Method for rapidly determining high-content fluorine in copper concentrate

Abstract

The invention relates to a method for rapidly determining high-content fluorine in copper concentrate, and belongs to the technical field of analysis and detection. The method comprises the following steps: (1) melting a sample; (2) leaching a melt; (3) adding an auxiliary reagent; (4) determination: measuring a potential value by using a composite fluorine ion electrode in an electromagnetic stirring state, and recording the potential value of the tested liquid; (5) drawing a working curve; and (6) according to the working curve obtained by fitting in the step (5) and the potential value measured in the step (4), obtaining the fluorine ion concentration in the test liquid. According to the method, people do not need to pay attention to electrode potential changes in the using process, and during analysis and detection, the measuring linear range is wide, reproducibility is good, precision is high, stability is good, operation is easy and convenient, and automatic, continuous, rapid and efficient monitoring is convenient.

Description

Technical Field

[0001] The present application relates to the field of analysis and detection, and in particular to a method for rapidly determining high-content fluorine in copper concentrate. Background Art

[0002] The raw materials of a certain enterprise in Yunnan are mainly low-quality and coarse copper materials, accounting for about 60% of the total incoming ore, and the copper grade fluctuates from 5% to 65%. At present, X-ray fluorescence spectrometry-tablet method is used to determine the high content of fluorine in copper concentrate. X-ray fluorescence analysis spectrometry has the advantages of fast analysis speed, high detection accuracy, and the ability to quickly realize the simultaneous detection of multiple analysis items. However, due to the influence of mineral effect and particle effect, the high content of fluorine in copper concentrate determined by X-ray fluorescence spectrometry-tablet method has a large deviation, and it is necessary to use ion selective electrode method for determination. The national standard "Chemical Analysis Method of Fluorine in Copper Concentrate" uses fluoride ion selective electrode and saturated calomel electrode. Under electromagnetic stirring, the equilibrium potential value is measured on the potentiometer, and the fluoride ion concentration is determined from low to high in the order of sample.

[0003] The equilibrium potential in the analysis method in the above national standard refers to the situation where the change in electrode potential under stirring is no more than 0.2 mV / min. As a result, in actual testing, the staff needs to pay attention to the change in electrode potential all the time, resulting in low analysis and detection efficiency. In addition, when using this analysis method for analysis and detection, the amount of test solution taken needs to be adjusted according to the amount of fluorine in the sample so that the measured potential value is within the established working curve. The amount of test solution taken is difficult to control more quickly, affecting the detection efficiency. Summary of the invention

[0004] In order to solve or partially solve the problems existing in the related art, the present application provides a method for quickly determining high-content fluorine in copper concentrate. During use, personnel do not need to pay attention to changes in electrode potential. During analysis and detection, the measurement linear range is wide, the reproducibility is good, the precision is high, the stability is good, the operation is simple, and it is convenient for automatic, continuous, rapid and efficient monitoring.

[0005] A method for rapidly determining high-content fluorine in copper concentrate in the present application comprises the following steps:

[0006] (1) Sample melting

[0007] Weigh 0.2-0.5g of the sample with an accuracy of 0.0001g and place it in a 50mL nickel crucible containing 3g of sodium hydroxide, then add 3g of sodium hydroxide to evenly cover it, place it in a muffle furnace below 300℃, adjust the temperature of the muffle furnace to 600℃, start timing when the temperature rises to 600℃, melt for 10 minutes, shake the melt evenly, take it out and cool it slightly;

[0008] Regarding the selection of melting temperature: 0.5g (accurate to 0.0001g) of sample was used to test the melting temperature. The sample was melted at 500℃, 600℃ and 700℃ for 10min respectively. The fluorine melting rate of the sample was not high at 500℃, resulting in low analysis results. At 700℃, the sample was extremely unstable and prone to splashing, causing sample loss, which ultimately led to low analysis results. Therefore, the melting temperature of 600℃ was selected.

