The method of obtaining chlorine-free potassium fertilizers

 

(57) Abstract:

The invention relates to the technology of production of potash fertilizers, namely ion exchange technology for the production of chlorine-free potassium fertilizers, and can be used in the agrochemical industry and agriculture. In the process for chlorine-free potassium fertilizers, including the use of at least two ion-exchange columns with a cation exchanger, through which is passed a solution of potassium chloride and translate the cation of the ionic form of any auxiliary component in the potassium form, simultaneously with than through the second column pass a solution of chlorine-free salt of the specified auxiliary component, and translate the cation of potassium in the form of the auxiliary component, use columns with fixed bed cation exchanger, through which alternately pass a solution of potassium chloride and a solution containing a chlorine-free salt of the auxiliary component, and the cation is chosen so that to its selectivity to the auxiliary component was less selectivity to potassium, the concentration of the specified chlorine-free salt of the auxiliary component in the specified age of the first and second columns get supersaturated solution of chlorine-free potassium salt, which is kept for the implementation of spontaneous crystallization chlorine-free potassium salt, the solution obtained in each cycle after the precipitate chlorine-free potassium salts, together with a solution of a specified chlorine-free salt of the auxiliary component before passing through each of the columns. The method provides waste reduction process, the possibility of use as a source of potassium waste potash production and wastewater, reduction of ion-exchange method of obtaining potassium fertilizers due to the receipt of the final products in the form of solid fertilizers, excluding losses of valuable chemicals. 6 C.p. f-crystals, 3 ill., table 1.

The invention relates to the technology of production of potash fertilizers, namely ion exchange technology for the production of chlorine-free potassium fertilizers, and can be used in the agrochemical industry and agriculture.

Known methods of ion-exchange obtain chlorine-free potassium fertilizers, including ion-exchange conversion of potassium chloride in the chlorine-free compound of potassium by contacting the salt solution containing chloride ions with a cation exchange resin in the form of subsequent re Uksa Y., Hentov Century. And. the Production of chlorine-free potassium fertilizers in the USSR and abroad: an Overview, M., 1981, 180C.]. The most well-known ion exchange methods of obtaining potassium nitrate from potassium chloride with nitric acid, calcium nitrate and ammonium nitrate [Higgins I. R., Chem. Ing. Progr. , 1964, V. 60, No. 11, P. 60-61; Vulich A. I. Ion-exchange synthesis, M., 1973, 185 S. ; Dedushkin B. F., Agatova O. I., League, to a post About. So, Volodkovich C. E., Obtaining chlorine-free potassium fertilizers from chlorine-containing raw material using ion exchange. Dept.VINITI 0.12.85 N 516].

The disadvantages of these methods are: contamination of the product used by the reagent, the need to use excessive amounts of potassium chloride for regeneration of ion exchanger, obtaining mixtures of substances in the form of trudnoozhidaemyh mixed solutions, wastewater generation, low efficiency exchange capacity of the ion exchanger.

The closest to the proposed invention to the technical essence and the achieved result is ion-exchange method of obtaining chlorine-free fertilizers, allowing to achieve a high degree of conversion of potassium chloride in the chlorine-free fertilizer without spending excessive amounts of reagents at each stage SUP> B 01 J 47/02, C 01 D 9/10, publ. 1986]. In the specified way to carry out a cyclic process of obtaining a concentrated solution of chlorine-free potassium fertilizers through the use of two ion-exchange columns with a cation exchanger, through which is passed a solution of potassium chloride and translate the cation of the ionic form of any auxiliary component, for example, ammonium, in the form of potassium ion, simultaneously, through the second column, omit solution containing chlorine-free salt of the specified auxiliary component, for example, ammonium nitrate, to obtain the solution of chlorine-free potassium fertilizers, and translate the cation of potassium in the form of auxiliary ion, the cation exchanger is moved in a closed path in the direction opposite direction of transmission solutions, namely, move the cation exchange resin in the potassium form of the first column to the second, and the cation exchanger, for example, in ammonium form, from the second column in the first. No cost of excess amounts of reagents and the absence of sewage in the specified method is achieved through the use of concentrated solutions of ammonium nitrate, which is the effect of treatment selectivity of cation ions of potassium and ASCII and return to the process of mixtures of substances.

