Optimization of leaching parameters for the extraction of rare earth metal using decision making method

• Evaluate, compared and ranked different leaching candidates.
• Elimination search, TOPSIS, line graphs and spider diagrams are used.
• The proposed methodology is illustrated with an example.
• The suitability index and the coefficient of similarity were calculated.

The optimization of leaching operation of Rare earth bearing ores is a complex process since many attributes simultaneously affect the operation, with some of them being conflicting in nature. Therefore a proper selection of the leaching process with pertinent attributes is crucial for the user in order to maximize the percentage recovery with minimal operating costs. In this paper a methodology is proposed for evaluation, comparison and ranking of various leaching process alternatives which we define as leaching candidates, in order to select the best candidate from the available options. Coding scheme for 28 attributes is proposed in order to evaluate the available candidates. A three stage procedure with elimination search, technique for order preference by similarity to ideal solution (TOPSIS) followed by line graphs and spider diagrams, is used for the optimal selection of candidate leaching system. The proposed methodology is illustrated with an example by choosing a few pertinent attributes from the attributes. The suitability index for the best leaching candidate was calculated to be 0.5225 and the coefficient of similarity (COS) values for the best candidate based on line graph and spider diagram obtained were 0.6183 and 0.2711 respectively.