Detection pretreatment method of lepidolite ore, detection method of lithium, magnesium, potassium, sodium and calcium, application and digestion container

Abstract

The invention provides a detection pretreatment method of lepidolite ore, a detection method of lithium, magnesium, potassium, sodium and calcium, application and a digestion container, and relates to the technical field of analysis and detection.The detection pretreatment method of the lepidolite ore comprises the following steps that a sample to be detected and an acid digestion agent are mixed, and a mixture is obtained; sequentially carrying out digestion, acid removal and volume metering to obtain a to-be-detected sample solution; wherein the digestion pressure is greater than the standard atmospheric pressure, and the pressure intensity in the digestion container is increased before digestion so as to increase the digestion reaction pressure, so that the digestion and detection efficiency is improved, and a large amount of acid digestion agent is not required to be used; the problems of long detection pretreatment time, high acid consumption and high analysis cost of the lepidolite ore are solved.

Description

Technical Field

[0001] The invention relates to the technical field of analysis and detection, and in particular to a detection pretreatment method for lepidolite ore and a detection method, application and digestion container for lithium, magnesium, potassium, sodium and calcium. Background Art

[0002] As an important lithium resource, lithium mica has significant application value in many industrial fields such as batteries, glass, ceramics, and coatings because it is rich in lithium. Especially in the development of electric vehicles and energy storage technology, lithium mica is regarded as a key raw material for sustainable development due to its low cost and relatively high lithium content. Lithium mica ore is often accompanied by valuable elements such as magnesium, potassium, sodium, and calcium. Therefore, in order to distinguish the grade of lithium mica ore and the comprehensive utilization of resources, it is necessary to quickly and accurately determine the element content in lithium mica ore.

[0003] However, the current technical means for determining the element content in lithium mica ore have obvious limitations. For example, the "Chemical Analysis Methods for Lithium Ores, Rubidium Ores and Cesium Ores Part 1: Determination of Lithium Content" (GB / T17413.1-2010) uses atmospheric pressure open digestion technology to decompose the sample by heating. Although this approach can measure the amount of lithium, its open operation mode poses a direct threat to the health of testers, and the entire pretreatment process takes a long time (more than four hours). It is only suitable for single element detection and cannot meet the needs of multi-element comprehensive analysis; Wang Guichao. Determination of rubidium and cesium in low-grade lithium mica by microwave digestion-inductively coupled plasma mass spectrometry [J]. Physical and Chemical Testing (Chemical Section), 2020, 56(04): 449-453. This scheme uses microwave digestion and requires the use of 15ml of reagent. In the acid-driving stage, 5mL of perchloric acid is added to digest the carbon in the lithium mica. Perchloric acid has strong oxidizing properties and is easy to explode. It is difficult to purchase high-purity reagents. It can be seen that the use of perchloric acid for the acid-driving process increases the operational risk, and it is difficult to obtain high-purity perchloric acid; Zou Yang, Yang Yuan, Luo You, et al. Inductively coupled plasma mass spectrometry Determination of seven elements including lithium, tantalum and niobium in lithium mica by combined plasma atomic emission spectrometry (ICP-AES) [J]. Chinese Journal of Inorganic Analytical Chemistry, 2016, 6(01): 41-44. The scheme adopted a normal pressure open digestion method, using 21 mL of reagent to digest 0.1 g of lithium mica sample. The sample amount was small, the digestion time was long, and perchloric acid was still used, which affected the safety of the operation; Hu Lanji, Huo Chengyu, Ma Long, et al. Determination of niobium and tantalum in geochemical samples and rare and rare earth ores by acid dissolution digestion-mass spectrometry [J]. Chemical Engineer, 2022, 36(11): 23-27. The scheme proposed a high-pressure closed acid dissolution method and a normal pressure acid dissolution method. The former had a pretreatment time of up to 28 hours and the sample weighed only 0.05 g; the latter used 20 mL of reagent and only digested 0.1 g of sample.

[0004] In summary, current technical means face problems such as long processing time, low operating safety, and high acid consumption in determining the element content of lithium mica ore.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] One of the purposes of the present invention is to provide a pre-treatment method for detecting lepidolite ore, so as to at least solve one of the technical problems existing in the prior art. The present invention increases the reaction pressure of digestion, thereby increasing the acid boiling point, thereby increasing the oxidizability of the acidic digester, and improving the digestion and testing efficiency.