[0009] (2) Melt Leaching

[0010] Place the crucible and the melt in a 250mL beaker filled with 30mL hot water, cover with a watch glass, heat and soak the melt, dilute to 60mL, heat and boil for 1 minute, cool and transfer to a 100mL volumetric flask, dilute to the mark with secondary water, shake well, and dry filter;

[0011] (3) Add auxiliary reagents

[0012] Transfer 10.0 mL of the filtrate to a 100 mL volumetric flask, add 30 mL of sodium citrate solution and 1 drop of phenol red indicator, adjust with nitric acid until the solution just turns yellow, then add 10.0 mL of triethanolamine solution, dilute to the mark with secondary water, and mix well;

[0013] In particular, the applicant found that for the selection of auxiliary reagents, 15 mL, 20 mL, 25 mL, 30 mL, and 35 mL of sodium citrate solution and 5 mL, 8 mL, 10 mL, 12 mL, and 15 mL of triethanolamine solution were added to the same sample, and the results of the measurements by adding 30 to 35 mL of sodium citrate solution and 10 to 12 mL of triethanolamine solution were consistent with the reference values, and the masking effect was better, so 30 mL of sodium citrate solution and 10 mL of triethanolamine solution were added.

[0014] (4) Determination

[0015] Pour all the solution into a dry 100mL titration cup, put in a magnetic stirrer, and use a composite fluoride ion electrode to measure the potential value under electromagnetic stirring, and record the potential value of the test solution;

[0016] (5) Drawing of working curve

[0017] Prepare a set of 0.1mg / L, 1mg / L, 5mg / L, 10mg / L, 50mg / L, 100mg / L fluorine standard solutions according to the experimental method, pour the solution into a dry 100mL beaker, put a stirring rod, measure the potential value on a potential measuring instrument, and measure the fluorine concentration from low to high in order with the test solution at the same time; draw a working curve with the fluorine ion concentration value as the horizontal axis and the equilibrium potential value as the vertical axis;

[0018] (6) Based on the working curve fitted in step (5) and the potential value measured in step (4), the fluoride ion concentration in the test liquid can be obtained.

[0019] Furthermore, the fluorine content in the sample of step (1) is ≤2%. In this application, the standard working solution is prepared to a maximum concentration of 100 mg / L, and the measurement process does not require liquid removal. After the potential value is directly titrated, the maximum fluorine content that can be directly measured is 2%.

[0020] The beneficial effects of this application are:

[0021] In the present application, a fluoride ion composite electrode is used to replace the traditional fluoride ion electrode and calomel electrode. During use, personnel do not need to pay attention to changes in electrode potential. During analysis and detection, the measurement linear range is wide, the reproducibility is good, the precision is high, the stability is good, the operation is simple, and automatic, continuous, rapid and efficient monitoring is convenient. DETAILED DESCRIPTION

[0022] The embodiments of the present application will be described in more detail below with reference to examples. Although the embodiments of the present application are shown in the examples, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and the scope of the present application can be fully communicated to those skilled in the art.

[0023] Example 1

[0024] The determination of fluorine in the copper concentrate in this embodiment comprises the following steps:

[0025] (1) Sample melting

[0026] Weigh 0.2-0.5g of copper concentrate-1 with an accuracy of 0.0001g and place it in a 50mL nickel crucible containing 3g of sodium hydroxide, then add 3g of sodium hydroxide to evenly cover it, place it in a muffle furnace below 300°C, adjust the temperature of the muffle furnace to 600°C, start timing when the temperature rises to 600°C, melt for 10 minutes, shake the melt evenly, take it out and cool it slightly;

[0027] (2) Melt Leaching

[0028] Place the crucible and the melt in a 250mL beaker filled with 30mL hot water, cover with a watch glass, heat and soak the melt, dilute to 60mL, heat and boil for 1 minute, cool and transfer to a 100mL volumetric flask, dilute to the mark with secondary water, shake well, and dry filter;

[0029] (3) Add auxiliary reagents

[0030] Transfer 10.0 mL of the filtrate to a 100 mL volumetric flask, add 30 mL of sodium citrate solution and 1 drop of phenol red indicator, adjust with nitric acid until the solution just turns yellow, then add 10.0 mL of triethanolamine solution, dilute to the mark with secondary water, and mix well;

