Method for separating and enriching iron, copper and zinc in geological sample by using N235 extraction resin

Abstract

The invention discloses a method for separating and enriching iron, copper and zinc in a geological sample by using N235 extraction resin, the efficiency of separating and enriching Cu, Fe and Zn is remarkably improved by using the high selectivity of the N235 extraction resin to Cu, Fe and Zn and the low adsorption capacity of other matrix elements, the matrix removal efficiency is high, and the method is suitable for industrial production. According to the method, matrix elements can be rapidly removed only by using hydrochloric acid with a small volume and lower concentration, then Cu is rapidly eluted by using hydrochloric acid with the concentration of 1 mol / L, Fe is eluted by using an HBr aqueous solution with the concentration of 0.4 mol / L, and finally Zn is eluted by using ultrapure water, so that the advantage of high recovery rate of Cu, Fe and Zn can be ensured, and the method is simple to operate.

Description

Technical field:

[0001] The invention relates to the technical field of separation and enrichment of Cu, Fe and Zn, and in particular to a method for separating and enriching iron, copper and zinc in geological samples by utilizing N235 leaching resin. Background technology:

[0002] Iron is one of the most abundant elements on Earth. Although Cu and Zn are trace elements, they are also present in high concentrations in most geological and environmental samples. Cu, Fe, and Zn are closely related to human production and daily life and are important industrial resources. Cu, Fe, and Zn, as well as their alloys, are widely used in military, aerospace, chemical, metallurgical, communications, construction, electronics, and manufacturing fields. Furthermore, Cu, Fe, and Zn are essential trace elements for life (including the human body). However, when Cu, Fe, and Zn are enriched beyond the required amount for living organisms (including the human body), they can also produce toxic effects. Therefore, Cu, Fe, and Zn have important research value and significance not only in industry but also in earth and environmental sciences. The traditional single-column separation of Cu, Fe, and Zn using anion exchange resins AG1-X8 or AG-MP-1M is less efficient, requiring a large volume of high-concentration hydrochloric acid (6-8 mol / L hydrochloric acid + 0.01-0.2% H2O2) to elute the matrix and receive Cu, followed by 2 mol / L hydrochloric acid + 0.01% H2O2 solution to elute Fe, and finally 0.5 mol / L nitric acid to elute Zn. Summary of the invention:

[0003] The purpose of the present invention is to provide a method for separating and enriching iron, copper and zinc in geological samples by using N235 leaching resin, which solves the problem of low efficiency of the prior art.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for separating and enriching iron, copper and zinc in geological samples using N235 leaching resin, the method comprising the following steps: loading trioctyldecyl tertiary amine on the surface of a polystyrene macroporous resin to obtain N235 leaching resin, then loading the N235 leaching resin into a column, and sequentially performing resin pre-cleaning, column equilibration, sample loading, matrix elution and target element elution; the solvents used for the resin pre-cleaning are 0.5-2 mol / L, preferably 1 mol / L, nitric acid and ultrapure water in sequence; 4 mol / L hydrochloric acid is used for the column equilibration; the loading solution is an aqueous solution containing elements such as Cu, Fe and Zn and having a hydrochloric acid concentration of 4 mol / L; 4 mol / L hydrochloric acid is used for eluting the matrix; and the specific steps of eluting the target element are as follows: first eluting Cu with 1 mol / L hydrochloric acid, then eluting Fe with a 0.4 mol / L HBr aqueous solution, and finally eluting Zn with ultrapure water.

[0006] The resistivity of the ultrapure water is preferably greater than 18 MΩ·cm.

[0007] The method of loading trioctyldecyl tertiary amine on the surface of a polystyrene macroporous resin to obtain an N235 leaching resin specifically includes the following steps: mixing the polystyrene macroporous resin, dilute hydrochloric acid and ethanol, adding the effective ingredient trioctyldecyl tertiary amine thereto, the volume ratio of trioctyldecyl tertiary amine to the polystyrene macroporous resin (measured with a measuring cup) being 1:5, and shaking to mix to obtain the N235 leaching resin; the polystyrene macroporous resin is of CHP20 / P120 type; and the concentration of the dilute hydrochloric acid is 0.1 to 0.5 mol / L.

