阅读说明：本技术 基于酸氧化低合金钢试样xrf分析用玻璃样品制备方法 (Preparation method of glass sample for XRF analysis based on acid oxidation low alloy steel sample ) 是由 张改梅 王彬果 商英 鲍希波 弓习峰 卢女平 赵靖 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种基于酸氧化低合金钢试样XRF分析用玻璃样品制备方法,首先用硝酸或盐酸在三角瓶中对试样进行充分预氧化,然后低温加热浓缩至体积为3~5mL；再转移至铂金坩埚中,烘干；最后加入硼酸锂熔剂和脱模剂充分混合后经高温熔融制成XRF分析用玻璃样片。本发明可使样品完全氧化,不会腐蚀铂金坩埚,制成的玻璃样片均匀透亮,用于X射线荧光光谱分析,拓宽了应用范围。(The invention relates to a preparation method of a glass sample for XRF analysis based on an acid oxidation low alloy steel sample, which comprises the steps of firstly, fully pre-oxidizing the sample in a triangular flask by using nitric acid or hydrochloric acid, and then heating and concentrating at low temperature until the volume is 3-5 mL; transferring the mixture into a platinum crucible and drying; and finally adding a lithium borate flux and a release agent, fully mixing, and melting at high temperature to prepare the glass sample wafer for XRF analysis. The invention can completely oxidize the sample, does not corrode the platinum crucible, and the prepared glass sample is uniform and transparent, is used for X-ray fluorescence spectrum analysis, and widens the application range.)

1. The preparation method of the glass sample for XRF analysis based on the acid oxidation low alloy steel sample is characterized by comprising the following steps of: the method comprises the following steps:

weighing a quantitative sample in a triangular flask, adding a nitric acid or hydrochloric acid solution, heating for 3-15 min until the reducing substances in the sample disappear, and then continuously heating at 70-90 ℃ to concentrate the volume of the solution to 3-5 mL;

step two, transferring the concentrated solution into a platinum crucible, and heating at the temperature of 60-80 ℃ to evaporate the liquid to dryness; then heating to 150-200 ℃ and continuing heating until the sample is cracked;

and step three, crushing and uniformly stirring the dried sample, then adding a mixed flux of lithium tetraborate and lithium metaborate, uniformly stirring the sample and the mixed reagent, adding a release agent, placing the sample and the mixed reagent into a sample melting furnace, heating to 1000-1100 ℃, shaking, casting and demolding to obtain the glass sheet sample for XRF.

2. The method of preparing a glass sample for XRF analysis based on an acid oxidized low alloy steel sample according to claim 1, wherein: in the first step, the using amount of the sample is 0.2000 g-0.5000 g, the concentration of nitric acid or hydrochloric acid is 20% -40% by mass, the using amount is 10 mL-15 mL, and the temperature is 70-90 ℃.

3. The method of preparing a glass sample for XRF analysis based on an acid oxidized low alloy steel sample according to claim 1, wherein: in the second step, the concentrated solution is transferred to a platinum crucible, then the triangular flask is rinsed with 2-3 mL of purified water for 3-5 times, and the rinsed solution is poured into the platinum crucible.

4. The method of preparing a glass sample for XRF analysis based on an acid oxidized low alloy steel sample according to claim 1, wherein: in the third step, the mixed flux is 67 percent by mass: 33% of mixed flux of lithium tetraborate and lithium metaborate, wherein the using amount is 5.0000-8.0000 g; the release agent is 0.2-0.5 g of halide solid or 1-2 mL of halide solution with the mass fraction of 30%; the sample melting time is 10-20 min.

Technical Field

The invention belongs to the technical field of analytical chemistry, and particularly relates to a preparation method of a glass sample for XRF analysis based on an acid oxidation low alloy steel sample.

Background

The low alloy steel generally refers to alloy steel with the total amount of alloy elements less than 5 wt%, wherein the contents of elements such as silicon, manganese, phosphorus, chromium, nickel, molybdenum, vanadium, titanium, aluminum and the like are important reference bases for adjusting the steelmaking process. At present, the detection of components of low alloy steel, particularly the detection of crumb-shaped low alloy steel, is generally carried out by a wet chemical method, an ICP (inductively coupled plasma) spectroscopy method and the like, and the detection requirements of laboratories configured with different instruments are met respectively. In recent years, with the rapid development of X-ray fluorescence spectrum detection technology, an X-ray fluorescence spectrometer has become a conventional configuration of mainstream laboratories, so that a detection method of scrap-shaped steel samples suitable for X-ray fluorescence spectrum analysis is developed, and more choices can be provided for laboratories on the detection method.

Disclosure of Invention

The invention aims to provide a preparation method of a glass sample for XRF analysis based on an acid oxidation low alloy steel sample.

