Formation of Coal in Chah Badam
Coal formation in Chah Badam occurs in the Jurassic shale layers, and shale and sandstone host the coal. The coal layers are concentrated in three zones: A, B, and C. Coal follows the shale layering trend throughout the mine, so the layering trend of coal is similar to the layering.
The thickness of the coal layers varies from 20 cm to 3 meters. In parts of the mine, the presence of folding increases the thickness of the coal layers at the hinge of the fold, but this increase in thickness does not extend very far.
The length of the coal layers depends on the geological structures of the region, so that in areas where the tectonic performance and faulting are less, the length of the coal layers is greater. However, in general, most coal layers have an average length of about 100 meters. It is important to note that along a coal layer, in some parts, the coal layers become thin and extraction becomes uneconomical.
The dip of the coal layers in the Chah Badam mine is generally low, around 15-25 degrees. In a small number of coal layers located near the axis of the fold, the dip of the coal layer reaches 70-80 degrees, and the coal layers located in the center of the fold hinge have a vertical dip.
The type of coal in the Behabad mine is thermal and has a specific gravity (density) of 1.4 gr/cm3.
Exploration Operations Performed
Exploration operations in the Chah Badam mine include digging exploration trenches, powder boreholes, and core boreholes.
In line with exploration operations in most parts of the mine and perpendicular to the coal layers, numerous exploration trenches were dug. The location of the trenches is shown on the geological map of the mine. The length of the trenches varies from 10 meters to about 50 meters depending on the number and extent of the coal layers, and the dominant width of the trenches varies between 1-2 meters. The depth of the trenches also varies between 1-5 meters.
Extraction in the Chah Badam Coal Mine
In this mine, after exploration stages and identifying the shape and reserves of the coal layers, and considering the low dip of the coal layers, extraction is done in an open pit manner using mining machinery, and after waste removal, the coal layers are extracted.
