Method for rapidly and accurately measuring Re content of black rock series

Abstract

The invention provides a method for rapidly and accurately measuring the content of black rock Re. The method comprises the following steps: collecting a black rock sample and carrying out superfine grinding; preparing a Re standard powder substance with lithology the same as that of the black rock series sample; respectively tabletting the black rock series sample and the Re standard powder substance which are subjected to superfine grinding so as to prepare a Re sample target and a Re standard target; according to the Re standard target, a laser in-situ analysis method is adopted to carry out total rock Re content preliminary determination on the Re sample target, and preliminary total rock Re content data of the black rock series sample are obtained; the adding ratio of the Re diluent is determined according to the preliminary total rock Re content of the black rock series sample, and the Re content is rapidly and accurately determined by adopting a low-temperature semi-closed isotope dilution method. The method for measuring the Re content of the black rock series is accurate and rapid in measurement and low in cost, and provides powerful technical support for rapid screening of Re resources in large-batch black rock series samples.

Description

Technical Field

[0001] The invention belongs to the technical field of Re content determination of black rock series, and particularly relates to a method for quickly and accurately determining the Re content of black rock series. Background Art

[0002] Rhenium (Re), as a strategic emerging mineral, is an indispensable key raw material in the fields of national defense and aerospace. In nature, molybdenite is the main mineral of Re, but the amount of resources that have been identified is limited, resulting in an increasingly prominent contradiction between supply and demand. In recent years, abnormal enrichment of Re has been discovered in black rock series (such as black shale, mudstone and limestone). my country has extensively developed black rock series, and the potential for Re resources is huge. It is expected to become an important source of Re metal reserves in the future. However, although Re in black rock series has great potential as a prospective strategic resource, its current research is still relatively weak, mainly facing the following challenges:

[0003] Next question:

[0004] Traditional testing methods (such as neutron activation, atomic emission spectroscopy, etc.) cannot accurately determine the Re content in black rock samples at the ppb-ppt level. Although isotope dilution combined with thermal ionization mass spectrometry or multi-collector mass spectrometry (ID-NTIMS /

[0005] ID-MC-ICP-MS can accurately determine the Re content in pg-ng samples. It generally takes two days from weighing the sample to cooling the sample to room temperature in a Carius tube and opening the tube. Preparation for the instrument also takes two days, from distilling and separating Os, removing interferences, to enriching and purifying Re through anion exchange or acetone extraction. Finally, testing on the instrument takes one day. A single experimental process takes five days. However, obtaining an accurate Re content result generally requires two steps: the first is primarily for preliminary measurement of Re content to determine the optimal Re diluent ratio; the second is for refinement measurement to obtain the precise Re content. From initial measurement and diluent addition to refinement measurement and obtaining an accurate result, a total of 10 days is required. Furthermore, the entire experimental process consumes a large amount of chemical reagents and laboratory equipment, making the testing costly.

[0006] In summary, the existing methods for determining the Re content in black rock series have problems such as complex analytical procedures, long testing cycles, and high testing costs. They cannot meet the testing needs of large quantities of samples, which seriously restricts the evaluation and mining and utilization of the Re resource potential in black rock series.

[0007] In view of the above problems, it is necessary to propose a method for rapid and accurate determination of Re content in black rock series that is reasonably designed and can effectively solve the above problems. Summary of the Invention

[0008] The present invention aims to solve at least one of the technical problems existing in the prior art and provide a method for quickly and accurately determining the Re content of black rock series.

[0009] The present invention provides a method for quickly and accurately determining the Re content of black rock series.

[0010] The law includes:

[0011] Collect black rock samples and grind them into ultrafine powder;

[0012] Prepare Re standard powder material with the same lithology as the black rock series sample;

[0013] The ultrafinely crushed black rock sample and the Re standard powder material are respectively tableted to prepare a Re sample target and a Re standard target;

[0014] The Re content of the whole rock of the Re sample target is preliminarily determined by using the laser in-situ analysis method based on the Re standard target to obtain preliminary whole rock Re content data of the black rock series sample;

[0015] The addition ratio of the Re diluent is determined based on the preliminary whole-rock Re content of the black rock series sample, and the Re content is quickly and accurately determined using a low-temperature semi-closed isotope dilution method.

[0016] Optionally, the semi-closed isotope dilution method is used to quickly and accurately determine the Re content, including:

[0017] Weigh the ultrafinely crushed black rock sample into a plastic centrifuge tube;

[0018] Add HCl, HNO3 and Re diluent to the plastic centrifuge tube;

[0019] The plastic centrifuge tube is capped and ultrasonically shaken;

[0020] Heat in an oven at 105℃~110℃;

[0021] After heating is completed, the plastic centrifuge tube is placed in a centrifuge for centrifugation;

[0022] The supernatant was diluted and then the Re content was determined quickly and accurately using MC-ICP-MS.

[0023] Optionally, 0.1 g to 0.2 g of ultrafinely crushed black rock sample is weighed into a plastic centrifuge tube; 1 mL to 2 mL of 12 mol / L HCl and 1.5 mL to 2 mL of 16 mol / L HNO3 are added to the plastic centrifuge tube; ultrasonic vibration is performed for 0.5 h to 0.6 h; and heating time in an oven is 12 h to 15 h.

