposit

Contraction ΔV of a calcined layer volume of limestone
particles

Investigations of the contraction of layers of limestone particles were performed using samples of the Devonian, Carboniferous and Jurassic limestones of the Trzuskawica, Czatkowice and Bukowa deposits, respectively. Therefore, the volumetric contraction of the layers and the particles, the initial and ultimate porosity of the layers, the percentage of cracked particles and the percentage of the fine particles generated were measured.

1 Introduction

The operational efficiency of reactors based on fixed or moving beds of solids is dependent inter alia on a.) bed porosity and b.) particle...

TEXT Dr. Ryszard Lech¹*, Patryk Weisser M.Sc.²
¹AGH University of Science and Technology, Department of Building Materials Technology, Cracow/Poland
²Institute of Ceramics and Building Materials, Building Materials Engineering Division, Opole/Poland
*Corresponding author: lech@agh.edu.pl

Issue 06-07/2009

Contraction in layers of particles of selected limestones as a result of thermal decomposition

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