SYNTHESIS OF FLOTATION BASED SEPARATION SYSTEMS
In this work a methodology is presented for defining the optimal configuration for flotation circuit and selection of appropriate equipment for the process. The problem is represented by three hierarchized superstructures. The first level represents separation tasks, which include: feed processing, concentrate processing, and tail processing. The second level represents the stream network needed to carry out each tasks. Where for each task a superstructure is developed which includes several operational stages. At the third level, several equipment alternatives are considered for each stage. The equipment discussed in the model includes flotation column and flotation cell banks, with and without grinding. The optimal selection of the circuit is made with an appropriate objective function, upon which the values of the operational and structural variables may be determined. The problem is formulated using disjunctive programming, which is converted to a MILP problem. The model includes mass balance, equipment models, operational conditions, and logic relationship. The paper presents an example to illustrate its application for effective design of a copper concentration plant.
An experimental investigation on column flotation circuit configuration
Abstract The integration of flotation columns into existing flotation circuits of conventional mechanical cells is becoming increasingly common in industry. Nevertheless, the study of column circuit configuration is scarce and problems relating to the selection of the appropriate circuit have not been addressed. Various column circuits for flotation of coal fines have been experimentally examined and theoretically analyzed in the present study to reveal the effect of circuit configuration on the overall circuit performance evaluated using separation efficiency and separation curves. The flotation circuits examined in this study included single–stage (SS), rougher–scavenger (RS), rougher–cleaner (RC), rougher–scavenger–scavenger cleaner (RSSC), rougher–scavenger–cleaner (RSC), and rougher–cleaner–recleaner (RCRC). The flotation tests were carried out with the Pittsburgh No. 8, Illinois No. 6 and Upper Freeport coal samples that were precleaned using conventional flotation. It has been demonstrated that the overall separation efficiency of the column flotation system was rather insensitive to circuit arrangements due to the unique characteristics of the unit flotation column distinguished from the conventional flotation cell. The flotation separation efficiency changed with ash or sulfur rejection and the Pittsburgh No. 8 and Illinois No. 6 coal samples showed a stronger dependence of separation efficiency on ash rejection than the Upper Freeport coal sample. The experimental results were shown to be in good agreement with theoretical circuit analysis conclusions.
The design of a flotation network using inequalities
Abstract A matrix inequality in terms of the row sums of a matrix has been applied to the configurational design of a flotation network. Each row sum refers to a given cell in the network. Each row sum is a function of circuit connections and cell operating conditions. By varying the row sums, variable upper and lower bounds for the mass flows in a network may be obtained. The total recovery is “quasi” monotonic with the row sums. The mass balance matrix equations result in coefficient M -matrices which consequently are regular and have non-negative inverses. These properties are used in the construction of the upper and lower bounds. The “quasi” monotonic property may be applied to the design and eventual optimisation of networks. The method has been applied to standard type circuits.