阅读说明：本技术 一种快速测定萤石中氟化钙含量的方法 (Method for rapidly determining content of calcium fluoride in fluorite ) 是由 左晓艳 周杰强 高志 陈兴华 倪青青 张迎杰 张磊磊 程相贵 于 2021-10-18 设计创作，主要内容包括：本发明提供了一种快速测定萤石中氟化钙含量的方法,包括以下步骤：配置盐酸溶液,配置硫酸溶液,配置CMP混合指示剂,配置三乙醇胺溶液,配置氢氧化钾溶液,配置碳酸钙标准溶液,标准滴定溶液配制,EDTA标准滴定溶液标定,测定,氟化钙的质量百分含量计算。本试验方法采用硼酸、盐酸、硫酸在氟化钙含量大于80％(含80％)时使用,氟化钙含量低于80％(不含80％)不使用硫酸,加热完全溶解试样,减少了多重过滤、沉淀等分析流程,避免因操作不当如溶解、洗涤而造成氟化钙含量的减少,优化了整个分析流程,本方法氟化钙测定范围全面,分析耗时短且测定结果准确度高,大幅度降低了人工成本和试剂消耗,同时能够在生产中推广应用。(The invention provides a method for rapidly determining the content of calcium fluoride in fluorite, which comprises the following steps: preparing a hydrochloric acid solution, preparing a sulfuric acid solution, preparing a CMP mixed indicator, preparing a triethanolamine solution, preparing a potassium hydroxide solution, preparing a calcium carbonate standard solution, preparing a standard titration solution, calibrating the EDTA standard titration solution, determining, and calculating the mass percentage content of calcium fluoride. The test method adopts boric acid, hydrochloric acid and sulfuric acid to be used when the content of calcium fluoride is more than 80 percent (80 percent), the content of calcium fluoride is less than 80 percent (80 percent is not contained), sulfuric acid is not used, samples are heated and completely dissolved, analysis processes such as multiple filtration, precipitation and the like are reduced, the reduction of the content of calcium fluoride caused by improper operation such as dissolution and washing is avoided, the whole analysis process is optimized, the method has the advantages of comprehensive measurement range of calcium fluoride, short analysis time consumption and high accuracy of measurement results, the labor cost and the reagent consumption are greatly reduced, and the method can be popularized and applied in production.)

1. A method for rapidly determining the content of calcium fluoride in fluorite is characterized by comprising the following steps:

the method comprises the following steps: preparing a hydrochloric acid solution, putting 50mL of water into a 100mL beaker, and putting 50mL of the hydrochloric acid solution into the same beaker;

step two: preparing a sulfuric acid solution, placing 30mL of water in a 100mL beaker, and slowly adding 30mL of the sulfuric acid solution into the same beaker;

step three: preparing a CMP mixed indicator, accurately weighing 1.000g of calcein, 1.000g of methyl thymol blue, 0.200g of phenolphthalein and 50.00g of potassium nitrate dried at 110 ℃ at 105-;

step four: preparing a triethanolamine solution, putting 50mL of water into a 100mL beaker, and putting 50mL of a hydrochloric acid solution into the same beaker;

step five: preparing a potassium hydroxide solution, dissolving 200g of potassium hydroxide in water, adding water to dilute to 1L of the scale, and storing in a glass bottle;

step six: preparing a calcium carbonate standard solution, taking 1.0008g of calcium carbonate (more than 99.9%) which is dried at 105-110 ℃ for 2h in advance and cooled to room temperature in a dryer, putting the calcium carbonate in a 400mL beaker, covering a surface dish, slowly adding 25mL of the prepared hydrochloric acid solution, adding 100mL of water after the calcium carbonate is dissolved, heating and boiling to drive off carbon dioxide, cooling to room temperature, transferring the solution into a 1000mL volumetric flask, diluting with water to a scale, and uniformly mixing;

step seven: preparing a standard titration solution, weighing 7.45g of EDTA (standard substance) which is pre-baked for 1h in an oven at 105 ℃ for standby, adding 200mL of pure water into a 400mL beaker, cooling to room temperature after heating and dissolving completely, and transferring all the solution into a 1000mL volumetric flask for constant volume;

step eight: calibrating an EDTA standard titration solution, transferring three parts of 25.00mL of prepared calcium carbonate standard solution, respectively placing the three parts in a 250mL beaker, diluting the three parts to 100mL by using water, adding 5mL of triethanolamine and 20mL of potassium hydroxide solution, adding a proper amount of a CMP mixed indicator, titrating the three parts by using the EDTA standard titration solution until green fluorescence of a test solution disappears (observed on a black background gasket) and red color appears as an end point, and simultaneously, in a blank test, the range of the volume of EDTA consumed by the three parts of the calcium carbonate standard solution is not more than 0.10mL, or else, calibrating again;