[0008] The mixture is shaken to mix, and the mixture is allowed to stand for 2 hours after each shaking. If some resin floats on the surface, a small amount of ethanol is added and shaken to mix, and this operation is repeated until the resin is completely soaked and precipitated. During the shaking process, the trioctyldecyl group is loaded onto the polystyrene macroporous resin.

[0009] The particle size of the CHP20 / P120 polystyrene macroporous resin is preferably 75 μm, and the pore size is preferably The particle size and pore size of the CHP20 / P120 polystyrene macroporous resin can affect the flow rate and adsorption capacity of the subsequent column separation process. If the flow rate is too fast, a small amount of Cu, Fe and Zn will be eluted before being adsorbed on the resin. If the flow rate is too slow, although the separation of Cu, Fe and Zn can be achieved and a high recovery rate of the target element can be obtained, the entire chemical separation time is long and the efficiency is low. The present invention selects a particle size of 75 μm and a pore size of The polystyrene macroporous resin can take into account both flow rate and adsorption capacity.

[0010] The N235 leaching resin prepared by the present invention is preferably sealed and stored in a mixed solution of dilute hydrochloric acid and ethanol, which can prevent the resin from being oxidized and has the function of soaking and cleaning the resin.

[0011] The N235 leaching resin prepared by the present invention has different adsorption properties for Cu, Fe, and Zn in different acid media. In 4 mol / L hydrochloric acid, Cu, Fe, and Zn are adsorbed, while most other ions are not adsorbed and are eluted. In 1 mol / L hydrochloric acid, Fe and Zn are still adsorbed on the resin, and Cu is completely eluted first. In 0.4 mol / L HBr aqueous solution, Zn is still adsorbed on the resin, and Fe can be completely eluted. Finally, ultrapure water can completely elute Zn. Therefore, the N235 leaching resin of the present invention can be used as a special-effect resin for separating and enriching Cu, Fe, and Zn.

[0012] In the present invention, the N235 leaching resin is preferably packed using a polypropylene centrifugal column (8 mm diameter, 6 cm height) to obtain an N235 leaching resin column. The filling volume of the polypropylene centrifugal column is preferably 0.5 mL (corresponding to a dry weight of 0.25 g of N235 leaching resin), and the column height is preferably 1 cm.

[0013] The loading solution is preferably prepared by a method comprising the following steps: dissolving a powdered sample thoroughly using a hydrofluoric acid-nitric acid-hydrochloric acid mixture at 120-140°C, more preferably 130°C, and then evaporating to obtain a sample residue; removing the residual nitric acid and hydrofluoric acid from the residue using 6 mol / L hydrochloric acid, and then centrifuging with 4 mol / L hydrochloric acid to obtain the loading solution. The hydrofluoric acid-nitric acid-hydrochloric acid mixture is prepared by mixing three solutions of hydrofluoric acid, nitric acid, and hydrochloric acid, wherein the volume ratio of the hydrofluoric acid solution, the nitric acid solution, and the hydrochloric acid solution is 2:1:3, wherein the concentration of the hydrofluoric acid solution is 22 mol / L, the concentration of the nitric acid solution is 14 mol / L, and the concentration of the hydrochloric acid solution is 11.5 mol / L.

[0014] The sample is preferably a geological and environmental sample, which includes one or more of rock powder, soil powder and sediment powder. The powder particle size is preferably 200 mesh, and the rock includes one or more of basalt, granite and andesite.

[0015] The beneficial effects of the present invention are as follows:

[0016] 1) The N235 leaching resin prepared by the present invention has different adsorption properties for Cu, Fe, and Zn. In 4 mol / L hydrochloric acid, Cu, Fe, and Zn are adsorbed, while most other ions are not adsorbed and are eluted. In 1 mol / L hydrochloric acid, Fe and Zn are still adsorbed on the resin, and Cu is completely eluted first. In 0.4 mol / L aqueous HBr solution, Zn is still adsorbed on the resin, while Fe can be completely eluted. Finally, ultrapure water can completely elute Zn. Therefore, N235 leaching resin can be used as a special resin for separating and enriching Cu, Fe, and Zn.

