Method for detecting tungsten content in tungsten-containing organic phase

Abstract

The invention discloses a method for detecting the tungsten content in a tungsten-containing organic phase, which is used for solving the problems that the tungsten content in the tungsten-containing organic phase is not accurately detected and the existing detection method is complicated. A method for detecting tungsten content in a tungsten-containing organic phase comprises the following steps: step 1, kneading quantitative filter paper into a crucible, dropwise adding a quantitative volume of tungsten-containing organic phase on the quantitative filter paper, covering the crucible on an electric furnace, heating at a constant temperature, leaving a gap between the cover and the crucible, heating until no smoke exists and the quantitative filter paper is carbonized, then transferring into a muffle furnace, and firing to constant weight, so as to obtain the tungsten-containing organic phase; cooling is performed; and 2, putting the cooled crucible in a beaker, adding an alkaline solution, boiling, cleaning the crucible in the beaker, collecting a sodium tungstate solution to a constant volume, and determining the concentration of tungsten by a colorimetric method to obtain the tungsten content in the tungsten-containing organic phase. The detection method provided by the invention has the advantages of simple and rapid steps, accurate detection result, rapid quantification, efficient improvement of the extraction efficiency, and reduction of the production cost.

Description

Technical Field

[0001] The invention belongs to the technical field of tungsten detection methods, and in particular relates to a method for detecting tungsten content in a tungsten-containing organic phase. Background Art

[0002] Ammonium Para-tungstate (APT) is an important tungsten compound, which is widely used in electronics, chemical industry, metal processing and other fields. At present, the production process of ammonium paratungstate mainly includes ion exchange method and solvent extraction method.

[0003] The ion exchange method is to use ion exchange resin to adsorb tungsten ions in a solution containing tungsten, and then use an analytical agent to decompose the tungsten ions from the resin to finally obtain ammonium paratungstate. This method is simple to operate, but it will produce a large amount of wastewater containing ammonia nitrogen, and the environmental pressure of wastewater treatment is high.

[0004] The solvent extraction method uses the organic solvent with high affinity for tungsten ions to transfer tungsten from the aqueous phase to the organic phase, and then transfers tungsten from the organic phase to the aqueous phase through back extraction to finally obtain ammonium paratungstate. The solvent extraction method has a high tungsten recovery rate and low energy consumption, but the selection and optimization of the organic phase is the key.

[0005] In the process of solvent extraction, the selection and optimization of the organic phase are the key factors that determine the extraction efficiency and tungsten recovery rate. Commonly used organic phases include kerosene, 2-octanol, and trioctylamine mixtures. The precise control of the tungsten content in the tungsten-containing organic phase is crucial. Too high a tungsten content will lead to waste of tungsten resources in the raffinate and environmental pollution, while too low a tungsten content will affect the extraction efficiency and increase production costs. Therefore, the precise detection and control of the tungsten content in the tungsten-containing organic phase is the key to improving the production efficiency and environmental performance of ammonium paratungstate.

[0006] At present, the commonly used analytical detection equipment in laboratories, such as inductively coupled plasma spectrometer (ICP), spectrophotometer colorimetry, etc., cannot directly perform sampling analysis on tungsten-containing organic phases. These equipment can usually only analyze the tungsten content in the aqueous phase, and there are certain technical difficulties in detecting the tungsten content in the organic phase.

[0007] Therefore, developing a detection method that can directly sample and analyze the tungsten-containing organic phase is of great significance for improving the efficiency and environmental performance of the ammonium paratungstate production process. This detection method should have high sensitivity, accuracy and stability, and can quickly and easily determine the tungsten content in the tungsten-containing organic phase, providing timely and accurate data support for the production process.

[0008] The precise control of tungsten content in the tungsten-containing organic phase in the production process of ammonium paratungstate is a challenging problem, which requires the development of new detection methods and optimization of existing processes. This will not only help improve production efficiency and environmental performance, but also help promote the sustainable development of the ammonium paratungstate industry. Summary of the invention

[0009] The purpose of the present invention is to solve the problems of inaccurate detection of tungsten content in a tungsten-containing organic phase and complicated existing detection methods, and to provide a method for detecting tungsten content in a tungsten-containing organic phase.

