A method for rapid and accurate determination of re content in black rock series

Abstract

The application provides a kind of black rock series Re content fast and accurate determination method, comprising: collecting black rock series sample and carrying out superfine crushing;Preparation and black rock series sample lithology same Re standard powder material;Ultrafine crushing after black rock series sample and Re standard powder material are pressed respectively to prepare Re sample target and Re standard target;According to Re standard target, preliminary determination of whole rock Re content is carried out to Re sample target using laser in-situ analysis method, and preliminary whole rock Re content data of black rock series sample is obtained;According to the preliminary whole rock Re content of black rock series sample, the addition ratio of Re diluent is determined, and the Re content is rapidly and accurately determined by using low-temperature semi-closed isotope dilution method. The method can be used to determine the Re content of black rock series, which is accurate, fast and low-cost, and can provide strong technical support for the rapid screening of Re resources in a large number of black rock series samples.

Description

Technical Field

[0001] This invention belongs to the field of Re content determination technology in black rock formations, specifically relating to a rapid and accurate method for determining the Re content in black rock formations. Background Technology

[0002] Rhenium (Re), as a strategic emerging mineral, is an indispensable key raw material in the defense and aerospace fields. In nature, molybdenite is the main mineral where Re is found, but the proven resources are limited, leading to an increasingly prominent supply-demand imbalance. In recent years, anomalous enrichment of Re has been discovered in black rock formations (such as black shale, mudstone, and limestone). Black rock formations are widely developed in my country, indicating a huge potential for Re resources, which are expected to become an important source of future Re metal reserves. However, despite the enormous potential of Re in black rock formations as a prospective strategic resource, current research on it remains relatively weak, mainly facing challenges such as…

[0003] The following question:

[0004] Traditional testing methods (such as neutron activation and atomic emission spectroscopy) cannot accurately determine the Re content in ppb-ppt level black rock samples. Although isotope dilution methods combined with thermal ionization mass spectrometry or multiple receiver mass spectrometry (ID-NTIMS / ) are effective, these methods are not universally applicable.

[0005] ID-MC-ICP-MS can accurately determine the Re content in pg-ng level samples. Generally, it takes two days from weighing the sample to dissolving it in a Carius tube and cooling it to room temperature before opening. From distilling to separate Os and remove interferences, to enriching and purifying Re via anion exchange or acetone extraction, preparing for the instrument also takes two days. Finally, the instrument testing takes one day. One experimental procedure takes five days. However, to obtain accurate Re content results, two procedures are generally required: the first is mainly used for initial Re content determination to determine the optimal Re diluent ratio; the second is used for precise determination to obtain the accurate Re content. Thus, from initial diluent addition to obtaining accurate results, it takes a total of 10 days. Moreover, the entire experimental process consumes a large amount of chemical reagents and equipment, resulting in high experimental costs.

[0006] In summary, existing methods for determining Re content in black rock formations suffer from problems such as complex analytical procedures, long testing cycles, and high testing costs. These methods cannot meet the testing needs of large-scale samples and severely restrict the evaluation and exploitation of Re resource potential in black rock formations.

[0007] To address the aforementioned issues, it is necessary to propose a well-designed and effective method for the rapid and accurate determination of Re content in black rock formations. Summary of the Invention

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

[0009] The present application provides a method for rapidly and accurately determining Re content in black rock series, which comprises

[0010] the following steps:

[0011] collecting a black rock series sample and performing ultrafine crushing;

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

[0013] performing tabletting on the ultrafine crushed black rock series sample and the Re standard powder material respectively to prepare a Re sample target and a Re standard target;

[0014] performing preliminary determination of whole rock Re content on the Re sample target according to the Re standard target by using a laser in-situ analysis method, to obtain preliminary whole rock Re content data of the black rock series sample;

[0015] determining the addition ratio of Re diluent according to the preliminary whole rock Re content of the black rock series sample, and performing rapid and accurate determination of Re content by using a low-temperature semi-closed isotope dilution method.

