A device and method for separating and enriching trace rhenium in geological samples.

Abstract

This application belongs to the field of rare element detection technology, and more specifically, relates to a separation and enrichment device and method for trace rhenium in geological samples. The separation and enrichment device includes a containment component and a multi-layered first adsorption component, wherein: the containment component is used to lay the geological sample to be tested; the first adsorption component is disposed above the containment component, and the multi-layered first adsorption component is stacked vertically; each layer of the first adsorption component includes a first support portion with holes for placing a heat-resistant and breathable membrane, which is used to lay rhenium vapor adsorbent. This invention pioneers an integrated "sintering-adsorption" separation mechanism. By layering the containment component and the first adsorption component, rhenium escapes as Re2O7 vapor at high temperature and is efficiently captured by the upper adsorbent, achieving physical isolation between the sample matrix and the target element, reducing matrix interference at the source, and significantly improving the accuracy and reliability of trace rhenium determination.

Description

Technical Field

[0001] This application belongs to the field of rare element detection technology, and more specifically, relates to a device and method for separating and enriching trace rhenium in geological samples. Background Technology

[0002] Rhenium (Re) is a typical rare and dispersed metal with extremely low abundance in the Earth's crust (approximately 1.0 × 10⁻⁶). -9 Rhenium rarely forms as an independent mineral, mainly occurring as an associated mineral in sulfide and silicate minerals, especially highly enriched within the molybdenite lattice. Under specific conditions, the rhenium content in molybdenite can reach 0.X%, but is typically below 0.002%, with even lower contents in other geological samples. Rhenium is an indispensable strategic metal in modern high-tech and defense industries; reliable analysis and efficient extraction of its resources are of great significance for resource exploration and development.

[0003] Currently, the analysis of rhenium in geological samples mainly employs the magnesium oxide semi-melt method. This method involves mixing the sample with magnesium oxide in a specific ratio (usually 1:2 or 1:4), then covering the surface with another layer of magnesium oxide (approximately 1.0 g), sintering at 650–700 °C for 90–120 min, followed by water extraction to obtain the analyte solution. Depending on the rhenium content level in the sample, the extract can be directly measured, or further separated and enriched using methods such as distillation, ion exchange, extraction, co-precipitation, and adsorption, followed by quantitative analysis using inductively coupled plasma mass spectrometry (ICP-MS). However, this method has the following prominent problems: (1) Significant matrix interference: After the sample is mixed and sintered with magnesium oxide, the sample matrix comes into direct contact with the reagent, causing matrix elements such as molybdenum, potassium, sodium, and calcium to enter the test solution during boiling water extraction, resulting in a matrix effect and affecting the accuracy of the determination; (2) Large background influence of reagents: The amount of magnesium oxide used is relatively large (3.0~5.0 g), and the impurities or blank signals contained in it will form a high background interference; (3) Insufficient sensitivity and complex pretreatment: For low-content samples, the method has limited sensitivity and must rely on subsequent further separation and enrichment steps. However, existing enrichment methods generally have complex operation procedures, cumbersome steps, high reagent consumption, and low efficiency, and it is difficult to completely remove the interference of coexisting elements such as molybdenum, resulting in the accuracy and sensitivity of the analytical results being difficult to meet the requirements of modern geological testing for efficient and accurate analysis. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a separation and enrichment device and method that integrates sintering and separation enrichment. Through structural innovation, the sample and adsorbent are arranged in layers. During sintering, rhenium volatilizes as Re₂O₇ vapor and is efficiently adsorbed by the adsorbent, thereby reducing matrix interference and reagent background effects at the source. This technical solution has advantages such as simple process, high adsorption efficiency, good selectivity, environmental friendliness, and reusable materials, significantly improving the analytical sensitivity and accuracy of trace rhenium. It is suitable for the rapid and reliable determination of trace rhenium in various geological samples.

[0005] To achieve the above objectives, in a first aspect, this application provides a device for the separation and enrichment of trace rhenium in geological samples, comprising a containment component and a multilayer first adsorption component, wherein: The receiving component is used to lay the geological sample to be tested; The multi-layer first adsorption component is disposed above the containing component, and the multi-layer first adsorption component is stacked in layers; each layer of the first adsorption component includes a first support portion with holes, the first support portion is used to place a heat-resistant and breathable membrane, and the heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent; when the geological sample to be tested is heated inside the containing component, the rhenium in it volatilizes in the form of Re2O7 vapor, and after passing through the heat-resistant and breathable membrane of each layer of the first adsorption component, it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested.

[0006] Preferably, the receiving component is an open-topped, flat-bottomed container with an annular flange on its upper part; The first support portion is provided with an annular upper flange and an annular lower flange in the circumferential direction; The annular flange of the receiving component is assembled and connected to the annular lower flange of the first adsorption component located at the bottom layer, and the annular upper flange of the first adsorption component located below is assembled and connected to the annular lower flange of the first adsorption component in the adjacent upper layer, so as to achieve side sealing of the separation and enrichment device.

[0007] More preferably, a second adsorption component is also provided at the opening of the receiving component. The second adsorption component includes a second support portion, which is an annular protrusion and is also used to place a heat-resistant and breathable membrane. The heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent.

[0008] More preferably, the annular lower flange of the first adsorption component in the upper layer is pressed onto the rhenium vapor adsorbent laid on the first support portion of the first adsorption component in the lower layer, or pressed onto the rhenium vapor adsorbent laid on the second support portion, so as to achieve radial sealing between layers.

[0009] Preferably, the pores between adjacent layers of the first adsorption component are arranged in an alternating pattern.

[0010] Preferably, the interior of the containment component is used to lay the geological sample to be tested, and the vertical distance between the heat-resistant and breathable membrane in the adsorption component layer adjacent to the containment component and the surface of the geological sample to be tested is 3-8 mm, more preferably 3-5 mm.

