Mass balancing for coal processing plant design

With the advent of modern mass balancing programmes, the roots of what makes up these programmes are being lost to all but the developers. This paper draws on the author's experience of designing coal processing plants whilst straddling the transition period of main frame computers using programmes such as Fortran4 and BASIC to PCs using spreadsheets. Their introduction transformed the ways in which mass balancing could be carried out and presented in easy-to-understand tables and graphs, as well as significantly reducing the time and effort involved. Many simple formulas in SI units were developed using Excel to solve the mass and volume flowrates of coal slurries in the numerous pumping and processing circuits of a dense medium plant and downstream processes. They all use the linking concepts of density and % solids and are far simpler than the equivalent formulas in Imperial units or those needed for chemical plants where liquids other than water are used. Their application in mass and water balances of coal processing plants is described using an example of a DMS coal processing cyclone plant.