[0007] The second object of the present invention is to provide an application of the pre-treatment method for detecting lithium mica ore in a method for detecting lithium, magnesium, potassium, sodium and calcium in lithium mica ore.

[0008] The third object of the present invention is to provide a method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore. The detection method uses a pre-treated sample solution for detection, thereby improving the detection efficiency.

[0009] A fourth object of the present invention is to provide a digestion container, wherein a hole is provided on the container cover of the digestion container for maintaining the pressure balance inside and outside the digestion container under pressurized conditions.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0011] In a first aspect, the present invention provides a method for pre-detection treatment of lepidolite ore, comprising the following steps:

[0012] The sample to be tested is mixed with an acidic digestion agent, and then digestion, acid removal and volume adjustment are performed in sequence to obtain a solution of the sample to be tested;

[0013] Wherein, the digestion pressure is greater than the standard atmospheric pressure.

[0014] Further, the acidic digester includes at least one of nitric acid, sulfuric acid and hydrofluoric acid;

[0015] Preferably, the concentration of the nitric acid is 67-70% w / w, the concentration of the sulfuric acid is 95-98% w / w, and the concentration of the hydrofluoric acid is 40% w / w;

[0016] Preferably, the acidic digester comprises nitric acid, sulfuric acid and hydrofluoric acid in a volume ratio of 1:(1-3):(1-3);

[0017] Preferably, the volume ratio of the mass of the sample to be tested to the acidic digestion agent is 0.2 g: 5-6 mL.

[0018] Furthermore, the digestion pressure is increased to be greater than the standard atmospheric pressure by increasing the pressure in the digestion container;

[0019] Preferably, the method of increasing the pressure in the digestion container includes introducing an inert gas;

[0020] Preferably, the pressure of the inert gas is 1.0-4.0 MPa;

[0021] Preferably, the inert gas comprises at least one of nitrogen, argon and helium;

[0022] Preferably, the digestion comprises microwave digestion;

[0023] Preferably, the microwave digestion procedure includes: first heating to 140-160°C, keeping warm for 0-3 min, then heating to 190-210°C, keeping warm for 0-3 min, then heating to 250-270°C, keeping warm for 20-40 min;

[0024] Preferably, the microwave digestion is performed using a microwave chemical workstation.

[0025] Furthermore, the temperature of the acid removal is 180-200°C and the time is 20-30 minutes.

[0026] Furthermore, before the acid removal, the digestion product is cooled;

[0027] Preferably, the cooling temperature is 50-60°C.

[0028] Furthermore, before the volume is fixed, a nitric acid aqueous solution is added to the acid-dried product;

[0029] Preferably, the concentration of the nitric acid aqueous solution is 50-70% v / v;

[0030] Preferably, the mass ratio of the sample to be tested to the volume ratio of the nitric acid aqueous solution is 0.2 g:5-6 mL.

[0031] In a second aspect, the present invention provides an application of the pre-treatment method for detecting lithium mica ore in a method for detecting lithium, magnesium, potassium, sodium and calcium in lithium mica ore.

[0032] In a third aspect, the present invention provides a method for detecting lithium, magnesium, potassium, sodium and calcium in lithium mica ore, comprising the following steps:

[0033] Standard series solutions of lithium, magnesium, potassium, sodium and calcium and the sample solution to be tested prepared by the pre-treatment method for testing lepidolite ore are tested to obtain the content of the element to be tested in the lepidolite ore.

[0034] Further, the concentration of the standard series solution is 0.00-10.00 mg / L;

[0035] Preferably, preparing the standard series solutions comprises: adding an acid solution to standard metal element solutions of lithium, magnesium, potassium, sodium and calcium;

[0036] Preferably, the acid solution comprises at least one of nitric acid and sulfuric acid;

[0037] Preferably, the acid ratio in the acid solution is the same as the acid ratio in the sample solution to be tested;

[0038] Preferably, inductively coupled plasma emission spectroscopy is used to detect the standard series solutions and the sample solutions to be tested.