[0016] Optionally, the rapid and accurate determination of Re content by using the semi-closed isotope dilution method comprises the following steps:

[0017] weighing the ultrafine crushed black rock series sample into a plastic centrifuge tube;

[0018] adding HCl, HNO3 and Re diluent into the plastic centrifuge tube;

[0019] covering the plastic centrifuge tube with a bottle cap and performing ultrasonic oscillation;

[0020] placing the plastic centrifuge tube into an oven at 105 DEG C to 110 DEG C for heating;

[0021] after heating, placing the plastic centrifuge tube into a centrifuge for centrifugation;

[0022] diluting the supernatant and performing rapid and accurate determination of Re content by using MC-ICP-MS.

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

[0024] Optionally, the sample of the ultrafine crushed black rock series and the Re standard powder substance are respectively pressed to prepare a Re sample target and a Re standard target, comprising:

[0025] The sample is pressed by using a device for in-situ analysis of a sample powder pressing plate, wherein the device comprises a base, a fixing ring, a splicing plate, a pressing column, an insertion rod, a plastic ring and a polyethylene powder filling body;

[0026] The splicing plate has a plurality of splicing plates, and each of the plurality of splicing plates is slidably connected to the upper surface of the base. The fixing ring is slidably connected to the outer sidewall of the base. Each of the splicing plates has a first limiting surface.

[0027] When the sample is pressed, the plurality of splicing plates are slidably spliced on the base, and the plurality of first limiting surfaces form a groove. The fixing ring is sleeved on the outer circumferential side of the plurality of splicing plates after splicing. The insertion rod is inserted into the base through the fixing ring. The pressing column is inserted into the groove.

[0028] The plastic ring is arranged in the groove, and the plastic ring is used to place the black rock series sample powder. The polyethylene powder filling body is used to fill the groove to cover the black rock series sample powder in the plastic ring and the outer side of the plastic ring.

[0029] Optionally, the pressing device further comprises:

[0030] The sidewall of the base is provided with a vertical sliding groove. The fixing ring comprises a ring body and a vertical sliding block. The inner sidewall of the ring body is provided with the vertical sliding block. The ring body is sleeved on the base. The vertical sliding block is slidably connected in the vertical sliding groove.

[0031] Optionally, the pressing device further comprises:

[0032] The top wall of the base is provided with a plurality of horizontal sliding grooves. Each of the splicing plates comprises a plate body and a first horizontal sliding block. One side surface of the plate body is provided with the first horizontal sliding block. When the sample is pressed, the first horizontal sliding block is slidably connected in the horizontal sliding groove one by one. The end surface of the inner side of the plate body is a first limiting surface.

[0033] The splicing plate further comprises a second horizontal sliding block. The other side surface of the plate body is provided with the second horizontal sliding block. When the sample after pressing is taken out, the second horizontal sliding block is slidably connected in the horizontal sliding groove.

[0034] Optionally, the preliminary determination of the whole rock Re content of the Re sample target is carried out by using a laser in-situ analysis method according to the Re standard target, to obtain the preliminary whole rock Re content data of the black rock series sample, comprising:

[0035] The Re standard target and the Re sample target are analyzed by laser dotting analysis under the same laser and mass spectrometry experimental conditions.

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

[0037] C2=(A2 / A1)xC1,

[0038] Wherein, C2 represents the preliminary whole rock Re content of the black rock series sample, C1 represents the whole rock Re content of the Re standard powder substance, A1 represents the measured count of the Re standard target, and A2 represents the measured count of the Re sample target.

[0039] Optionally, the laser spot beam used is 70-80 mu m, and the dotting residence time is 0.4-0.5 s.

