In this work, solar
drying technology was applied for the deep
dewatering of coal slime to save thermal energy and reduce the dust
produced during the hot drying process of coal slime. Solar drying
technology is used to dry coal slime to realize its resource utilization.
The influence of solar radiation intensity and slime thickness is
investigated on the drying process. The greater the solar radiation
intensity (SRI) is, the faster the drying indoor air and coal slime
are heated, and the faster the drying efficiency is. As the slime
becomes thinner, the internal water diffusion resistance becomes smaller
and the drying efficiency correspondingly becomes faster. In addition,
to facilitate the application of coal slime drying in the actual project,
the Page model is fitted and found to have a good fit for solar drying
coal slime. Meanwhile, the optimal drying conditions are determined
by analyzing the energy utilization under different conditions. It
is found that the target moisture content of 10% is optimal for coal
slime drying with the highest energy utilization. The laying thickness
(
L
) of 1 cm has the highest solar thermal efficiency
of 54.1%. More importantly, economic calculation and analysis are
conducted in detail on solar drying. It is found that the cost of
solar drying (¥38.59/ton) is lower than that of hot air drying
(¥ 65.09/ton). Therefore, solar drying is a promising method
for the drying of coal slime.