Dataset: cleancoal_rsm.dat

Source: N. Aslan (2007). "Application of Response Surface Methodology
and Central Composite Rotatble Design for Modeling the Influence of
Some Operating Variables of a Multi-Gravity Separator for Coal Cleaning,"
Fuel, Vol. 86, pp.  769-776.

Description: 4 Factors: Drum Speed (175 to 275 by 25 rpm), Tilt Angle
(1 to 9 by 2 degrees), Wash water (1 to 9 by 2 litres/min), feed solids
(10 to 50 by 10%) on 2 responses Ash Content (%) and Combustible Recovery (%)
in 30 run CCD.

Variables/Columns
Run Number   7-8
Coded Drum Speed   15-16
Coded angle   23-24
Coded wash water   31-32 
coded feed solids   39-40
drum speed    45-48
angle     56
wash water   64
feed solids   71-72
ash content   75-80
combustible recovery    83-88