Process for the production of potassium sulphate and magnesium sulphate from carnallite and sodium sulphate

Abstract

According to some embodiments there is provided a process for the recovery of SOP from Sulphate bearing mineral and Carnallite or Sylvenite, comprising: Dissolving Carnallite in water to obtain Sylvenite and high Magnesium Chloride brine; Adding Sodium Sulphate to said Carnallite to produce mixture of Kainte\Leonite, KCl and NaCl precipitant and brine containing Mg Cl.sub.2, KCl, NaCl; Separating the NaCl from the mixture; Obtaining a precipitant mixture of Leonite with KCl; Filtering said Leonite and washing with water to yield pure mixture of Leonite with KCl; Adding KCl to the Leonite with the KCl; and Decompose said Leonite with the KCl to SOP.

Claims

1. A process for the recovery of SOP from sulphate bearing mineral carnallite, comprising: dissolving said carnallite in water to obtain sylvenite and high magnesium chloride brine; adding sodium sulphate to said dissolved carnallite to produce mixture of kainite\leonite, KCl and NaCl precipitant and brine containing MgCl.sub.2, KCl, NaCl; separating the NaCl from the mixture; obtaining a precipitant mixture of leonite with KCl; filtering said leonite and washing with water to yield pure mixture of leonite with KCl; adding KCl to the leonite with the KCl; and decomposing said leonite with the KCl to SOP.

2. The process of claim 1, wherein said SOP is separated from said mixture using a method selected from the group including filtration and centrifugation.

3. The process of claim 2, wherein said SOP is further washed with water to yield an appropriate grade.

4. The process of claim 3, wherein said SOP is further dried and packaged.

5. The process of claim 1, wherein said sodium sulphate is added in a proportion to said dissolved carnallite to yield said mixture of kainite\leonite.

6. The process of claim 1, wherein said precipitant mixture of leonite with KCl is obtained by a floatation method.

7. The process of claim 1, wherein said leonite with the KCl is decomposed to SOP in a crystallizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

(1) According to some demonstrative embodiments, there is provided a process for the production Potassium Sulphate (SOP) and Potassium Magnesium Sulphate as a product of reaction between Carnallite (KClMgCl.sub.2*6H.sub.2O) and Sodium Sulphate bearing minerals.

(2) According to some embodiments, the process may preferably be used in salt water lakes and/or brines.

(3) According to some embodiments, the process may include recovery of SOP from Sulphate bearing mineral and Carnallite and/or Sylvenite.

(4) According to some embodiments, the process of the present invention may include the following steps:

(5) Dissolving Carnallite in water to obtain Sylvenite and high Magnesium Chloride brine;

(6) Adding Sodium Sulphate in various proportion to Carnallite to produce mixture of Kainte\Leonite, KCl and NaCl precipitant and brine containing MgCl.sub.2, KCl, NaCl, e.g., in equilibrium with the solid;

(7) Separating the NaCl from the mixture;

(8) Obtaining a precipitant mixture of Leonite with KCl, e.g., by flotation method;

(9) Filtering the Leonite and washing with water to yield pure mixture of Leonite with KCl;

(10) Adding proper quantity of KCl to the Leonite with the KCl;

(11) Decompose the Leonite with the KCl to SOP in Crystallizer.

(12) Separating the crude SOP, e.g., using by filtration and/or centrifugation; and

(13) Washing the SOP with water to appropriate grade.

(14) According to some embodiments, the final SOP may be dried and packaged according to methods known in the art.

(15) According to some demonstrative embodiments the process may include selecting a specific ratio of Water\Carnallite to lead to Carnallite decomposition and to MgCl.sub.2 brine saturated with KCl. According to some embodiments, the process may further include a reaction between a Sulphate anion from a Sulphate mineral coming in contact with the brine thereby producing Kainite, Leonite, and Shenite.

(16) According to some embodiments, the process may further include a reaction between the Carnallite and the Sodium Sulphate to produce mixture of Kainite\Leonite KCl and NaCl.

(17) According to some embodiments, the process may include further separation of the NaCl from the solids of the mixture, for example, by flotation.

(18) According to some embodiments, the process may include addition of water to results in Leonite decomposing to SOP.

(19) According to some embodiments, the decomposition of Leonite to SOP can also be carried out by adding only water, which will yield SOP and Magnesium Sulphate brine.