[0024] Optionally, the ultrafinely crushed black rock sample and the Re standard powder are respectively tableted to prepare a Re sample target and a Re standard target, comprising:

[0025] A powder tabletting device for micro-area in-situ analysis of sample powder is used for tableting; wherein the tableting device includes a base, a fixing ring, a splicing plate, a pressing column, an inserting rod, a plastic ring and a polyethylene powder filling body;

[0026] There are multiple splicing plates, each of which is slidably connected to the upper surface of the base, the fixing ring is slidably connected to the outer side wall of the base, and each of the splicing plates has a first limiting surface;

[0027] During sheet pressing, the plurality of splicing plates are slidably spliced ​​on the base and the plurality of first limiting surfaces are combined to form a groove, the fixing ring is sleeved on the outer peripheral side of the plurality of spliced ​​splicing plates, the insertion rod passes through the fixing ring and is inserted into the base, and the pressure column is inserted into the groove;

[0028] The plastic ring is arranged in the groove, and is used to place black rock sample powder. The polyethylene powder filler is used to fill the groove to cover the black rock sample powder in the plastic ring and the outside of the plastic ring.

[0029] Optionally, the tablet pressing device further comprises:

[0030] A vertical sliding groove is provided on the side wall of the base. The fixed ring includes a ring body and a vertical sliding block. The vertical sliding block is provided on the inner side wall of the ring body. The ring body is sleeved on the base. The vertical sliding block can be slidably connected in the vertical sliding groove.

[0031] Optionally, the tablet pressing device further comprises:

[0032] The top wall of the base is provided with a plurality of transverse sliding grooves, and each of the splicing plates includes a plate body and a first transverse sliding block. The first transverse sliding block is provided on one side of the plate body. When pressing the plate, the first transverse sliding block is slidably connected in the transverse sliding groove in a one-to-one correspondence, and the inner end surface of the plate body is a first limiting surface;

[0033] The splicing plate further comprises a second transverse sliding block, and the second transverse sliding block is provided on the other side of the plate body. When the sample after tableting is taken out, the second transverse sliding block can be slidably connected in the transverse sliding groove.

[0034] Optionally, the whole-rock Re content of the Re sample target is preliminarily determined using a laser in-situ analysis method based on the Re standard target to obtain preliminary whole-rock Re content data of the black rock series sample, including:

[0035] Under the same laser and mass spectrometry experimental conditions, laser point ablation was used to perform laser point analysis on the Re standard target and the Re sample target respectively;

[0036] The preliminary whole-rock Re content of the black rock series sample was obtained according to the following formula:

[0037] C2=(A2 / A1)×C1,

[0038] Among them, C2 represents the preliminary whole-rock Re content of the black rock sample, C1 represents the whole-rock Re content of the Re standard powder material, A1 represents the measurement count of the Re standard target, and A2 represents the measurement count of the Re sample target.

[0039] Optionally, the laser spot beam used is 70 μm to 80 μm, and the dot dwell time is 0.4 s to 0.5 s.

[0040] Optionally, prepare a Re standard powder material having the same lithology as the black rock series sample, including:

[0041] Collect alternative reference materials with the same lithology as the black rock series samples;

[0042] Grinding the candidate standard substance to less than 200 mesh;

[0043] The crushed candidate standard substances are divided into a plurality of wide-mouth bottles and mixed evenly;

[0044] The candidate standard substances were tested for homogeneity, stability and normality of fixed value data.

[0045] Optionally, collecting black rock samples and performing ultrafine grinding includes:

[0046] Black rock series samples were collected and cleaned with deionized water;

[0047] The black rock samples were ultrafinely ground and pulverized using a planetary ball mill to a size below 200 mesh, and the ultrafinely ground black rock samples were mixed evenly to increase the homogeneity of the samples.

[0048] The present invention provides a method for rapidly and accurately determining the Re content of black rock series. The method uses a laser in-situ analysis method based on a Re standard target to perform a preliminary determination of the Re content of the whole rock on a Re sample target, and adopts a low-temperature semi-closed isotope dilution method to perform a rapid and accurate determination of the Re content. The isotope dilution method is combined with a multi-collector inductively coupled plasma mass spectrometer to determine the Re content, which can rapidly and accurately determine the Re content at the pg-ng level, thereby ensuring the accuracy of the Re content determination of the black rock series. The entire Re content preliminary and fine measurement process only takes two days, which is significantly shorter than the traditional 10 days and improves the efficiency of single sample analysis. At the same time, during the rapid and accurate determination of the Re content of the black rock series, the use of chemical reagents and laboratory utensils is relatively small, and the detection cost is reduced by 70%, thus saving costs. The method for determining the Re content of black rock series can accurately and quickly measure the Re content at a low cost, and will provide strong technical support for the rapid screening of Re resources in large quantities of black rock series samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of a process for rapidly and accurately determining the Re content of a black rock series according to an embodiment of the present invention.

[0050] Figure 2 This is a three-dimensional diagram of a powder tabletting device for micro-area in-situ analysis of samples provided by another embodiment of the present invention.

[0051] Figure 3 This is a top view of a powder tabletting device for micro-area in-situ analysis of samples provided in another embodiment of the present invention.

[0052] Figure 4 A side view of a powder tabletting device for micro-area in-situ analysis of samples provided in another embodiment of the present invention.

[0053] Figure 5 This is a cross-sectional view of a device for pressing sample powder for in-situ analysis of micro-area samples provided in another embodiment of the present invention.

[0054] Figure 6 This is a first perspective view of a base of a powder tabletting device for micro-area in-situ analysis of samples provided by another embodiment of the present invention.

[0055] Figure 7 This is a second perspective view of a base of a powder tabletting device for micro-area in-situ analysis of samples provided by another embodiment of the present invention.