[0040] Optionally, the Re standard powder substance with the same lithology as the black rock series sample is prepared, comprising:

[0041] The alternative standard substance with the same lithology as the black rock series sample is collected;

[0042] The alternative standard substance is crushed and ground to less than 200 mesh;

[0043] The crushed alternative standard substance is divided into multiple jars and mixed uniformly;

[0044] The alternative standard substance is subjected to normality detection of uniformity, stability and value data, respectively.

[0045] Optionally, the black rock series sample is collected and ultra-finely crushed, comprising:

[0046] The black rock series sample is collected and cleaned with deionized water;

[0047] The black rock series sample is ultra-finely ground and crushed by a planetary ball mill, the black rock series sample is ground to less than 200 mesh, and the ultra-finely ground and crushed black rock series sample is mixed uniformly to increase the uniformity of the sample.

[0048] The method for rapidly and accurately determining the Re content of the black rock series provided by the application comprises the following steps: preliminarily determining the Re content of a sample target by using a laser in-situ analysis method according to a Re standard target, and rapidly and accurately determining the Re content by using a low-temperature semi-closed isotope dilution method, wherein the Re content is rapidly and accurately determined in the pg-ng level by using the isotope dilution method and a multi-receiving inductively coupled plasma mass spectrometry, so that the accuracy of the determination of the Re content of the black rock series is ensured; the preliminary determination and the accurate determination of the Re content only need 2 days, which is greatly shorter than the traditional 10 days, and the analysis efficiency of a single sample is improved; meanwhile, the use amount of chemical reagents and experimental vessels is small during the rapid and accurate determination of the Re content of the black rock series, and the detection cost is reduced by 70%, so that the cost is saved; the Re content of the black rock series is determined by using the method, the determination is accurate and fast, and the cost is low, which provides strong technical support for the rapid screening of Re resources in a large number of black rock series samples. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 A flowchart of a method for rapidly and accurately determining the Re content of the black rock series according to an embodiment of the application.

[0050] Figure 2 A perspective view of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0051] Figure 3 A top view of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0052] Figure 4 A side view of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0053] Figure 5 A sectional view of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0054] Figure 6 A first view of a perspective view of a base of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0055] Figure 7 A second view of a perspective view of a base of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0056] Figure 8 A perspective view of a fixing ring of a sample powder pressing device for micro-area in-situ analysis according to another embodiment of the application.

[0057] Figure 9A first view of a perspective view of a splice plate of a sample powder tabletting device for micro-area in-situ analysis according to another embodiment of the present application.

[0058] Figure 10 A second view of a perspective view of a splice plate of a sample powder tabletting device for micro-area in-situ analysis according to another embodiment of the present application.

[0059] Figure 11 A perspective view of a pressing column of a sample powder tabletting device for micro-area in-situ analysis according to another embodiment of the present application.

[0060] Figure 12 A perspective view of an insertion rod of a sample powder tabletting device for micro-area in-situ analysis according to another embodiment of the present application. DETAILED DESCRIPTION

[0061] In order for those skilled in the art to better understand the technical solutions of the present application, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0062] As shown in Figure 1 The present application provides a method S100 for rapidly and accurately determining the Re content of black rock series, and the method S100 comprises the following steps:

[0063] S110, collecting a black rock series sample and performing superfine crushing.

[0064] Specifically, first, a black rock series sample is collected and cleaned with deionized water. The black rock series sample can be a limestone sample, a black shale sample, or a mudstone sample.

[0065] Second, a planetary ball mill is used to perform superfine grinding and crushing on the black rock series sample, the black rock series sample is ground to 200 mesh or less, and the black rock series sample after superfine grinding and crushing is mixed uniformly to increase the uniformity of the sample.

[0066] S120, preparing a Re standard powder substance with the same lithology as the black rock series sample.

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

[0068] First, a candidate standard substance with the same lithology as the black rock series sample is collected.