[0017] 2) Compared with the traditional anion exchange resins AG1-X8 and AG-MP-1M, which both require the use of a large amount of high-concentration hydrochloric acid for the separation of Cu, Fe, and Zn, the present invention utilizes the high selectivity of N235 leaching resin for Cu, Fe, and Zn and the low adsorption capacity of other matrix elements to significantly improve the efficiency of separation and enrichment of Cu, Fe, and Zn. The matrix removal efficiency is high, and only a small volume of low-concentration hydrochloric acid (4 mol / L hydrochloric acid) is required to quickly remove the matrix elements. Cu is then quickly eluted with 1 mol / L hydrochloric acid, Fe is eluted with a 0.4 mol / L HBr aqueous solution, and Zn is finally eluted with ultrapure water. The advantages of high recovery rates (>98%) of Cu, Fe, and Zn are guaranteed, and the operation is simple, making it an efficient and environmentally friendly analytical technology. Description of the drawings:

[0018] Figure 1 This is the elution curve of the N235 leaching resin prepared in Example 1 for separating Cu, Fe and Zn. Specific implementation method:

[0019] The following is a further description of the present invention, but not a limitation of the present invention.

[0020] Example 1: Preparation of N235 leaching resin

[0021] First, the particle size is 75 μm and the pore size is CHP20 / P120 polystyrene macroporous resin (purchased from Mitsubishi Chemical Corporation, Japan) is soaked in a mixed solution of dilute hydrochloric acid (0.1mol / L) and ethanol, shaken evenly at room temperature (25°C) and allowed to stand. After the polystyrene macroporous resin is precipitated, the active ingredient trioctyldecyl tertiary amine is added. The volume ratio of the added trioctyldecyl tertiary amine to the polystyrene macroporous resin is 1:5 (measured with a measuring cup). Shake evenly at room temperature (25°C) and let stand for 2 hours. If some resin floats on the surface, add a small amount of ethanol and shake to mix. Repeat this operation until the resin is completely soaked and precipitated. During the shaking process, the trioctyldecyl tertiary amine is loaded onto the polystyrene macroporous resin.

[0022] Application Example 1: Separation of Cu, Fe and Zn in basalt standard sample using N235 leaching resin via column

[0023] Using the basalt standard BCR-2 as the analysis target, three replicate samples (0.051g, 0.048g, and 0.052g, respectively) were weighed and reacted in a hydrofluoric acid-nitric acid-hydrochloric acid mixture (a mixture of hydrofluoric acid, nitric acid, and hydrochloric acid in a volume ratio of 2:1:3, with a hydrofluoric acid concentration of 22 mol / L, a nitric acid concentration of 14 mol / L, and a hydrochloric acid concentration of 11.5 mol / L) on a 130°C hot plate for three days. The sample was evaporated to dryness and then added with 4 mL of 6 mol / L hydrochloric acid for six hours. The sample was then clear and transparent and evaporated again to dryness. The solution was then brought to volume with 2 mL of 4 mol / L hydrochloric acid and centrifuged. The supernatant was used as the loading solution for chemical separation.

[0024] The N235 leaching resin prepared in Example 1 was loaded into a polypropylene centrifugal column (8 mm diameter, 6 cm high) with a column height of 1 cm and a volume of 0.5 mL. The resin column was pre-cleaned with 6 mL of 1 mol / L nitric acid and ultrapure water, and then the column was balanced with 2 mL of 4 mol / L hydrochloric acid solution. 1 mL of the sample solution was loaded onto the N235 leaching resin. After the solution dried, 6 mL of 4 mol / L hydrochloric acid was added to wash out impurities and interfering ions. Cu was then eluted with 7 mL of 1 mol / L hydrochloric acid solution, Fe was eluted with 6 mL of 0.4 mol / L HBr aqueous solution, and Zn was eluted with 6 mL of ultrapure water. The specific separation process is as follows. Figure 1 As shown, the eluent in the experimental process was collected at 1 mL each, and after dilution, the element signals of the solution were measured by ICP-MS. Figure 1 This is the elution curve of the N235 leaching resin prepared in Example 1 for separating Cu, Fe and Zn.