[0010] In the first aspect, a method for detecting the tungsten content in a tungsten-containing organic phase adopts the following technical scheme:

[0011] A method for detecting the tungsten content in a tungsten-containing organic phase comprises the following steps:

[0012] Step 1, knead a quantitative filter paper into a crucible, drop a quantitative volume of tungsten-containing organic phase onto the quantitative filter paper, cover the crucible and place it on an electric furnace for constant temperature heating, leaving a gap between the cover and the crucible, heat until there is no smoke and the quantitative filter paper is carbonized, transfer it to a muffle furnace and burn it to constant weight, and cool it;

[0013] Step 2: Place the cooled crucible in a beaker, add an alkaline solution and boil, wash the crucible in a beaker, collect the sodium tungstate solution to make it constant, and determine the concentration of tungsten by colorimetry to obtain the tungsten content in the tungsten-containing organic phase.

[0014] Furthermore, the organic phase in the tungsten-containing organic phase includes one or more of tributyl phosphate, trialkylphosphine oxide, trioctyldecyl tertiary amine, trioctyldecyl tertiary amine, methyl trioctyl ammonium chloride, N-tert-octyl acrylamide, and lubricating oil.

[0015] Furthermore, the capacity of the crucible can be selected as one of 20 mL, 25 mL, 30 mL, and 40 mL; the diameter specification of the quantitative filter paper can be selected as one of 7 cm, 9 cm, 11 cm, and 12.5 cm.

[0016] Furthermore, in step 1, the quantitative volume B of the tungsten-containing organic phase is 2 mL to 5 mL.

[0017] Furthermore, in step 2, a gap of 2 mm to 5 mm is left between the cover and the crucible, and the constant temperature on the electric furnace is 200° C. to 300° C.

[0018] Furthermore, in step 1, the calcination temperature is 750° C. to 800° C., and the calcination time is 10 min to 20 min.

[0019] Furthermore, the alkaline solution is a 10wt% to 20wt% sodium hydroxide solution, and the added amount is 10mL to 50mL.

[0020] Furthermore, in step 2, the fixed volume is one of 50 mL, 100 mL, and 250 mL.

[0021] Furthermore, in step 2, the colorimetric method for determining tungsten includes the steps of: transferring a quantitative volume of sodium tungstate solution into a colorimetric tube, adding potassium thiocyanate solution and diluting to the scale with a titanium trichloride-hydrochloric acid mixture, mixing, standing, using a reagent blank as a reference, measuring the absorbance at a wavelength of 400 nm, and obtaining the tungsten content in the working curve.

[0022] Furthermore, the steps for drawing the working curve are as follows: 0.00mL, 0.50mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, 5.00mL, and 6.00mL of tungsten standard solution are transferred into a colorimetric tube, the solution is made up to 10mL with sodium hydroxide solution, the absorbance is determined according to the colorimetric method for determining tungsten, and the working curve is drawn.

[0023] Beneficial effects of the present invention:

[0024] The present invention provides a method for detecting the tungsten content in a tungsten-containing organic phase. A small amount of a quantitative volume of the tungsten-containing organic phase is absorbed into a quantitative test paper, and a quantitative reagent absorbs the organic phase, smokes and carbonizes under low temperature conditions, and then burns, and a colorimetric method is used to obtain the tungsten content in the organic phase. The detection method is simple and fast, and the detection method result is accurate, can be quickly quantified, and the extraction efficiency is effectively improved, and the production cost is reduced. DETAILED DESCRIPTION

[0025] The following is a further specific description of the method for detecting the tungsten content in a tungsten-containing organic phase described in the present invention in conjunction with the examples. For the sake of simplicity of description, this document cannot list all the alternative technical features and implementation schemes contained in the present invention. Therefore, those skilled in the art should know that any technical features and implementation schemes in this embodiment do not limit the scope of protection of the present invention, which includes any alternative technical features and implementation schemes adopted by all those skilled in the art without creative labor. Specifically, the implementation schemes obtained by replacing any technical feature in the present invention or combining any two or more technical features provided by the present invention should be within the scope of protection of the present invention.

