DD285585A5 - PROCESS FOR COMBINED PROCESSING OF MINE SALT AND CARNALITE SOLE FROM A SOLVROCESS - Google Patents

Abstract

The invention relates to the combined processing of Bergmaennisch obtained mixed salt and Carnallitsole from a Solprozesz. According to the invention, the excess amount of mother solution from the mixed salt processing heating step is wholly or partly taken up in the sol process solvent loop by mixing with carnallite mother solution, decomposition solutions and thin process solutions, and the equivalent amount of MgCl2 is carried out together with the excess amount of MgCl2 resulting from the sol process. By applying the invention, the energy economy is substantially improved and the MgCl2 and bromide concentration of the MgCl2 solution leaving the process is increased. Fig. 1 {mixed salt processing; Sole processing; Combination process; Heiszloeseprozesz; Spoon circuit; Mixed salt mother solution; Carnallitmutterloesung}

Description

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Field of application of the invention

The invention relates to the combined processing of mined mixed salt or hard salt and carnallite sols from a sol process. Both obtained in various ways raw materials can be processed by the inventive method to high-proof potash fertilizers with 50 to 60% KiO ₁ a highly concentrated MgCl ₂ -SoIe with> 300g / l MgCl ₂ and bromine at high Wertstoffausbul.

Characteristic of bekannton state of the art

In the manufacture of potash fertilizers from a carnallite and hard salt deposit, a mixed crude salt consisting of both crude salt species is generally recovered by mining mining and processed into potassium chloride and a MgCl 2 solution and bromine in a hot dissolving process. Such a method is described in DD WP116210. The leaving the processing process MgCl ₂ solution (mixed salt mother solution) has 260 to 280g / l MgCl ₂ and is concentrated by evaporation to 350 to 360g / l MgCl ₂ and returned the recovered KCI-containing evaporating crystals directly or after decomposition of carnallite in the dissolution process. According to DD WP 200272, a processing method is known which provides a higher-grade MgCl ₂ solution and avoids the repeated hot-dissolving of the KCl fraction from the evaporation stage. Furthermore, it is known, for example according to DD WP147131, the Aussolen a Carnallitlagerstätta on drilling from overground and the processing of the obtained hot carnallite sols to carnallite and Carnallitmutterlauge with subsequent decomposition of carnallite.

Further processing variants are described in DD WP 200020 and DD WP 220013.

Carnallite sols from a sol process and minerally promoted carnallitaltiges mixed salt can be processed according to DD WP 144403 together to potash fertilizers. In this process, carnallite sols obtained by sonification are introduced into the hot dissolving process temperature without further processing after heating to the temperature of the hot dissolving process and, together with further hot dissolving solution, serve for hot dissolving of the mining solubilized saline salt. The KCl and MgCl ₂ -containing brine is completely mixed with the process solutions of the hot-dissolving process and leaves it with a maximum MgCl ₂ concentration of <300 g / l MgCl ₂ . The bromide contained in the crude salt accumulates in the solutions as in all hard and mixed salt processes and is recovered from the mother liquor.

The achievable bromide concentration is only 2.5 to 2.9 g / l. Higher bromide concentrations of 3.5 to 4.6 g / l Br are obtained by evaporation, the higher the attainable bromide content, the higher the MgCl ₂ content of the solution So far, that both in the known methods of Mischsalzverarbeilung and the combined carnallite salt Mischsalzverarbeitung without evaporation plants only <300g / l MgCl ₂ and 2.5 to 2,9g / l Br ^- achieved and higher MgCl ₂ - and bromide-containing solutions only by very energy-consuming water evaporation can be realized.

Zlei of the invention

The aim of the invention is to improve the economics of potash fertilizer, MgCl ₂ and bromine recovery in combined carnallite brine, mixed salt or hard salt processing.

