Thermophysical properties of rocks from the Bushveld Complex
MQW Jones
This paper presents a compilation of physical properties of rocks from the
Bushveld Complex. The database consists of more than 900 measurements
each of thermal conductivity and density. The data are well distributed
from localities around the Complex and most rock types are well
represented. Thermal conductivity and density are shown to vary widely in
the ranges 1.8–4.2 W m-1 K-1 and 2600–4200 kg m-3 respectively. Although
only 190 heat capacity measurements are available, this parameter is quite
uniform for most rock types present, 800–900 J kg-1 K-1, except for
chromitite, which has a lower average, 750 J kg-1 K-1. Rocks encountered in
deep platinum mines are particularly well characterized and this has
important implications for prediction of mine refrigeration requirements.
The heat flux into a semi-infinite region with properties typical of the
Bushveld Complex as a function of time is substantially lower than an
equivalent model for the Witwatersrand Basin.
Keywords: thermophysical rock properties, platinum mines, mine cooling.