[0031] (4) Determination

[0032] Pour all the solution into a dry 100mL titration cup, put in a magnetic stirrer, and use a composite fluoride ion electrode to measure the potential value under electromagnetic stirring, and record the potential value of the test solution;

[0033] (5) Drawing of working curve

[0034] Take a set of 0.1mg / L, 1mg / L, 5mg / L, 10mg / L, 50mg / L, 100mg / L fluorine standard solutions, pour the solution into a dry 100mL beaker, put a stirring rod, measure the potential value on the potential measuring instrument, and measure it simultaneously with the test solution in the order of fluorine concentration from low to high; draw a working curve with the fluorine ion concentration value as the horizontal axis and the equilibrium potential value as the vertical axis;

[0035] (6) Based on the working curve fitted in step (5) and the potential value measured in step (4), the fluoride ion concentration in the test liquid can be obtained.

[0036] Example 2

[0037] The difference between Example 2 and Example 1 is that the method in Example 1 is used to determine copper concentrate-1.

[0038] The measurement results of Example 1 and Example 2 are shown in Table 1.

[0039] Table 1 Measurement results of Example 1 and Example 2

[0040]

[0041] It can be seen from the measurement results in Table 1 that the relative standard deviation is between 0.19% and 0.30% when the method is used for measurement. The method has high precision, good reproducibility and stability.

[0042] Example 3

[0043] On the basis of Example 1 and Example 2, copper concentrate-3 and copper concentrate-4 were further measured, and the spiked recovery rate was calculated. The test results are shown in Table 2.

[0044] Table 2 Spiked recovery

[0045]

[0046]

[0047] From the results in Table 2, it can be seen that the recovery rate of the spiked sample in this method is between 99.20% and 100.20%, indicating that the method has a high accuracy rate.

[0048] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for rapidly determining high-content fluorine in copper concentrate, characterized in that: The following steps are involved: (1) Sample melting Weigh 0.2-0.5g of the sample with an accuracy of 0.0001g and place it in a 50mL nickel crucible containing 3g of sodium hydroxide, then add 3g of sodium hydroxide to evenly cover it, place it in a muffle furnace below 300℃, adjust the temperature of the muffle furnace to 600℃, start timing when the temperature rises to 600℃, melt for 10 minutes, shake the melt evenly, take it out and cool it slightly; (2) Melt Leaching Place the crucible and the melt in a 250mL beaker filled with 30mL hot water, cover with a watch glass, heat and soak the melt, dilute to 60mL, heat and boil for 1 minute, cool and transfer to a 100mL volumetric flask, dilute to the mark with secondary water, shake well, and dry filter; (3) Add auxiliary reagents Transfer 10.0 mL of the filtrate to a 100 mL volumetric flask, add 30 mL of sodium citrate solution and 1 drop of phenol red indicator, adjust with nitric acid until the solution just turns yellow, then add 10.0 mL of triethanolamine solution, dilute to the mark with secondary water, and mix well; (4) Determination Pour all the solution into a dry 100mL titration cup, put in a magnetic stirrer, and use a composite fluoride ion electrode to measure the potential value under electromagnetic stirring, and record the potential value of the test solution; (5) Drawing of working curve Take a set of 0.1mg / L, 1mg / L, 5mg / L, 10mg / L, 50mg / L, 100mg / L fluorine standard solutions, pour the solution into a dry 100mL beaker, put a stirring rod, measure the potential value on the potential measuring instrument, and measure it simultaneously with the test solution in the order of fluorine concentration from low to high; draw a working curve with the fluorine ion concentration value as the horizontal axis and the equilibrium potential value as the vertical axis; (6) Based on the working curve fitted in step (5) and the potential value measured in step (4), the fluoride ion concentration in the test liquid can be obtained.

2. A method for rapidly determining high-content fluorine in copper concentrate according to claim 1, characterized in that: The fluorine content in the sample in step (1) is ≤ 2%.

Images