step nine: measuring, weighing 0.1000g of a sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure), 10mL of hydrochloric acid solution and 0.7mL of sulfuric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the beaker on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of CMP (chemical mechanical polishing) mixed indicator, and titrating the solution with 0.02mol/L of EDTA (ethylene diamine tetraacetic acid) standard solution until green fluorescence disappears and the solution is red;

step ten: calculated by the mass percentage of calcium fluoride, omega CaF₂＝c×(V1-V0)×78.07×100/m/1000-ωCaCO₃×78.08/100.08。

2. The method for rapidly determining the content of calcium fluoride in fluorite according to claim 1, wherein: in the tenth step, c is the concentration of the EDTA standard titration solution, and the unit is mol/L; v1 is the volume of EDTA standard titration solution consumed by titration, and the unit is mL; v0 is the volume of EDTA standard titration solution consumed by the blank test in mL; 78.07 is the molecular mass of calcium fluoride, g/mol; m is the weight of the sample, and the unit is g; omega CaCO₃The mass fraction of calcium carbonate in the sample (the determination method of the amount of calcium carbonate is shown in GB/T5195.2-2006 by EDTA titration) is expressed in%.

3. The method for rapidly determining the content of calcium fluoride in fluorite according to claim 1, wherein: in the tenth step, when the calcium fluoride content of the measurement result is more than or equal to 80%, the allowable difference of the same laboratory is 0.35%, and the allowable difference of different laboratories is 0.40%; when the content of calcium fluoride in the measured result is less than 80%, the allowable difference of the same laboratory is 0.30%, and the allowable difference of different laboratories is 0.35%.

Technical Field

The invention relates to the technical field of calcium fluoride content determination, in particular to a method for rapidly determining the content of calcium fluoride in fluorite.

Background

Fluorite is a fluorine mineral with wide industrial application, is also called fluorite, is mainly used in three industries of metallurgy, chemical industry and building materials, and is used in light industry, optics, carving and national defense industry; in addition, fluorite is widely applied to building material industries such as glass, ceramics, cement and the like, and can also be used as a fluxing agent for steel smelting. The content of calcium fluoride in fluorite is the most important index for determining the quality grade of fluorite, so that the measurement of the content of calcium fluoride has important significance for the sustainable development of industry.

The method is characterized in that an ion chromatography method, an X-ray fluorescence method and an EDTA titration method are generally adopted for analyzing the content of calcium fluoride in fluorite, and because partial calcium carbonate-containing minerals and calcium silicate-containing minerals usually exist in fluorite ore, the EDTA titration method in the GB/T5195.1-2006 method is generally adopted for analyzing the calcium fluoride in the fluorite ore to measure the calcium fluoride in the fluorite, calcium-containing acetic acid is mainly used as leaching liquid, calcium carbonate and calcium sulfate are separated and then measured, dissolution, precipitation and multiple filtration are carried out during the measurement, the measurement result is high in accuracy, but the analysis period is long, the flow is complex, the labor cost is high, the calcium fluoride measurement range is not complete (the measurement range (mass fraction), the content of calcium fluoride is not less than 60 percent), and the method is not suitable for the current industrial production.

Disclosure of Invention

The invention aims to provide a method for rapidly determining the content of calcium fluoride in fluorite, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a method for rapidly determining the content of calcium fluoride in fluorite comprises the following steps:

the method comprises the following steps: preparing a hydrochloric acid solution, putting 50mL of water into a 100mL beaker, and putting 50mL of the hydrochloric acid solution into the same beaker;

step two: preparing a sulfuric acid solution, placing 30mL of water in a 100mL beaker, and slowly adding 30mL of the sulfuric acid solution into the same beaker;

step three: preparing a CMP mixed indicator, accurately weighing 1.000g of calcein, 1.000g of methyl thymol blue, 0.200g of phenolphthalein and 50.00g of potassium nitrate dried at 110 ℃ at 105-;

step four: preparing a triethanolamine solution, putting 50mL of water into a 100mL beaker, and putting 50mL of a hydrochloric acid solution into the same beaker;

step five: preparing a potassium hydroxide solution, dissolving 200g of potassium hydroxide in water, adding water to dilute to 1L of the scale, and storing in a glass bottle;

