RU2062810C1 - Method for selective extraction of scandium form hydrochloric solutions - Google Patents

Abstract

FIELD: extraction of scandium. SUBSTANCE: method is carried out by sorption of scandium from hydrochloric solutions with the help of N-(2-oxypropyl)-N′-(2-oxy-3-pyridinium propyl)-N"-methylene phosphonium polyethylene polyamine followed by washing and by desorption. Said washing takes place with the help of water, desorption being carried out by carbonate or fluoride solutions. EFFECT: improves efficiency of the method. 2 tbl

Description

 The invention relates to the field of metallurgy and can be used to extract and concentrate scandium from solutions containing impurities of related elements. The invention can be used, in particular, for the extraction of scandium from various industrial wastes.

 The known method / 1 / selective extraction of scandium from solutions containing impurities of related elements. The method is as follows. Sorption of scandium is carried out by carboxyl cation exchangers. The initial solution is treated with an alkaline reagent to a pH of 3.0-4.5 and sent to ion exchange recovery. After sorption, the ion exchangers in the column are washed with 0.5-2.0 n. a solution of chloride, perchlorate or sodium sulfate (ammonium). Scandium is desorbed 0.3-3.0 n. a solution of nitric, hydrochloric, phosphoric or nitric acid.

 The known method allows with high efficiency to extract scandium from complex composition solutions containing, in addition to scandium, large quantities of metals accompanying it.

 The disadvantage of this method is the need for preliminary neutralization of solutions to pH 3.0-4.5, which complicates the technology, leads to additional consumption of reagents. On the other hand, neutralized solutions are very unstable and quickly hydrolyze; a precipitate appears in the solution, which adsorbs a significant amount of scandium.

 The known method / 2 / selective extraction of scandium from solutions. This method is as follows. A nitric acid solution containing scandium and associated metals is brought into contact (passed through a sorption column) with a phosphorus-containing ion exchanger, which is used as a macroporous phosphoric acid cation exchanger based on styrene and divinylbenzene. In this case, scandium is selectively extracted from the solution - it is sorbed by cation exchange resin, while other metals mostly remain in the filtrate. After sorption, the cation exchange resin is washed successively with water and 1-3 N hydrochloric acid solution. Then carry out the desorption of scandium 0.5-1.0 N. ammonium fluoride solution.

 The known method makes it possible to selectively extract scandium from solutions containing 5-10-fold amounts of yttrium, lanthanum, aluminum, iron, calcium, manganese (II) and other related metals.

 The disadvantage of this method is the relatively low sorption capacity for scandium and, as a consequence, the unsatisfactory performance of the process.

 Of the known analogues, the closest in technical essence to the proposed method is the well-known / 3 / method for the selective extraction of scandium from hydrochloric acid solutions (prototype).

 The known prototype method consists in the sorption of scandium by amphosphate ampholytes of the type ANKF-1B, ANKF-2B, ANKF-251x12P from hydrochloric acid (chloride) solutions, followed by washing of the ampholyte and desorption of scandium.

 The disadvantage of this method (prototype) is the relatively low sorption capacity for scandium and, therefore, the increased consumption of ampholyte and reagents for the extraction of scandium, which generally leads to a low productivity of the process.

 The objective of the proposed invention is to remedy these disadvantages of the known method and provide conditions for increasing the productivity of the process by increasing the sorption load on scandium for ampholyte.

 The problem is solved through the application of the proposed method for the selective extraction of scandium from solutions that differs from the known (prototype) in that sorption is carried out using N- / 2-hydroxypropyl / -N '- / 2-hydroxy-3-pyridinium propyl chloride as a phosphorus-containing ampholyte / -N "methylenephosphonium polyethylene polyamine.

The choice of this ampholyte to solve the problem of increasing the productivity of the process by increasing the sorption load on scandium on the ampholyte is made on the basis of experimental data, the results of comparative tests for the following reasons:
firstly, it was experimentally established that this ampholyte practically does not adsorb scandium-related metals (manganese, iron, chromium, REE, alkaline and alkaline-earth metals);
secondly, this ampholyte very effectively extracts scandium from highly saline solutions in a wide range of acidity (from 0.1 to 9 g-equiv / dm ³ ).