[0039] In a fourth aspect, the present invention provides a digestion container, the digestion container comprising a container body and a container cover;

[0040] The container body is provided with a cavity, and the cavity is used to accommodate the sample to be tested and the acidic digestion agent in the pre-treatment method for detecting the lepidolite ore;

[0041] The container cover is arranged at the opening of the container body, and a hole for balancing the air pressure inside and outside the container body is opened on the container cover.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The detection pretreatment method of lepidolite ore provided by the present invention increases the pressure in a digestion container before digestion to increase the reaction pressure during digestion treatment, thereby promoting the digestion reaction and improving the digestion efficiency. In addition, due to the improvement of the oxidation performance of the acidic digester, a large amount of acidic digester is not required, thereby solving the problems of long detection pretreatment time, large acid consumption and high analysis cost of lepidolite ore.

[0044] The method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore provided by the invention adopts a pre-treated sample solution for detection, thereby improving the detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A schematic diagram of the structure of a digestion container provided by an embodiment of the present invention;

[0047] Figure 2 This is the standard curve diagram of calcium in Example 4;

[0048] Figure 3 It is the standard curve diagram of potassium in Example 4;

[0049] Figure 4 is the standard curve diagram of lithium element in Example 4;

[0050] Figure 5 It is the standard curve diagram of magnesium element in Example 4;

[0051] Figure 6 This is the standard curve diagram of the sodium element in Example 4.

[0052] Icon: 100 - container body; 200 - container cover; 210 - hole. DETAILED DESCRIPTION

[0053] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0054] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] A first aspect of the present invention provides a method for pre-detection treatment of lepidolite ore, the method comprising the following steps:

[0056] The sample to be tested is mixed with an acidic digestion agent, and then digestion, acid removal and volume adjustment are performed in sequence to obtain a solution of the sample to be tested;

[0057] Wherein, the digestion pressure is greater than the standard atmospheric pressure.

[0058] In the present invention, the reaction pressure during the digestion treatment is increased to promote the digestion reaction and improve the digestion efficiency. In addition, due to the improvement of the oxidation performance of the acidic digester, a large amount of acidic digester is not required, thereby solving the problems of long pre-treatment time, large acid consumption and high analysis cost of the lepidolite ore detection.

[0059] Among them, the volume adjustment includes: transferring the acidic digestion agent containing the sample to be tested in the digestion container to a volumetric flask, cleaning the container cover and the inner wall of the digestion container with ultrapure water for multiple times, combining the cleaning liquid into the previous volumetric flask, and adjusting the volume to the scale with ultrapure water to obtain a solution of the sample to be tested.

[0060] In some preferred embodiments, the acidic digester includes at least one of nitric acid, sulfuric acid and hydrofluoric acid;

[0061] In the present invention, nitric acid, sulfuric acid and hydrofluoric acid are used as acidic digesters for digestion treatment, wherein nitric acid has strong oxidizing property, can dissolve most metal ions, and has a good decomposition effect on organic matter; sulfuric acid can provide a strong acid environment, which is helpful to further decompose insoluble substances; and hydrofluoric acid can effectively dissolve silicate minerals and other silicon-containing compounds.

[0062] Preferably, the concentration of the nitric acid is 67-70% w / w, for example, 67% w / w, 68% w / w, 69% w / w, 70% w / w, etc., the concentration of the sulfuric acid is 95-98% w / w, for example, 95% w / w, 96% w / w, 97% w / w, 98% w / w, etc., and the concentration of the hydrofluoric acid is 40% w / w;

[0063] Preferably, the volume ratio of the nitric acid, the sulfuric acid and the hydrofluoric acid is 1:(1-3):(1-3); wherein "1-3" can be, for example, 1, 2, 3, etc.;

[0064] Preferably, the volume ratio of the mass of the sample to be tested to the acidic digestion agent is 0.2 g:5-6 mL, for example, 0.2 g:5 mL, 0.2 g:6 mL, etc.

[0065] In the present invention, the volume ratio of the mass of the sample to be tested to the acidic digestion agent is 0.2g:5-6mL. For example, only 6mL of a combination of nitric acid, sulfuric acid and hydrofluoric acid can be used to completely digest 0.2g of a lithium mica ore sample. The digestion and testing can be completed within 100 minutes, which significantly improves the test efficiency and solves the problem of poor result precision caused by a small sample weight.

