RU2411188C1 - Floatation agent for extracting thallium (iii) and lanthanum ions from aqueous solutions - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: invention relates to floatation agents used to extract thallium (III) and lanthanum ions from aqueous solutions, and can be used to extract said ions from waste water and other process solutions. The invention is based on the capacity of potassium bis-(alkylpolyoxyethylene)phosphate of formula [CnH2n+1O(C2H4O)m]2POOK, where n=8-10, m=6, to float thallium (III) and lanthanum ions from aqueous solutions. Extraction of thallium (III) ions takes place at pH approximately equal to 1.5, and extraction of lanthanum ions takes place at pH approximately equal to 1.0 or approximately equal to 10.2. ^ EFFECT: invention enables quantitative extraction of thallium (III) and lanthanum ions using a cheap and non-toxic reagent. ^ 2 dwg, 5 ex

Description

The invention relates to flotation methods for the separation of thallium (III) or lanthanum ions from aqueous solutions and can be used to extract them from wastewater and other technological solutions.

Ion flotation is widely used to extract metal ions from solutions [A. Golman. Ion flotation. - M .: Nedra, 1982. - 144 s]. However, the range of flotation reagents for the extraction of thallium and rare earth elements is limited.

The closest in structure and flotation properties are potassium soaps of dialkylphosphinic acids [Skrylev LD, Nilova OV, Menchuk VV Flotation separation of uranium (VI) from acidic wastewater using potassium soaps of dialkylphosphinic acids. // Journal of Applied Chemistry. - 1991. - T.64. - No. 5. - S.1039-1043 .; Skrylev L.D., Nilova O.V., Menchuk V.V. Flotation separation of thorium ions collected from dilute acidic solutions using potassium soaps of dialkylphosphinic acids. // News of universities. Chemistry and chemical technology. - 1991 - No. 12 - S.67-71]. The interaction of collectors (0.03-0.08% aqueous solutions of diheptyl-, dioctyl- and didecylphosphinate of potassium) with ions proceeds quickly and is accompanied by the formation of colloidal solutions of sparingly soluble soaps - sublates. The most complete flotation emission of uranium ions occurs in the range of pH 2.0-5.0, thorium ions at pH 1-4. Of more acidic solutions, the degree of flotation release decreases, which is associated with the destruction of the sublate and the formation of weakly dissociating dialkylphosphinic acids. The decrease in the degree of flotation separation from more alkaline solutions is explained by the hydrolysis of the corresponding dialkylphosphinic acid soaps.

The disadvantages of these flotation reagents include their relatively high cost, since they are individual compounds. In addition, no information was found on the flotation of thallium (III) ions with these reagents.

The objective of the invention is to expand the range of flotation reagents for the separation of thallium or lanthanum ions from solutions and to reduce the cost of the flotation process by eliminating expensive substances.

To solve this problem, a flotation reagent for the extraction of thallium (III) ions or lanthanum from aqueous solutions is proposed, which is a potassium bis (alkylpolyoxyethylene) phosphate of the general formula [C _n H _{2 + 1} O (C ₂ H ₄ O) _m ] ₂ POOK, where n = 8-10, m = 6, which is used for the extraction of thallium (III) ions at a pH of approximately 1.5, and for the extraction of lanthanum ions at a pH of approximately 1.0, or at a pH of approximately 10 , 2.

Potassium bis (alkylpolyoxyethylene) phosphate of the general formula [C _n H _{2 + 1} O (C ₂ H ₄ O) _m ] ₂ POOK, where n = 8-10, m = 6. (oxyphos B) - a surfactant, a large-tonnage product of the chemical industry [TU 2484-344-05763441-2001].

The invention is based on the complexation ability of oxyphos B. Oxyphos B forms a floated compound with thallium (III) or lanthanum ions in an acidic environment. Lanthanum hydroxide is flotated from alkaline solutions.

It is known to use oxyphos B as a component of detergent compositions [Surfactants: a reference. / Ed. A.A. Abramzon and G.M. Gaev. - L .: Chemistry, 1979, - 376 s]. Descriptions of its use as a flotation agent for ion flotation were not found in the information sources. This allows us to conclude that the solution meets the criteria of the invention of "novelty" and "inventive step".

The use of oxyphos B as a flotation reagent allows the quantitative extraction of thallium (III) or lanthanum ions from aqueous solutions and the use of inexpensive and non-toxic reagents.

Figure 2 shows the dependence of the degree of flotation emission of lanthanum ions of oxyphosomes B on the pH of the solution.

Oxyfos B flotation

~ 200 ml of distilled water is added to 10 ml of a 0.1 M aqueous solution of a metal salt, adjusted to the desired pH value using 1 M solutions of NaOH or H ₂ SO ₄ , 5 ml of a 5% solution of oxyphos B are added, the solution volume is adjusted to 250 ml distilled water and stirred for 1-2 minutes. The mixture is then transferred to a glass column with a diameter of 35 mm and a height of 600 mm. The bottom of the column is a Schott filter with a pore diameter of 40 μm. Compressed air is supplied from below the compressor through a Schott filter. The air pressure is regulated by the foam lifting speed ~ 10 cm / min. Flotation is carried out for 20 min at room temperature 20 ± 2 ° C. A sample of the purified solution is analyzed for the residual content of metals in it by the complexometric method. The flotation efficiency is evaluated by the degree of metal extraction from the solution (R,%).

The possibility of carrying out the invention is illustrated by the following examples.

Flotation extraction of thallium (III) ions.

Example D. Flotation is carried out according to the method described above at a pH of about 1.5. The flotation degree of oxyphosome B is 97%.

Example 2. Flotation is carried out according to the above method at a pH of less than 1. The resulting white cloudy solution does not float.

Example 3. Flotation is carried out according to the above procedure at a pH value of more than 3. A brown precipitate Tl (OH) ₃ , formed before the addition of oxyphos B, remains in solution during flotation and does not pass into the foam.

The influence of the pH of the solution on the degree of flotation emission of thallium (III) ions, see figure 1.

In the extraction of lanthanum ions, various flotation mechanisms operate, depending on the acidity of the solution. In acidic media, a chemical compound with oxyphos B is formed, and in alkaline media lanthanum hydroxide is formed and flotated. Depending on the acidity of the solution, the degree of flotation emission of lanthanum ions of oxyphosomes B passes through two maxima: at a pH of about 1 and at a pH of about 10.

Example 4. Flotation is carried out according to the above method at pH≈1. The degree of flotation of oxyphosomes B is ~ 99%.

Example 5. Flotation is carried out according to the above method at pH≈10.2. The degree of flotation of oxyphosomes B is 97%.

The dependence of the degree of flotation emission of lanthanum ions from the pH of the solution, see figure 2.

Advantages of oxyphos B as flotation agent

1. Lower cost in comparison with dialkylphosphoric acids.

2. Low toxicity, oxyphos B refers to low-hazard substances of hazard class IV.

Claims (1)

A flotation reagent for the extraction of thallium (III) or lanthanum ions from aqueous solutions, which is potassium bis (alkylpolyoxyethylene) phosphate of the general formula [C _n H _{2n + 1} O (C ₂ H ₄ O) _m ] ₂ POOK, where n = 8- 10, m = 6, which is used for the extraction of thallium (III) ions at a pH of approximately 1.5, and for the extraction of lanthanum ions at a pH of approximately 1.0, or at a pH of approximately 10.2.

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