 An essential distinguishing feature of the claimed invention is that N- / 2-hydroxypropyl / -N '- / 2-hydroxypyridinium propyl / -N "-methylenephosphonium polyethylene polyamine is used as an ampholyte.

 The essence of the method is as follows.

 A solution containing scandium and its accompanying metals is brought into contact (passed through a sorption column) with a phosphorus-containing ampholyte, which is used as chloride N- / 2-hydroxypropyl / -N '- / - 2-hydroxy-3-pyridinium propyl / -N "-methylenephosphoniumpolyethylenepolyamine. In this case, scandium is sorbed by ampholyte, and the metals accompanying it are mainly passed into the filtrate. After the sorption process, the ampholyte in the column is washed with a solution of mineral acid to remove impurities located in the intergranular space and in the resin phase, then flushes ampholyte water. Thereafter, the desorption scandium fluoride or carbonate solutions.

 In the examples, the results of experiments showing the advantages of the proposed method in comparison with the known / 2,3 /.

Example 1
Sorption extraction of scandium was carried out from hydrochloric acid solutions at a HCl concentration of from 5 to 350 g / l. The concentration of scandium in a solution of 0.7 g / l; the concentration of sodium chloride is 50 g / l. Sorption was carried out under static conditions until equilibrium was established in the ion-solution system.

To compare the effectiveness of various methods known / 2,3 / and proposed, sorption of scandium was carried out using as phosphorus-containing ion exchangers:
macroporous phosphate cation exchanger type KFP-12 based on styrene and divinylbenzene / 2 /;
phosphorus-containing ampholytes of the type ANKF-1B, ANKF-2B and ANKF-251x12P; / 3 / - prototype.

 phosphorus-containing ampholyte: N- / 2-hydroxypropyl / -N '- / - 2-hydroxy-3-pyridinium propyl / -N "-methylenephosphonium polyethylene polyamine chloride.

 The results of the experiments are given in table. 1.

Example 2
From solutions containing 0.16 g-equiv / dm ^{3 of} scandium; 3.4 g-eq / dm ³ sodium chloride and 5 g-eq / dm ³ hydrochloric acid, selective extraction of scandium was carried out according to the known / 2 / and the proposed methods in static conditions. The sorption time is 5-7 days, the temperature is 20 ± 2 ^o C, the ratio of the mass of the ion exchanger and the volume of the solution is 1: 100.

The experiments showed that the sorption capacity of ion exchangers for scandium was:
by the known / 2 / method 48 g / kg;
by the proposed method 63 g / kg

Example 3
A hydrochloric acid (5 g-equiv / dm ³ in hydrochloric acid) solution containing 1.5 g / dm ³ scandium, 80 g / dm ³ calcium chloride was passed through sorption columns, one of which contained 10 g of macroporous phosphate cation exchange resin based on styrene and divinylbenzene, in another 10 g of chloride of N- / 2-hydroxypropyl / -N '- / 2-hydroxy-3-pyridinium propyl / -N "-methylene phosphonium polyethylene polyamine.

The temperature of the process 20 ± 2 ^o C, the transmission rate of the solution 1 cm ³ / min • cm ² . The diameter of the columns is 15 mm. Sorption was carried out before the “slip” of scandium ions into the filtrates. After sorption, the ion exchangers were washed with 1 N. hydrochloric acid solution and water. Scandium desorption was carried out 3 N. sodium carbonate solution; volume of solutions for 100% desorption 300 ml.

 In the table. 2 shows data on comparing the productivity of the sorption process cycle: sorption washing of ion exchanger desorption regeneration of ion exchanger according to the known / 2 / and the claimed methods.

 From the data presented in table. 2, it can be seen that the productivity of the process (both in solution and in metal) under identical experimental conditions by the present method is 1.6 times higher than by the known method.

 In the following examples 4-7 presents the results of experiments on the selective extraction of scandium from hydrochloric acid solutions containing some of the accompanying elements according to the proposed method using N- / 2-hydroxypropyl / -N '- / 2-hydroxy-Z- chloride as a phosphorus-containing ampholyte pyridinium propyl N-methylenephosphonium polyethylene polyamine.