[0056] Figure 8 A three-dimensional diagram of a fixing ring of a powder tabletting device for micro-area in-situ analysis of samples provided in another embodiment of the present invention.

[0057] Figure 9This is a first perspective view of a splicing plate of a powder tabletting device for micro-area in-situ analysis of samples provided by another embodiment of the present invention.

[0058] Figure 10 This is a second perspective view of a splicing plate of a powder tabletting device for micro-area in-situ analysis of samples provided by another embodiment of the present invention.

[0059] Figure 11 This is a three-dimensional diagram of a pressing column of a powder tabletting device for micro-area in-situ analysis of samples provided in another embodiment of the present invention.

[0060] Figure 12 This is a three-dimensional diagram of an insertion rod of a powder tabletting device for micro-area in-situ analysis of samples provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0062] like Figure 1 As shown, the present invention provides a method S100 for quickly and accurately determining the Re content of a black rock series, the method S100 comprising:

[0063] S110. Collect black rock samples and perform ultrafine grinding.

[0064] Specifically, first, a black rock sample is collected and cleaned with deionized water, wherein the black rock sample may be a limestone sample, a black shale sample, or a mudstone sample.

[0065] Secondly, a planetary ball mill is used to ultrafinely grind the black rock samples to below 200 mesh, and the ultrafinely ground black rock samples are mixed evenly to increase the homogeneity of the samples.

[0066] S120. Prepare a Re standard powder material having the same lithology as the black rock series sample.

[0067] The specific process of step S120 may be as follows:

[0068] First, alternative standard materials with the same lithology as the black rock series samples are collected.

[0069] Specifically, if the black rock series sample is limestone, limestone is also sampled as the candidate standard material to ensure that the lithology of the candidate standard material is consistent with that of the collected black rock series sample. In this embodiment, the Re standard material development work was carried out using Permian limestone from the Dongchuanling area of ​​Guangde, Anhui Province, and Sinian black shale from the Kunyang Phosphate Mine. Two black rock series Re analysis standard materials, carbonate and silicate, were developed, respectively.

[0070] Secondly, the candidate standard substance is crushed and ground to less than 200 mesh.

[0071] Specifically, the collected candidate standard substances were cleaned with deionized water, ultrafinely ground to less than 200 mesh, and mixed evenly.

[0072] Next, the crushed candidate standard substances are divided into a plurality of wide-mouth bottles and mixed evenly.

[0073] Specifically, the crushed candidate standard substance was dispensed into 100 2L plastic jars, with 10g of the substance per jar. After filling, the jars were shaken by hand to ensure uniform mixing. Each jar was numbered for sampling for homogeneity and stability testing.

[0074] Finally, the candidate standard substances were tested for homogeneity, stability and normality of fixed value data.

[0075] Specifically, 12 bottles of limestone and 12 bottles of black shale alternative standard materials were respectively extracted, 0.5 g of each was weighed, and after sample dissolution, chemical separation, enrichment and purification, the uniformity, stability and normality of the fixed value data were tested in turn.

[0076] The inter-bottle average (AV1) of the limestone candidate standard material was 6.473 ppb, the inter-bottle standard deviation (s1) was 0.144, the total standard deviation (s2) within the bottle was 0.117, and the RSD (%, 2s, n=15) was 0.02. The inter-bottle average (AV1) of the black shale candidate standard material was 26.39, the inter-bottle standard deviation (s1) was 0.55, the total standard deviation (s2) within the bottle was 0.332, and the RSD (%, 2s, n=15) was 0.02. These results demonstrate good uniformity for both black rock candidate standard materials. Stability testing revealed that the deviations in test results six months apart did not exceed the standard deviation of the variance itself and were consistent with the total average value obtained from the fixed value analysis, indicating good sample stability. The Shapiro-Wilk method was used to test the normality of all raw measurement data, and the Re values ​​of the limestone reference material were determined to be 6.473 ppb with an uncertainty of 0.016; the Re values ​​of the black shale reference material were 26.71 ppb with an uncertainty of 0.07. Collaborative value determination research conducted by the Institute of Geology and Geophysics, Chinese Academy of Sciences, yielded the Re values ​​of the limestone reference material to be 6.413 ppb with an uncertainty of 0.387; and the Re values ​​of the black shale reference material to be 25.85 ppb with an uncertainty of 0.27. These results are consistent with those reported in this paper within the uncertainty range.

[0077] In this embodiment, a Re standard powder material for Re component analysis of black rock series is provided, which fills the gap in the domestic Re standard material of black rock series, provides a solid guarantee for the accuracy and reliability of Re content analysis results, and meets my country's demand for the development and utilization of black rock series rhenium resources.

[0078] S130 , respectively tableting the ultrafinely crushed black rock sample and the Re standard powder material to prepare a Re sample target and a Re standard target.

[0079] Conventional tableting devices, after pressing the sample, require a second, reverse pressing operation to remove the sample tablet due to structural issues with the pressing mold. This is inefficient, time-consuming, and labor-intensive. Furthermore, because rock sample powders are difficult to bond, conventional tableting equipment uses too little pressure, often requiring the addition of a binder to effectively form tablets. This introduces additional chemical interference, loosely pressing the powder sample, uneven surfaces, and the presence of mineral and particle effects.

[0080] In response to this, Figures 2 to 12 As shown, in this embodiment, a powder tableting apparatus for micro-area in-situ analysis of samples is used to tablet ultrafinely pulverized black rock sample and Re standard powder, respectively, to prepare Re sample targets and Re standard targets. In this embodiment, the preparation of the Re sample target is used as an example for illustration; the process for preparing the Re standard target is the same as that for preparing the Re sample target.