[0069] Specifically, if the black rock series sample is limestone, the candidate standard substance is also collected as limestone to ensure that the lithology of the candidate standard substance is consistent with that of the collected black rock series sample. In this embodiment, the Re standard substance development work is carried out on the Permian limestone collected from Dongchuanling area of Guangde in Anhui and the Sinian black shale collected from Kunyang phosphorite, and two black rock series Re analysis standard substances of carbonate and silicate are developed.

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

[0071] Specifically, after the collected alternative standard substance is washed clean with deionized water, it is finely ground and crushed to less than 200 mesh and mixed uniformly.

[0072] Thirdly, the crushed alternative standard substance is divided into multiple jars and mixed uniformly.

[0073] Specifically, the crushed alternative standard substance is divided into 100 2L plastic jars, 10g per jar, and shaken by hand after filling to mix it uniformly in the jar. Each jar is numbered for drawing for uniformity and stability tests.

[0074] Finally, the alternative standard substance is respectively subjected to normality tests of uniformity, stability and value data.

[0075] Specifically, 12 bottles of limestone and 12 bottles of black shale alternative standard substances are drawn, 0.5g each, and subjected to normality tests of uniformity, stability and value data in sequence after sample dissolution, chemical separation, enrichment and purification.

[0076] Among them, the inter-bottle average value (AV1) of the limestone alternative standard substance is 6.473 ppb, the inter-bottle standard deviation (s1) is 0.144, the total intra-bottle standard deviation (s2) is 0.117, and the RSD (%) (2s, n=15) is 0.02; the inter-bottle average value (AV1) of the black shale alternative standard substance is 26.39, the inter-bottle standard deviation (s1) is 0.55, the total intra-bottle standard deviation (s2) is 0.332, and the RSD (%) (2s, n=15) is 0.02. The results show that the uniformity of the two black rock series alternative standard substances is good. The stability test shows that the deviation of the test results after 6 months apart is not more than the standard deviation of the variance itself, and is consistent with the total average value obtained by value analysis, indicating that the stability of the sample is good. The Shapiro-Wilk method is used for normality test of all original measurement data, and the Re standard value of the limestone standard substance is determined as 6.473 ppb with an uncertainty of 0.016; the Re standard value of the black shale standard substance is 26.71 ppb with an uncertainty of 0.07. Through the cooperative value research of the Institute of Geology and Geophysics of the Chinese Academy of Sciences, the Re standard value of the limestone standard substance is 6.413 ppb with an uncertainty of 0.387; the Re standard value of the black shale standard substance is 25.85 ppb with an uncertainty of 0.27. The results obtained are consistent with those in the range of uncertainty in this paper.

[0077] This embodiment provides a Re standard powder material for Re composition analysis of black rock formations, filling the gap in domestic Re standard materials for black rock formations, providing a solid guarantee for the accuracy and reliability of Re content analysis results, and meeting my country's needs for the development and utilization of rhenium resources in black rock formations.

[0078] S130. The ultrafine pulverized black rock sample and the Re standard powder were pressed into tablets to prepare Re sample targets and Re standard targets, respectively.

[0079] Conventional tableting devices, due to the limitations of the pressing mold structure, require a second reverse pressing after sample compression to remove the tablet, resulting in low efficiency and wasted time and manpower. Furthermore, because rock sample powders are difficult to bind, conventional tableting equipment often requires insufficient pressure to effectively compress the sample into tablets. This introduces additional chemical interference, leads to loose powder sample compression, uneven powder sample surfaces, and issues such as mineral effects and particle effects.

[0080] In response to this, such as Figures 2 to 12 As shown, in this embodiment, a sample powder pressing device for in-situ micro-area analysis is used to press ultrafinely pulverized black rock samples and Re standard powder materials into pellets to prepare Re sample targets and Re standard targets, respectively. In this embodiment, the preparation of the Re sample target is used as an example for explanation; 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 sample powder pressing device for in-situ analysis of micro-area, comprising a base 1, a fixing ring 2, a splicing plate 3, a pressing column 4, an insert rod 5, a plastic ring 6, and a polyethylene powder filler 7.