Example 4
Through a sorption column with 10 g of ion exchanger (1) and a sorption column with 10 g of ion exchanger (2) at a speed of 1 cm ³ / min • cm ² , 200 cm ^{3 of a} solution containing geq / dm ³ : hydrochloric acid 5 was passed, scandium 0.169, calcium 4.235. Then the ion exchangers were washed with 200 cm ³ water and 200 cm ³ 1 N. hydrochloric acid solution for leaching of impurity ions. Scandium desorption was carried out 200 cm ³ 3 N. sodium carbonate solution.

As a result of the experiment, it was established (%):
passed to scandium sorbate 0.0;
passed to calcium sorbate 92.7;
washed with water wash scandium 0.0;
washed with water, washing with calcium 8.9;
washed with 1 n. scandium HCl solution 0.0;
washed with 1 n. a solution of calcium HCl 0.2;
desorbed scandium 97.0;
calcium desorbed 0.0.

Example 5
A 200 cm ³ solution containing, geq / dm ³ : hydrochloric acid 5 was passed through a sorption column with 10 g of phosphorus-containing ampholyte (according to the proposed method) at a speed of 1 cm ³ / min • cm ² ; scandium 0.143; Manganese 9.498. Then the ampholytes were washed with 200 cm ^{3 of} water and 200 cm ³ 1 N. hydrochloric acid solution for leaching of impurity ions. Scandium desorption was carried out 200 cm ³ 3 N. sodium carbonate solution.

As a result of the experiment, it was established (%):
passed to scandium sorbate 0.0;
passed to manganese sorbate 74;
washed with water wash scandium 0.0;
washed with water washing with manganese 24.5;
washed with 1 n. scandium HCl solution 0.0;
washed with 1 n. a solution of manganese HCl 0.5;
desorbed scandium 98.6;
desorbed manganese 0.0.

Example 6
200 cm ^{3 of a} solution containing geq / dm ³ : hydrochloric acid 5 were passed through a sorption column with 10 g of ampholyte at a speed of 1 cm ³ / min • cm ² ; scandium 0.097; iron (III) 1.8. Then the ampholyte was washed with 200 cm ^{3 of} water and 200 cm ^{3 of a} solution of 1 N. hydrochloric acid for leaching of impurity ions. Scandium desorption was carried out 200 cm ³ 3 N. sodium carbonate solution.

As a result of the experiment, it was established (%):
passed to the sorbate:
scandium Oh
iron (III) 45.8;
washed with water:
scandium Oh
iron (III) 39.6;
washed with 1 n. HCl solution:
scandium O;
desorbed:
scandium 97.9,
iron (III) O.

Example 7
200 cm ^{3 of a} solution containing geq / cm ³ : hydrochloric acid 5 were passed through a sorption column with 10 g of ampholyte at a speed of 1 cm ³ / min • cm ² ; scandium 0.02; lanthanum 0.863. Then the ampholyte was washed with 200 cm ^{3 of} water and 200 cm ³ 1 N. hydrochloric acid solution for leaching of impurity ions. Scandium desorption was carried out 200 cm ³ 3 N. sodium carbonate solution.

As a result of the experiment, it was established (%):
passed to the sorbate:
scandium Oh
lanthanum 75.0;
washed with water:
scandium Oh
lanthanum 24.0;
washed with 1 n. HCl solution:
scandium Oh
lanthanum 0.3;
desorbed:
scandium 99,
lantana O.

 Thus, according to the proposed method, compared with the known significantly higher sorption capacity for scandium, which provides an increase in the productivity of the process. TTT1 TTT2 TTT3

Claims (1)

 A method for the selective extraction of scandium from hydrochloric acid solutions, including sorption on a phosphorus-containing ampholyte, its subsequent washing and desorption of scandium, characterized in that the sorption is carried out using N - (2-hydroxypropyl) -N '- (2-hydroxy-) chloride as a phosphorus-containing ampholyte 3-pyridinium propyl-N ’- methylene phosphonium polyethylene polyamine.

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