[0026] If no specific techniques and conditions are specified in the examples, the procedures are carried out according to the techniques and conditions described in the literature in the art or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0027] The specific information of the solutions used in the following examples is as follows:

[0028] Sodium hydroxide solution, concentration 48g / L;

[0029] Potassium thiocyanate solution, concentration 350g / L;

[0030] Titanium trichloride-hydrochloric acid mixed solution: Pipette 0.5 mL of titanium trichloride solution (150 g / L), dilute to 100 mL with hydrochloric acid (2+3), and mix well;

[0031] Tungsten standard solution: Weigh 0.1260g of dried pure tungsten trioxide, place it in a 250mL beaker, add 48g of sodium hydroxide and about 100mL of water, heat slightly until completely dissolved, cool, transfer to a 1000mL volumetric flask, dilute to the scale with water, mix well, and store in a plastic bottle. 1mL of this solution contains 0.100mg of tungsten.

[0032] Example

[0033] Example 1

[0034] Embodiment 1 provides a method for detecting the tungsten content in a tungsten-containing organic phase, comprising the following steps:

[0035] Step 1, knead a quantitative filter paper with a diameter of 7 cm and place it in a crucible with a capacity of 25 mL, drop a quantitative volume of 2 mL of tungsten-containing organic phase on the quantitative filter paper, cover the crucible and place it on an electric furnace for constant temperature heating at 250° C., leaving a gap of 5 mm between the cover and the crucible, heat until smokeless and the quantitative filter paper is carbonized, transfer it to a muffle furnace and burn it at 760° C. for 15 min to constant weight, and cool it;

[0036] Step 2, place the cooled crucible in a 250mL beaker, add 50mL of 10wt% sodium hydroxide solution and heat to boil, wash the crucible in a beaker, collect the sodium tungstate solution and dilute to 100mL, transfer 2mL of the sodium tungstate solution into a 50mL colorimetric tube, make up to 10mL with sodium hydroxide solution, add 2mL of potassium thiocyanate solution and dilute to the scale with titanium trichloride-hydrochloric acid mixture, mix well, let stand for 10min, use the reagent blank as a reference, measure the absorbance at a wavelength of 400nm, obtain the tungsten content in the working curve, and calculate the tungsten content in the tungsten-containing organic phase.

[0037] Example 2

[0038] Embodiment 2 provides a method for detecting the tungsten content in a tungsten-containing organic phase, comprising the following steps:

[0039] Step 1, knead a quantitative filter paper with a diameter of 9 cm and place it in a crucible with a capacity of 30 mL, drop a quantitative volume of 5 mL of tungsten-containing organic phase on the quantitative filter paper, cover the crucible and place it on an electric furnace at a constant temperature of 200° C., leaving a gap of 2 mm between the cover and the crucible, heat until there is no smoke and the quantitative filter paper is carbonized, transfer it to a muffle furnace and burn it at 750° C. for 15 minutes to constant weight, and cool it;

[0040] Step 2, place the cooled crucible in a 250mL beaker, add 50mL of 20wt% sodium hydroxide solution and heat to boil, wash the crucible in a beaker, collect the sodium tungstate solution and dilute to 250mL, transfer 5mL of the sodium tungstate solution into a 50mL colorimetric tube, make up to 10mL with sodium hydroxide solution, add 2mL of potassium thiocyanate solution and dilute to the scale with titanium trichloride-hydrochloric acid mixture, mix well, let stand for 10min, use the reagent blank as a reference, measure the absorbance at a wavelength of 400nm, obtain the tungsten content in the working curve, and calculate the tungsten content in the tungsten-containing organic phase.

[0041] Example 3

[0042] Embodiment 3 provides a method for detecting the tungsten content in a tungsten-containing organic phase, comprising the following steps:

[0043] Step 1, knead a quantitative filter paper with a diameter of 12.5 cm and place it in a crucible with a capacity of 40 mL, drop a quantitative volume of 2 mL of tungsten-containing organic phase on the quantitative filter paper, cover the crucible and place it on an electric furnace at 300° C. to heat it at a constant temperature, leaving a gap of 4 mm between the cover and the crucible, heat it until there is no smoke and the quantitative filter paper is carbonized, then transfer it to a muffle furnace and burn it at 800° C. for 10 min to constant weight, and cool it;