[0025] Depend on Figure 1 It can be seen from the elution curve that the present invention uses N235 leaching resin to separate and enrich Cu, Fe and Zn and remove the matrix. The separation effect of Cu, Fe and Zn and other matrix elements is good and the selectivity is high. The recovery rates of Cu, Fe and Zn are all above 98%, which greatly improves the separation and enrichment efficiency of Cu, Fe and Zn in geological and environmental samples. It has the potential to become a special resin separation method for laboratory analysis of Cu, Fe and Zn elements and isotopes. Figure 1 Based on the experimental results, the chemical separation process of Cu, Fe and Zn by N235 leaching resin was determined (Table 1).

[0026] Table 1 Process of separation of Cu, Fe and Zn by N235 leaching resin

[0027] Purpose Reagents Volume (mL) Pre-cleaning 1M nitric acid 6 Pre-cleaning Ultrapure water 2 Column balance 4M hydrochloric acid 2 Loading 4M hydrochloric acid 1 Eluent matrix 4M hydrochloric acid 8 Elution of Cu 1M hydrochloric acid 6 Elution of Fe 0.4MHBr aqueous solution 8 Elution Zn Ultrapure water 6

[0028] The received Cu, Fe, and Zn solutions were evaporated to dryness, dissolved in 0.03 mL of concentrated nitric acid, and then 0.97 mL of ultrapure water was added to the volume. After dilution by appropriate multiples, the contents of Cu, Fe, and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). -1 A mixed standard solution of Cu, Fe and Zn was used as an external standard, and rhodium (Rh) was added to each sample as an internal standard element to monitor the drift of instrument sensitivity.

[0029] The Cu, Fe and Zn contents of the BCR-2 finally obtained by the test are shown in Table 2. The recovery rates of Cu, Fe and Zn of the three parallel samples of BCR-2 are all above 98%.

[0030] Table 2 Analysis results of Cu, Fe and Zn in rock standard sample BCR-2

[0031]

[0032]

[0033] Application Example 2: Using the national soil standard material GSS-1a as the analysis object, its Cu, Fe and Zn contents were determined.

[0034] Three GSS-1a samples of 0.045 g, 0.043 g, and 0.040 g were weighed as parallel samples and recorded as GSS-1a-1, GSS-1a-2, and GSS-1a-3, respectively. A hydrofluoric acid-nitric acid-hydrochloric acid mixed acid solution (the hydrofluoric acid-nitric acid-hydrochloric acid mixed acid solution is a mixture of hydrofluoric acid, nitric acid and hydrochloric acid, with a volume ratio of hydrofluoric acid solution, nitric acid solution and hydrochloric acid solution of 2:1:3, wherein the concentration of the raw hydrofluoric acid solution is 22 mol / L, the concentration of the nitric acid solution is 14 mol / L, and the concentration of the hydrochloric acid solution is 11.5 mol / L) is reacted on a hot plate at 130°C for 2 days; after evaporation to dryness, aqua regia is added at a volume ratio of hydrochloric acid: nitric acid = 3:1, and the lid is tightened and reacted on a hot plate at 80°C overnight, followed by low-temperature evaporation to dryness; 6 mol / L hydrochloric acid is used to further dissolve the residual solid until the solution is clear and transparent; after the sample is evaporated to dryness, 2 mL of 6 mol / L hydrochloric acid is added to convert the sample into a chlorine medium, the solution is evaporated to dryness again, and the volume is adjusted with 4 mol / L hydrochloric acid, and after centrifugation, a sample solution is obtained for chemical separation. The chemical separation and enrichment of Cu, Fe and Zn in the sample was carried out by using the N235 leaching resin prepared in Example 1. The specific process is the same as in Table 1. The received Cu, Fe and Zn solutions were evaporated to dryness, dissolved in 0.03 mL of concentrated nitric acid, and then 0.97 mL of ultrapure water was added to the volume. After dilution by appropriate multiples, the contents of Cu, Fe and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). 2 ng·g -1A mixed standard solution of Cu, Fe and Zn was used as an external standard, and rhodium (Rh) was added to each sample as an internal standard element to monitor the drift of instrument sensitivity.

[0035] The Cu, Fe and Zn contents of the GSS-1a finally obtained by the test are shown in Table 3. The recoveries of Cu, Fe and Zn of the three parallel samples of GSS-1a are all above 98%.

