Method for preparing sample wafer for X fluorescence analysis of bentonite by melting method

Abstract

The invention relates to a method for preparing a sample wafer for X fluorescence analysis of bentonite by using a melting method, which comprises the following steps: 1) adding a flux and a bentonite sample into a crucible, dropwise adding a boric acid-glycerol solution, and stirring until the mixture is muddy; (2) adding a liquid oxidant into the crucible, uniformly stirring, wiping the head of the glass rod with quantitative filter paper, and putting the wiped filter paper into the crucible; and 3) firing the crucible on a high-frequency sample melting machine until the solid in the crucible is molten into a liquid state, adding a release agent, slightly cooling, and demolding to obtain the sample for X fluorescence analysis. The method has the advantages that the operation is simple, the flaking rate is high, and prerequisite conditions are provided for quickly, accurately and reliably measuring the primary and secondary components of the bentonite. According to the method, the sample does not need to be fired at high temperature by a muffle furnace in advance, the platinum crucible does not need to be pretreated, the detection period is remarkably shortened, and the power consumption cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of X-ray fluorescence analysis, and in particular relates to a method for preparing a bentonite sample for X-ray fluorescence analysis by a melting method. Background Art

[0002] Bentonite is a mineral material with low density, low thermal conductivity, strong adsorption capacity, high porosity, large specific surface area and light weight. Its density is generally 2-3g / cm 3 . In the process of preparing bentonite samples by using X-ray fluorescence spectrometer for component analysis, the existing melting preparation method for preparing bentonite samples by using glass samples for X-ray fluorescence analysis may cause splashing due to the lightness of the powder or uneven thickness and pores due to the large pores. Therefore, the requirements for operators are high and the probability of causing analysis deviation is high. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing bentonite X-ray fluorescence analysis samples by a melting method, thereby improving the sample forming rate and improving the accuracy and reliability of X-ray fluorescence analysis when used to determine the major and minor components of bentonite.

[0004] To achieve the above object, the present invention is implemented through the following technical solutions:

[0005] A method for preparing a bentonite sample for X-ray fluorescence analysis by a melting method comprises the following steps:

[0006] 1) Add flux and bentonite sample into a crucible, then drop boric acid-glycerol solution and stir until it becomes muddy;

[0007] 2) Add liquid oxidant into the crucible, continue to stir thoroughly with a glass rod, wipe the head of the glass rod with a quantitative filter paper after stirring evenly, and put the wiped filter paper into the crucible;

[0008] 3) Place the crucible on a high-frequency melting machine and slowly heat it up until the solid in the crucible melts into a liquid state and turns bright red. Turn off the heat and add a release agent.

[0009] 4) Remove the crucible, lay it flat, and demould it after cooling it down slightly to obtain a sample for X-ray fluorescence analysis.

[0010] The preparation method of the boric acid-glycerol solution is as follows: boric acid, water and glycerol are heated in a water bath according to a mass ratio of 10:20:(15-30), and stirred until they are completely dissolved.

[0011] The flux is one or both of lithium tetraborate and lithium metaborate.

[0012] The liquid oxidant is a solution of lithium carbonate, lithium nitrate, lithium bromide or a mixed solution of several of them.

[0013] The release agent is ammonium iodide or potassium iodide.

[0014] In step 3), the crucible is continuously shaken during the melting process to fully mix the materials in the crucible.

[0015] In step 3), the melting time of the sample in the crucible is 8 to 10 minutes.

[0016] The crucible is a platinum crucible.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The invention has the advantages of simple operation and high tableting rate, and provides the prerequisite for quickly, accurately and reliably determining the major and minor components of bentonite.

[0019] 1. The present invention does not need to pre-burn the sample with a muffle furnace at high temperature, nor does it need to pre-treat the platinum crucible, which significantly shortens the detection cycle and reduces electricity costs.

[0020] 2. The present invention pre-bonds the powders that are easy to splash together, thereby reducing the loss of the samples to be tested and also reducing the test risks.