[0081] like Figures 2 to 12 As shown, the present invention provides a powder tabletting device for micro-area in-situ analysis of sample powder, which includes a base 1, a fixing ring 2, a splicing plate 3, a pressing column 4, an inserting rod 5, a plastic ring 6 and a polyethylene powder filling body 7.

[0082] There are multiple splicing plates 3, and all of the splicing plates 3 can be slidably connected to the upper surface of the base 1. The fixing ring 2 and the outer wall of the base 1 can be slidably connected up and down. Each splicing plate 3 has a first limiting surface 311.

[0083] When pressing the sheets, multiple splicing plates 3 are slid and spliced ​​on the base 1 and multiple first limiting surfaces 311 are combined to form a groove. The fixing ring 2 is sleeved on the outer peripheral side of the multiple splicing plates 3 after splicing. The insertion rod 5 passes through the fixing ring 2 and is inserted on the base 1, and the pressure column 4 is inserted in the groove.

[0084] The plastic ring 6 is set in the groove, and the plastic ring 6 is used to place the black rock sample powder. The polyethylene powder filling body 7 is used to fill the groove to cover the top and outside of the plastic ring 6.

[0085] In the above embodiment, it should be noted that the shape of the base 1 is cylindrical, the shape of the fixing ring 2 is annular, and the shape of the splicing plate 3 is fan-shaped. When the black rock sample powder needs to be tableted, multiple splicing plates 3 are slid and spliced ​​on the base 1 to form a cylindrical structure in the shape of an annular ring. The first limiting surfaces 311 of the multiple splicing plates 3 are combined to form a circular groove. Then the fixing ring 2 is slid upward until the upper end surface of the fixing ring 2 is flush with the upper end surface of the splicing plate 3. At this time, a part of the fixing ring 2 is sleeved on the base 1, and the fixing ring The other part of 2 is sleeved on a cylindrical structure formed by splicing multiple splicing plates 3 into a circular ring shape, and then the fixing ring 2 is fixed to the base 1 by the insertion rod 5, and the multiple splicing plates 3 are limited by the fixing ring 2; when tableting is required, the plastic ring 6 is placed in the groove, the black rock sample powder is poured into the plastic ring 6, and the polyethylene powder filling body 7 is filled into the groove to cover the black rock sample powder in the plastic ring 6 and the outside of the plastic ring 6, and then the pressing column 4 is inserted into the groove, and then the tablet press is used to press the pressing column 4 for tableting.

[0086] After the black rock sample powder is pressed into the Re sample target, first pull out the pressure column 4 from the groove, then pull out the insertion rod 5 from the base 1, then slide the fixing ring 2 downward until the fixing ring 2 is completely separated from the splicing plate 3, then slide and withdraw the multiple splicing plates 3 on the base 1, and then take out the Re sample target from the side. By placing the sample on the plastic ring 6, the shape and size of the black rock sample powder can be fixed during the sample pressing. At the same time, since the plastic ring 6 has a certain degree of deformability, when the polyethylene powder filling body covers the top of the black rock sample powder and the outside of the plastic sealing ring 6 and is pressurized, the ring wall of the plastic ring 6 also applies pressure to the surrounding side of the black rock sample powder, so that the black rock sample powder can be better formed into sheets.

[0087] Optional, such as Figures 2 to 12 As shown, in some embodiments, a vertical slide groove 14 is provided on the side wall of the base 1, the fixing ring 2 includes a ring body 21 and a vertical slider 23, the inner side wall of the ring body 21 is provided with a vertical slider 23, the ring body 21 is sleeved on the base 1, and the vertical slider 23 can be slidably connected in the vertical slide groove 14.

[0088] In the above optional embodiment, it should be noted that there are multiple vertical slide grooves 14, and multiple vertical slide grooves 14 are distributed in a circular array on the outer periphery of the base 1. The number of vertical sliders 23 is equal to the number of vertical slide grooves 14, and multiple vertical sliders 23 are slidingly connected in the vertical slide grooves 14 in a one-to-one manner. The cross-sectional shape of the vertical slide groove 14 and the cross-sectional shape of the vertical slider 23 are both "convex" shapes. The top end face of the vertical slide groove 14 is the fifth limiting surface 16. When the tableting operation is performed, the fifth limiting surface 16 abuts against the upper end face of the vertical slider 23.

[0089] The beneficial effects of the above optional embodiments are: reliable sliding of the fixing ring 2 relative to the base 1 is achieved through the coordinated arrangement of the vertical slide groove 14 and the vertical slider 23, and reliable positioning of the fixing ring 2 can be achieved through the arrangement of the fifth limiting surface 16 abutting against the upper end surface of the vertical slider 23, thereby ensuring the reliability of the fixing ring 2 in limiting and fixing the multiple splicing plates 3.

[0090] Optional, such as Figures 1 to 11 As shown, in some embodiments, a plurality of transverse sliding grooves 15 are provided on the top wall of the base 1, and each splicing plate 3 includes a plate body 31 and a first transverse sliding block 32. The first transverse sliding block 32 is provided on one side of the plate body 31. When pressing the plate, the first transverse sliding block 32 can be slidably connected in the transverse sliding groove 15 one by one, and the inner end face of the plate body 31 is the first limiting surface 311.

[0091] The splicing plate 3 further includes a second transverse slide block 33 . The second transverse slide block 33 is provided on the other side of the plate body 31 . When the pressed sample 6 is taken out, the second transverse slide block 33 is slidably connected in the transverse slide groove 15 in a one-to-one correspondence.

