Summary: | Potash is the main source of Potassium which is one of the three basic plant
nutrients along with nitrogen and phosphorus. Between 60 to 80% of the potash ore is
processed by flotation, the other two important unit operations are hot or cold
crystallization and electrostatic separation.
Almost all the published literature on potash flotation refers to the insoluble
minerals as "collector robbers" and increased collector usage is mentioned as the
consequence of the presence of slimes in potash flotation circuits. The real effect of the
presence of slimes in potash flotation is far more complex.
The test program developed in the following chapters aimed to determine the most
suitable modifying reagent(s) and the optimum dosage to optimize grade and recovery
of KCI, and to evaluate various flocculants used in flotation desliming in order to
determine the factors that affect flotation desliming efficiency.
Based on the results, it can be stated that guar gum is probably the most effective
insoluble slimes depressant for the ores under the conditions tested. The depressing
action of the guar gum is strong even at low dosages (50 g/t). Carboxymethyl cellulose
shows poor depressing ability at low dosages, with increasing depression performance
at high dosages (200 g/t). Synthetic polyacrylamides can hardly be considered insoluble
slimes "depressants" as a considerable amount of the insoluble slimes present in the
feed report to the concentrate.
Anionic flocculants increase insoluble slimes recovery when used instead of non-ionic
flocculant at the same dosage. The recovery of KCI to the insolubles concentrate
increases with the use of anionic flocculants as well but in a much smaller proportion.
The flocculation-flotation of insoluble minerals is a flocculant dependent process, and
the addition of a "insolubles collector" or a frother, or nothing at all merely affects the
kinetics of the process. === Applied Science, Faculty of === Mining Engineering, Keevil Institute of === Graduate
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