[0044] Step 2, place the cooled crucible in a 250mL beaker, add 15mL of 15wt% sodium hydroxide solution and heat to boil, wash the crucible in a beaker, collect the sodium tungstate solution and dilute to 50mL, transfer 2mL of the sodium tungstate solution into a 50mL colorimetric tube, make up to 10mL with sodium hydroxide solution, add 2mL of potassium thiocyanate solution and dilute to the scale with titanium trichloride-hydrochloric acid mixture, mix well, let stand for 10min, use the reagent blank as a reference, measure the absorbance at a wavelength of 400nm, obtain the tungsten content in the working curve, and calculate the tungsten content in the tungsten-containing organic phase.

[0045] Example 4

[0046] Example 4 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the diameter specification of the quantitative filter paper is 12.5 cm.

[0047] Example 5

[0048] Example 5 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the quantitative volume B of the tungsten-containing organic phase is 5 mL.

[0049] Comparative Example

[0050] Comparative Example 1

[0051] Comparative Example 1 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the crucible capacity is 100 mL.

[0052] Comparative Example 2

[0053] Comparative Example 2 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the quantitative volume B of the tungsten-containing organic phase is 6 mL.

[0054] Comparative Example 3

[0055] Comparative Example 3 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the quantitative volume B of the tungsten-containing organic phase is 1 mL.

[0056] Comparative Example 4

[0057] Comparative Example 4 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that in step 2, no gap is left between the cover and the crucible.

[0058] Comparative Example 5

[0059] Comparative Example 5 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that in step 2, the crucible is not covered and placed on an electric furnace to be heated at a constant temperature until there is no smoke and the quantitative filter paper is carbonized. The details are as follows:

[0060] Comparative Example 5 provides a method for detecting the tungsten content in a tungsten-containing organic phase, comprising the following steps:

[0061] Step 1, knead a quantitative filter paper with a diameter of 7 cm and place it in a crucible with a capacity of 30 mL, drop a quantitative volume of 2 mL of tungsten-containing organic phase on the quantitative filter paper, leave a gap of 2 mm between the cover and the crucible, transfer to a muffle furnace and burn at 750° C. for 15 min to constant weight, and cool;

[0062] Step 2, place the cooled crucible in a 250mL beaker, add 50mL of 10wt% sodium hydroxide solution and heat to boil, wash the crucible in a beaker, collect the sodium tungstate solution and dilute to 100mL, transfer 2mL of the sodium tungstate solution into a 50mL colorimetric tube, make up to 10mL with sodium hydroxide solution, add 2mL of potassium thiocyanate solution and dilute to the scale with titanium trichloride-hydrochloric acid mixture, mix well, let stand for 10min, use the reagent blank as a reference, measure the absorbance at a wavelength of 400nm, obtain the tungsten content in the working curve, and calculate the tungsten content in the tungsten-containing organic phase.

[0063] Comparative Example 6

[0064] Comparative Example 6 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that the calcination temperature in step 1 is 860°C.

[0065] Comparative Example 7

[0066] Comparative Example 7 provides a method for detecting the tungsten content in a tungsten-containing organic phase. The difference from Example 1 is that in step 1, the constant temperature heating temperature of the electric furnace is 150°C.

[0067] Determination of tungsten content in tungsten-containing organic phase

[0068] The method for drawing a working curve comprises the following steps:

[0069] Pipette 0.00mL, 0.50mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, 5.00mL of tungsten trioxide standard solution into a 50mL colorimetric tube, make up the solution to 10mL with sodium hydroxide solution, add 2mL of potassium thiocyanate solution and dilute to the scale with titanium trichloride-hydrochloric acid mixture, mix well, let stand for 10min, use the reagent blank as a reference, measure the absorbance at a wavelength of 400nm, use tungsten content as the horizontal axis and absorbance as the vertical axis, draw a working curve, and the working curve data is shown in Table 1 below.

[0070] Table 1 Working curve absorbance

[0071] Standard solution volume / (mL) Concentration / (mg) Absorbance / (A) 0.00 0.00 0.000 0.05 0.05 0.038 0.10 0.10 0.077 0.20 0.20 0.160 0.30 0.30 0.239 0.40 0.40 0.318 0.50 0.50 0.397

[0072] The working curve is A = 1.2585V, and the correlation coefficient is R 2 The linear detection range is 0.05~30g / L.