[0092] The cross-sectional shapes of the transverse sliding groove 15 , the first transverse sliding block 32 , and the second transverse sliding block 33 are all convex.

[0093] The plurality of transverse sliding grooves 15 are distributed in a circular array.

[0094] An end surface of the first transverse sliding block 32 close to the first limiting surface 311 is a third limiting surface 321 , and an end surface of the second transverse sliding block 33 close to the first limiting surface 311 is a fourth limiting surface 331 .

[0095] The distance between the third limiting surface 321 and the first limiting surface 311 is smaller than the distance between the fourth limiting surface 331 and the first limiting surface 311 .

[0096] In the above optional embodiments, it should be noted that the inner end face of the transverse sliding groove 15 is the second limiting surface 12, the first limiting surface 311, the second limiting surface 12, the third limiting surface 321 and the fourth limiting surface 331 are all arc surfaces, and the arcs of the second limiting surface 12, the third limiting surface 321 and the fourth limiting surface 331 have the same center.

[0097] When the tableting operation is carried out, the second limiting surface 12 and the third limiting surface 321 abut against each other; when the sample 6 after tableting needs to be removed, the other splicing plates 3 are removed, and a splicing plate 3 is used to be slidably connected to the horizontal sliding groove 15 through the corresponding second horizontal sliding block 33, and the second sliding block 33 is slid to drive the first limiting surface 311 of the plate body 31 to move, and the first limiting surface 311 moves to push the sample 6 after tableting to separate it from the base 1, thereby ensuring the integrity of the sample 6 after tableting after separation from the base 1, and increasing the convenience of separating the sample 6 from the base 1.

[0098] The beneficial effect of the above optional embodiment is that by setting the distance between the third limiting surface 321 and the first limiting surface 311 to be smaller than the distance between the fourth limiting surface 331 and the first limiting surface 311, the integrity of the sample 6 after being separated from the base 1 after tableting is ensured, and the convenience of separating the sample 6 from the base 1 is increased.

[0099] Optional, such as Figures 2 to 12 As shown, in some embodiments, the pressure column 4 includes a column portion 41 and a positioning ring 42 , and a positioning ring 42 is provided at one end of the column portion 41 ; when working, the column portion 41 is inserted into the groove.

[0100] In the above optional embodiment, it should be noted that the positioning ring 42 is an annular column structure, and the column portion 41 and the positioning ring 42 are integrally formed.

[0101] The beneficial effect of the above optional embodiment is that the setting of the positioning ring 42 can realize the setting of the tablet press shaft centering, realize the reliable fixation of the mold during tableting, and thus ensure the reliability of powder tableting.

[0102] Optional, such as Figures 2 to 12 As shown, in some embodiments, a slot 13 is formed on the side wall of the base 1 , and a plug hole 22 is formed on the side wall of the ring body 21 . The insertion rod 5 passes through the plug hole 22 and is inserted into the slot 13 .

[0103] In the above optional embodiment, it should be noted that the number of slots 13 and sockets 22 is at least two, at least two slide grooves 13 are distributed in a circular array on the side wall of the base 1, and at least two sockets 22 are distributed in a circular array on the side wall of the ring body 21, and the sockets 22 and slots 13 are coaxially arranged in a one-to-one correspondence.

[0104] The beneficial effect of the above optional embodiment is that the fixing ring 2 is reliably fixed during operation by the coordinated arrangement of the inserting rod 5 , the slot 13 and the inserting hole 22 .

[0105] Optional, such as Figures 2 to 12As shown, in some embodiments, the insertion rod 5 includes a pull block 51 and a rod body 52. ​​During operation, one end of the rod body 52 passes through the insertion hole 22 and is inserted into the slot 13, and the other end of the rod body 52 is provided with a pull block 51.

[0106] Pull grooves 53 are formed on both sides of the pull block 51 .

[0107] The beneficial effect of the above optional embodiment is that the arrangement of the pull block 51 and the pull groove 53 ensures the convenience of inserting and removing the insertion rod 5.

[0108] In this embodiment, a micro-area in-situ analysis sample powder tableting device is used to tablet ultrafinely crushed black rock sample and Re standard powder material to prepare Re sample target and Re standard target respectively, so that the black rock sample powder can be pressed more compactly without adding a binder, thereby improving the sensitivity of in-situ analysis element testing; efficiency is improved, and the splicing plate is set to move backward after tableting, and the sample tablet is taken out from the side of the groove, without the need for secondary reverse pressing to take out the sample tablet, which further improves efficiency; at the same time, the surface of the pressed powder tablet is flat, avoiding problems such as mineral effect and particle effect, and has overall representativeness; in addition, the device places a plastic ring in the groove, then places the black rock sample powder in the plastic ring, and then fills the groove with a polyethylene powder filler to cover the top and outside of the plastic ring, and then presses it by the tableting equipment, so that different sizes of plastic rings can be set to press stable tablet-formed black rock sample powder of different sizes, which can be suitable for the sample bin size of different analytical instruments and can be directly sent to the sample analysis chamber of the analytical instrument.

[0109] S140. Perform a preliminary whole-rock Re content determination on the Re sample target using a laser in-situ analysis method based on the Re standard target to obtain preliminary whole-rock Re content data of the black rock series sample.