This method is limited to the receipt of potassium nitrate from ammonium nitrate and allows you to get other agrokhimichesky valuable chlorine-free potassium fertilizers, such as potassium sulfate or mixed phosphates of potassium and ammonium. Obtained in the form of an aqueous solution of the product requires further processing to highlight chlorine-free potassium fertilizers in the solid phase. Another disadvantage of this method is that the recirculation of the mixture of substances to prevent loss of reactants and education effluent is it a return to the process of mixed ionic forms of the cation movement through the sorbent in a counter-current ion-exchange scheme, which is significantly more costly than recycling solutions.

The objective of the invention is the expansion of the obtained ion-exchange method chlorine-free potassium fertilizers by providing opportunities potassium sulfate, potassium bicarbonate, mixed phosphates of potassium and ammonium. Another objective is to increase the efficiency and reduce the cost of the ion exchange method of obtaining chlorine-free potassium fertilizers due to the receipt of the final products in the form of solid fertilizers. The objective of izobretaet, but due to the recirculation of the resulting mixtures of substances in aqueous solutions.

The task is solved by the fact that in the ion-exchange method of obtaining chlorine-free potassium fertilizers, including the use of at least two ion-exchange columns with a cation exchanger, through which is passed a solution of potassium chloride and translate the cation of the ionic form of any auxiliary component in a potassium form with obtaining sodium chloride solution, simultaneously with than through the second column pass solution containing chlorine-free salt of the specified auxiliary component, and translate the cation of potassium in the form of the auxiliary component with obtaining as a product of chlorine-free potassium salt and return to the process of mixtures of substances, formed by passing the solutions through these columns, use the column fixed bed cation exchanger, through which alternately pass a solution of potassium chloride and a solution containing a chlorine-free salt of the auxiliary component, and the cation is chosen so that its selectivity to the auxiliary component was less selectivity to potassium, the concentration of the specified chlorine-free CPA chlorine-free potassium salt, alternately output from the first and second columns get supersaturated solution of chlorine-free potassium salt, which is kept for the implementation of spontaneous crystallization chlorine-free potassium salt, the solution obtained in each cycle after the precipitate chlorine-free potassium salts, together with a solution of a specified chlorine-free salt of the auxiliary component before passing through each of the columns; passing through each of the columns of a solution of potassium chloride and the combined solution containing the chlorine-free salt of the auxiliary component, is carried out in opposite directions, so that within each column the more dense solution was below the less dense solution; passing through each of the columns of a solution of potassium chloride and subsequent transmission of the combined solution containing the chlorine-free salt of the auxiliary component, carried out at different temperature; passing the combined solution containing the chlorine-free salt of the auxiliary component, and the crystallization of chlorine-free potassium salt is carried out at different temperature; solution of chlorine-free salt of the auxiliary component, displaced from each column at the beginning of the process of transmission of RA is e process transmittance of a solution of potassium chloride through a given column; a solution of potassium chloride, displaced from each column at the beginning of the process of transmission of the combined solution of chlorine-free salt of the auxiliary component through a given column, separated from the solution chlorine-free potassium salt, displaced at the end of the process transmittance of a solution of chlorine-free salt of the auxiliary component through a given column; use three columns fixed bed cation exchange resin, in each cycle of the process through two of the three columns sequentially pass a solution of potassium chloride, simultaneously with than through a third column in the opposite direction pass solution containing chlorine-free salt of the auxiliary component, and in each subsequent cycle column, used in the previous cycle as the first as the transmittance of a solution of potassium chloride, is used for transmission of a solution of chlorine-free salt of the auxiliary component, and the column used for the transmission of a solution of chlorine-free salt ancillary component is used in a subsequent cycle for transmission of a solution of potassium chloride as the second column in the course of transmission of the specified solution.

In Fig. 1 shows the output curves of ion-exchange processes is Alieva form one pillar on the example of the steady-state cyclic process of obtaining potassium sulfate from potassium chloride and sodium sulfate on the proposed method. I - exit supersaturated solution of potassium sulfate: 1 and 2 - the concentration of sodium and, consequently, potassium leaving the solution in the process of the potassium form of the cation exchanger of the United circulating solution mixture of sodium sulfate (3.2 g-EQ/l) and potassium sulfate (0.8 g-EQ/l) at 35oC; 3 - residual concentration of potassium in the solution after spontaneous fracture of the supersaturated solution. II or III - translation of cation exchange resin in the potassium form of transmission 0.125 N. solution of potassium chloride at 20oWith: 4 and 5 - output curves of sodium ions and, respectively, of potassium.

In Fig.2 shows the schematic diagram of the process for the implementation of the proposed method to obtain chlorine-free potassium fertilizers. 1, 2 - ion exchange columns, 3 - capacity to collect supersaturated solution and crystallization chlorine-free potassium fertilizers, 4 - capacity to prepare consolidated circulating solution containing chlorine-free salt of the auxiliary component, 5 - bin for the filing of the original chlorine-free salt of the auxiliary component, 6 - capacity to supply water.

In Fig.3 shows a schematic diagram of the process for the implementation of the proposed cm cation exchange resin. 1-3 - ion-exchange columns, 4 - capacity to collect supersaturated solution and crystallization chlorine-free potassium fertilizers, 5 - capacity to prepare consolidated circulating solution containing chlorine-free salt of the auxiliary component, 6 - hopper for the filing of the original chlorine-free salt of the auxiliary component, 7 - capacity to supply water.

A distinctive feature of the proposed method ion exchange obtain chlorine-free potassium fertilizers is the discovery and use of a new phenomenon - isothermal supersaturation of solutions of inorganic substances in ion exchange (Hamitov R. H., Myasoedov B. F., N. Tikhonov.A., Rudenko B. A. , and About the General nature of the phenomenon isothermal supersaturation in ion exchange. Dokl. Academy of Sciences, 1997). The essence of the phenomenon is that when holding the column of ion-exchange reaction accompanied by the formation of compounds with limited solubility, ion exchange layer is formed and stabilized supersaturated solution of this compound, which after exiting the column spontaneously disintegrates with the crystallization of the specified connection. The use of this phenomenon for ion exchange obtain chlorine-free mineral UD is olitely processing, to use in the loop current solutions, formed after crystallization of the product without loss of valuable chemicals and without the formation of solid wastes and sewage.

It is advisable to carry out the transmission through the ion exchange columns solution of potassium chloride and the combined solution containing the chlorine-free salt of the auxiliary component in opposite directions, so that within each column the more dense solution was below the less dense solution. This avoids mixing dissimilar fluids and loss of valuable components.

It is advisable to carry out the transmission through the ion exchange columns solution of potassium chloride and subsequent transmission of the combined solution containing the chlorine-free salt of the auxiliary component at a different temperature. This allows you to affect the solubility (to increase solubility) chlorine-free potassium salt in supersaturated solution in the layer of sorbent, in order to provide a stable ion-exchange process without precipitation in the column.

It is advisable to carry out the transmission of the combined solution containing the chlorine-free salt of the auxiliary component, and crystallize remote) of the obtained product chlorine-free potassium fertilizers and increase its output in each cycle of the process.

It is advisable to carry out a process to separate a solution of chlorine-free salt of the auxiliary component, displaced from each column at the beginning of the process of transmission of a solution of potassium chloride through the ion exchange column, from a solution of sodium chloride, displaced at the end of the process transmittance of a solution of potassium chloride through the column. This allows the process without the formation of waste water in the form of trudnoozhidaemyh the mixed aqueous solution and to prevent the loss of valuable product.

It is advisable to carry out a process to separate a solution of potassium chloride, displaced from each column at the beginning of the process of transmission of the combined solution of chlorine-free salt of the auxiliary component through the specified column from a solution of chlorine-free potassium salt, displaced at the end of the process transmittance of a solution of chlorine-free salt of the auxiliary component through the column. It also allows to carry out the process without the formation of waste water in the form of trudnoozhidaemyh mixed solutions.

It is advisable to carry out the process using three columns with n the scat solution of potassium chloride, at the same time with than through a third column in the opposite direction to pass a solution containing chlorine-free salt of the auxiliary component. In each subsequent cycle, the column used in the previous cycle as the first as the transmittance of a solution of potassium chloride, can be used for transmission of a solution of chlorine-free salt of the auxiliary component, and the column used for the transmission of a solution of chlorine-free salt of the auxiliary component can be used in a subsequent cycle for transmission of a solution of potassium chloride as the second along the columns to pass the specified solution. This allows, in case of application of concentrated solutions of potassium chloride as a source of potassium, to exclude the possibility of its loss, and the possibility of sewage in the form of mixed solutions.

Examples of the proposed method.

Example 1. Conduct the process in a laboratory setup, collected by the scheme shown in Fig.2, and includes two identical ion-exchange column with a square internal cross-section 3.25 cm2and a height of 35 cm, equipped with a thermostatic jacket, drain filtration devices in the th sulfonation KU-2x8, the mass of the sorbent loaded into each column, in the air-dry state 50, the Sorbent is loaded into the column in the form of a suspension in 0.1 N. the NaCl solution. The parameters of the layer of sorbent in each column under various conditions: 0.1 N. NaCl: L=34 cm (layer volume =110.5 cm3); 4 N. Na2SO4: L=31.5 cm (=102.4 cm3). The porosity of the dense layer in a solution of sodium chloride (fraction of volume between the grains of the resin from the volume of the layer in the column) - = 35%, while the volume polosnogo space in the column - V= 38.5 cm3; free volume in each column under a layer of sorbent and pipelines to the lower output of each of the column - 31.5 cm3; maximum free volume in each column above the layer of sorbent and in the piping to the upper output of each of the column - 31.5 cm3. The process is carried out as follows.

A. Through each of the columns at room temperature is passed in 2200 ml of 0.125 N. solution of potassium chloride (KCl). The transmission rate of the solution through each column - 550 ml/hour, the time of transmission - 4 hours. The resulting diluted 0.125 N. solution of sodium chloride (NaCl) is directed to drain.

B. Through the first column at a temperature of 35oWith miss 240 ml of 4 n solution of Na2SO4in the direction of the SNO corresponds to the volume of the diluted solution of KCl, remaining in porezna space (38.5 ml) and in the free volume above the resin bed (31.5 ml), send in the supply line source solution of potassium chloride, which is performed by means of valves installed in the upper part of the diagram in Fig.2. Further portions of the eluate is directed into the container 3, which is at room temperature and is equipped with a filter plate. Bandwidth 4 n solution of Na2SO4120 ml/hour, the total time of transmission 2 hours. Just in the vessel 3 collect 240-70=170 ml of the eluate. This solution is left to stand (stand) for 2 hours for crystallization of potassium sulfate (K2SO4).

C. the resulting suspension divide that remaining in the vessel 3, the solution is directed into the container 4, which is at a temperature of 35oC. While the solution passes through a layer of a crystalline precipitate and filter the bottom of the vessel 3. Only after these operations are provided: capacity 3 wet sediment, containing 12 g K2SO4and 12 of water in the tank 4 - 158 ml of a solution containing a mixture of potassium sulfate and sodium sulfate in concentrations: K2SO4- 0.8 mEq/ml and Na2SO4- 2.8 mEq/ml.

, Capacity 4 add 9.68 g of anhydrous sodium sulfate and 12 m is in the downward direction at room temperature is passed diluted (0.125 N. ) solution of KCl with a speed of 550 ml/hour. The process of transmission continue for four hours. The first portion of the eluate (70 ml), the appropriate volume of concentrated solution of sodium sulfate in porezna volume and the free volume above the resin bed, is directed back into the tank 4, and the following portions (a total of 1030 ml) in the form of a dilute solution of chloride sent to drain. In the implementation of operations under item"D" of the concentration of the components in the output of the first column of the solution is changed in accordance with the output curves 4 and 5, shown in Fig.1.

E. Simultaneously with operations under item"D", through the second column at a temperature of 35oWith the bottom-up pass supplied from the tank 4 a concentrated solution of sodium sulfate (3.2 mg-kV/ml), mixed with residual solutions of potassium sulfate (0.8 mEq/ml). The speed and time of transmission, and the transmission procedure is completely analogous to that described above in paragraph "B". In the process of passing a concentrated solution through a second column component concentration at the outlet from the top of the specified column is changed in accordance with the output curves 1 and 2, shown in Fig.1. Received supersaturated by UB>. After crystallization of potassium sulfate residual concentration of potassium ions in the solution is equal to 0.8 mEq/ml and corresponds to curve 3 in Fig.1.

J. the resulting suspension is separated as described in paragraph "B", namely, remaining in the vessel 3, the solution is directed into the container 4, which is at a temperature of 35oC. While the solution passes through a layer of a crystalline precipitate and filter the bottom of the vessel 3. Only after these operations are provided: capacity 3 wet sediment, containing 17.6 g2SO4and 17.5 water in the tank 4 - 152.5 ml of a solution containing a mixture of potassium sulfate and sodium sulfate in concentrations of K2SO4- 0.8 mEq/ml and Na2SO4- 2.02 mEq/ml.