[0066] In some preferred embodiments, the method of increasing the pressure in the digestion container includes introducing an inert gas;

[0067] Preferably, the pressure of the inert gas is 1.0-4.0 MPa, for example, 1.0 MPa, 2.0 MPa, 3.0 MPa, 4.0 MPa, etc.;

[0068] Preferably, the inert gas comprises at least one of nitrogen, argon and helium;

[0069] Preferably, the digestion comprises microwave digestion;

[0070] Preferably, the microwave digestion procedure includes: first heating to 140-160°C, for example, 140°C, 145°C, 150°C, 155°C, 160°C, etc., keeping warm for 0-3min, for example, 0min, 1min, 2min, 3min, etc., then heating to 190-210°C, for example, 190°C, 195°C, 200°C, 205°C, 210°C, etc., keeping warm for 0-3min, for example, 0min, 1min, 2min, 3min, etc., then heating to 250-270°C, for example, 250°C, 255°C, 260°C, 265°C, 270°C, etc., keeping warm for 20-40min, for example, 20min, 25min, 30min, 35min, 40min, etc.;

[0071] Preferably, the microwave digestion is performed using a microwave chemical workstation.

[0072] In the present invention, microwave digestion is adopted, preferably EXPEC 790S super microwave chemical workstation, microwave transmission power 150-1200W, PID temperature control, equipped with high-pressure nitrogen, pre-pressurization function, and microwave closed digestion is adopted to reduce the health risk of the test personnel; the present invention also adopts a gradient heating method, which can gradually heat up the mixed solution such as the sample, which helps the sample to start decomposing at a lower temperature, and then gradually transition to a higher temperature to ensure that the sample is fully decomposed. It can avoid the problem of local overheating or incomplete decomposition of the sample due to too fast heating, and at the same time can reduce the pressure fluctuation in the container, reduce the risk of pressure mutation caused by rapid heating, and improve the safety of the experiment.

[0073] The specific process of the sample to be tested entering the microwave chemical workstation is as follows: weigh the sample to be tested (lepidolite ore) into the digestion container, add the acidic digestion agent, cover the container lid, and shake to mix; transfer the digestion tube to the liner barrel, which is pre-filled with the load solution, and then transfer the liner barrel to the pre-treatment equipment (i.e., the microwave chemical workstation). Then, 1.0-4.0MPa nitrogen is filled into the cavity of the pre-treatment equipment, and the above-mentioned gradient heating method is used for digestion treatment.

[0074] In some preferred embodiments, the temperature of the acid-driving is 180-200°C, for example, 180°C, 185°C, 190°C, 195°C, 200°C, etc., and the time of the acid-driving is 20-30min, for example, 20min, 21min, 22min, 23min, 24min, 25min, 26min, 27min, 28min, 29min, 30min, etc.

[0075] In some preferred embodiments, the digestion product is cooled before the acid removal;

[0076] Preferably, the cooling temperature is 50-60°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, etc.

[0077] In some preferred embodiments, before the volume is fixed, an aqueous nitric acid solution is added to the acid-dried product;

[0078] In the present invention, hydrofluoric acid is removed by acid removal, and nitric acid is added after the acid removal to redissolve the fluoride.

[0079] Preferably, the concentration of the nitric acid aqueous solution is 50-70% v / v, for example, it can be 50% v / v, 51% v / v, 52% v / v, 53% v / v, 54% v / v, 55% v / v, 56% v / v, 57% v / v, 58% v / v, 59% v / v, 60% v / v, 61% v / v, 62% v / v, 63% v / v, 64% v / v, 65% v / v, 66% v / v, 67% v / v, 68% v / v, 69% v / v, 70% v / v, etc.;

[0080] Preferably, the volume ratio of the mass of the sample to be tested to the aqueous nitric acid solution is 0.2 g:5-6 mL, for example, it can be 0.2 g:5 mL, 0.2 g:6 mL, etc.

[0081] The second aspect of the present invention provides an application of the pre-treatment method for detecting lithium mica ore in a method for detecting lithium, magnesium, potassium, sodium and calcium in the lithium mica ore.

[0082] The third aspect of the present invention provides a method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore, comprising the following steps:

[0083] Standard series solutions of lithium, magnesium, potassium, sodium and calcium and the sample solution to be tested prepared by the pre-treatment method for testing lepidolite ore are tested to obtain the content of the element to be tested in the lepidolite ore.

[0084] In the present invention, the pre-treated sample solution is used for detection, super microwave digestion is adopted, and a certain pressure of inert gas is injected into the digestion container in advance. The high pressure can increase the acid boiling point, thereby increasing the oxidizability of the digestion reagent and improving the detection efficiency.