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

[0083] During tablet pressing, multiple splicing plates 3 slide and splice on the base 1, and multiple first limiting surfaces 311 combine to form a groove. The fixing ring 2 is sleeved on the outer periphery of the multiple splicing plates 3 after splicing. The insertion rod 5 passes through the fixing ring 2 and is inserted into the base 1. The pressure column 4 is inserted into the groove.

[0084] A plastic ring 6 is set in the groove. The plastic ring 6 is used to place black rock sample powder. The polyethylene powder filler 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 base 1 is cylindrical, the fixing ring 2 is annular, and the splicing plate 3 is fan-shaped. When the black rock sample powder needs to be pressed into tablets, multiple splicing plates 3 slide and splice 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 combine to form a circular groove. Then, the fixing ring 2 slides 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 fitted onto the base 1. Another part of 2 is fitted onto a cylindrical structure formed by splicing multiple splicing plates 3 to form a ring shape. Then, the fixing ring 2 is fixed to the base 1 by the insert rod 5. The fixing ring 2 realizes the limiting of multiple splicing plates 3. 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 groove is filled with polyethylene powder filler 7 to cover the black rock sample powder inside the plastic ring 6 and the outside of the plastic ring 6. Then, the pressing column 4 is inserted into the groove, and then the tableting machine is used to press the pressing column 4 to compress the tablet.

[0086] After the black rock sample powder is pressed into a Re sample target, firstly, the pressing column 4 is pulled out of the groove, then the insert rod 5 is pulled out of the base 1, and then the fixing ring 2 is slid downwards until it is completely detached from the splicing plate 3. Then, multiple splicing plates 3 are slid off the base 1, and then the Re sample target is taken out 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 pressing. At the same time, since the plastic ring 6 has a certain degree of deformability, when the polyethylene powder filler is applied to the top of the black rock sample powder and the outside of the plastic ring 6, the ring wall of the plastic ring 6 also applies pressure to the periphery 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, the side wall of the base 1 is provided with a vertical sliding groove 14, and 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 is slidably connected in the vertical sliding groove 14.

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

[0089] The beneficial effect of the above-mentioned optional embodiment is that the reliable sliding of the fixed ring 2 relative to the base 1 is realized through the cooperation of the vertical sliding groove 14 and the vertical sliding block 23, and the reliable limiting of the fixed ring 2 is realized through the abutting arrangement of the fifth limiting surface 16 and the upper end surface of the vertical sliding block 23, thereby guaranteeing the reliability of the limiting and fixing of the plurality of splicing plates 3 by the fixed ring 2.

[0090] Optionally, as shown in the drawings, in some embodiments, the top wall of the base 1 is provided with a plurality of horizontal sliding grooves 15, and each splicing plate 3 comprises a plate body 31 and a first horizontal sliding block 32. One side surface of the plate body 31 is provided with the first horizontal sliding block 32. When the tablet is pressed, the first horizontal sliding block 32 is slidably connected in the horizontal sliding groove 15 one by one, and the end surface of the inner side of the plate body 31 is a first limiting surface 311. Figures 1 to 11

[0091] The splicing plate 3 further comprises a second horizontal sliding block 33, and the other side surface of the plate body 31 is provided with the second horizontal sliding block 33. When the sample 6 after pressing the tablet is taken out, the second horizontal sliding block 33 is slidably connected in the horizontal sliding groove 15 one by one.

[0092] The cross-sectional shape of the horizontal sliding groove 15, the cross-sectional shape of the first horizontal sliding block 32, and the cross-sectional shape of the second horizontal sliding block 33 are all "convex" characters.

[0093] The plurality of horizontal sliding grooves 15 are distributed in a circumferential array.

[0094] The end surface of the first horizontal sliding block 32 close to the first limiting surface 311 is a third limiting surface 321, and the end surface of the second horizontal 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 less than the distance between the fourth limiting surface 331 and the first limiting surface 311.