3. In the capacity of 4 add 14 g of anhydrous sodium sulfate and 17.6 ml of water (or 23.5 g of salt in the form of hydrated - Na2SO410H2O).

K. Repeat all the processes in accordance with PP "D","C", except that a dilute solution of potassium chloride is passed through the second column in the downward direction, at the same time with a concentrated solution of the mixed sulphates of sodium and potassium is passed through the first column in the upward direction. At the end of all operations get separated and dried 17.6 g self the glue columns 1 and 2 alternately, at the stage of sorption, at the stage of regeneration, with the production of a supersaturated solution of potassium sulfate. In each cycle (4 hours) obtain 17.6 g of potassium sulfate and spend 14 g of anhydrous sodium sulfate. In the process there is no waste except diluted 0.125 N. solution of sodium chloride.

Example 2. Conduct the process in a laboratory setup, collected by the scheme shown in Fig.3, and includes three identical ion-exchange column with a square internal cross-section 3.25 cm2and a height of 35 cm, equipped with thermostatically shirt, drain filtration devices in the upper and lower parts of the column and the boot device for the ion exchange resin. Use industrial strong acid of sulfonation KU-2x8, weight sorbent loaded into each column, in the air-dry state 50, the Parameters of the layer of sorbent in each column are similar to the settings shown in Example 1. The process is carried out as follows.

A. Through the columns 1, 2 and 3 sequentially pass at room temperature for 3 H. the solution (226.5 g/l) potassium chloride (KCl) before the discovery of "breakthrough" of potassium ions through the bottom outlet of the column 3. Just skip 168 ml. bandwidth solution of 84 ml/hour, the time bandwidth - 2 hours. Received Ghai salt or chlorine in the production of chlorine and alkali using membrane electrolysis).

B. Through the first column at a temperature of 35oWith miss 240 ml of 4 n solution of Na2SO4in the direction from the bottom to the top of the column. In the beginning of the process of transmission of the specified solution, namely, 70 ml of the first portions of the eluate, which corresponds to the amount of dilute KCl solution remaining in porezna space (38.5 ml) and in the free volume above the resin bed (31.5 ml), send in the supply line source solution of potassium chloride, which is performed by means of valves installed in the upper part of the diagram in Fig.3. Further portions of the eluate is directed into the container 4, which is at room temperature and is equipped with a filter plate. Bandwidth 4 n solution of Na2SO4- 240 ml/hour, the total time of transmission 1 hour. Just in the vessel 4 collect 240-70=170 ml of the eluate. This solution is left to stand (stand) for 1 hour for crystallization of potassium sulfate (K2SO4).

C. the resulting suspension divide that remaining in the vessel 4, the solution is directed into the tank 5 is at a temperature of 35oC. While the solution passes through a layer of a crystalline precipitate and filter the bottom of the vessel 4. Only after these operations are provided: capacity 4 - wet salfate sodium concentrations: K2SO4- 0.8 mEq/ml and Na2SO4- 2.8 mEq/ml.

, Capacity 5 add 9.68 g of anhydrous sodium sulfate and 12 ml of water (or 22 grams of salt in the form of hydrated - Na2SO410H2O).

D. Through the third and first column sequentially in the direction 3-->1, at the same time within each column from top to bottom, at room temperature miss concentrated 3 n KCl solution with a speed of 70 ml/hour to "overshoot" of potassium ions through the bottom outlet of the first column. The process of transmission continue for two hours. The first portion of the eluate (70 ml), the appropriate volume of concentrated solution of sodium sulfate in porezna the volume of the first column and in the free volume above the resin bed, is directed back into the tank 5, and the subsequent portion (70 ml) in a 3 n solution of chloride sent for recycling.

E. Simultaneously with operations under item "D", through the second column at a temperature of 35oWith the bottom-up pass supplied from the tank 4 a concentrated solution of sodium sulfate (3.2 mg-kV/ml), mixed with residual solutions of potassium sulfate (0.8 mEq/ml). The speed and time of transmission, and the procedure for carrying capacity, the Sano in p. "In", namely, remaining in the vessel 4, the solution is directed into the tank 5 is at a temperature of 35oC. While the solution passes through a layer of a crystalline precipitate and filter the bottom of the vessel 4. Only after these operations are provided: capacity 4 - wet sludge containing 17.6 g2SO4and 17.5 water; capacity 5 - 152.5 ml of a solution containing a mixture of potassium sulfate and sodium sulfate in concentrations of K2SO4- 0.8 mEq/ml and Na2SO4- 2.02 mEq/ml.

