Authors:M. Mostafa, N. Afify, A. Gaber, and E. Abu Zaid
This work aims in studying the temperature dependence of the thermal properties (thermal diffusivity, k, specific heat, Cp and thermal conductivity, ) of some basalt group samples, collected from different regions in the eastern desert of Egypt. The thermal properties of these samples were measured in the temperature range from r.t. to 900 K. The average values of the thermal conductivity of these investigated samples lie in the range from 0.4·10–3 to 2.01·10–3 cal cm–1 s–1 K–1. This means that these samples are considered as thermal insulating materials. The thermogravimetric analysis (TG) confirmed that these investigated samples are dry rocks. X-ray fluorescence (XRF) and X-ray diffraction (XRD) confirmed that these rock samples have a crystalline phase, the peaks of XRD have a small change in their location as a result of heat treatment. This behaviour was attributed to the oxidation and firing of some minerals after the heat treatment.
Cavity filling natrolites in basalts from several localities of Balaton Highland were investigated by different methods. The
measurements of different thermal parameters (corrected decomposition temperature and activation energy) were first applied
for natrolite. Energy dispersive spectroscopy (EDS) was used for the observation of chemical composition. Few of the minerals
are regular, ordered natrolite, the majority proved to be so called ‘tetranatrolite’. According to our observations both natrolite
and ‘tetranatrolite’ may appear in the same locality and chemical inhomogenity can be demonstrated within a single natrolite
Authors:J. Rincon, J. Cáceres, C. González-Oliver, D. Russo, A. Petkova, and H. Hristov
A study of three Spanish and one Bulgarian basaltic rock demonstrated that, after thermal treatment at temperatures higher
than 800C, crystallization of pyroxenes, anorthite and magnetic occurred. Following sintering of the original basalts and
powdered original glasses, the same crystalline phases were nucleated and grown in the resulting glass-ceramics. Chemical
and DTA/TG analyses suggested similar behaviour for the synthesized Canarian basalt glasses, which are located in the tephrite-basanite
field, and different behaviour for the trachy-andesite Canarian and the basaltic-andesite Bulgarian basalt glass. In consequence
of the high sensitivity of the specific heat to phase transformations, Cp(T) and TMA experiments allowed a distinction between the tephrite-basanite and trachy-andesite Canarian glasses on the basis
of their different thermal behaviour.
Thermal insulation and fire protection have been a point of interest and discussion for several decades. Due to its excellent
performances, basalt fiber has been widely used in the fields of thermal insulation and fire protection. The morphological
structure and thermal stability of continuous basalt fiber were analysed using CH-2 projection microscope, scanning electron
microscope (SEM) and thermogravimetry (TG). In order to evaluate the thermal radiation protective performance when exposed
to fire environment, the spectral reflectances of nonwoven fabrics with different thicknesses were evaluated by ultraviolet-visible-near
infrared (UV–Vis–NIR) spectrophotometer analysis. The jointly analysis of TG and UV–Vis–NIR spectrophotometer revealed that
the basalt fiber exhibits good thermal stability, and the nonwoven fabrics present excellent thermal protective performance.
Authors:Y. Minai, Y. Nakamura, H. Wakita, and T. Tominaga
Cesium content in eleven positions of a continental basalt with a columnar joint was determined by means of neutron activation analysis. Concentration of cesium is about four times higher at the altered portions of the fracture than at the unaltered. Water and Fe3+ content determined by gravimetry, Mössbauer spectroscopy, and inductively coupled plasma optical emission spectroscopy were also correlated with cesium concentration, suggesting accumulation of cesium with ferric components. Such processes may be important for estimating the behavior of radiocesium in the environment.