A discussion about the inapplicability of the flotation testing related standards

In order to analyze the applicability of the flotation testing related standards currently in effect, the paper presents an interpretation of both the old and the newly-formulated standards, and points out, based on the results of analysis and practical testing, that the existing standards are inapplicable in such aspects as poor systematicness, mutual contradiction and nonconformity with the practical production situations.These result in consequently the lack of integrity in making assessment of flotation performance, which is reflected mainly in two aspects: one is that the inability to achieve the desired flotation effect is mistakenly attributed to flotability and it is believed that flotability has its inherent characteristics and is subject to the effects of flotation process and operating parameters; and the other is that the meanings of organic efficiency and perfection indices based on which the flotation performance evaluation indicators are derived are not clearly defined.To address the issue, the principle of taking the yield vs ash curve as the flotability is proposed.Following an analysis of the three current flotability standards, a series of exploratory tests are conducted on the way to obtain an ideal flotation effect.Through the tests, several important laws are brought to light, the principles which need to be followed are clearly defined, and the process flowsheet and operating conditions for making flotability test are proposed.Based on the findings obtained, an in-depth analysis is made of the insufficiencies of the existing flotation performance evaluation standards, which are based only on two factors—organic efficiency and perfection index.It is proposed to carry out “ideal separation” test on flotation feed, concentrate and tailings separately to obtain their respective ash composition.In this way, an aggregative flotation performance evaluation index can be obtained based on the indices like elementary ash, concentrate ash error, organic efficiency, content of total misplaced materials, concentrate contamination and loss of tailings derived.Furthermore, in order to enable a comprehensive fine coal flotability and flotation performance evaluation to be made in a scientific manner, it is proposed to make representation of flotability with such factors as content of near-ash ±1.0 material, content of materials with a highest ash and content of materials with an ash higher than elementary ash.Finally, the suggestions for making revision of the current standards are put forward.