Explanation of the essence of the invention

The technical problem to be solved by the invention is to increase the MgCl ₂ and bromide concentration in the MgCl ₂ solution leaving the processing process while avoiding an energy-consuming evaporation plant. In this case, both the sol process and the mixed salt or Hartsalzanteil stemming potassium chloride in high-percentage quality (> 48% K ₂ O) must be recovered.

Di6se object is achieved in that the leadership of the Stoffströmo is changed so that all the excess magnesium chloride and thus the entire bromide from both raw material species in highly concentrated form as Carnallitmutterlösung with 300g / l MgCl ₂ and 3.0g / l Br " be executed.

It has been found that this objective can be achieved by processing the mixed salt without adding sols from a carnalline leaching and conversely using the excess mother liquor of the hot leaching process in synthesizing the solvent for the camallitol process and thus into the cycle of the sol process which also transfers the potassium chloride, MgCl ₂ and bromide contained therein from the process of mixed salt processing to the sol process. The brine obtained by carnallite extraction can be processed into carnallite crystallizate and carnallite mother solution according to methods known per se, and the entire excess of MgCl ₂ and bromide from both partial processes is carried out exclusively in the form of carnallite mother solution from the process. In this case, the potassium content of the processed potash crude salt is largely recovered as occlusive vacuum crystallizate and the potassium content of carnallite sols including the KCl from the transferred to the sol process mother liquor of the process of mixed salt processing as carnallite and after its decomposition with minimal amounts of water as also coverable decomposition KCl and further processed to potash fertilizers together. The pesamic potassium chloride from both partial processes and all the excess MgCl ₂ and bromide leave the overall system together with the highest possible degree of enrichment in high concentration. This eliminates the need for a lot of energy-intensive evaporation plant as a special process step.

Sovvuii! the processing process for the mixed salt and the processing of the carnallitols work under optimal conditions substantially separated from each other and without mutual interfering jssung tion, the carnalline solubility takes the concentration increase for the transferred to the low-concentrated mixed salt mother solution to the concentration level> 360g / l MgCl ₂ . In a refinement of the method according to the invention, it is possible to convert either excess mixed mixed-salt mother solution into the solution circuit of the solution or only part of it. The introduction of only a subset takes place when either a part of the Mischselzmutterlösung is to be sold as a product (brine for thawing purposes) or when the mined raw salt and thus the accumulation of mixed salt mother solution is much greater than the azul to accommodate under the Lösemittelsynthetis for the sol process amount

 The invention is explained in more detail by an embodiment.

embodiment

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1000 t carnallite Kalirohsalz with 20.1% KCl, 9.0% MgCl ₂ , 43.4% NaCl, 11.8% H ₂ 0.15.6% sulfate minerals and insoluble and 0.1% bromide are known process 1 with a MgCl ₂ -containing hot dissolving solution at 90 to 95 ⁰ C triggered. As solvent solution 2 240 m ³ with the composition 73g / l KCl, 77 g / l NaCl, 212g / l MgCl _2, 20 g / l MgSO _4, 836g / l H ₂ O requires. After separation of the solvent residues and sludge 2566m ³ hot clarified solution of the composition 141 g / l KCl, 81 g / l NaCl, 227 g / l MgCl ₂ , 30g / l MgSO ₄ , 807g / l H ₂ O won. These were cooled in a vacuum cooling system 2 under dehydration (self-evaporation) in a known manner, wherein 384t KCl-NaCl crystals of composition 54.2% KCl, 5.5% MgCl 2, 20.3% NaCl, 18.1% H ₂ 0.1,9% other ingredients are recovered. Of the resulting 2159m ³ mixed salt mother solution of composition 71 g / l KCI, 59g / l NaCl, 260g / l MgCl ₂ , 35g / l MgSO ₄ , 858g / l H ₂ 0.2,6g / l bromide 1866m ¹ are used to prepare the solvent , 293m ³ are carried out from the process of mixed salt processing and introduced into the sol process 3. The hot Aussolen the underground Carnallititlagerstätto 'takes place according to known per se method.