[0096] In the above-mentioned optional embodiment, it should be noted that the inner end surface of the horizontal sliding groove 15 is a 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 circular arc surfaces, and the circular arcs of the second limiting surface 12, the third limiting surface 321, and the fourth limiting surface 331 are the same center.

[0097] ​When the tabletting work is carried out, the second limiting surface 12 and the third limiting surface 321 abut; when it is necessary to take down the tabletted sample 6, the other splicing plates 3 are taken down, one splicing plate 3 is slidably connected in the horizontal sliding groove 15 through the corresponding second horizontal sliding block 33, the second sliding block 33 is slid, the first limiting surface 311 of the plate body 31 is moved, the tabletted sample 6 is pushed to separate from the base 1 by the movement of the first limiting surface 311, and then the integrity of the tabletted sample 6 after being separated from the base 1 is guaranteed, and the convenience of separating the sample 6 from the base 1 is increased.

[0098] The beneficial effect of the above-mentioned optional embodiment is that the integrity of the tabletted sample 6 after being separated from the base 1 is guaranteed, and the convenience of separating the sample 6 from the base 1 is increased, through the setting that the distance between the third limiting surface 321 and the first limiting surface 311 is less than the distance between the fourth limiting surface 331 and the first limiting surface 311.

[0099] Optionally, as shown in Figures 2 to 12 In some embodiments, the pressing column 4 includes a column body 41 and a positioning ring 42, and the column body 41 is provided with the positioning ring 42 at one end; during work, the column body 41 is inserted in the groove.

[0100] In the above-mentioned optional embodiment, it should be noted that the positioning ring 42 is a ring-shaped column structure, and the column body 41 and the positioning ring 42 are integrally formed.

[0101] The beneficial effect of the above-mentioned optional embodiment is that the centering of the pressing shaft of the tablet press can be achieved through the setting of the positioning ring 42, reliable fixation of the mold during tabletting is achieved, and then the reliability of powder tabletting is guaranteed.

[0102] Optionally, as shown in Figures 2 to 12 In some embodiments, the sidewall of the base 1 is provided with a slot 13, the sidewall of the ring body 21 is provided with a insertion hole 22, and the insertion rod 5 is inserted in the slot 13 through the insertion hole 22.

[0103] In the above-mentioned optional embodiment, it should be noted that the number of the slot 13 and the insertion hole 22 is at least two, the at least two slots 13 are circumferentially arrayed on the sidewall of the base 1, the at least two insertion holes 22 are circumferentially arrayed on the sidewall of the ring body 21, and the insertion hole 22 and the slot 13 are coaxially arranged one by one.

[0104] The beneficial effect of the above-mentioned optional embodiment is that reliable fixation of the fixing ring 2 during work is achieved through the cooperation of the insertion rod 5, the slot 13 and the insertion hole 22.

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

[0106] The pulling block 51 is provided with pulling grooves 53 on both sides.

[0107] The above-mentioned optional embodiments have the beneficial effect that the pulling block 51 and the pulling groove 53 ensure the convenience of insertion and extraction of the insertion rod 5.

[0108] In the embodiment, a sample powder tabletting device for micro-area in-situ analysis is used to press the black rock series sample and the Re standard powder substance after superfine crushing to prepare Re sample targets and Re standard targets, so that the black rock series sample powder is pressed more tightly without adding a binder, the sensitivity of in-situ analysis element testing is improved; the efficiency is improved, the splicing plate is moved backward after the tabletting is completed, the sample tablet is taken out from the groove from the side, the sample tablet does not need to be taken out after being pressed in the reverse direction for the second time, and the efficiency is further improved; at the same time, the pressed powder tablet surface is flat, mineral effect, particle effect and other problems are avoided, and the whole sample is representative; in addition, the device places a plastic ring in the groove, sets the black rock series sample powder on the plastic ring, fills polyethylene powder filling body on the top and outside of the plastic ring, and then presses the sample by a tabletting device, so that different sizes of plastic rings are set to press different sizes of stable black rock series sample powder tablets, which can be suitable for different sample chamber sizes of analysis instruments and can be directly sent into the sample analysis chamber of the analysis instrument.