[0021] 3. The present invention mixes the flux, the sample and the liquid oxidant directly in the crucible, and wipes the head of the glass rod with a quantitative filter paper containing less impurities, and puts them into the crucible together. There is almost no sample loss in the whole process, which reduces errors.

[0022] 4. During the melting process, the temperature does not need to be controlled too high, which will reduce the consumption of the crucible. DETAILED DESCRIPTION

[0023] The present invention is described in detail below, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0024] A method for preparing a bentonite sample for X-ray fluorescence analysis by a melting method comprises the following steps:

[0025] 1) Add flux and bentonite sample into a crucible, then drop boric acid-glycerol solution and stir until it becomes muddy;

[0026] Preparation method of boric acid-glycerol solution: heat boric acid, water and glycerol in a water bath at a mass ratio of 10:20:(15-30), and stir until completely dissolved. The flux is one or both of lithium tetraborate and lithium metaborate.

[0027] 2) Add liquid oxidant to the crucible, continue to stir thoroughly with a glass rod, wipe the head of the glass rod with a quantitative filter paper after stirring evenly, and put the wiped filter paper into the crucible; the liquid oxidant is a solution of lithium carbonate, lithium nitrate, lithium bromide or a mixed solution of several. A platinum crucible can be used as the crucible.

[0028] 3) Place the crucible on a high-frequency melting machine, stir thoroughly at low temperature, and then slowly heat up and burn until the solid in the crucible melts into liquid and turns bright red, turn off the heat, and add a release agent; the release agent can be ammonium iodide or potassium iodide.

[0029] 4) Remove the crucible, lay it flat, and demould it after cooling it down slightly to obtain a sample for X-ray fluorescence analysis.

[0030] Example 1

[0031] A method for preparing bentonite X-ray fluorescence analysis samples by melting method:

[0032] 1) Weigh 10 g of boric acid (analytical grade) and put it into a 100 ml beaker. Add 20 ml of water and 15 ml of glycerol. Heat in a water bath and stir with a glass rod until the solid is dissolved to obtain a boric acid-glycerol solution.

[0033] 2) Weigh 5g of lithium tetraborate and place it in a platinum crucible. Then accurately weigh 1.0000g of sodium bentonite available in the laboratory and pour it into the center of the crucible. Use a dropper to draw boric acid-glycerol solution and inject it into the bentonite sample until the sample is completely wet. Stir it with a glass rod into a mud-like state. Then add 5ml of 220mg / ml lithium nitrate solution, stir it thoroughly, and wipe the head of the glass rod with a quantitative filter paper. The wiped filter paper is then placed in the platinum crucible.

[0034] 3) Place the platinum crucible on a high-frequency melting machine, slowly heat up and burn, and control the solid to melt completely. When the mixture in the platinum crucible is completely melted into a liquid state and bright red, turn off the fire, add potassium iodide, and continue to shake the platinum crucible during the melting process to fully mix the materials in the platinum crucible. The sample melting time is 10 minutes; remove the platinum crucible with crucible tongs, lay it flat, and wait until the melt is completely solidified. After cooling slightly, demould it to obtain a glass sample for X-ray fluorescence analysis.

[0035] Example 2

[0036] A method for preparing bentonite X-ray fluorescence analysis samples by melting method:

[0037] 1) Weigh 10 g of boric acid (analytical grade) and put it into a 100 ml beaker. Add 20 ml of water and 20 ml of glycerol. Heat in a water bath and stir with a glass rod until the solid is dissolved to obtain a boric acid-glycerol solution.