step six: preparing a calcium carbonate standard solution, taking 1.0008g of calcium carbonate (more than 99.9%) which is dried at 105-110 ℃ for 2h in advance and cooled to room temperature in a dryer, putting the calcium carbonate in a 400mL beaker, covering a surface dish, slowly adding 25mL of the prepared hydrochloric acid solution, adding 100mL of water after the calcium carbonate is dissolved, heating and boiling to drive off carbon dioxide, cooling to room temperature, transferring the solution into a 1000mL volumetric flask, diluting with water to a scale, and uniformly mixing;

step seven: preparing a standard titration solution, weighing 7.45g of EDTA (standard substance) which is pre-baked for 1h in an oven at 105 ℃ for standby, adding 200mL of pure water into a 400mL beaker, cooling to room temperature after heating and dissolving completely, and transferring all the solution into a 1000mL volumetric flask for constant volume;

step eight: calibrating an EDTA standard titration solution, transferring three parts of 25.00mL of prepared calcium carbonate standard solution, respectively placing the three parts in a 250mL beaker, diluting the three parts to 100mL by using water, adding 5mL of triethanolamine and 20mL of potassium hydroxide solution, adding a proper amount of a CMP mixed indicator, titrating the three parts by using the EDTA standard titration solution until green fluorescence of a test solution disappears (observed on a black background gasket) and red color appears as an end point, and simultaneously, in a blank test, the range of the volume of EDTA consumed by the three parts of the calcium carbonate standard solution is not more than 0.10mL, or else, calibrating again;

step nine: measuring, weighing 0.1000g of a sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure), 10mL of hydrochloric acid solution and 0.7mL of sulfuric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the beaker on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of CMP (chemical mechanical polishing) mixed indicator, and titrating the solution with 0.02mol/L of EDTA (ethylene diamine tetraacetic acid) standard solution until green fluorescence disappears and the solution is red;

step ten: calculated by the mass percentage of calcium fluoride, omega CaF₂＝c×(V1-V0)×78.07×100/m/1000-ωCaCO₃×78.08/100.08。

Preferably, in the tenth step, c is the concentration of the EDTA standard titration solution, and the unit is mol/L; v1 is the volume of EDTA standard titration solution consumed by titration, and the unit is mL; v0 is the volume of EDTA standard titration solution consumed by the blank test in mL; 78.07 is the molecular mass of calcium fluoride, g/mol; m is the weight of the sample, and the unit is g; omega CaCO₃The mass fraction of calcium carbonate in the sample (the determination method of the amount of calcium carbonate is shown in GB/T5195.2-2006 by EDTA titration) is expressed in%.

Preferably, in the tenth step, when the calcium fluoride content is greater than or equal to 80%, the allowable difference in the same laboratory is 0.35%, and the allowable difference in different laboratories is 0.40%; when the content of calcium fluoride in the measured result is less than 80%, the allowable difference of the same laboratory is 0.30%, and the allowable difference of different laboratories is 0.35%.

Compared with the prior art, the invention has the beneficial effects that:

according to the test method, boric acid, hydrochloric acid and sulfuric acid are used when the content of calcium fluoride is more than 80% (containing 80%), sulfuric acid is not used when the content of calcium fluoride is less than 80% (not containing 80%), the sample is completely dissolved by heating, complex analysis processes such as multiple filtration and precipitation are reduced, the reduction of the content of calcium fluoride caused by improper operation such as dissolution and washing is avoided, the whole analysis process is optimized, the calcium fluoride measurement range in the GB/T5195.1-2006 method is incomplete (the content of calcium fluoride in the measurement range (mass fraction) is more than or equal to 60%), the calcium fluoride measurement range is comprehensive, the analysis time is short, the accuracy of the measurement result is high, the labor cost and the reagent consumption are greatly reduced, and meanwhile, the method can be popularized and applied in production.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite comprises the following steps of determining a fluorite standard sample GBW (E)070104a (CaF2 standard value 98.25%, CaCO3 standard value 0.15%):

weighing 0.1000g of a sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure), 10mL of hydrochloric acid solution and 0.7mL of sulfuric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the beaker on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker by water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixing indicator, titrating the solution by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the solution appears red, wherein the milliliter number of the consumed EDTA standard titration solution is 63.3mL, the milliliter number of the titrated blank sample is 0.3mL, and according to the calculation formula of calcium fluoride: omega CaF2 ═ c x (V1-V0). times. 78.07 x 100/m/1000-omega CaCO3 x 78.08/100.08, the mass fraction of calcium fluoride is calculated to be 98.25%, the mass fraction of calcium fluoride measured by the GB/T5195.1-2006 method is 98.15%, the deviation between the measurement value of the method and the national standard method is 0.10%, the method and the national standard measurement value have better consistency, and the analysis result of the calcium fluoride content is shown in Table 1;