[0073] Sample testing

[0074] Sample information: The test sample is the extract obtained by extracting tungsten solution with a mixture of three organic solvents: kerosene, 2-octanol and trioctylamine.

[0075] The tungsten content of the test sample was tested three times using the detection method for the tungsten content in the tungsten-containing organic phase provided in Examples 1-5 and Comparative Examples 1-7, and the average concentration results are shown in Table 2 below.

[0076] Table 2 Detection method measurement data provided by Examples 1-5 and Comparative Examples 1-7

[0077]

[0078]

[0079] It can be seen from Table 2 that a small amount of sample is easily affected by pipetting, resulting in a high result; the crucible size is too large, the sample amount exceeds the absorption limit of the filter paper, there is no gap in ashing, the sample is not ashed, the burning temperature is high, the ashing temperature is low, etc., which are easily affected by the fact that the organic phase loaded with tungsten is not completely converted into sodium tungstate solution, and the loss of tungsten splashed out during the treatment of the organic phase loaded with tungsten.

[0080] For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, and the obvious changes or modifications derived from them are still within the scope of protection of the claims of the invention.

Claims

1. A method for detecting the tungsten content in a tungsten-containing organic phase, characterized in that: The following steps are involved: Step 1, knead a quantitative filter paper into a crucible, drop a quantitative volume of tungsten-containing organic phase onto the quantitative filter paper, cover the crucible and place it on an electric furnace for constant temperature heating, leaving a gap between the cover and the crucible, heat until there is no smoke and the quantitative filter paper is carbonized, transfer it to a muffle furnace and burn it to constant weight, and cool it; Step 2: Place the cooled crucible in a beaker, add an alkaline solution and boil, wash the crucible in a beaker, collect the sodium tungstate solution to make it constant, and determine the concentration of tungsten by colorimetry to obtain the tungsten content in the tungsten-containing organic phase.

2. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: The organic phase in the tungsten-containing organic phase includes one or more of tributyl phosphate, trialkylphosphine oxide, trioctyldecyl tertiary amine, trioctyldecyl tertiary amine, methyl trioctyl ammonium chloride, N-tert-octyl acrylamide, and cutting lubricating oil.

3. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: The capacity of the crucible can be selected as one of 20 mL, 25 mL, 30 mL, and 40 mL; the diameter specification of the quantitative filter paper can be selected as one of 7 cm, 9 cm, 11 cm, and 12.5 cm.

4. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: In step 1, the quantitative volume B of the tungsten-containing organic phase is 2 mL to 5 mL.

5. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: In step 2, a gap of 2 mm to 5 mm is left between the cover and the crucible, and the constant temperature on the electric furnace is 200° C. to 300° C.

6. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: In step 1, the calcination temperature is 750° C. to 800° C., and the calcination time is 10 min to 20 min.

7. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: The alkaline solution is a 10wt% to 20wt% sodium hydroxide solution, and the added amount is 10mL to 50mL.

8. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: In step 2, the fixed volume is one of 50 mL, 100 mL, and 250 mL.

9. The method for detecting the tungsten content in a tungsten-containing organic phase according to claim 1, characterized in that: In step 2, the colorimetric method for determining tungsten includes the steps of: transferring a quantitative volume of sodium tungstate solution into a colorimetric tube, adding potassium thiocyanate solution and diluting to the scale with a titanium trichloride-hydrochloric acid mixture, mixing, standing, using a reagent blank as a reference, measuring the absorbance at a wavelength of 400 nm, and obtaining the tungsten content in the working curve.

10. A method for detecting tungsten content in a tungsten-containing organic phase according to claim 9, characterized in that: The steps for drawing the working curve are as follows: 0.00 mL, 0.50 mL, 1.00 mL, 2.00 mL, 3.00 mL, 4.00 mL, 5.00 mL, and 6.00 mL of tungsten standard solution are transferred into a colorimetric tube, the solution is supplemented to 10 mL with sodium hydroxide solution, the absorbance is determined according to the colorimetric method for determining tungsten, and the working curve is drawn.

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