[0038] 2) Weigh 5g of lithium tetraborate and place it in a platinum crucible, then accurately weigh 0.5000g of a calcium-based bentonite standard sample and pour it into the center of the platinum crucible, use a dropper to draw a boric acid-glycerol solution and inject it into the bentonite sample until the sample is completely wet, and stir it with a glass rod into a mud-like state; then add 10ml of a 220mg / ml lithium nitrate solution, stir well, and wipe the head of the glass rod with a quantitative filter paper, and put the wiped filter paper into the platinum crucible;

[0039] 3) Place the platinum crucible on a high-frequency melting machine, slowly heat up and burn, and control the solid to melt completely. When the mixture in the platinum crucible is completely melted into a liquid and bright red, turn off the fire, add potassium iodide, and continue to shake the platinum crucible during the melting process to fully mix the materials in the platinum crucible. The sample melting time is 8 minutes; remove the platinum crucible with crucible tongs, lay it flat, and remove it from the mold until the melt is completely solidified. After cooling slightly, remove it from the mold to obtain a glass sample for X-ray fluorescence analysis.

[0040] Example 3

[0041] A method for preparing bentonite X-ray fluorescence analysis samples by melting method:

[0042] 1) Weigh 10 g of boric acid (analytical grade) and put it into a 100 ml beaker. Add 20 ml of water and 20 ml of glycerol. Heat in a water bath and stir with a glass rod until the solid is dissolved to obtain a boric acid-glycerol solution.

[0043] 2) Weigh 6g of lithium metaacid and place it in a platinum crucible, then accurately weigh 0.5000g of a calcium-based bentonite standard sample, pour it into the center of the platinum crucible, use a dropper to draw a boric acid-glycerol solution and inject it into the bentonite sample until the sample is completely wet, and stir it into a muddy state with a glass rod; then add 10ml of a 220mg / ml lithium nitrate solution, stir well, and wipe the head of the glass rod with a quantitative filter paper, and put the wiped filter paper into the platinum crucible;

[0044] 3) Place the platinum crucible on a high-frequency melting machine, slowly heat up and burn, and control the solid to melt completely. When the mixture in the platinum crucible is completely melted into a liquid and bright red, turn off the fire, add ammonium iodide, and continue to shake the platinum crucible during the melting process to fully mix the materials in the platinum crucible. The sample melting time is 8 minutes; remove the platinum crucible with crucible tongs, lay it flat, and remove it from the mold until the melt is completely solidified. After cooling slightly, remove it from the mold to obtain a glass sample for X-ray fluorescence analysis.

[0045] The present invention omits the process of high-temperature burning of the sample, avoids the problem of splashing of the sample with low density, and reduces the problem of uneven sample slices. It is simple to operate, has a high slice rate, good slice making effect, and the sample slice surface is smooth and uniform. The analysis results of the sample are not significantly different from the original determination method.

Claims

1. A method for preparing bentonite X-ray fluorescence analysis samples by melting method, characterized in that: The following steps are involved: 1) Add flux and bentonite sample into a crucible, then drop boric acid-glycerol solution and stir until it becomes muddy; 2) Add liquid oxidant into the crucible, continue to stir thoroughly with a glass rod, wipe the head of the glass rod with a quantitative filter paper after stirring evenly, and put the wiped filter paper into the crucible; 3) Place the crucible on a high-frequency melting machine and slowly heat it up until the solid in the crucible melts into a liquid state and turns bright red. Turn off the heat and add a release agent. 4) Remove the crucible, lay it flat, and demould it after cooling it down slightly to obtain a sample for X-ray fluorescence analysis.

2. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: The preparation method of the boric acid-glycerol solution is as follows: boric acid, water and glycerol are heated in a water bath according to a mass ratio of 10:20:(15-30), and stirred until they are completely dissolved.

3. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: The flux is one or both of lithium tetraborate and lithium metaborate.

4. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: The liquid oxidant is a solution of lithium carbonate, lithium nitrate, lithium bromide or a mixed solution of several of them.

5. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: The release agent is ammonium iodide or potassium iodide.

6. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: In step 3), the crucible is continuously shaken during the melting process to fully mix the materials in the crucible.

7. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: In step 3), the melting time of the sample in the crucible is 8 to 10 minutes.

8. The method for preparing bentonite X-ray fluorescence analysis sample by melting method according to claim 1, characterized in that: The crucible is a platinum crucible.