Abstract: The present invention provides a process for producing sodium carbonate monohydrate crystals by introduction of anhydrous sodium carbonate into a saturated sodium carbonate brine solution under conditions in which sodium carbonate monohydrate formation is favored. As the anhydrous sodium carbonate dissolves, the brine becomes supersaturated resulting in relief of supersaturation by formation of sodium carbonate monohydrate crystals. The process includes controlling supersaturation and its relief to achieve growth of existing sodium carbonate monohydrate crystals rather than nucleation and formation of new sodium carbonate monohydrate crystals. The resulting crystals are separated from insoluble impurities on a size separation basis.

Abstract: A process is provided for recovering a saline mineral from an ore containing the saline mineral and impurities. In one aspect, the process generally includes the steps of separating a first portion of impurities from the ore by density separation, electrostatically separating a second portion of impurities from the ore, and magnetically separating a third portion of impurities from the ore. The process can further include the steps of crushing the ore and dividing the crushed ore into a plurality of size fractions before the above-referenced separating steps. In another aspect, the process includes the steps of calcining the ore and subsequently separating a first portion of impurities by density separation. Indirect heating may be utilized for the calcining process and, preferably, calcining gases are recycled and utilized for heating fluidizing another portion of ore. Water vapor may be condensed from the calcining gas and utilized for other purposes.