[0085] In some preferred embodiments, the concentration of the standard series solution is 0.00-10.00 mg / L;

[0086] Preferably, preparing the standard series solutions comprises: adding an acid solution to standard metal element solutions of lithium, magnesium, potassium, sodium and calcium;

[0087] In the present invention, the preparation of the standard series solution mainly includes: taking a certain amount of lithium, magnesium, potassium, sodium, calcium standard metal element solution, and diluting it with dilute acid to form the standard series solution.

[0088] Preferably, the acid solution comprises at least one of nitric acid and sulfuric acid;

[0089] Preferably, the acid ratio in the acid solution is the same as the acid ratio in the sample solution to be tested;

[0090] Preferably, inductively coupled plasma emission spectroscopy is used to detect the standard series solutions and the sample solutions to be tested.

[0091] In the present invention, the sample solution and the standard series solution are detected by inductively coupled plasma emission spectrometer (ICP-OES), and the content of each element to be measured in the test solution of lithium mica ore is calculated by external standard method; the present invention adopts inductively coupled plasma emission spectrometry (ICP-OES), by optimizing microwave digestion conditions and various instrument parameters of ICP-OES, to achieve simultaneous determination of 5 elements such as lithium, magnesium, potassium, sodium, and calcium, with a precision of 0.3-2.8%, and a spike recovery rate range of 95.3-102%, which meets the needs of daily detection of lithium mica ore. Among them, the detection equipment used is an inductively coupled plasma emission spectrometer, preferably EXPEC 6100D, and the observation direction is axial observation.

[0092] A fourth aspect of the present invention provides a digestion container, the digestion container comprising a container body 100 and a container cover 200;

[0093] The container body 100 is provided with a cavity, and the cavity is used to contain the sample to be tested and the acidic digestion agent in the pre-treatment method for detecting the lepidolite ore;

[0094] The container cover 200 is disposed on the opening of the container body, and a hole 210 is provided on the container cover for balancing the air pressure inside and outside the container body.

[0095] Specifically, if Figure 1 As shown, the container body 100 is a tubular structure, and the container body 100 is preferably a digestion tube. A microhole with a diameter of 1-5 mm is opened on the top side of the container cover. The microwave workstation pre-pressurizes 1-4 MPa nitrogen gas for the digestion tube through the microhole. The pre-pressurization can increase the boiling point of the acidic digestion agent. During microwave operation, the pressure generated by sample digestion can be discharged through the microhole to keep the internal and external pressures consistent.

[0096] Preferably, the digestion tube is made of modified polytetrafluoroethylene.

[0097] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0098] In the embodiments and comparative examples of the present invention, the instruments and reagents used are as follows:

[0099] 1. Instrument model and configuration:

[0100] The pre-treatment equipment model used in the pre-treatment method of lithium mica ore is EXPEC 790S super microwave digester, which is equipped with: 35mL TFM digestion tube;

[0101] The detection and analysis equipment model in the detection method of lithium, magnesium, potassium, sodium and calcium in lepidolite ore is EXPEC 6100D ICP-OES, which is equipped with: quartz injection system.

[0102] Among them, the detection parameters of the inductively coupled plasma atomic emission spectrometer are shown in Table 1 below.

[0103] Table 1

[0104]

[0105]

[0106] 2. Reagents and samples

[0107] Reagents: nitric acid, hydrofluoric acid, sulfuric acid, all of high-grade purity;

[0108] Pure water: 18.2MΩ·cm deionized water;

[0109] Sample 1 to be tested: GBW07152 lithium ore composition analysis standard substance, Sample 2 to be tested: GBW07153 lithium ore composition analysis standard substance;

[0110] Standard solution: lithium, magnesium, potassium, sodium, and calcium element standard solutions, 1000 μg / mL, National Research Institute of Nonferrous Metals.

[0111] Example 1

[0112] This example provides a pre-detection treatment method for lithium mica ore, comprising the following steps:

[0113] Accurately weigh 0.2 g (accurate to 0.001 g) of the sample 1 to be tested into a digestion tube, add 1 mL of nitric acid, 2 mL of sulfuric acid, and 3 mL of hydrofluoric acid in sequence, shake well, transfer to the super microwave platform, and digest according to the program in Table 2 (super microwave digestion heating program). Among them, the concentration of nitric acid is 68% w / w, the concentration of sulfuric acid is 96% w / w, and the concentration of hydrofluoric acid is 40% w / w;

[0114] After cooling to 60°C, transfer to an acid remover at 200°C for 25 minutes. After cooling slightly, add 5 mL of nitric acid aqueous solution (1+1) and make up to volume, wherein the concentration of nitric acid aqueous solution is 50% v / v. After cooling, make up to 100 mL with deionized water. At this time, sample 1 is completely digested, and the digestion solution is colorless and transparent.

