Planning for Reliable Coal Quality Delivery Considering Geological Variability: A Case Study in Polish Lignite Mining

Table 2

Basic statistics of calorific value based on 68 boreholes of the operational exploration and of the both models.

	Data from the exploratory holes	Model ordinary Kriging	Model-exemplifying simulation
Number of holes/number of blocks	68	195 (30 30 m)	195 (30 30 m)
The mean value	8267 kJ/kg	8274 kJ/kg	8260 kJ/kg
The standard deviation	521 kJ/kg	316 kJ/kg	485 kJ/kg
Coefficient of variation	6,30%	3,80%	5,9%
The minimum value	6137 kJ/kg	7517 kJ/kg	6225 kJ/kg
The maximum value	9259 kJ/kg	8759 kJ/kg	9006 kJ/kg