Comparative study of coal washability curve plotting methods

Coal cleaning is an essential prerequisite for clean and high-efficiency utilization of coal while coal washability curve is an important basis for guiding selection of coal cleaning methods. With an aim to providing a reference for plotting coal washability curve in coal cleaning operations, a detailed analytical study is made of the five plotting methods using respectively Origin, Excel, AutoCAD, Matlab and PowerPoint and with, for example, the float-and-sink analysis data of Yangquan No.1 Mine Coal Preparation Plant as the basis, to explore the advantages and disadvantages as well as the applicability of each method from three aspects. Analysis shows the AutoCAD method is simple in process yet comparatively low in accuracy; the Origin method is tedious but accurate; the Excel and PowerPoint methods are both easy for curve plotting and fitting, but may present difficulties in subsequent data query stage; and the Matlab method can offer complete functions and processing flexibility, however, for its use certain programming processes are required. The study-dervied result may serve as a useful reference for plotting coal washability curves and as a basis for decision-making in coal washing operations.