[0011] According to another aspect of the present invention, a method for determining trace rhenium in geological samples is provided, which uses the separation and enrichment device to separate, enrich, and determine rhenium in the geological sample to be tested, specifically including the following steps: (1) The geological sample to be tested is laid inside the containment component; multiple layers of the first adsorption component are assembled in sequence, and the heat-resistant and breathable membrane is placed on the first support of each layer of the first adsorption component, and then the rhenium vapor adsorbent is laid on each first support; (2) The separation and enrichment device is placed in a heating furnace and the sample to be tested is heated and sintered. The rhenium in it volatilizes in the form of Re2O7 vapor. After passing through the heat-resistant and breathable membrane of each layer of the first adsorption component, it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested. (3) The rhenium-containing substances enriched in the adsorption component are extracted by water leaching, and after solid-liquid separation and volume adjustment, the rhenium content is determined.

[0012] Preferably, the separation and enrichment device further includes a second adsorption component. The separation and enrichment device is used to separate, enrich, and determine rhenium in the geological sample to be tested, specifically including the following steps: (1) The geological sample to be tested is laid inside the containment component; the second adsorption component and the multi-layer first adsorption component are assembled in sequence, and the heat-resistant and breathable membrane is placed on the second support part of the second adsorption component and the first support part of each layer of the first adsorption component, and then the rhenium vapor adsorbent is laid on the second support part and each first support part; (2) The separation and enrichment device is placed in a heating furnace and the sample to be tested is heated and sintered. The rhenium in it volatilizes in the form of Re2O7 vapor. After passing through the heat-resistant and breathable membrane of each layer of the first adsorption component, it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested. (3) The rhenium-containing substances enriched in the adsorption component are extracted by water leaching, and after solid-liquid separation and volume adjustment, the rhenium content is determined.

[0013] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art: (1) This invention pioneered the "sintering-adsorption" integrated separation mechanism and proposed a separation and enrichment device with an upper and lower split structure, which includes a container component for laying the geological sample to be tested and a multi-layer first adsorption component stacked on the upper part. At high temperature, rhenium escapes in the form of Re2O7 vapor and is efficiently captured by the upper adsorbent, realizing the physical isolation between the sample matrix and the target element, significantly reducing matrix interference from the source, and greatly improving the accuracy and reliability of trace rhenium determination.

[0014] (2) The present invention optimizes the sample heating mode in terms of device structure. By increasing the bottom heating area (approximately 5 to 10 times that of a conventional crucible), it effectively ensures that rhenium is fully heated and completely oxidized and volatilized. At the same time, combined with the flexible selection of multi-level gradient adsorption layer design, it supports flexible selection of sample weighing amount in the range of 0.1 to 10 g, and achieves in-situ enrichment by small volume constant volume, which significantly improves the detection sensitivity of the method for trace rhenium.

[0015] (3) By designing a multilayer adsorption structure and optimizing its layout, this invention makes full use of the multiple adsorption equilibrium effect of Re2O7 between the solid and gas phases, thereby further improving the adsorption completeness of rhenium and the stability of the method.

[0016] (4) Compared with the traditional method of mixing and sintering the sample and the adsorbent, in some embodiments of the present invention, the amount of adsorbent is reduced from 3.0~5.0 g to 75 mg, which significantly reduces the background interference caused by the adsorbent to the test, and at the same time effectively reduces the reagent cost and the amount of solid waste generated.

[0017] (5) The quartz membrane and adsorbent used in the separation and enrichment device of the present invention can be reused and maintain stable performance in continuous analysis, which has the advantages of economy, environmental protection and practicality.

[0018] (6) The apparatus and method of the present invention integrate the distillation, adsorption and enrichment steps into a single sintering process, eliminating the need for traditional subsequent separation and enrichment operations, simplifying the process and shortening the working time, and making it more suitable for efficient and accurate analysis of trace rhenium in large batches of geological samples. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the rhenium separation and enrichment device in geological samples provided in the embodiments of this application; Figure 2 This is a schematic diagram of the component structure in the rhenium separation and enrichment device for geological samples provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the first single-layer adsorption component in the rhenium separation and enrichment device for geological samples provided in the embodiments of this application; Figure 4This is a schematic diagram of the structure of the rhenium separation and enrichment device in the geological sample provided in this application embodiment after the accommodating component and the first adsorption component of the first layer are assembled and connected; Figure 5 This is a cross-sectional view of the rhenium separation and enrichment device in geological samples provided in the embodiments of this application; Figure 6 This is a top view of the rhenium separation and enrichment device in geological samples provided in the embodiments of this application; Figure 7 This is a photograph of the crucible used in Comparative Example 4 of this application; Figure 8 A photograph of the crucible used in Comparative Example 5 of this application; Figure 9 This is a schematic diagram of the overall structure of the separation and enrichment device of this application when the first adsorption component has 5 layers; Figure 10 This is a cross-sectional view of the separation and enrichment device of this application when the first adsorption component has 5 layers; Figure 11 This is a comparison chart of rhenium recovery rates at different roasting temperatures in the embodiments of this application; Figure 12 This is a comparison chart of rhenium recovery rates under different roasting times in the embodiments of this application; Figure 13 This is a comparison chart of rhenium recovery rates under different adsorbent addition amounts in the embodiments of this application.

[0020] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Accommodating component; 11-Accommodating component opening; 12-Annular flange; 13-Accommodating component bottom surface; 14-Second support part; 2-First adsorption component; 21-First support part; 22-Annular upper flange; 23-Annular lower flange; 24-Hole. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] Based on an in-depth analysis of the fundamental principles of rhenium determination in geological samples, this invention provides a geological sample pretreatment device (separation and enrichment device) and testing method that integrates sintering and separation enrichment. This method, through a separate structural design of the sample layer and the adsorption layer, ensures efficient adsorption of rhenium while significantly reducing the interference of the sample matrix and the background of the adsorbent itself on the determination. This constructs a new technical system suitable for the separation, enrichment and determination of trace rhenium in geological samples, aiming to solve the problem of insufficient testing accuracy caused by the inability of existing crucibles to achieve matrix separation and multilayer adsorption during sample pretreatment, thereby achieving efficient separation, enrichment and accurate determination of trace rhenium.