As solvent for the sol process 3, a dissolution solution with about 315g / l MgCl ₂ content is used, consisting of 293m ³ mixed salt mother solution, 620m ³ solution of Carnallitkristallisatzeretzung with 340g / l MgCl ₂ , 40g / l KCl, 20g / l NaCl, 16g MgSO ₄ , 880 g / l H ₂ 0.1110 m ³ carnallite mother solution and 200 to 240 t of water or vapors in a Lösamittelsynthetisierung 7 is mixed. Obtained by resolution of carnallite directly from the reservoir in the Solkaverne 3 werden2300m ³ heißeCarnallitsolederZusammenset2ung63g / IKCI, 349g / IMgCI _2, 19g / IMgSO _<, 27g / INaCI, 850g / IH ₂ O, 3.6 g / l bromide at about 6O ⁰ C , By cooling 4 to about 25 ⁰ C with removal of 375t H ₂ O crystallized carnallite. There are 695t Carnallitkristallisat consisting of 69.3% carnallite, 8.7% NaCl adhering Carnallitmutterlösung separated. This produces 1486m ³ Carnallitmutterlösung with 398g / l MgCl ₂ , 10g / l KCl, 8g / l NaCl, 28g / l MgSO ₄ , 4.0 to 4.2 g / l Br, 870g / l H ₂ O, of the 376m ³ the Entbromung 6 are fed by a known method. The Carnallitkristallisat is further processed by per se known method by decomposition 5 with water and cooling the ZerseUungslösung. In the process, 156 tons of decomposition crystallizate (69% KCl) are combined, which is combined with dom vacuum crystals of mixed salt processing and prepared by blanketing to form potash fertilizers.

In the amount of carnallite mother solution fed to the bromine factory are about 150 tonnes of MgCl ₂ and 1.5 to 1.6 tonnes of bromide, which come from approximately the same proportions from the mining and brine extraction process. As a result of the high input concentration, the bromine yield increases to> 90% during entbromination, while the bromination of the mixed salt mother solution has bromine yields <85%. The solution resulting after debromination has a MgCl ₂ content higher by> 100 g / l MgCl ₂ and a greatly reduced KCl content than entbrominated mixed salt mother solution. Because of the higher

MgCl ₂ and bromide concentration decreases the specific energy consumption of the Entbromung, and the specific Apparate throughput rises. In addition, MgCl ₂ -SoIe with> 360g / l MgCl _{2 has} a much higher utility value than Mixed salt stock solution. This results in multiple advantages of the method according to the invention, which can be applied both to a higher Wertetoffausbringen of bromine and potassium, as well as on a higher quality of the recovered intermediates and end products and

refer to a lower energy consumption.

Claims (2)

1. A method for the combined processing of mined mixed salts and carnallite from a sol process by Heißverlösung the crude salt, separation of the solvent residues and crystallization in a vacuum cooling system and cooling of the hot won from the sol process carnallisole and subsequent decomposition of the resulting carnallite according to known methods and joint processing of KCI Crystallisates, characterized in that the excess amount of mother liquor of the KCl-FeId the quaternary system MgCl ₂ , KCl, NaCl and H ₂ O operated hot dissolving process with a MgCl ₂ concentration of 240 to 285g / l wholly or partially in the solution cycle the operated in the carnallite field of said quaternary system sol process by mixing with Camallitmutterlösung, decomposition solution and thin process or repelling solutions to be determined by the intended brine concentration of the sol process Me In the solvent synthesis, the equivalent MgCl ₂ amount is carried out together with the excess amount of MgCl ₂ originating from the sol procedure of the carnallite as carnallitrile feed solution with 360 to 420 g / l MgCl ₂ concentration. 2. The method according to claim 1, characterized in that the carnallite mother solution is entbromt by known methods.