(20) According to some demonstrative embodiments, Magnesium Sulphate salt can also produce from the above referenced brine.

EXAMPLES

Examples—1

(21) 2000 gr of Carnallite containing 5% NaCL and 5% adhering moisture mixed at 35° C. with 1200 gr of water. The suspension has been stirred for 1 hour. 142 gr of Na2SO4 has been added and stirring continue for 120 minutes at 35° C. The result suspension was separate and the solid 490 gr and the brine sent to analysis.

(22) Solid composition in wt %:

(23) NaCl—20.5

(24) KCl—58.7

(25) Kainite—20.8

(26) Brine composition in mol/1000 mol H.sub.2O:

(27) Na.sub.2Cl.sub.2—10.2

(28) K.sub.2Cl.sub.2—9.8

(29) MgSO.sub.4 7.7

(30) MgCl.sub.2—50.2.

Example—2

(31) 2000 gr of Carnallite 5% NaCl 5% adhering moisture mixed at 35° C. with 1200 gr of water. The suspension has been stirred for 1 hour. 284 gr of Na.sub.2SO.sub.4 has been added and stirring continue for 120 minutes at 35° C. The result suspension was separate and the solid 608 gr and the brine sent to analysis.

(32) Solid composition in wt %:

(33) NaCl—33.6

(34) KCl—43.3

(35) Leonite—23.1

(36) Brine composition in mol/1000 mol H.sub.2O:

(37) Na.sub.2Cl.sub.2—10.9

(38) K.sub.2Cl.sub.2—10.8,

(39) MgSO.sub.4—13.1

(40) MgCl.sub.2—46.5.

Example—3

(41) 2000 gr of Carnallite 5% NaCl 5% adhering moisture mixed at 35° C. with 1200 gr of water. The suspension has been stirred for 1 hour. 426 gr of Na.sub.2SO.sub.4 has been added and stirring continue for 120 minutes at 35° C. The result suspension was separate and the solid 811 gr and the brine sent to analysis.

(42) Solid composition in wt %:

(43) NaCl—42.7

(44) KCl—25.3

(45) Leonite—32.

(46) Brine composition in mol/1000 mol H.sub.2O:

(47) Na.sub.2Cl.sub.2—11.5

(48) K.sub.2Cl.sub.2—11.4

(49) MgSO.sub.4—19.3

(50) MgCl.sub.2—40.3.

Example—4

(51) 2000 gr of Carnallite 5% NaCl 5% adhering moisture mixed at 35° C. with 1200 gr of water. The suspension has been stirred for 1 hour. 568 gr of Na.sub.2SO.sub.4 has been added and stirring continue for 120 minutes at 35° C. The result suspension was separate and the solid 811 gr and the brine sent to analysis.

(52) Solid composition in wt %:

(53) NaCl—42.8

(54) KCl—10

(55) Leonite—47.2.

(56) Brine composition in mol/1000 mol H.sub.2O:

(57) Na.sub.2Cl.sub.2—14.3

(58) K.sub.2Cl.sub.2—12.4

(59) MgSO.sub.4—18.4

(60) MgCl.sub.2—36.3

Example—5

(61) 2778 gr of Carnallite was added to 8580 gr of brine with a composition of:

(62) 21.6 Na.sub.2Cl.sub.2

(63) 10.57 K.sub.2Cl.sub.2

(64) 14.91 MgSO.sub.4

(65) 23.16 MgCl.sub.2

(66) the resulting suspension was mixed for 30 minutes.

(67) 1440 gr of Na.sub.2SO.sub.4 were gradually added in three steps.

(68) The suspension was mixed for 30 minutes after each step.

(69) The suspension was then mixed for additional 30 minutes and then pumped directly to Denver D-10 flotation cell and the NaCl was floated. The product composition contained 1367 gr of Leonite and 248 gr of NaCl.

Example—6

(70) The same process of example 5 was applied with regard to mixing of 2778 gr of Carnallite with a brine having a composition of:

(71) 21.6 Na.sub.2Cl.sub.2

(72) 10.57 K.sub.2Cl.sub.2

(73) 14.91 MgSO.sub.4

(74) 23.16 MgCl.sub.2.

(75) The final resulting product contained: 1351 gr of Leonite and 297.4 gr NaCl.

(76) While this invention has been described in terms of some specific examples, many modifications and variations are possible. It is therefore understood that within the scope of the appended claims, the invention may be realized otherwise than as specifically described.