Sylvinite, Other Potash Ore Processing

The modern processing of sylvinite and other potash ores is usually a comparatively simple and standardized procedure, practiced in much the same way at most potash plants. In the early days of the industry, and still with some operations having complex ores or to process fines or waste streams, the ore was given a hot leach, the undissolved salt and insolubles rejected, and the clarified brine crystallized. Now, however, in most plants the ore is first ground to a size where the potash is liberated from the halite, it is “deslimed” to remove the insolubles and fines, and the coarser particles are separated by flotation (although a few plants use a dry electrostatic or wet heavy media separation). After benefication (and possibly a quick leach) the potash is dried, part of it is compacted to a larger size, the fines (and perhaps the slimes) are leached and recrystallized and the rest is sold as is or further processed. As might be expected, differences in the ore, the total recovery achieved, and individual preference among processing steps have resulted in many variations in the details of these procedures. The generalities and some of the typical practices in the industry will be discussed in the following chapter. Again it must be cautioned that the descriptions are of the practice at the time of the listed reference, and might currently be quite different.