[0110] In this embodiment, the specific process of step S140 is as follows:

[0111] The Re content of the whole rock was preliminarily determined by LA-MC-ICP-MS. The black rock samples were all subjected to laser point ablation mode with an energy of 5.3 J cm -2 , frequency 8 Hz, background acquisition 20 s, analysis 50 s, rinse 30 s.

[0112] Under the same laser and mass spectrometry experimental conditions, laser point ablation was used to perform laser point analysis on the Re standard target and the Re sample target respectively;

[0113] The preliminary whole-rock Re content of the black rock series sample was obtained according to the following formula:

[0114] C2=(A2 / A1)×C1,

[0115] Among them, C2 represents the preliminary whole-rock Re content of the black rock sample, C1 represents the whole-rock Re content of the Re standard powder material, A1 represents the measurement count of the Re standard target, and A2 represents the measurement count of the Re sample target.

[0116] The laser spot size used is 70 μm to 80 μm, and the dot dwell time is 0.4 s to 0.5 s. Preferably, in this embodiment, the laser spot size used is 80 μm, and the dot dwell time is 0.5 s.

[0117] As shown in Table 1, the Re content of the whole rock of the Re sample target was preliminarily determined by the laser in-situ analysis method based on the Re standard target, and the preliminary whole-rock Re content data of the black rock series samples were obtained.

[0118] Table 1 Preliminary whole-rock Re content data analysis results of black shale and mudstone samples

[0119]

[0120]

[0121] Table 1 shows that the laser in-situ measurement results for the high-Re shale (GRe-1) (7375±420.05 ppb) agree with the reference result (7529.07±56.25 ppb) within the acceptable range, with a relative error of 2.09%. The laser in-situ measurement results for the low-Re shale (DRe-1) are 121±8.84 ppb, slightly higher than the reference result of 91.89±0.6788 ppb, with a relative error of 24.06%. The analysis reveals that the SiO2 content of the DRe-1 sample is only 40%, the lowest among all samples, while its CaO content is close to 15%, far higher than the other samples (all around 1%), indicating a significant matrix effect. The relative errors of the test results for three mudstone samples (16BZ-17, 16BZ-19, and 16BZ-98) with Re contents in the units, tens, and hundreds of ppb range, respectively, compared to the standard results were all less than 20%, at 9.4%, 10.7%, and 17.65%, respectively. Sample 16BZ-98, despite containing only 1.4 ppb of Re, still exhibited a relative error of less than 20%, strongly demonstrating that the S100 method for rapid and accurate Re content determination in black rock series is also applicable to black shale samples with ultra-low Re contents.

[0122] In this embodiment, from the preparation of the Re sample target to the preliminary determination of the whole-rock Re content of the Re sample target using the laser in-situ analysis method based on the Re standard target, the entire whole-rock Re content preliminary measurement process only takes one hour, while the process of the Re content preliminary measurement in the existing technology takes 5 days. Compared with the Re content preliminary measurement process in the existing technology, the test time is greatly saved and the test analysis efficiency is improved; and no chemical reagents are used in the entire preliminary measurement process, which fully meets the "fast" and "cheap" requirements for obtaining the optimal Re diluent ratio test. The whole-rock Re content preliminary measurement process can also be used for the rapid screening of Re resources in large quantities of black rock samples.

[0123] S150. Determine the addition ratio of the Re diluent based on the preliminary whole-rock Re content of the black rock series sample, and use a low-temperature semi-closed isotope dilution method to quickly and accurately determine the Re content.

[0124] Compared to Os, Re is chemically stable and less volatile. To further improve the efficiency of Re content determination, this embodiment proposes a low-temperature semi-closed isotope dilution method for sample digestion of black rock samples. The specific process of step S150 can be as follows:

[0125] First, weigh the ultrafinely ground black rock sample into a plastic centrifuge tube. Specifically, use a high-precision electronic analytical balance to weigh 0.1 g to 0.2 g of the ultrafinely ground black rock sample into the plastic centrifuge tube. Preferably, in this embodiment, weigh 0.1 g of the ultrafinely ground black rock sample into a 15 mL plastic centrifuge tube.

[0126] Next, HCl, HNO 3 and Re diluent were added to the plastic centrifuge tube.

[0127] According to the preliminary whole-rock Re content data of the black rock series sample obtained in step S140, the addition ratio of Re diluent is determined. 1 mL to 2 mL of 12 mol / L HCl, 1.5 mL to 2 mL of 16 mol / L HNO3 and 185 Re diluent. Specifically, in this embodiment, 1 ml of 12 mol / L HCl and 1.5 ml of 16 mol / L HNO3 were added.

[0128] Then, the plastic centrifuge tube is capped and ultrasonically shaken for 0.5 to 0.6 hours. Preferably, in this embodiment, ultrasonic shaking is performed for 0.5 hours.

[0129] Then, the mixture was placed in an oven at 105° C. to 110° C. and heated for 12 to 15 hours. Specifically, the shaken plastic centrifuge tube was placed in an oven at 105° C. and heated for 12 hours.

[0130] Then, after heating is completed, the plastic centrifuge tube is placed in a centrifuge for centrifugation. Specifically, the plastic centrifuge tube is placed in a centrifuge and centrifuged at 2500 rpm for 10 minutes.

[0131] Finally, the supernatant was diluted and then quickly and accurately determined using MC-ICP-MS. Specifically, 0.1 mL of the supernatant was diluted 10-fold and then tested on the instrument.