TABLE 1

Example two

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite comprises the following steps of determining a fluorite standard sample GBW (E)070104a (CaF2 standard value is 90.72%, and CaCO3 standard value is 0.87%):

weighing 0.1000g of a sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure), 10mL of hydrochloric acid solution and 0.7mL of sulfuric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the beaker on an electric hot plate at 300 ℃, heating for slight boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker by water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixing indicator, titrating the solution by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the solution appears red, wherein the milliliter number of the consumed EDTA standard titration solution is 58.9mL, and the milliliter number of the titrated blank sample is 0.29mL according to the calculation formula of calcium fluoride: omega CaF2 ═ c x (V1-V0). times. 78.07 x 100/m/1000-omega CaCO3 x 78.08/100.08, the mass fraction of calcium fluoride is calculated to be 90.83%, the mass fraction of calcium fluoride measured by the GB/T5195.1-2006 method is 90.64%, the deviation between the measurement value of the method and the national standard method is 0.21%, the method has better consistency with the national standard measurement value, and the analysis result of the calcium fluoride content is shown in Table 2;

TABLE 2

EXAMPLE III

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite comprises the following steps of determining a fluorite standard sample GBW (E)070104a (CaF2 standard value 76.33%, CaCO3 standard value 2.05%):

weighing 0.1000g of a sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure) and 10mL of hydrochloric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating and microboiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker by water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating the solution by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the solution is red, wherein the milliliter number of the consumed EDTA standard titration solution is 50.36mL, and the milliliter number of the titrated blank sample is 0.31mL according to the calculation formula of calcium fluoride: omega CaF2 ═ c x (V1-V0). times. 78.07 x 100/m/1000-omega CaCO3 x 78.08/100.08, the mass fraction of calcium fluoride is calculated to be 76.55%, the mass fraction of calcium fluoride measured by the GB/T5195.1-2006 method is 76.33%, the deviation of the measured value of the method from the national standard method is 0.29%, the method has better consistency with the national standard measured value, and the analysis result of the calcium fluoride content is shown in Table 3;

TABLE 3

Example four

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite is used for determining the content of calcium fluoride in raw ore in fluorite ore samples of ore dressing plants in Nanyang city, Henan province:

weighing 0.1000g of sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure) and 10mL of hydrochloric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the condition of continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the green fluorescence is red, wherein the milliliter number of the consumed EDTA standard titration solution is 16.8mL, the milliliter number of the titrated blank sample solution is 0.3mL, and the mass fraction of calcium carbonate is 0.49 percent by adopting an EDTA titration method in GBT5195.2-2006, according to the calculation formula of calcium fluoride: ω CaF2 ═ c × (V1-V0) × 78.07 × 100/m/1000- ω CaCO3 × 78.08/100.08, the mass fraction of calcium fluoride calculated is 25.38%, the mass fraction of calcium fluoride measured by the method GB/T5195.1-2006 is 25.32%, the deviation between the values measured by the method and the national standard method is 0.24%, there is better agreement with the values measured by the national standard method, and the analysis results of the calcium fluoride content are shown in table 4;

TABLE 4

EXAMPLE five

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite is used for determining the content of calcium fluoride in concentrate in fluorite ore samples of ore dressing plants in Nanyang city, Henan south China: weighing 0.1000g of sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure), 10mL of hydrochloric acid solution and 0.7mL of sulfuric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating for slight boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the condition of continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the green fluorescence is red, wherein the milliliter number of the consumed EDTA standard titration solution is 63.4mL, the milliliter number of the titrated blank sample solution is 0.3mL, and the mass fraction of calcium carbonate is 0.14 percent by adopting an EDTA titration method in GBT5195.2-2006, according to the calculation formula of calcium fluoride: omega CaF2 ═ c x (V1-V0). times. 78.07 x 100/m/1000-omega CaCO3 x 78.08/100.08, the mass fraction of calcium fluoride is calculated to be 98.42%, the mass fraction of calcium fluoride measured by the GB/T5195.1-2006 method is 98.53%, the deviation between the measured values of the method and the national standard method is 0.12%, the method and the measured values of the national standard method have better consistency, and the analysis result of the calcium fluoride content is shown in Table 5;

TABLE 5

EXAMPLE six

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite is used for determining the content of calcium fluoride in tailings in fluorite ore samples of ore dressing plants in Nanyang city, Henan south China: weighing 0.1000g of sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure) and 10mL of hydrochloric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the condition of continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the green fluorescence is red, wherein the milliliter number of the consumed EDTA standard titration solution is 3.65mL, the milliliter number of the titrated blank sample solution is 0.3mL, and the mass fraction of calcium carbonate is 1.36 percent by adopting an EDTA titration method in GBT5195.2-2006, according to the calculation formula of calcium fluoride: ω CaF2 ═ c × (V1-V0) × 78.07 × 100/m/1000- ω CaCO3 × 78.08/100.08, the mass fraction of calcium fluoride calculated is 4.17%, the mass fraction of calcium fluoride measured by the method GB/T5195.1-2006 is 4.16%, the deviation between the values measured by the method and the national standard method is 0.23%, there is better agreement with the values measured by the national standard method, and the analysis results of the calcium fluoride content are shown in table 6;

TABLE 6

EXAMPLE seven

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite is used for determining the content of calcium fluoride in fluorite ore samples of a certain concentrating mill in Henan province:

weighing 0.1000g of sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure) and 10mL of hydrochloric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the condition of continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the green fluorescence is red, wherein the milliliter number of the consumed EDTA standard titration solution is 31.09mL, the milliliter number of the titrated blank sample solution is 0.28mL, and the mass fraction of calcium carbonate is 30.79 percent by adopting an EDTA titration method in GBT5195.2-2006, according to the calculation formula of calcium fluoride: ω CaF2 ═ c × (V1-V0) × 78.07 × 100/m/1000- ω CaCO3 × 78.08/100.08, the mass fraction of calcium fluoride was calculated to be 24.09%, the mass fraction of calcium fluoride measured by the method GB/T5195.1-2006 was 24.03%, the deviation between the measured values by the method and the national standard method was 0.23%, there was better agreement with the measured values by the national standard method, and the analysis results of the calcium fluoride content are shown in table 7;

TABLE 7

Example eight

The invention provides a technical scheme that: a method for rapidly determining the content of calcium fluoride in fluorite is used for determining the content of calcium fluoride in fluorite ore samples of a certain concentrating mill in Hunan province:

weighing 0.1000g of sample, placing the sample into a 400mL beaker, adding 0.7g of boric acid (analytically pure) and 10mL of hydrochloric acid solution, adding 2mL of distilled water, shaking uniformly, covering a watch glass, placing the watch glass on an electric hot plate at 300 ℃, heating for slightly boiling for about 15 minutes, shaking once every 2 minutes, taking down and cooling, washing the watch glass and the wall of the beaker with water, adding water into the solution to dilute the solution to 120mL, slowly adding 10mL of triethanolamine solution, adding 20mL of potassium hydroxide solution under the condition of continuous stirring of a polytetrafluoroethylene stirring rod, adding a proper amount of a CMP mixed indicator, titrating by using 0.02mol/L of EDTA standard solution until green fluorescence disappears and the green fluorescence is red, wherein the milliliter number of the consumed EDTA standard titration solution is 24.95mL, the milliliter number of the titrated blank sample solution is 0.28mL, determining that the mass fraction of calcium carbonate is 43.3% by adopting an EDTA titration method in GBT5195.2-2006, and according to the calculation formula of calcium fluoride: ω CaF2 ═ c × (V1-V0) × 78.07 × 100/m/1000- ω CaCO3 × 78.08/100.08, the mass fraction of calcium fluoride calculated is 4.74%, the mass fraction of calcium fluoride measured by the method GB/T5195.1-2006 is 4.75%, the deviation between the values measured by the method and the national standard method is 0.25%, there is better agreement with the values measured by the national standard method, the analysis results of the calcium content are shown in table 8;

TABLE 8

The invention has the advantages that: boric acid, hydrochloric acid and sulfuric acid are used when the content of calcium fluoride is more than 80 percent (containing 80 percent), the content of calcium fluoride is less than 80 percent (not containing 80 percent), sulfuric acid is not used, samples are heated and completely dissolved, complex analysis processes such as multiple filtration, precipitation and the like are reduced, the reduction of the content of calcium fluoride caused by dissolution and washing due to improper operation is avoided, the whole analysis process is optimized, the calcium fluoride measuring range in the GB/T5195.1-2006 method is incomplete (the content of calcium fluoride in the measuring range (mass fraction) is more than or equal to 60 percent), the calcium fluoride measuring range is comprehensive, the analysis time is short, the labor cost and the reagent consumption are greatly reduced, the measuring result accuracy is high, the error of the measured value of the calcium fluoride is controlled within 0.3 percent relative to the national standard, the method has higher practical value, and simultaneously meets the rapid measuring requirement of a production site.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.