[0115] Meanwhile, a blank solution is prepared, wherein the preparation of the blank solution comprises: replacing the sample with deionized water, and sequentially preparing according to the above steps to obtain a blank solution.

[0116] Table 2

[0117]

[0118]

[0119] Example 2

[0120] This example provides a pre-treatment method for detecting lepidolite ore, which is different from Example 1 in that the sample to be detected in Example 2 adopts the sample to be detected 2, and the remaining steps are consistent with Example 1.

[0121] Example 3

[0122] This example provides a pre-treatment method for detecting lepidolite ore, comprising the following steps:

[0123] Accurately weigh 0.2 g (accurate to 0.001 g) of the sample 1 to be tested into a digestion tube, add 1.2 mL of nitric acid, 2.4 mL of sulfuric acid, and 2.4 mL of hydrofluoric acid in sequence, shake well, transfer to the super microwave platform, and digest according to the program in Table 3 (super microwave digestion heating program), wherein the concentration of nitric acid is 67% w / w, the concentration of sulfuric acid is 98% w / w, and the concentration of hydrofluoric acid is 40% w / w;

[0124] After cooling to 60℃, transfer to an acid remover at 180℃ for 30min. After cooling slightly, add 6mL of nitric acid aqueous solution and make up to volume, wherein the concentration of nitric acid aqueous solution is 55% v / v. After cooling, make up to 100mL with deionized water. At this time, sample 1 is completely digested, and the digestion solution is colorless and transparent.

[0125] Meanwhile, a blank solution is prepared, wherein the preparation of the blank solution comprises: replacing the sample with deionized water, and sequentially preparing according to the above steps to obtain a blank solution.

[0126] Table 3

[0127]

[0128] Example 4

[0129] This example provides a pre-detection treatment method for lithium mica ore, comprising the following steps:

[0130] Accurately weigh 0.2 g (accurate to 0.001 g) of the sample 1 to be tested into a digestion tube, add 1 mL of nitric acid, 1 mL of sulfuric acid, and 3 mL of hydrofluoric acid in sequence, shake well, transfer to the super microwave platform, and digest according to the program in Table 4 (super microwave digestion heating program), wherein the concentration of nitric acid is 67% w / w, the concentration of sulfuric acid is 98% w / w, and the concentration of hydrofluoric acid is 40% w / w;

[0131] After cooling to 50℃, transfer to an acid remover at 190℃ for 20min. After cooling slightly, add 5mL of nitric acid aqueous solution and make up to volume, wherein the concentration of nitric acid aqueous solution is 70% v / v. After cooling, make up to 100mL with deionized water. At this time, sample 1 is completely digested, and the digestion solution is colorless and transparent.

[0132] Meanwhile, a blank solution is prepared, wherein the preparation of the blank solution comprises: replacing the sample with deionized water, and sequentially preparing according to the above steps to obtain a blank solution.

[0133] in, Figure 2-6 This is a standard curve diagram of each element in Example 4.

[0134] Table 4

[0135]

[0136] Embodiment 5-8

[0137] Embodiment 5-8 provides a method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore, comprising the following steps:

[0138] (1) Prepare Li, Mg, K, Na, Ca standard intermediate solutions: Pipette 5 mL of each Li, Mg, K, Na, Ca element standard solution into the same 50 mL volumetric flask, dilute to scale with water, and shake well. The mass concentration of Li, Mg, K, Na, Ca in this solution is 100 mg / L.

[0139] (2) Preparation of calibration solution series: In a series of 50 mL volumetric flasks, take 0.00 mL, 0.25 mL, 0.50 mL, 1.00 mL, 2.50 mL, and 5.00 mL of Li, Mg, K, Na, and Ca standard intermediate solutions, add dilute acid, the acid ratio in the dilute acid is the same as the acid ratio of the sample solution to be tested in Examples 1-3 (wherein, the dilute acid in Examples 5 and 6 is the same, both including 1 mL sulfuric acid and 2.5 mL nitric acid, the dilute acid in Example 7 includes 1.2 mL sulfuric acid and 3.3 mL nitric acid, and the dilute acid in Example 8 includes 0.5 mL sulfuric acid and 3.5 mL nitric acid), dilute with water to the scale, and shake well. The mass concentrations of this series of solutions are shown in Table 5 (Standard Solution Concentration Gradient).

[0140] Table 5

[0141] Solution No. element Standard solution concentration (mg / L) 1 Li, Mg, K, Na, Ca 0.00 / 0.50 / 1.00 / 2.00 / 5.00 / 10.0

[0142] (3) Calibration curve drawing:

[0143] Using an inductively coupled plasma atomic emission spectrometer, according to the detection parameters in Table 1, the emission intensity of each element spectral line in the calibration solution series and the sample solutions to be tested in Examples 5-8 and the blank solution was measured respectively.

[0144] (4) Calculation of results:

[0145] The mass fraction of each element compound is ω(X n O), the value is expressed in %, calculated according to formula (1):

[0146] Formula (1):

[0147] Where:

[0148] ρ——The mass concentration of the element in the sample solution, in micrograms per milliliter (μg / mL);

[0149] ρ0——The mass concentration of the element in the blank test solution, in micrograms per milliliter (μg / mL);

[0150] V——volume of the sample solution, in milliliters (mL);

[0151] m——mass of the sample, in grams (g);

[0152] A Xn0 ——Relative atomic mass of the oxide, in grams per mole (g / mol);

[0153] A X ——Relative atomic mass of an element, expressed in grams per mole (g / mol).

[0154] Example 9

[0155] This embodiment provides a method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore, which is different from Embodiment 5 in that the pre-pressurization is 0.5 MPa, and the remaining steps are consistent with Embodiment 5.

[0156] Example 10

[0157] This embodiment provides a method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore, which is different from Embodiment 5 in that the pre-pressurization is 4.5 MPa, and the remaining steps are consistent with Embodiment 5.

[0158] Comparative Example 1

[0159] This comparative example provides a pretreatment method for detecting lepidolite ore, which is different from Example 1 in that: before digestion, nitrogen is not filled into the cavity of the pretreatment equipment, that is, no pre-pressurization is performed, and the remaining steps are consistent with Example 1.

[0160] Comparative Example 2

[0161] This comparative example provides a method for detecting the trace element content of polyetheretherketone plastics. The difference from Example 5 is that the test sample solution, blank solution and measurement calibration solution series in Comparative Example 1 are respectively used for detection, and the remaining steps are consistent with Example 5.

[0162] Test results:

[0163] It should be noted that Example 5 uses the test sample solution prepared in Example 1, Example 6 uses the test sample solution prepared in Example 2, Example 7 uses the test sample solution prepared in Example 3, and Example 8 uses the test sample solution prepared in Example 4. Comparative Example 2 uses the test sample solution prepared in Comparative Example 1.

[0164] (1) Accuracy test results

[0165] Table 6 shows the element contents in samples measured in Examples 5 and 6, in units of %. Table 7 shows the element contents in samples measured in Example 7, in units of %. Table 8 shows the element contents in samples measured in Example 8, in units of %. Table 9 shows the element contents in samples measured in Example 9, in units of %. Table 10 shows the element contents in samples measured in Example 10. Table 11 shows the element contents in samples measured in Comparative Example 2, in units of %.

[0166] Table 6

[0167]

[0168] Table 7

[0169]

[0170] Table 8

[0171]

[0172] Table 9

[0173]

[0174] Table 10

[0175]

[0176] Table 11

[0177]

[0178] It can be seen from the data in the table that the determination results of the two standard substances in the embodiments of the present invention are within the uncertainty range, proving that the results of this method are accurate.

[0179] (2) Precision test results

[0180] The method of Example 5 was adopted and 7 parallel experiments were performed at the same time. The results are shown in Table 12 (element content in the sample, unit: %).

[0181] Table 12

[0182]

[0183]

[0184] From the data in Table 12, it can be seen that the relative standard deviation between the results is between 0.3% and 2.8%, indicating that the test precision of this method is good.

[0185] (3) Spike recovery test results

[0186] Weigh 12 portions of GBW07152 samples and divide them into two groups, one group as background and one group with standard solution added. Tests were performed under the same conditions according to the method of Example 5. The results are shown in Table 13 (sample spike recovery test).