[0023] Specifically, the present invention provides a device for separating and enriching trace rhenium in geological samples, comprising a containment component and at least two layers of first adsorption components, wherein: the containment component is used to lay the geological sample to be tested; the first adsorption components are disposed above the containment component, and the at least two layers of first adsorption components are stacked vertically; each layer of the first adsorption component includes a first support portion, the first support portion having holes, the first support portion being used to place a heat-resistant and breathable membrane, the heat-resistant and breathable membrane being used to lay rhenium vapor adsorbent; when the geological sample to be tested, laid at the bottom of the containment component, is heated, the rhenium therein volatilizes in the form of Re2O7 vapor, and after passing through the heat-resistant and breathable membrane of each layer of the first adsorption component, reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby achieving the separation and enrichment of rhenium in the geological sample to be tested.

[0024] In some embodiments, the containing component is an open, flat-bottomed container with an annular flange on its upper part; the first support portion of the first adsorption component is provided with an annular upper flange and an annular lower flange in the circumferential direction; the annular flange of the containing component is axially assembled with the annular lower flange of the first adsorption component located at the bottom layer, and the annular upper flange of the first adsorption component located below is axially assembled with the annular lower flange of the first adsorption component in the adjacent upper layer, so as to achieve side sealing of the separation and enrichment device.

[0025] The shape and size of the containing component and the first adsorption component in the separation and enrichment device of this invention are not limited and can be customized or purchased according to actual usage requirements. To meet the requirement of maintaining a thin and flat installation even with large sample volumes and to avoid excessive adsorbent usage in the first adsorption component, a preferred embodiment of this invention adopts a device configuration with the same width at the top and bottom, or a configuration that is narrower at the top and wider at the bottom. The narrower-at-the-top-wider-at-the-bottom configuration also increases the bottom heating area, and the narrower cross-section of the first adsorption component promotes the rise and enrichment of rhenium vapor.

[0026] The cross-sections of the containing component and the first adsorption component described in this invention can be of various shapes, including but not limited to circular, rectangular, trapezoidal, etc.

[0027] In a preferred embodiment, the containing component and the first adsorption component of the present invention are separately configured, and the multi-layered first adsorption components can be flexibly disassembled and combined, facilitating sample loading and allowing selection of the number of layers of the first adsorption components as needed. The containing component is an open-topped, flat-bottomed container, into which the geological sample to be tested is loaded and laid flat at the bottom during sample loading.

[0028] In some embodiments, the separation and enrichment device is made of ceramic, corundum, or quartz.

[0029] Preferably, the pores between adjacent layers of the first adsorption component are arranged in an alternating pattern to promote the full absorption of rhenium vapor.

[0030] In a preferred embodiment, a second adsorption component is further provided at the opening of the receiving component. The second adsorption component includes a second support portion, which is an annular protrusion and is also used to place a heat-resistant and breathable membrane. The heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent. More preferably, the annular protrusion of the second support portion is integrally formed with the receiving component.

[0031] More preferably, between two adjacent adsorption components, the annular lower flange of the first adsorption component in the upper layer is pressed onto the rhenium vapor adsorbent laid on the first support portion of the first adsorption component in the lower layer, or pressed onto the rhenium vapor adsorbent laid on the second support portion, to achieve radial sealing between layers, thereby completing the side sealing of the entire device. The rhenium vapor adsorbent is similar to the water at the mouth of a kimchi jar, acting as a "water seal." Once rhenium vapor passes through, it is promptly adsorbed by the rhenium vapor adsorbent to prevent overflow and leakage.

[0032] The heat-resistant and breathable membrane described in this invention can be any heat-resistant and breathable membrane that allows rhenium vapor to pass through. In some embodiments, the heat-resistant and breathable membrane is a quartz membrane, a porous metal membrane, or a ceramic membrane, the maximum temperature that the heat-resistant and breathable membrane can withstand is at least 800°C, the thickness of the heat-resistant and breathable membrane is 400~1000 μm, and the pore size is 1~3 μm.

[0033] The separation and enrichment device of this invention is applicable to the analysis and determination of rhenium in geological samples with rhenium content ranging from 0.2 ng / g to 1000 μg / g. When the rhenium content is low, the sample weight can be appropriately increased; conversely, the sample weight can be appropriately decreased. In some embodiments, when the sample weight of the geological sample to be tested is 0.1 g to 10 g, the amount of rhenium vapor adsorbent laid on each adsorption layer is 25 to 100 mg.

[0034] The rhenium vapor adsorbent described in this invention can be any adsorbent commonly used in the prior art to react with rhenium to convert it into rhenium salts. The high-temperature resistant rhenium vapor adsorbent used in this invention can be selected from magnesium oxide, magnesium silicate, magnesium carbonate, calcium carbonate, etc., preferably light magnesium oxide, with a rhenium blank value of less than 0.01 ng / g.

[0035] The experiment found that, in the preferred embodiment, the vertical distance between the heat-resistant and breathable membrane closest to the surface of the geological sample to be tested (which may be the heat-resistant and breathable membrane placed on the first adsorption component at the bottom layer or on the second adsorption component) and the surface of the geological sample to be tested is 3-8 mm, and more preferably 3-5 mm, which can improve the accuracy of the measurement to a certain extent.

[0036] The first adsorption component in the separation and enrichment device of the present invention can be configured as multiple layers, preferably, for example, 2-6 layers. Rhenium vapor passes through a heat-resistant and breathable membrane and a high-temperature resistant adsorbent such as magnesium oxide laid on the surface of the heat-resistant and breathable membrane step by step, effectively preventing volatilization loss while achieving enrichment. When a multi-layer adsorption component is set, the distance between the layers is 3-5 mm.

[0037] In a preferred embodiment, the separation and enrichment device has an overall configuration that is narrower at the top and wider at the bottom. The increased bottom heating area facilitates uniform heating of the sample and full volatilization of elements. The narrower cross-section at the top promotes vapor rise and enrichment, and can reduce the amount of adsorbent used, thus reducing background interference. In some embodiments, the upper multi-layer first adsorption components of the separation and enrichment device can be flexibly disassembled and assembled according to actual needs. Simultaneously, the receiving component and the bottommost first adsorption component, as well as adjacent first adsorption components, are sequentially axially connected via their annular upper and lower flanges. Furthermore, the annular lower flange of each component is pressed against the rhenium vapor adsorbent of the support portion of the next layer of adsorption component, thereby achieving radial sealing between layers and preventing rhenium vapor leakage from the side. The heat-resistant and breathable membrane of this invention uses a high-temperature resistant and breathable material, such as a quartz membrane, with a maximum withstand temperature of at least 800°C. The adsorbent is uniformly and completely spread on the heat-resistant and breathable membrane to ensure that all Re2O7 vapor is fully adsorbed as it passes through.

[0038] When using the separation and enrichment device of the present invention, the sample to be tested is heated and sintered. The preferred sintering temperature is 700~750℃, the sintering time is 0.25~2 h, and the sintering atmosphere is air.

[0039] The present invention also provides a method for determining trace rhenium in geological samples, comprising the following steps: using the separation and enrichment device for trace rhenium in geological samples described in the present invention to separate and enrich the rhenium in the geological sample to be tested, extracting the rhenium-containing substance enriched in the adsorption zone by water leaching, performing solid-liquid separation and volume adjustment, and determining the rhenium content by inductively coupled plasma mass spectrometry.

[0040] In some embodiments, the following steps are specifically included: (1) Weigh the geological sample to be tested and lay it flat at the bottom of the containment component. Lay a heat-resistant and breathable membrane on the support of each layer of the first adsorption component. Then, lay rhenium vapor adsorbent evenly on each heat-resistant and breathable membrane. The containment component and the bottommost first adsorption component, as well as the two adjacent layers of first adsorption components, are axially connected by their annular upper and lower flanges. At the same time, the annular lower flange of each layer of adsorption component is pressed onto the magnesium oxide layer of the support of the next layer of adsorption component. Place the assembled separation and enrichment device in a muffle furnace, heat it to 700~750℃ through a program, calcine it for 0.25~2 h, and then take it out and cool it to room temperature. (2) Transfer the adsorbent loaded with the adsorbent product in step (1) and the heat-resistant and breathable membrane together into a container, add distilled water to disperse it fully, heat to boiling, and keep boiling for 1-5 minutes; filter while hot and wash the filter residue and filter paper with hot water 3-4 times; add a certain volume of nitric acid (the final concentration of nitric acid is 2%) to the filtrate, and finally dilute to volume with distilled water, let stand for testing or dilute to a certain factor according to the sample content before testing; (3) The rhenium content of the sample solution obtained in step (2) was determined by inductively coupled plasma mass spectrometry (ICP-MS).

[0041] The testing device and method of this invention are applicable to geological samples including but not limited to rhenium-containing tungsten ore, rhenium-containing molybdenum ore, rhenium-containing copper-lead-zinc ore, rhenium-containing uranium ore, rhenium-containing soil, or rhenium-containing sediments.

[0042] In some preferred embodiments, the present invention provides a method for determining trace rhenium in geological samples, specifically including the following steps: (1) Sample separation and enrichment: Accurately weigh a certain amount (0.1 g~10.0 g) of pulverized sediment sample to a density of 200 g, place it inside a clean container, lay a quartz membrane on the annular protrusion of the second support, and then lay quartz membranes on the support of the multilayer first adsorption component. Subsequently, evenly lay high-temperature resistant adsorbents such as magnesium oxide on each layer of quartz membrane to completely cover the support of the adsorption component. Place the separation and enrichment device in a muffle furnace, heat it to 700~750℃ through a program, calcine it for 0.25~2 h, and then remove it and cool it to room temperature.

[0043] (2) Extraction and volume determination: Transfer the adsorbent layers and quartz membrane loaded with the adsorbent product in step (1) to a 50 mL beaker, add 25 mL of distilled water, disperse thoroughly, heat on a hot plate to boiling, and maintain boiling for 1-5 min; filter while hot through rapid filter paper, wash the filter residue and filter paper 3-4 times with hot water; add 5 mL of nitric acid to the filtrate, and finally dilute to 250 mL with distilled water, and let stand for testing.

[0044] (3) Test: The rhenium content of the sample solution obtained in step (2) was determined by inductively coupled plasma mass spectrometry (ICP-MS).

[0045] Preferably, the container in step (1) must be cleaned before use to ensure no background contamination. Preferably, the quartz membrane in step (1) is pretreated by boiling and drying in distilled water before being laid; and there is no gap between the edge of the quartz membrane and the inner wall of the first and second supports. The adsorbent in step (1) is high-purity light magnesium oxide, and the impurity content meets the requirements for trace analysis (rhenium content is less than 0.01 ng / g). In step (2), material spillage should be avoided when transferring the adsorbent and the quartz membrane to ensure the recovery rate. Nitric acid is added before volume adjustment in step (2) to keep the sample medium consistent with the standard solution and improve the accuracy of the determination. The sintering procedure in step (1) is as follows: heat to 650~750℃ within 50~70 min, preferably 680~750℃, more preferably 700~750℃; maintain the sintering time for 0.2~2.5 h, preferably 0.25~2 h, and remove and cool to room temperature after completion. Compared with the prior art, the present invention has the following beneficial effects: By placing the adsorption component above the containment component, and optionally equipping it with a multilayer adsorption component structure, efficient separation of the target element rhenium from the sample matrix is ​​achieved, significantly reducing the interference of matrix effects on trace testing and improving the accuracy and sensitivity of the determination method.

[0046] Meanwhile, by increasing the sample weight, the amount of magnesium oxide used is significantly reduced, which not only lowers reagent costs and reduces background interference but also improves the detection sensitivity of the method. The rhenium vapor adsorbent and quartz membrane of this invention can be regenerated and reused.

[0047] The pretreatment process of this method is rationally designed and easy to operate. It is not only applicable to various conventional rhenium-containing samples such as ores and materials, but also meets the analytical needs of rhenium in geochemical samples such as soil and sediments with low rhenium content. It has excellent sample versatility and therefore has significant industrial application value and broad application prospects.

[0048] The determination method proposed in this invention is applicable to the analysis and determination of volatile trace elements. Applicable fields include, but are not limited to: geological exploration and mineral resource evaluation; detection of trace rhenium in environmental samples; analysis of rhenium in metallurgical materials or secondary resources; and quality control of rhenium content in military or high-tech materials.

[0049] The apparatus for separating and enriching volatile elements proposed in this invention has the following technical advantages: Structural isolation reduces interference: By physically separating the sample containment component from the adsorption component, the influence of matrix effects on test results is significantly reduced.

[0050] Increased sample weighing capacity enhances sensitivity: The bottom-wide and top-narrow structural design allows for increased sample weighing, thereby lowering the method detection limit and making it suitable for trace analysis.

[0051] Multi-layer first adsorption module ensures high recovery rate: The structure of the multi-layer first adsorption module effectively prevents the loss of volatile components during high-temperature processes, improving analytical accuracy.

[0052] Modular design facilitates operation: The detachable multi-layer first adsorption component structure simplifies the sample loading, experimental processing, cleaning and maintenance process, improving experimental efficiency and the practicality of the device.

[0053] This invention discloses a specialized device and method for the separation and enrichment of trace rhenium in geological samples, belonging to the field of trace element analysis technology. The device is a heat-resistant container with a split structure. The lower part is the sample-containing component, and the upper part has at least two layers of first adsorption components for laying quartz membranes and high-temperature resistant adsorbents such as magnesium oxide. During high-temperature sintering, rhenium in the sample volatilizes as Re₂O₇ vapor, which, after being isolated by the quartz membrane, enters the upper adsorption components for fractional capture and enrichment. This effectively solves the problems of incomplete rhenium distillation, low adsorption efficiency, high reagent background, and severe matrix interference in traditional calcination methods. The determination method based on this separation and enrichment device includes: sintering adsorption, water leaching extraction, filtration, and volume adjustment, combined with inductively coupled plasma mass spectrometry (ICP-MS) to determine the rhenium content. This method, through its separate adsorption design, achieves efficient rhenium enrichment while significantly reducing matrix effects, thus improving detection sensitivity and accuracy. This invention integrates dual innovations in both apparatus and method, and has advantages such as simplified process, high adsorption efficiency, good selectivity, environmental friendliness, and reusability. It is especially suitable for the separation, enrichment, and high-precision determination of ultra-trace rhenium in geological samples.

[0054] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0055] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0056] The embodiments of this application are described below with reference to the accompanying drawings.

[0057] Example 1 A device for separating and enriching trace amounts of rhenium in geological samples, the device being as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, it includes a housing component 1 and a multi-layer first adsorption component 2.

[0058] like Figure 2 As shown, the container 1 is an open-top flat-bottomed container with a container opening 11, an upper annular flange 12, a container bottom surface 13 for laying the geological sample to be tested, and a second support part 14. The second support part 14 is an annular boss provided at the opening of the container 1.

[0059] In this embodiment, the first adsorption component 2 consists of two layers, with the two layers of the first adsorption component 2 disposed above the receiving component 1, forming a stacked arrangement. For example... Figure 3 As shown, each layer of the first adsorption component 2 includes a first support portion 21. The first support portion 21 has an annular upper flange 22 and an annular lower flange 23 arranged circumferentially. The first adsorption component support portion 21 has holes 24. Both the first support portion 21 and the second support portion 14 are used to place a heat-resistant and breathable membrane. The heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent magnesium oxide. When the geological sample to be tested, which is laid on the bottom surface 13 of the receiving component, is heated, the rhenium in it volatilizes in the form of Re2O7 vapor. After passing through the second adsorption component and the heat-resistant and breathable membrane of each layer of the first adsorption component, it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested.

[0060] like Figure 5 As shown, during assembly, the annular flange 12 of the receiving component 1 is axially connected to the annular lower flange 23 of the bottommost first adsorption component 2, and the annular upper flange 22 of the bottom first adsorption component 2 is connected to the annular lower flange 23 of the adjacent upper first adsorption component. At the same time, the annular lower flange 23 of each layer of the first adsorption component 2 is pressed onto the magnesium oxide layer laid on the first support part 21 of the next layer of the first adsorption component 2. The annular lower flange 23 of the bottommost first adsorption component 2 is pressed onto the rhenium vapor adsorbent magnesium oxide laid on the second support part 14 of the second adsorption component, and so on, so as to realize the assembly connection between the receiving component 1 and the multilayer first adsorption components 2, so as to ensure the side sealing of the separation and enrichment device.

[0061] In this embodiment, the separation and enrichment device is made entirely of ceramic material, which has the characteristics of high temperature resistance, structural stability and good chemical inertness. It can effectively avoid the device itself from interfering with the test results, and its smooth inner surface is also conducive to the escape and passage of the target element vapor.

[0062] In this embodiment, the cross-sections of the containing component 1, the first adsorption component 2, and the second adsorption component are all circular, with an overall structure that is narrower at the top and wider at the bottom. The larger bottom area is beneficial for uniform heating of the sample and full volatilization of elements, while the narrowing at the top promotes vapor rise and improves enrichment efficiency.

[0063] A quartz membrane is laid flat on the first support section. The quartz membrane has good high-temperature stability and chemical inertness, which can effectively isolate the sample from the adsorbent, while allowing the vapor of the target element to pass freely and enter the adsorption layer.

[0064] The first adsorption components of any two adjacent layers are tightly assembled and connected by their respective annular flanges. The annular upper flange of the upper layer is pressed onto the magnesium oxide laid on the first support part of the lower layer to prevent rhenium vapor leakage from the side. The first support part has holes 24, and the holes 24 between adjacent layers are staggered. This structure not only facilitates the upward escape of rhenium vapor during high-temperature sintering and its capture by the upper adsorbent, but also ensures the adsorption efficiency of the target element.

[0065] This embodiment also provides a method for the separation, enrichment, and determination of trace rhenium in geological samples, specifically including the following steps: Step 1: Quartz Membrane Pretreatment Cut a commercially available quartz membrane (Whatmam QMA, item number 1851-090) into a circle with a radius of approximately 2 cm (or purchase the required size), boil it in distilled water for 5 minutes, remove it, rinse it with distilled water, and dry it in a 50°C oven for later use. The quartz membrane has a maximum temperature resistance of 800°C, a thickness of 475 μm, and a pore size of 2.2 μm.

[0066] Step Two: Weighing and Loading Samples Accurately weigh 0.10 g of molybdenum ore standard material GBW07373 and load it onto the clean bottom surface 13 of the container through the opening 11. Place a circular quartz membrane with a radius of approximately 2 cm on the second support 14 and each layer of the first support 21, ensuring the membrane adheres to the inner walls of the second support 14 and the first support 21. From bottom to top, these are referred to as the first layer of quartz membrane (located on the second support 14), the second layer of quartz membrane, and the third layer of quartz membrane (located on the first support 21). The distance between the first layer of quartz membrane and the sample surface on the bottom surface 13 of the container is approximately 3 mm; the distance between the first and second layers of quartz membrane is 5 mm, and the distance between the second and third layers of quartz membrane is 5 mm. Then, evenly spread 25 mg of magnesium oxide adsorbent on each layer of quartz membrane to completely cover the adsorption area. The container 1 and the bottommost first adsorption component 2, as well as the two adjacent layers of first adsorption components 2, are sequentially axially assembled and connected through their annular upper flange and annular lower flange, respectively. Meanwhile, the annular lower flange 23 of the upper layer first adsorption component 2 is pressed onto the magnesium oxide adsorbent laid on the first support part 21 of the lower layer first adsorption component 2, and the annular lower flange 23 of the first adsorption component 2 is pressed onto the magnesium oxide adsorbent laid on the second support part 14 to achieve radial sealing between layers. In this way, the first layer and the second layer first adsorption components 2 are assembled sequentially on the upper part of the receiving component 1.

[0067] Step 3: Sintering Adsorption The sample-loaded separation and enrichment device was placed in a muffle furnace, and the temperature was raised to 750 °C and maintained for 15 min. During this process, rhenium in the sample was oxidized to volatile rhenium heptaoxide (Re₂O₇), whose vapor permeated through a quartz membrane and was adsorbed and fixed by the upper magnesium oxide layer. The main chemical reactions are as follows: 2ReS2(s)+15 / 2O2(g)=Re2O7(g)+4SO2(g) 2MoS2(s) + 7O2(g) = 2MoO3 + 4SO2(g) 2MgO(s)+Re2O7(g)→Mg2Re2O8(s) Meanwhile, the molybdenum present in the sample is converted into molybdenum trioxide (MoO3), which has a sublimation temperature of about 795°C, much higher than the sintering temperature in this step. Therefore, most of the molybdenum is fixed in the residue, effectively avoiding interference from molybdenum.

[0068] Step 4: Extraction and Volume Adjustment After sintering, remove the apparatus and cool to room temperature. Transfer the magnesium oxide layer and quartz membrane together to a 50 mL beaker. Add 25 mL of distilled water and heat on a hot plate to boiling, maintaining a gentle boil for 2 minutes. While still hot, filter through rapid filter paper into a 250 mL volumetric flask, washing the residue and filter paper 3-4 times with hot water. After cooling the filtrate, add 5 mL of nitric acid, dilute to volume with distilled water, shake well, and let stand until analysis or dilute before analysis.

[0069] Step 5: Content determination The rhenium content in the solution obtained in step four was determined by inductively coupled plasma mass spectrometry (ICP-MS).

[0070] Examples 2-4 and Comparative Examples 1-3 The remaining steps were the same as in Example 1, and the rhenium content detection results under different roasting conditions were also investigated: Example 2: The calcination conditions were 700℃ for 0.5 h.

[0071] Example 3: The calcination conditions were 700℃ for 2 hours.

[0072] Example 4: The calcination conditions were 750℃ for 2 hours.

[0073] Comparative Example 1: Calcination conditions were 450℃ for 2 hours.

[0074] Comparative Example 2: Calcination conditions were 650℃ for 2 h.

[0075] Comparative Example 3: Calcination conditions were 800℃ for 2 hours.

[0076] Comparative Example 4: Other steps are the same as in Example 1, except that the following method is used. Figure 4 The crucible shown is then roasted.

[0077] Comparative Example 5: Other steps are the same as in Example 1, except that the following method is used. Figure 5 The crucible shown is then fired.

[0078] Comparative Example 6: The other steps are the same as in Example 1, except that only the first layer of quartz membrane is used for adsorption treatment.

[0079] Comparative Example 7: The other steps are the same as in Example 1, except that the first and second layers of quartz membranes are used for adsorption treatment.

[0080] Example 5: The other steps are the same as in Example 1, except that the first to fifth layers of quartz membrane are used for adsorption treatment.

[0081] Example 6: The other steps are the same as in Example 1, except that the first to seventh layers of quartz membrane are used for adsorption treatment.