[0132] The Re content was directly analyzed and determined using the Neptune Plus MC-ICP-MS produced by Thermo Fisher. The multi-collector inductively coupled plasma mass spectrometer of the Re-Os Key Laboratory of the National Center for Geological Experiments and Testing uses both energy and mass focusing methods. The dynamic zoom technology can increase the ion mass dispersion by 17%. It is equipped with 7 Faraday cup receivers and a fixed central channel ion counter receiver in the middle. In addition to the central cup, 4 electric motors are used on each side of the high and low mass numbers to drive precise position changes. An electron multiplier is configured behind the central cup, and 4 ion counters are installed outside the lowest mass cup. It can realize static simultaneous reception measurement of the Faraday cup and quasi-static measurement of the ion counter with a single jump peak. The use of high-sensitivity JET sampling cones and X-type interceptor cones significantly improves the sensitivity by about 2 times. The instrument's internal measurement accuracy is less than 0.05% (Re content greater than 1ng / g), and the sensitivity of a 1pg Re sample can reach 60,000cps (1mV). For the Re element, static Faraday mode is used for simultaneous determination 185 Re and 187 Re.

[0133] As shown in Table 2, the Re content data measured by the low-temperature semi-closed isotope dilution method in this example and the traditional high-temperature Teflon closed digestion tank dissolution method were compared.

[0134] Table 2 Re content results of two analysis methods using low-temperature semi-closed and high-temperature Teflon sealed digestion tanks

[0135] Sample type Sample number Original name Re content (ppb) Test Method black shale 240128-1 B54 26.1 Low temperature semi-enclosed black shale 240128-2 B54 26.2 Low temperature semi-enclosed black shale 240128-3 DRe-1 95.5 Low temperature semi-enclosed black shale 240129-4 DRe-1 98.4 Low temperature semi-enclosed black shale 240201-1 B54 26.9 High temperature sealed black shale 240201-2 B54 26.2 High temperature sealed black shale 240201-3 DRe-1 96.2 High temperature sealed black shale 240201-4 DRe-1 97.7 High temperature sealed

[0136] As shown in Table 2, the same samples of B54 and DRe-1 were analyzed using the low-temperature semi-closed rapid digestion method and the high-temperature Teflon sealed digestion vessel method, respectively. The results are shown in Table 3.5. The low-temperature semi-closed method yielded Re contents of 26.1 ppb and 26.2 ppb, respectively, for the B54 sample, and 95.5 ppb and 98.4 ppb, respectively, for the DRe-1 sample. The high-temperature Teflon sealed digestion vessel method yielded Re contents of 26.9 ppb and 26.2 ppb, respectively, for the B54 sample, and 96.2 ppb and 97.7 ppb, respectively, for the DRe-1 sample. The two test results are largely consistent, indicating that the majority of the Re in the samples was dissolved under the conditions of 105°C for 12 hours. Furthermore, the low-temperature semi-closed method requires less time, has more readily available materials, and simplifies the experimental procedure.

[0137] Table 3 shows a comparison of the low-temperature, semi-enclosed rapid Re test results with the standard recommended values. As shown in Table 3, the test value of the B54 sample (26.15±0.07ppb) is completely consistent with the standard recommended value (26.71±0.07ppb), with a relative error of only 0.2%. The test value of the DRe-1 sample (96.95±2.05ppb) is approximately 5% higher than the value measured by the traditional Carius tube method. This may be due to the DRe-1 sample's lower homogeneity than the black rock series candidate standard material B54, resulting in a "nugget effect." However, this result is still acceptable within the error range. In summary, the above results are basically consistent with the recommended values ​​within the error range, demonstrating the accuracy and reliability of the low-temperature, semi-enclosed rapid Re test method established in this example.

[0138] Table 3 Comparison of low temperature semi-enclosed rapid Re test results with standard recommended values

[0139]

[0140] In this example, a low-temperature semi-closed isotope dilution method was used to quickly and accurately determine the Re content. 187 Os will 187 Re interferes with the measurement. Compared to Os, Re is chemically more stable and less volatile. Therefore, a low-temperature, semi-enclosed dissolution method is employed. Firstly, the low temperature prevents Re from volatilizing and losing, which could affect measurement accuracy. Secondly, the semi-enclosed environment ensures that the interfering element Os evaporates cleanly, preventing interference with the measurement, thereby improving Re content determination accuracy. Furthermore, the separate distillation of Os is unnecessary, saving time and costs. This Re content determination method can be completed in just one day, significantly improving single-sample analysis efficiency by more than fivefold. Furthermore, only inexpensive plastic centrifuge tubes are used. While maintaining analytical accuracy at the ppt-ppb level, the testing cost is reduced by 70%.

[0141] In summary, the method for rapid and accurate determination of Re content in black rock series of the present invention adopts a laser in-situ analysis method to perform a preliminary determination of Re content in the whole rock on Re sample target based on Re standard target, and adopts a low-temperature semi-closed isotope dilution method to perform rapid and accurate determination of Re content, wherein the isotope dilution method and multi-collector inductively coupled plasma mass spectrometry are combined to determine Re content, which can quickly and accurately determine pg-ng level Re content, thereby ensuring the accuracy of Re content determination in black rock series; the entire Re content preliminary determination and fine determination process only takes two days, which is greatly shortened compared to the traditional 10 days, and the single sample analysis efficiency is increased by more than 5 times; at the same time, in the process of rapid and accurate determination of Re content in black rock series, the use of chemical reagents and laboratory utensils is relatively small, the detection cost is reduced by 70%, and the cost is saved; the method for determining Re content in black rock series can measure accurately, quickly and at low cost, and will provide strong technical support for the rapid screening of Re resources in large quantities of black rock series samples.

