Review article
APPLICATION OF EXPERIMENTS PLANNING IN THE MINERAL PROCESSING
SLAVKA PFAFF
BRANKO SALOPEK
Abstract
Statistical design of experiments deals with methods of planning the experiment so that appropriate data are collected, which may be analyzed by statistical methods resulting in objective and valid conclusions. These methods extend over two closely related experimental problems: the design of the experiment and the statistical analysis of the data. Moreover, designed experiments maintain a balance between statistical accuracy and the cost of the experimental process. Factorial designs are used in experiments involving several factors where it is necessary to study the joint effects of these factors on a dependent variable i.e. response. In case of k factors, each at only two levels, the full 2k factorial design in which the response is tested in all possible combinations of settings is widely used. If the response is investigated with more than two different values of each factor then, in addition to the effect estimates of factors and their interactions, the curvilinear regression equation of the relationship between response and factors can be obtained. In case of two factors such equation represents a surface in three-dimensional space, so designs for fitting the response surface are often called response surface designs. One of them is the central composite design. The paper presents the full 24 factorial design and the central composite design and their analysis exemplified by the results of investigation about how the four factors (pressure, humidity, temperature and granulation of the coal) affect the water absorption. The methods of analysis and the way of drawing conclusions have been outlined.
Keywords
satistical design of experiments; full factorial design; central composite design; mineral processing
Hrčak ID:
13375
URI
Publication date:
4.12.2004.
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