In order to solve the technical problems, the invention adopts the technical scheme that:

the preparation method of the glass sample for XRF analysis based on the acid oxidation low alloy steel sample comprises the following steps:

weighing a quantitative sample in a triangular flask, adding a nitric acid or hydrochloric acid solution, heating for 3-15 min until the reducing substances in the sample disappear, and then continuously heating at 70-90 ℃ to concentrate the volume of the solution to 3-5 mL;

step two, transferring the concentrated solution into a platinum crucible, and heating at the temperature of 60-80 ℃ to evaporate the liquid to dryness; then heating to 150-200 ℃ and continuing heating until the sample is cracked;

and step three, crushing and uniformly stirring the dried sample, then adding a mixed flux of lithium tetraborate and lithium metaborate, uniformly stirring the sample and the mixed reagent, adding a release agent, placing the sample and the mixed reagent into a sample melting furnace, heating to 1000-1100 ℃, shaking, casting and demolding to obtain the glass sheet sample for XRF.

In the above preparation method of the glass sample for XRF analysis based on the acid oxidation low alloy steel sample, in the first step, the use amount of the sample is 0.2000 g-0.5000 g, the concentration of nitric acid or hydrochloric acid is 20% -40% by mass, the use amount is 10 mL-15 mL, the temperature is 70-90 ℃, and the liquid level of the solution is calm and does not boil under the condition.

In the second step, the concentrated solution is transferred to a platinum crucible, then the triangular flask is respectively rinsed for 3-5 times with 2-3 mL of purified water, and the rinsing liquid after each rinsing is poured into the platinum crucible;

in the above preparation method of the glass sample for XRF analysis based on the acid oxidation low alloy steel sample, in the third step, the mixed flux is 67% by mass: 33% of mixed flux of lithium tetraborate and lithium metaborate, the dosage is 5.0000 g-8.0000 g; the release agent is 0.2 to 0.5g of halide solid or 1 to 2mL of halide solution with the mass fraction of 30 percent; the sample melting time is 10 min-20 min.

Theoretical analysis:

the pretreatment method for measuring the sample by the XRF method comprises a tabletting method and a glass melt-extrusion method, wherein the tabletting method requires that the granularity of the sample reaches 200 meshes, and the sample has cohesiveness or can be tabletted under the action of a caking agent. Low alloy steel has ductility and thermoplasticity, and a sample cannot be prepared in a uniform powder state in a sample preparation process by a lathe or a drilling machine, so that a powder tableting method cannot be adopted. During the glass melting process, the sample particles are large and the specific surface area is small, so that the solid oxidizer such as lithium carbonate, lithium nitrate, potassium nitrate and the like cannot completely oxidize the sample, and the sample corrodes a platinum crucible during the melting process and cannot be melted into a uniform and transparent glass sheet.

XRF can oxidize the sample with acid before glass melting in the fuse process, but two technical problems need to be solved: 1. how to ensure the safety of the platinum crucible in the sample oxidation process; 2. the volume of the platinum crucible is 20-50mL, and how to avoid the deviation of the measurement result caused by the splashing of the solution in the heating and dissolving process in the process of dissolving the sample by acid. For the first problem, a wall-hung platinum crucible can be used, i.e. the inner wall of the platinum crucible is formed with a flux such as lithium tetraborate to isolate the contact between the sample and the crucible, but the volume of the wall-hung platinum crucible is only 10-20mL, the volume is small, and the wall-hung glass layer is easy to crack, which can cause the corrosion of the sample on the platinum crucible in the sample dissolving process.

In order to overcome the problems, the method comprises the steps of oxidizing outside a platinum crucible for the first time, heating in a triangular flask for 3-15 min by using a liquid oxidant acid until reducing substances in a sample completely disappear, wherein the sample can be incompletely dissolved in a solution and can have oxidizing particles, the oxidizing particles can be generated only in a lithium borate flux, then continuously heating at the temperature of 70-90 ℃ to concentrate the volume of the solution to 3-5 mL, transferring the concentrated solution into the platinum crucible, rinsing the triangular flask for 3-5 times by using 2-3 mL of purified water to ensure that a sample to be tested remaining in the triangular flask is completely transferred into the platinum crucible, and heating at the temperature of 60-80 ℃ to evaporate the liquid to dryness; then heating to 150-200 ℃ and continuing to heat for 2min until the sample is dry cracked; since the sample was completely oxidized at this time, it was no longer corrosive. The process saves the operation step of hanging the platinum crucible on the wall, avoids the risk of corroding the crucible by the sample and does not cause loss to the sample.

The invention has the beneficial effects that:

1. the low alloy steel sample is oxidized by hydrochloric acid or nitric acid to be completely converted into oxide, so that the problem that the conventional solid oxidant is difficult to oxidize the crumb-shaped low alloy steel is solved;

2. by using the liquid concentration, transfer and drying modes, the problems that the sample is easy to splash and lose when a liquid oxidant is used are solved; the whole process is simple to operate, and the prepared glass sample is uniform and transparent, is completely suitable for X-ray fluorescence spectrum analysis, and widens the application range of the X-ray fluorescence spectrum method.

3. Compared with the traditional chemical method, the method realizes zero discharge of waste acid, and accords with the development direction of green laboratories.

Detailed Description

The invention is described in further detail below with reference to specific examples 1 to 5: