A method for analyzing the composition of limestone

Abstract

The application discloses a limestone component analysis method, comprising the following steps: step S1: preparing two samples, performing step S2 on the first sample, and performing step S3 on the second sample; step S2: burning the first sample, and obtaining the magnesium oxide content, the calcium oxide content and the loss on ignition by a thermogravimetric analysis method; and step S3: burning the second sample, and obtaining the carbon content by an infrared detection analysis method. The application has the advantage that the content data of various key components in the limestone can be analyzed.

Description

Technical Field

[0001] This invention relates to the field of sample analysis equipment technology, and in particular to a method for analyzing the composition of limestone. Background Technology

[0002] Thermogravimetric analysis (TG or TGA) is a thermal analysis technique that measures the relationship between the mass of a sample and temperature change under programmed temperature control. It can be used to study the thermal stability and composition of materials.

[0003] Currently, thermogravimetric analysis (TGA) is commonly used to analyze the composition of limestone. This involves heating the sample in a high-temperature furnace by introducing nitrogen gas and monitoring the mass change using a balance. However, in a nitrogen environment, TGA cannot distinguish whether the mass loss originates from the decomposition of the main component, CaCO3, or from other carbonates with similar decomposition temperatures (such as MgCO3 or CaMg(CO3)2 in dolomite). If the sample contains multiple carbonates, the TGA curve will show overlapping weight loss steps, making it difficult to accurately quantify each component. Furthermore, relying solely on TGA provides limited information and cannot simultaneously detect the carbon dioxide content of limestone decomposition products. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a limestone composition analysis method that can analyze the content data of multiple key components in limestone.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for analyzing the composition of limestone includes the following steps: Step S1: Prepare two samples. Perform step S2 for the first sample and step S3 for the second sample. Step S2: The first sample is ignited, and the magnesium oxide content, calcium oxide content, and loss on ignition are obtained by thermogravimetric analysis. Step S3: The second sample is burned and the carbon content is obtained by infrared detection analysis.

[0006] As a further improvement to the above technical solution: Step S2 specifically includes the following steps: Step S201: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S202: Introduce a second gas into the high-temperature furnace to change the gas atmosphere inside the furnace from the first gas atmosphere to the second gas atmosphere; the second gas is used to inhibit the decomposition of calcium carbonate to increase the decomposition temperature of calcium carbonate; Step S203: The high-temperature furnace is heated to the first temperature and burned until the weight is constant, and the magnesium oxide content is calculated; Step S204: The high-temperature furnace is heated to the second temperature and burned until the weight is constant, and the calcium oxide content is calculated.

[0007] The first gas is nitrogen.

[0008] The second gas is carbon dioxide.

[0009] Following step S204, the method further includes... Step S205: The high-temperature furnace is heated to the third temperature and burned until the weight is constant, and the loss on ignition is calculated.

[0010] The first temperature is 800℃, the second temperature is 960℃, and the third temperature is 1000℃.

[0011] Step S201 specifically includes the following steps: Step S2011: Transfer the sample to a high-temperature furnace and introduce the first gas into the furnace. Heat the furnace to the fourth temperature to remove the free water from the sample and calculate the free water content. Step S2012: The high-temperature furnace is heated to the fifth temperature to remove the water of crystallization from the sample, and the water of crystallization content is calculated.

[0012] The fourth temperature is 110°C, and the fifth temperature is 200°C.

[0013] Step S3 specifically includes the following steps: Step S301: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S302: The high-temperature furnace is heated to the third temperature and burned until the weight is constant. The gas in the high-temperature furnace is passed into the infrared detection cell to detect the change in carbon dioxide concentration in the gas flow and calculate the carbon content.

[0014] The sample is a limestone sample.

[0015] Compared with the prior art, the advantages of the present invention are as follows: 1. The limestone composition analysis method of the present invention divides the sample into two parts. One part is analyzed by thermogravimetric analysis to obtain data such as magnesium oxide and calcium oxide content; the other part is analyzed by high-temperature ignition combined with infrared detection analysis to directly detect the change in carbon dioxide concentration produced by decomposition and then calculate the total carbon content. This method makes up for the deficiency of single thermogravimetric analysis, which relies solely on mass change for calculation and lacks sufficient information dimensions. The combination of the two methods can obtain the content data of multiple key components in limestone, meeting the accuracy requirements of limestone composition analysis.

[0016] 2. The limestone composition analysis method of the present invention involves calcining the sample in stages under different atmospheres, using a second gas to inhibit the decomposition of calcium carbonate, thereby increasing the decomposition temperature of calcium carbonate and allowing magnesium carbonate to decompose before calcium carbonate. This separates the originally overlapping weight loss steps, avoids interference from the overlapping weight loss intervals of different carbonates, and enables the accurate quantitative calculation of the content of magnesium oxide and calcium oxide, effectively improving the accuracy of composition detection.

[0017] 3. The limestone composition analysis method of the present invention removes free water and crystal water from the sample by staged heating, and can calculate the content of the two types of water separately, further enriching the composition information obtained by the analysis. Complete moisture content data of limestone sample can be obtained without additional detection, further improving the information richness of a single analysis.

[0018] 4. The limestone composition analysis method of the present invention directly measures the amount of carbon dioxide released by burning through infrared detection, which can eliminate the calculation error caused by the decomposition of other carbonates in the sample, further improve the accuracy of carbon content detection results, and corroborate the data obtained by thermogravimetric analysis, resulting in higher reliability of the overall detection results. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of the limestone composition analysis method of the present invention.

[0020] Figure 2 This is a schematic flowchart of the thermogravimetric analysis process in the limestone composition analysis method of the present invention.

[0021] Figure 3 This is a schematic flowchart of the infrared detection process in the limestone composition analysis method of the present invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] like Figures 1 to 3 As shown, the limestone composition analysis method of this embodiment includes the following steps: Step S1: Prepare two samples. Perform step S2 for the first sample and step S3 for the second sample. Step S2: The first sample is ignited, and the magnesium oxide content, calcium oxide content, and loss on ignition are obtained by thermogravimetric analysis. Step S3: The second sample is burned and the carbon content is obtained by infrared detection analysis.

[0027] Specifically, in this embodiment, the sample is a limestone sample.

[0028] The limestone composition analysis method in this embodiment divides the sample into two parts. One part is analyzed by thermogravimetric analysis to obtain data such as the content of magnesium oxide and calcium oxide. The other part is analyzed by high-temperature ignition combined with infrared detection analysis to directly detect the change in the concentration of carbon dioxide produced by decomposition and then calculate the total carbon content. This method makes up for the deficiency of single thermogravimetric analysis, which relies solely on mass change calculation and lacks sufficient information dimensions. The combination of the two methods can obtain the content data of multiple key components in limestone, meeting the accuracy requirements of limestone composition analysis.

[0029] Furthermore, in this embodiment, step S2 specifically includes the following steps: Step S201: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S202: Introduce a second gas into the high-temperature furnace to change the gas atmosphere inside the furnace from the first gas atmosphere to the second gas atmosphere; the second gas is used to inhibit the decomposition of calcium carbonate to increase the decomposition temperature of calcium carbonate. Step S203: The high-temperature furnace is heated to the first temperature and burned until the weight is constant, and the magnesium oxide content is calculated; Step S204: The high-temperature furnace is heated to the second temperature and burned until the weight is constant, and the calcium oxide content is calculated.

[0030] By subjecting the sample to segmented burning in different atmospheres, the decomposition of calcium carbonate is inhibited by a second gas, thereby increasing the decomposition temperature of calcium carbonate. This allows magnesium carbonate to decompose before calcium carbonate, thus separating the originally overlapping weight loss steps and avoiding interference from the overlapping weight loss intervals of different carbonates. This enables the accurate quantitative calculation of the contents of magnesium oxide and calcium oxide, effectively improving the accuracy of component detection.

[0031] Specifically, in this embodiment, the first gas is nitrogen and the second gas is carbon dioxide. Nitrogen is an inert gas and will not react with the components in the sample. It can stably remove the water vapor generated during the sample heating process, ensuring the smooth progress of the drying process. Since calcium carbonate is sensitive to the partial pressure of carbon dioxide, the carbon dioxide atmosphere in the high-temperature furnace can effectively inhibit the forward decomposition reaction of calcium carbonate, thereby raising the decomposition temperature of calcium carbonate to a level higher than that of magnesium carbonate, ensuring that magnesium carbonate decomposes first, and achieving the separation of the weight loss ranges of the two carbonates.

[0032] Furthermore, in this embodiment, after step S204, it also includes... Step S205: The high-temperature furnace is heated to the third temperature and burned until the weight is constant, and the loss on ignition is calculated.

[0033] After the determination of the contents of magnesium oxide and calcium oxide was completed, By continuing to heat and ignite until the weight is constant, the total loss on ignition of the sample can be calculated from the mass change throughout the process, eliminating the need for additional sample preparation for testing and further improving analytical efficiency.

[0034] Preferably, in this embodiment, the first temperature is 800℃, the second temperature is 960℃, and the third temperature is 1000℃. Under this temperature gradient, magnesium carbonate and calcium carbonate can sequentially decompose to release carbon dioxide, forming corresponding separation weightlessness steps, thus ensuring the accuracy of the calculation. Of course, in other embodiments, the first, second, and third temperatures can also be adjusted to other suitable values ​​according to actual detection needs to meet the accuracy requirements of different detection scenarios.

[0035] Furthermore, in this embodiment, step S201 specifically includes the following steps: Step S2011: Transfer the sample to a high-temperature furnace and introduce the first gas into the furnace. Heat the furnace to the fourth temperature to remove the free water from the sample and calculate the free water content. Step S2012: The high-temperature furnace is heated to the fifth temperature to remove the water of crystallization from the sample, and the water of crystallization content is calculated.

[0036] Preferably, in this embodiment, the fourth temperature is 110°C and the fifth temperature is 200°C.

[0037] By sequentially removing free water and crystal water from the sample through segmented heating, the contents of the two types of water can be calculated separately, further enriching the compositional information obtained from the analysis. Complete moisture content data of limestone samples can be obtained without additional testing, further enhancing the information richness of a single analysis.

[0038] Furthermore, in this embodiment, step S3 specifically includes the following steps: Step S301: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S302: The high-temperature furnace is heated to the third temperature and burned until the weight is constant. The gas in the high-temperature furnace is passed into the infrared detection cell to detect the change in carbon dioxide concentration in the gas flow and calculate the carbon content.

[0039] The amount of carbon dioxide released during combustion can be directly measured by infrared detection, which can eliminate the calculation error caused by the decomposition of other carbonates in the sample, further improving the accuracy of carbon content detection results. The data obtained from thermogravimetric analysis are corroborated, resulting in higher reliability of the overall detection results.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for analyzing the composition of limestone, characterized in that, Includes the following steps: Step S1: Prepare two samples. Perform step S2 for the first sample and step S3 for the second sample. Step S2: The first sample is ignited, and the magnesium oxide content, calcium oxide content, and loss on ignition are obtained by thermogravimetric analysis. Step S3: The second sample is burned and the carbon content is obtained by infrared detection analysis.

2. The limestone composition analysis method according to claim 1, characterized in that: Step S2 specifically includes the following steps: Step S201: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S202: Introduce a second gas into the high-temperature furnace to change the gas atmosphere inside the furnace from the first gas atmosphere to the second gas atmosphere; the second gas is used to inhibit the decomposition of calcium carbonate to increase the decomposition temperature of calcium carbonate; Step S203: The high-temperature furnace is heated to the first temperature and burned until the weight is constant, and the magnesium oxide content is calculated; Step S204: The high-temperature furnace is heated to the second temperature and burned until the weight is constant, and the calcium oxide content is calculated.

3. The limestone composition analysis method according to claim 2, characterized in that: The first gas is nitrogen.

4. The limestone composition analysis method according to claim 2, characterized in that: The second gas is carbon dioxide.

5. The limestone composition analysis method according to claim 2, characterized in that: Following step S204, the method further includes... Step S205: The high-temperature furnace is heated to the third temperature and burned until the weight is constant, and the loss on ignition is calculated.

6. The limestone composition analysis method according to claim 5, characterized in that: The first temperature is 800℃, the second temperature is 960℃, and the third temperature is 1000℃.

7. The limestone composition analysis method according to claim 2, characterized in that: Step S201 specifically includes the following steps: Step S2011: Transfer the sample to a high-temperature furnace and introduce the first gas into the furnace. Heat the furnace to the fourth temperature to remove the free water from the sample and calculate the free water content. Step S2012: The high-temperature furnace is heated to the fifth temperature to remove the water of crystallization from the sample, and the water of crystallization content is calculated.

8. The limestone composition analysis method according to claim 7, characterized in that: The fourth temperature is 110°C, and the fifth temperature is 200°C.

9. The limestone composition analysis method according to any one of claims 1 to 8, characterized in that: Step S3 specifically includes the following steps: Step S301: Transfer the sample to a high-temperature furnace and introduce the first gas into the high-temperature furnace. Heat the high-temperature furnace to dry the sample and remove the moisture from the sample. Step S302: The high-temperature furnace is heated to the third temperature and burned until the weight is constant. The gas in the high-temperature furnace is passed into the infrared detection cell to detect the change in carbon dioxide concentration in the gas flow and calculate the carbon content.

10. The limestone composition analysis method according to any one of claims 1 to 8, characterized in that: The sample is a limestone sample.

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