[0082] The specific test results are shown in Table 1 below: Table 1 Measurement results of Examples 1-6 and Comparative Examples 1-7

[0083] In Table 1, the relative error (%) represents the relative error between the average of seven parallel determinations and the standard value, while RSD (%) represents the relative deviation (%) of the seven parallel determinations. In Table 1, "three-layer quartz film" means two layers of quartz film on the two first support parts corresponding to the two first adsorption components, and one layer of quartz film laid on the second support part, for a total of three layers of quartz film; in Comparative Example 6, "one-layer quartz film" means only the quartz film on the second support part, without containing the first adsorption component.

[0084] Analysis of the results of Examples 1-4 shows that the GBW07373 sample achieved relatively ideal separation and enrichment results after calcination at 750℃ for 0.25h, 700℃ for 0.5h, 700℃ for 2h, and 750℃ for 2h (relative error <5%). Analysis of the results of Comparative Examples 1-3 shows that the results obtained by sintering at 450℃, 650℃, and 800℃ for 2h were all low, indicating that excessively low or high temperatures are not conducive to the accuracy of the test results. The optimal experimental conditions are 700~750℃, and calcination for 0.25~2h is acceptable.

[0085] Comparative analysis of Comparative Examples 4, 5, and 6 shows that using a common crucible (such as...) Figure 7 When the results were as shown, the values ​​were too low, with a relative error of 25.2%. Furthermore, the use of ordinary crucibles easily leads to uneven adsorbent distribution, incomplete coverage, and inconvenient operation, resulting in poor reproducibility (the relative deviation of 7 parallel measurements exceeded 20%). However, using a method such as... Figure 8 When using the cylindrical crucible shown, the measurement results were also lower. This may be because the height between the sample and the adsorbent is about 5 cm, forming a large cavity in the middle, which is not conducive to the immediate and effective absorption of rhenium, thus leading to lower measurement results.

[0086] Analysis of the measurement results of Examples 1, 6-7, 5, and 6 shows that the multilayer adsorption method is beneficial for the full absorption of rhenium vapor and magnesium oxide; when the number of adsorption layers (the total number of heat-resistant and breathable membrane layers) reaches three, the measurement results tend to stabilize. Therefore, it is determined that the preferred number of adsorption layers in this example is three or more.

[0087] Figure 9 and Figure 10 The diagram shows the overall schematic and cross-sectional view of a separation and adsorption device with a first adsorption component consisting of 5 layers.

[0088] Example 7 The other steps are the same as in Example 1, except that a foreign standard molybdenum concentrate CGL 202 (with a rhenium content as high as 500 μg / g) was used for testing. The test result was 505 μg / g, with a relative error of 1.0%, indicating that this device and method are also suitable for high-content samples.

[0089] Examples 8-11 Examples 8-11 employed the same detection method as in Example 1, aiming to verify the effectiveness of this method in increasing sample volume to achieve ultra-trace sample testing. The main difference was that 10.0 g of soil standard material (GBW07447) was weighed, 0.5 mL of nitric acid was added, and the final volume was adjusted to 25 mL, while other parameters remained unchanged.

[0090] To investigate the effect of calcination process under large sample size conditions, the following comparative experiment was conducted, with all other steps being consistent with this embodiment: Example 8: The calcination conditions were 750°C for 0.25 h.

[0091] Example 9: The calcination conditions were 700℃ for 0.5 h.

[0092] Example 10: Calcination conditions were 700℃ for 2 hours.

[0093] Example 11: The calcination conditions were 750°C for 2 hours.

[0094] The determination results of soil composition analysis standard material GBW07447 are shown in Table 2 below.

[0095] Table 2 Comparison of ultra-trace rhenium determination results under different conditions in GBW07447

[0096] As can be seen from the test results of Examples 8-11 in Table 2, under the condition of significantly increasing the sample weight (10.0 g) while reducing the fixed volume, the determination results of the standard material containing ultra-trace rhenium using the method of the present invention (Examples 8-11) are in high agreement with the standard values, and the relative error is controlled within 5%. This indicates that the method of the present invention can maintain excellent accuracy and stability while achieving ultra-trace enrichment, and is suitable for high-sensitivity detection of ultra-trace rhenium.

[0097] A blank experiment was conducted under the conditions of Example 1, with 7 parallel experiments. The standard deviation of the rhenium concentration values ​​in the 7 measurements was calculated to be 3.14 times, resulting in a method detection limit of 0.07 ng / g. This is 50 to 1000 times lower than the existing standard methods GB / T 14352.18-2010 (lower limit of quantitation 1 μg / g), GB / T 14353.20-2019 (detection limit 4 ng / g), and DZ / T 0421.1-2022 (detection limit 5 ng / g).

[0098] The technical solution provided by this invention has the following significant effects, as verified by experiments: (1) Innovation in Structure, Performance, and Flexibility: This invention aims to solve the problems of severe matrix interference, limited sample weighing, and insufficient method sensitivity caused by direct mixing of samples and adsorbents in existing technologies. To this end, this invention adopts a novel structure in which the adsorption layer and sample layer are physically separated, and combines it with a multilayer adsorption design to effectively reduce the matrix effect. At the same time, the integrated structure of the housing components and the press-fit assembly of the multilayer first adsorption components significantly improve the operability and side sealing performance of the device. In addition, the device adopts a modular multilayer design that can be freely assembled, which greatly enhances the convenience and flexibility of use, making it more suitable for large-scale analysis scenarios.

[0099] (2) High accuracy: The measurement results of high and low content national standard substances are highly consistent with the certified values, and the relative error is less than 5%, which fully meets the quality requirements of trace analysis of geological samples.

[0100] (3) The method is robust: Under different calcination conditions, the test results showed good stability and reproducibility, indicating that the method has a certain tolerance for key process parameters and is easy to operate and standardize.

[0101] (4) The process parameters have been optimized: Comparative experiments show that the preferred low-temperature short-time sintering scheme of the present invention (700~750°C, 0.25~2 h) ensures the best accuracy while minimizing reagent consumption, energy costs and analysis time, achieving a balance between accuracy, speed and economy.