[0036] Table 3 Analysis results of Cu, Fe and Zn in soil standard sample GSS-1a

[0037] sample Cu content (μg / g) Fe content (μg / g) Zn content (μg / g) GSS-1a-1 42.33 30889 482 GSS-1a-2 43.56 30876 479 GSS-1a-3 43.15 30884 484 average value 43.01 30883 481 Reference value 42 30870 475

[0038] In Application Examples 1 and 2, the present invention can efficiently separate and enrich Cu, Fe, and Zn and accurately determine them regardless of whether they are rock or soil samples. The recovery rates of Cu, Fe, and Zn are greater than 98%. Therefore, the N235 leaching resin of the present invention can be used as a special resin for separating and enriching Cu, Fe, and Zn.

[0039] Although the above embodiments provide a detailed description of the present invention, they are only part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on the embodiments of the present invention without creative work, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A method for separating and enriching iron, copper and zinc in geological samples using N235 leaching resin, characterized in that: The method comprises the following steps: loading trioctyldecyl tertiary amine on the surface of a polystyrene macroporous resin to obtain an N235 leaching resin; then loading the N235 leaching resin into a column; and sequentially performing resin pre-cleaning, column balancing, sample loading, matrix elution, and target element elution; the solvents used for the resin pre-cleaning are 0.5-2 mol / L nitric acid and ultrapure water in sequence; 4 mol / L hydrochloric acid is used for the column balancing; the loading solution is an aqueous solution containing Cu, Fe, and Zn elements and having a hydrochloric acid concentration of 4 mol / L; 4 mol / L hydrochloric acid is used for eluting the matrix; and the specific steps of eluting the target element are as follows: first, eluting Cu with 1 mol / L hydrochloric acid, then eluting Fe with a 0.4 mol / L HBr aqueous solution, and finally eluting Zn with ultrapure water.

2. The method according to claim 1, characterized in that The solvents used for the resin pre-cleaning are 1 mol / L nitric acid and ultrapure water.

3. The method according to claim 2, characterized in that The resistivity of the ultrapure water is greater than 18 MΩ·cm.

4. The method according to claim 1, wherein The method of loading trioctyldecyl tertiary amine on the surface of a polystyrene macroporous resin to obtain an N235 leaching resin specifically comprises the following steps: mixing the polystyrene macroporous resin with dilute hydrochloric acid and ethanol, adding the effective ingredient trioctyldecyl tertiary amine thereto, wherein the volume ratio of trioctyldecyl tertiary amine to the polystyrene macroporous resin is 1:5, and shaking to obtain the N235 leaching resin; the polystyrene macroporous resin is a CHP20 / P120 type; The concentration of the dilute hydrochloric acid is 0.1-0.5 mol / L.

5. The method according to claim 4, characterized in that The particle size of the CHP20 / P120 polystyrene macroporous resin is 75 μm and the pore size is 6. The method according to claim 1, characterized in that The N235 levextrin resin was packed using a polypropylene centrifugal column with a diameter of 8 mm, a height of 6 cm, a filling volume of 0.5 mL, and a filling column height of 1 cm.

7. The method according to claim 1, characterized in that The loading liquid is prepared by a method comprising the following steps: thoroughly dissolving a powder sample using a hydrofluoric acid-nitric acid-hydrochloric acid mixture at 120-140° C., and then evaporating to dryness to obtain a sample residue; driving away residual nitric acid and hydrofluoric acid from the residue using 6 mol / L hydrochloric acid, and then centrifuging and extracting with 4 mol / L hydrochloric acid to obtain the loading liquid.

8. The method according to claim 7, characterized in that The hydrofluoric acid-nitric acid-hydrochloric acid mixed acid is prepared by mixing three solutions of hydrofluoric acid, nitric acid and hydrochloric acid, wherein the volume ratio of the hydrofluoric acid solution, the nitric acid solution and the hydrochloric acid solution is 2:1:3, wherein the concentration of the hydrofluoric acid solution is 22 mol / L, the concentration of the nitric acid solution is 14 mol / L, and the concentration of the hydrochloric acid solution is 11.5 mol / L.

9. The method according to claim 7, characterized in that The samples are geological and environmental samples, which include one or more of rock powder, soil powder and sediment powder. The powder particle size is 200 mesh, and the rocks include one or more of basalt, granite and andesite.

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