Z capacity 5 add 14 g of anhydrous sodium sulfate and 17.5 ml of water (or 23.5 g of salt in the form of hydrated - Na2SO410H2O).

K. Repeat all the processes in accordance with PP "D","C", except that 3 n solution of potassium chloride is passed through the first and second column direction 1-->2 and in the direction from top to bottom within each column, simultaneously with a concentrated solution of the mixed sulphates of sodium and potassium is passed through the column 3 in the upward direction. At the end of all operations get separated and dried 17.6 g of potassium sulfate.

Then continue the process in accordance with the above description, using in each cycle of the column alternately, and two of the three Colo is the generation with the production of a supersaturated solution of potassium sulfate. The mentioned processes are performed on the columns in accordance with the following sequence of columns in each cycle stages of sorption and regeneration, starting with the first cycle (see table).

In each cycle (2 hours) obtain 17.6 g of potassium sulfate and spend 14 g of anhydrous sodium sulfate. In the process there is no waste, provided useful utilization of concentrated sodium chloride solution.

Example 3. Carry out the process as described in example 2, except that instead of concentrated 4 n solution of sodium sulfate using a 4 n solution of ammonium nitrate (320 g/l), the stage of regeneration of the sorbent, pre-saturated in potassium specified solution of ammonium nitrate, is carried out at room temperature (ambient temperature is 18-25o(C) obtained supersaturated solution is cooled to 0oWith by maintaining in the tank 4 to the specified low temperature, capacity 5 support the ambient temperature. In each cycle of the process (2 hours) get 20 grams of potassium nitrate calculated on the dry anhydrous salt. In each cycle of the process in the reverse recovery solution after separation of the precipitate of potassium nitrate residual concentration is 1.25 g-EQ/l (127.5 g/CLASS="ptx2">

When carrying out the described process in each cycle at the stage of sorption of potassium receive 70 ml of a 3 n solution of ammonium chloride (NH4Cl), which gradually accumulate and process the second time the method is completely analogous to the procedure described in Example 2, except that of the product receiving ammonium sulfate (13.2 g in each cycle). Thus in each cycle at the stage of sorption of potassium chloride receive 70 ml of a 3 n solution of sodium chloride, which acts in accordance with Example 2.

Obtained during all the operations described above in this example, the products are potassium nitrate (20 g, every two hours) and ammonium sulfate (13.2 g, every two hours) is used as a valuable mineral fertilizers alone or in mixed form.

Example 4. Carry out the process as described in Example 2, except that instead of concentrated 4 n solution of sodium sulfate use 3 ad (ammonium) solution of ammonium dihydrophosphate (NH4H2PO4, 354 g/l) obtained by blowing through a solution of phosphoric acid calculated amount of ammonia, the stage of regeneration of the sorbent, pre-saturated in potassium specified solution of ammonium dihydrophosphate, are at room Tyr>With by maintaining in the tank 4 to the specified low temperature, capacity 5 support the ambient temperature. Another difference from example 2 is that at the stage of regeneration through the column miss not 240 ml, and 300 ml of concentrated solution. In each cycle of the process (2 hours) obtain 27.5 g of potassium dihydrophosphate (KN2RHO4) calculated on the dry anhydrous salt. In each cycle of the process in the reverse recovery solution after separation of the precipitate of potassium nitrate residual concentration is 1.1 g-EQ/l (152 g/l). In each cycle of the circulating regeneration solution doubleplay added 23.5 g of ammonium dihydrophosphate and 20 ml of water.

When carrying out the described process in each cycle at the stage of sorption of potassium receive 70 ml of a 3 n solution of ammonium chloride (NH4Cl), which gradually accumulate and process the second time the method is completely analogous to the procedure described in Example 2, except that of the product receiving ammonium sulfate (13.2 g in each cycle). Thus in each cycle at the stage of sorption of potassium chloride receive 70 ml of a 3 n solution of sodium chloride, which acts in accordance with Example 2.

Obtained in the course of all described two hours) is used as a valuable mineral fertilizers alone or in mixed form.