[0102] Figure 11 , Figure 12 and Figure 13The figures show a comparison of rhenium recovery rates in GBW07373 under the same conditions as Example 1, with only changes in calcination temperature, calcination time, and magnesium oxide addition. Analysis reveals that lower temperatures (below 680℃) are detrimental to the complete oxidation and volatilization of rhenium, while higher temperatures (above 750℃) are detrimental to the thermal stability of magnesium rhenate, leading to lower results. When the sintering temperature is fixed at 750℃, changing the holding time shows that adsorption is essentially complete after 15 minutes. With further extension of time, magnesium rhenate remains stable, indicating good thermal stability of the complex at 750℃. This also demonstrates that the method is simple to operate, easy to control, and has good application value. Changing the amount of magnesium oxide in each layer shows that as the magnesium oxide addition increases from 5 mg to 25 mg, the measured rhenium value gradually increases; further increasing the magnesium oxide amount leads to a stable measured value. Therefore, based on the comprehensive results, the optimal implementation scheme of this device and method is as follows: when using a three-layer quartz membrane for adsorption, the amount of adsorbent in each layer is 25-100 mg, the muffle furnace is heated to 700-750℃, and calcination is maintained for 0.25-2 h.

[0103] It should be noted that the above embodiments are only used to illustrate the structural principles and usage methods of the present invention, and are not intended to limit the scope of protection. Without departing from the design concept of the present invention, those skilled in the art can make reasonable adjustments to the specific structure, materials, number of layers, etc., to suit different analysis scenarios and application needs.

[0104] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A device for separating and enriching trace amounts of rhenium in geological samples, characterized in that, It includes a housing component (1) and a multilayer first adsorption component (2), wherein: The receiving component (1) is used to lay the geological sample to be tested; The multilayer first adsorption component (2) is disposed above the containing component, and the multilayer first adsorption component (2) is stacked in layers; and each layer of the first adsorption component (2) includes a first support part (21), the first support part (21) is provided with a hole (24), the first support part (21) is used to place a heat-resistant and breathable membrane, the heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent; when the geological sample to be tested is heated inside the containing component (1), the rhenium in it volatilizes in the form of Re2O7 vapor, and after passing through the heat-resistant and breathable membrane of each layer of the first adsorption component (2), it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested.

2. The separation and enrichment apparatus as described in claim 1, characterized in that, The container assembly (1) is an open-top flat-bottomed container with an annular flange (12) on its upper part. The first support portion (21) is provided with an annular upper flange (22) and an annular lower flange (23) in the circumferential direction. The annular flange (12) of the receiving component (1) is axially assembled with the annular lower flange (23) of the first adsorption component (2) located at the bottom layer, and the annular upper flange (22) of the first adsorption component (2) located below is axially assembled with the annular lower flange (23) of the first adsorption component (2) of the adjacent upper layer, so as to achieve the side sealing of the separation and enrichment device.

3. The separation and enrichment apparatus as described in claim 2, characterized in that, A second adsorption component is also provided at the opening (11) of the receiving component. The second adsorption component includes a second support (14). The second support is an annular protrusion, which is also used to place a heat-resistant and breathable membrane. The heat-resistant and breathable membrane is used to lay rhenium vapor adsorbent. Preferably, the annular lower flange (23) of the first adsorption component (2) of the upper layer is pressed onto the rhenium vapor adsorbent laid on the first support part (21) of the first adsorption component (2) of the lower layer, or pressed onto the rhenium vapor adsorbent laid on the second support part (14) to achieve interlayer radial sealing.

4. The separation and enrichment apparatus as described in claim 1, characterized in that, The holes (24) between adjacent layers of the first adsorption component (2) are arranged in an alternating pattern.

5. The separation and enrichment apparatus as described in claim 1, characterized in that, The separation and enrichment device is made of ceramic, corundum, or quartz.

6. The separation and enrichment apparatus as described in claim 1, characterized in that, The heat-resistant and breathable membrane is a quartz membrane, a porous metal membrane, or a ceramic membrane. The maximum temperature that the heat-resistant and breathable membrane can withstand is at least 800°C. The thickness of the heat-resistant and breathable membrane is 400~1000 μm, and the pore size is 1~3 μm.

7. The separation and enrichment apparatus as described in claim 2, characterized in that, The interior of the receiving component (1) is used to lay the geological sample to be tested, and the vertical distance between the heat-resistant and breathable membrane closest to the surface of the geological sample to be tested and the surface of the geological sample to be tested is 3-8 mm.

8. A method for determining trace rhenium in geological samples, characterized in that, The separation, enrichment, and determination of rhenium in a geological sample using the separation and enrichment apparatus as described in any one of claims 1 to 7 specifically includes the following steps: (1) The geological sample to be tested is laid inside the containment component (1); the multiple layers of the first adsorption component (2) are assembled in sequence, and the heat-resistant and breathable membrane is placed on the first support of each layer of the first adsorption component, and then the rhenium vapor adsorbent is laid on each first support; (2) The separation and enrichment device is placed in a heating furnace and the sample to be tested is heated and sintered. The rhenium in it volatilizes in the form of Re2O7 vapor. After passing through the heat-resistant and breathable membrane of each layer of the first adsorption component, it reacts with the rhenium vapor adsorbent laid on the surface of the heat-resistant and breathable membrane and is captured, thereby realizing the separation and enrichment of rhenium in the geological sample to be tested. (3) The rhenium-containing substances enriched in the adsorption component are extracted by water leaching, and after solid-liquid separation and volume adjustment, the rhenium content is determined.

9. The determination method as described in claim 8, characterized in that, When the sample weight of the geological sample to be tested is 0.1 g to 10 g, the amount of rhenium vapor adsorbent laid on each layer of the first adsorption component (2) is 25 to 100 mg. The rhenium vapor adsorbent is one or more of magnesium oxide, magnesium silicate, magnesium carbonate, and calcium carbonate.

10. The determination method as described in claim 8, characterized in that, The sample to be tested was heated and sintered at a temperature of 700~750℃ for 0.25~2 h in an air atmosphere.

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