Abstract An improved process for the recovery of ore values from carnalitte by solution mining techniques is disclosed. The carnallite-containing ore deposit is contacted with an aqueous stream, which may be merely water or an aqueous solution of magnesium chloride, to impregnate the same with magnesiumcontaining ore values. These dissolved ore values are primarily carnallite when the aqueous stream contains at least about 25 percent magnesium chloride and magnesium chloride when the aqueous stream initially contains a smaller quantity of magnesium chloride. The impregnated stream is removed from the ore deposit and sufficient water is removed to precipitate substantially all the potassium-containing ore values dissolved from the formation. The precipitated potassium containing ore values are in the form of carnallite. The resulting slurry is filtered and the magnesium chloride-containing filtrate is removed, at least part of which provides magnesium chloride product. The filter cake is slurried with sufficient water to decompose the carnallite to soluble magnesium chloride and insoluble potassium chloride. The magnesium chloride solution is removed and advantageously recycled to the earlier water removal step in the process. The insolubles may be treated to provide potassium chloride products.
The process of claim 1 wherein the magnesium chloride-containing filtrate from step (g) is recycled to step (c).
Claim 2
Dependent Claim
21 words
The process of claim 2 wherein said first aqueous stream contains less than 10 percent by weight of dissolved magnesium chloride.
Claim 3
Dependent Claim
28 words
The process of claim 3 wherein said carnallite-containing ore deposit is contacted with said first aqueous stream at a temperature of from about 20* to about 100* C.
Claim 4
Dependent Claim
46 words
The process of claim 4 wherein said magnesium chloride-impregnated stream is cooled to a temperature of from about 25* to about 75* C. in step (c) to form said slurry after water is removed therefrom at a temperature of from about 50* to about 110* C.
Claim 5
Dependent Claim
29 words
The process of claim 5 wherein from about 35 to about 45 percent by weight of the water content of the magnesium chloride-impregnated solution is removed in step (c).
Claim 6
Dependent Claim
30 words
The process of claim 6 wherein at least part of said second aqueous stream is a recycle strEam of the solution separated from the precipitated potassium chloride in step (k).
Claim 7
Dependent Claim
27 words
The process of claim 7 wherein said carnallite-containing deposit is contacted with said first aqueous stream at a temperature of from about 30* to about 60* C.
Claim 8
Dependent Claim
46 words
The process of claim 8 wherein said magnesium chloride-impregnated stream is cooled to a temperature of from about 50* to about 70* C. in step (c) to form said slurry after water is removed therefrom at a temperature of from about 90* to about 110* C.
Claim 9
Dependent Claim
29 words
The process of claim 9 wherein from about 38 to about 44 percent by weight of the water content of the magnesium chloride-impregnated solution is removed in step (c).