The proposed method, due to the use of the new phenomenon of open-authors - Isothermal supersaturation in ion exchange", as well as in the implementation described above the individual operations and their special combinations with each other, provides: waste reduction and environmental cleanliness of the process; can be used as a source of potassium waste potash production and other industrial and agricultural wastewater; expansion of the resulting chlorine-free potassium fertilizers; reduction of ion-exchange method of obtaining chlorine-free potassium fertilizers due to the receipt of the final products in the form of solid fertilizers and reducing energy consumption, and also exclude losses of valuable chemicals through recycling of the resulting mixtures of substances in aqueous solutions.

1. The method of obtaining chlorine-free potassium fertilizers, including the use of at least two ion-exchange columns with a cation exchanger, through which is passed a solution of potassium chloride and translate the cation of the ionic form of any auxiliary component in the potassium form, simultaneously with than through the second column skip restoy in the form of an auxiliary component to produce in the quality of the product is chlorine-free potassium salt and return to the process of mixtures of substances, formed by passing the solutions through these columns, characterized in that use columns with fixed bed cation exchanger, through which alternately pass a solution of potassium chloride and a solution containing a chlorine-free salt of the auxiliary component, and the cation is chosen so that its selectivity to the auxiliary component was less selectivity to potassium, the concentration of the specified chlorine-free salt of the auxiliary component in the specified solution is chosen greater than the concentration of a saturated solution of chlorine-free potassium salt, alternately output from the first and second columns get supersaturated solution of chlorine-free potassium salt, which is kept for the implementation of spontaneous crystallization chlorine-free potassium salt, the solution obtained in each cycle after the precipitate chlorine-free potassium salts, together with a solution of a specified chlorine-free salt of the auxiliary component before passing through each of the columns.

2. The method according to p. 1, characterized in that the transmission through each of the columns of a solution of potassium chloride and the combined solution containing the chlorine-free salt of the auxiliary component, is carried out in PR the pilot solution.

3. The method according to p. 1, characterized in that the transmission through each of the columns of a solution of potassium chloride and subsequent transmission of the combined solution containing the chlorine-free salt of the auxiliary component, carried out at different temperatures.

4. The method according to p. 1, characterized in that the transmission of the combined solution containing the chlorine-free salt of the auxiliary component, and the crystallization of chlorine-free potassium salt is carried out at different temperatures.

5. The method according to p. 1, characterized in that a solution of chlorine-free salt of the auxiliary component, displaced from each column at the beginning of the process of transmission of a solution of potassium chloride through a given column, separated from the sodium chloride solution, displaced at the end of the process transmittance of a solution of potassium chloride through the column.

6. The method according to p. 1, characterized in that the solution of potassium chloride, displaced from each column at the beginning of the process of transmission of the combined solution of chlorine-free salt of the auxiliary component through a given column, separated from the solution chlorine-free potassium salt, displaced at the end of the process transmittance of a solution of chlorine-free salt of the auxiliary component through this A, at the same time in each cycle of the process through two of the three columns sequentially pass a solution of potassium chloride, simultaneously with than through a third column in the opposite direction pass solution containing chlorine-free salt of the auxiliary component, and in each subsequent cycle, the column used in the previous cycle as the first as the transmittance of a solution of potassium chloride, is used for transmission of a solution of chlorine-free salt of the auxiliary component, and the column used for the transmission of a solution of chlorine-free salt ancillary component is used in a subsequent cycle for transmission of a solution of potassium chloride as the second column in the course of transmission of the specified solution.

 

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FIELD: chemical industry.

SUBSTANCE: device comprises vertical cylindrical housing whose bottom section receives drain unit with deflector and central pipe whose top section is provided with the hopper for charging grain phase. The top of the cylindrical housing is pressure-tightly connected with the hopper of the central pipe, and the top section of the ring zone defined by the housing and central pipe additionally receives distributor of grain and liquid phases made of overturned trancated cone that defines a ring space together with the central pipe. The branch pipe for discharging exhaust grain phase is provided with valving device, and the top section of the hopper additionally receives branch pipe mounted above the level of the grain phase and provided with the drain for discharging liquid phase which is supplied from the central pipe and hopper and branch pipe for tangential inflow of initial grain phase. The ring space between the distributor and central pipe is equal or greater than the diameter of the branch pipe for discharging exhaust grain phase.

EFFECT: improved performance.

4 cl, 1 dwg

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