[0187] Table 13

[0188] element Background value% Added amount% Measurement value% Recovery rate % <![CDATA[Li2O]]> 0.462 0.5 0.948 97.2 MgO 0.054 0.05 0.101 93.9 <![CDATA[K2O]]> 3.18 5 8.280 102 <![CDATA[Na2O]]> 4.15 5 8.950 96.0 CaO 0.335 0.5 0.840 101

[0189] It can be seen from the data in the table that the spiked recovery rate of Example 5 of the present invention is between 93.9% and 102%, which shows that the analysis method of the embodiment of the present invention is accurate and reliable.

[0190] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for pre-treatment of lepidolite ore, characterized in that: The following steps are involved: The sample to be tested is mixed with an acidic digestion agent, and then digestion, acid removal and volume adjustment are performed in sequence to obtain a solution of the sample to be tested; Wherein, the digestion pressure is greater than the standard atmospheric pressure.

2. The method for pre-detection treatment of lepidolite ore according to claim 1, characterized in that: The acidic digester includes at least one of nitric acid, sulfuric acid and hydrofluoric acid; Preferably, the concentration of the nitric acid is 67-70% w / w, the concentration of the sulfuric acid is 95-98% w / w, and the concentration of the hydrofluoric acid is 40% w / w; Preferably, the acidic digester comprises nitric acid, sulfuric acid and hydrofluoric acid in a volume ratio of 1:(1-3):(1-3); Preferably, the volume ratio of the mass of the sample to be tested to the acidic digestion agent is 0.2 g: 5-6 mL.

3. The method for pre-detection treatment of lepidolite ore according to claim 1, characterized in that: By increasing the pressure in the digestion container, the digestion pressure is made greater than the standard atmospheric pressure; Preferably, the method of increasing the pressure in the digestion container includes introducing an inert gas; Preferably, the pressure of the inert gas is 1.0-4.0 MPa; Preferably, the inert gas comprises at least one of nitrogen, argon and helium; Preferably, the digestion comprises microwave digestion; Preferably, the microwave digestion procedure includes: first heating to 140-160°C, keeping warm for 0-3 min, then heating to 190-210°C, keeping warm for 0-3 min, then heating to 250-270°C, keeping warm for 20-40 min; Preferably, the microwave digestion is performed using a microwave chemical workstation.

4. The method for pre-detection treatment of lepidolite ore according to claim 1, characterized in that: The temperature of the acid removal is 180-200°C and the time is 20-30 minutes.

5. The method for pre-detection treatment of lepidolite ore according to claim 1, characterized in that: Before the acid removal, the digestion product is cooled; Preferably, the cooling temperature is 50-60°C.

6. The method for pre-detection treatment of lepidolite ore according to claim 1, characterized in that: Before the volume is fixed, a nitric acid aqueous solution is added to the acid-dried product; Preferably, the concentration of the aqueous nitric acid solution is 50-70% v / v; Preferably, the mass ratio of the sample to be tested to the volume ratio of the nitric acid aqueous solution is 0.2 g:5-6 mL.

7. Application of the pre-treatment method for detecting lithium mica ore according to any one of claims 1 to 6 in a method for detecting lithium, magnesium, potassium, sodium and calcium in lithium mica ore.

8. A method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore, characterized in that: The following steps are involved: Standard series solutions of lithium, magnesium, potassium, sodium and calcium and the sample solution to be tested prepared by the pre-treatment method for detecting lithium mica ore according to any one of claims 1 to 6 are tested to obtain the content of the element to be tested in the lithium mica ore.

9. The method for detecting lithium, magnesium, potassium, sodium and calcium in lepidolite ore according to claim 8, characterized in that: The concentration of the standard series solution is 0.00-10.00 mg / L; Preferably, preparing the standard series solutions comprises: adding an acid solution to standard metal element solutions of lithium, magnesium, potassium, sodium and calcium; Preferably, the acid solution comprises at least one of nitric acid and sulfuric acid; Preferably, the acid ratio in the acid solution is the same as the acid ratio in the sample solution to be tested; Preferably, inductively coupled plasma emission spectroscopy is used to detect the standard series solutions and the sample solutions to be tested.

10. A digestion container, characterized in that: The digestion container comprises a container body and a container cover; The container body is provided with a cavity, and the cavity is used to accommodate the sample to be tested and the acidic digestion agent in the pre-detection treatment method of the lepidolite ore according to any one of claims 1 to 6; The container cover is arranged at the opening of the container body, and a hole for balancing the air pressure inside and outside the container body is opened on the container cover.

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