[0142] It will be understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art will appreciate that various modifications and improvements can be made without departing from the spirit and substance of the present invention, and such modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for quickly and accurately determining the Re content of black rock series, characterized in that: The method comprises: Collect black rock samples and grind them into ultrafine powder; Prepare Re standard powder material with the same lithology as the black rock series sample; The ultrafinely crushed black rock sample and the Re standard powder material are respectively tableted to prepare a Re sample target and a Re standard target; The Re content of the whole rock of the Re sample target is preliminarily determined by using the laser in-situ analysis method based on the Re standard target to obtain preliminary whole rock Re content data of the black rock series sample; The addition ratio of the Re diluent is determined based on the preliminary whole-rock Re content of the black rock series sample, and the Re content is quickly and accurately determined using a low-temperature semi-closed isotope dilution method.

2. The method according to claim 1, characterized in that The semi-closed isotope dilution method is used to quickly and accurately determine the Re content, including: Weigh the ultrafinely crushed black rock sample into a plastic centrifuge tube; Add HCl, HNO3 and Re diluent to the plastic centrifuge tube; The plastic centrifuge tube is capped and ultrasonically shaken; Heat in an oven at 105℃~110℃; After heating is completed, the plastic centrifuge tube is placed in a centrifuge for centrifugation; The supernatant was diluted and then the Re content was determined quickly and accurately using MC-ICP-MS.

3. The method according to claim 2, characterized in that Weigh 0.1 g to 0.2 g of ultrafinely crushed black rock sample into a plastic centrifuge tube; add 1 mL to 2 mL of 12 mol / L HCl and 1.5 mL to 2 mL of 16 mol / L HNO3 to the plastic centrifuge tube; perform ultrasonic vibration for 0.5 h to 0.6 h; and heat in an oven for 12 h to 15 h.

4. The method according to any one of claims 1 to 3, characterized in that The ultrafinely crushed black rock sample and the Re standard powder material are respectively tableted to prepare a Re sample target and a Re standard target, comprising: A powder tabletting device for micro-area in-situ analysis of sample powder is used for tableting; wherein the tableting device includes a base, a fixing ring, a splicing plate, a pressing column, an inserting rod, a plastic ring and a polyethylene powder filling body; There are multiple splicing plates, each of which is slidably connected to the upper surface of the base, the fixing ring is slidably connected to the outer side wall of the base, and each of the splicing plates has a first limiting surface; During sheet pressing, the plurality of splicing plates are slidably spliced ​​on the base and the plurality of first limiting surfaces are combined to form a groove, the fixing ring is sleeved on the outer peripheral side of the plurality of spliced ​​splicing plates, the insertion rod passes through the fixing ring and is inserted into the base, and the pressure column is inserted into the groove; The plastic ring is arranged in the groove, and is used to place black rock sample powder. The polyethylene powder filler is used to fill the groove to cover the black rock sample powder in the plastic ring and the outside of the plastic ring.

5. The method according to claim 4, characterized in that The tablet pressing device also includes: A vertical sliding groove is provided on the side wall of the base. The fixed ring includes a ring body and a vertical sliding block. The vertical sliding block is provided on the inner side wall of the ring body. The ring body is sleeved on the base. The vertical sliding block can be slidably connected in the vertical sliding groove.

6. The method according to claim 4, characterized in that The tablet pressing device also includes: The top wall of the base is provided with a plurality of transverse sliding grooves, and each of the splicing plates includes a plate body and a first transverse sliding block. The first transverse sliding block is provided on one side of the plate body. When pressing the plate, the first transverse sliding block is slidably connected in the transverse sliding groove in a one-to-one correspondence, and the inner end surface of the plate body is a first limiting surface; The splicing plate further comprises a second transverse sliding block, and the second transverse sliding block is provided on the other side of the plate body. When the sample after tableting is taken out, the second transverse sliding block can be slidably connected in the transverse sliding groove.

7. The method according to any one of claims 1 to 3, characterized in that The whole-rock Re content of the Re sample target is preliminarily determined using the laser in-situ analysis method based on the Re standard target to obtain preliminary whole-rock Re content data of the black rock series sample, including: Under the same laser and mass spectrometry experimental conditions, laser point ablation was used to perform laser point analysis on the Re standard target and the Re sample target respectively; The preliminary whole-rock Re content of the black rock series sample was obtained according to the following formula: C2=(A2 / A1)×C1, Among them, C2 represents the preliminary whole-rock Re content of the black rock sample, C1 represents the whole-rock Re content of the Re standard powder material, A1 represents the measurement count of the Re standard target, and A2 represents the measurement count of the Re sample target.

8. The method according to claim 7, characterized in that The laser spot beam used is 70μm to 80μm, and the dot dwell time is 0.4s to 0.5s.

9. The method according to any one of claims 1 to 3, characterized in that Preparation of Re standard powder material with the same lithology as the black rock series sample, including: Collect alternative reference materials with the same lithology as the black rock series samples; Grinding the candidate standard substance to less than 200 mesh; The crushed candidate standard substances are divided into a plurality of wide-mouth bottles and mixed evenly; The candidate standard substances were tested for homogeneity, stability and normality of fixed value data.

10. The method according to any one of claims 1 to 3, characterized in that The black rock sample is collected and ultra-finely crushed, including: Black rock series samples were collected and cleaned with deionized water; The black rock samples were ultrafinely ground and pulverized using a planetary ball mill to a size below 200 mesh, and the ultrafinely ground black rock samples were mixed evenly to increase the homogeneity of the samples.

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