[0109] S140, preliminarily determining the whole rock Re content of the Re sample target according to the Re standard target by using a laser in-situ analysis method, to obtain preliminary whole rock Re content data of the black rock series sample.

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

[0111] The LA-MC-ICP-MS is used to preliminarily determine the whole rock Re content of the Re sample target, the black rock series sample is subjected to laser point ablation mode, the energy is 5.3 J cm -2 , the frequency is 8 Hz, the background collection is 20 s, the analysis is 50 s, and the flushing is 30 s.

[0112] Under the same laser and mass spectrometry conditions, the Re standard target and the Re sample target are subjected to laser point analysis in sequence by using laser point ablation.

[0113] According to the following formula, the preliminary whole rock Re content of the black rock series sample is obtained:

[0114] C2=(A2 / A1)xC1,

[0115] wherein C2 represents the preliminary whole rock Re content of the black rock series sample, C1 represents the whole rock Re content of the Re standard powder material, and A1 represents the measured counts of the Re standard target, and A2 represents the measured counts of the Re sample target.

[0116] wherein the laser spot beam used is 70 μm to 80 μm, and the dotting residence time is 0.4 s to 0.5 s. Preferably, in the present embodiment, the laser spot beam used is 80 μm, and the dotting residence time is 0.5 s.

[0117] As shown in Table 1, the preliminary whole rock Re content data of the black rock series sample was obtained by using the laser in-situ analysis method to preliminarily determine the whole rock Re content of the Re sample target according to the Re standard target.

[0118] Table 1 Analysis results of preliminary whole rock Re content data of black shale and mudstone samples

[0119]

[0120]

[0121] As shown in Table 1, the laser in-situ test result (7375±420.05 ppb) of the high Re content shale (GRe-1) is consistent with the standard result (7529.07±56.25 ppb) within the error range, and the relative error is 2.09%, which is within the controllable range. The laser in-situ test result of the low Re shale (DRe-1) is 121±8.84 ppb, which is larger than the standard result 91.89±0.6788 ppb, and the relative error is 24.06%. The analysis result shows that the SiO2 content of the DRe-1 sample is only 40%, which is the lowest among all samples, and its CaO content is close to 15%, which is much higher than the rest of the samples (all around 1%), so the matrix effect has a significant impact on it. The relative errors of the test results of the three mudstone samples (16BZ-17, 16BZ-19, 16BZ-98) with Re content of individual, ten, and hundred ppb levels and the standard results are all less than 20%, which are 9.4%, 10.7%, and 17.65% respectively. Among them, the Re content of the 16BZ-98 sample is only 1.4 ppb, but the relative error of the result is still less than 20%, which powerfully proves that the rapid and accurate determination method S100 of the Re content of the black rock series is also applicable to the ultra-low Re content black shale sample.

[0122] In the embodiment, from the preparation of the Re sample target to the preliminary determination of the whole rock Re content of the Re sample target according to the Re standard target by the laser in-situ analysis method, the whole rock Re content preliminary determination process only needs one hour, while the Re content preliminary determination process in the prior art needs five days. Compared with the Re content preliminary determination process in the prior art, the test time is greatly saved, and the test analysis efficiency is improved. In the whole preliminary determination process, no chemical reagent is used, which fully meets the requirements of "fast" and "cheap" for obtaining the Re diluent optimal ratio test. The whole rock Re content preliminary determination process can also be used for rapid screening of a large number of black rock series samples.

[0123] S150, determining the addition ratio of the Re diluent according to the preliminary whole rock Re content of the black rock series sample, and performing rapid and accurate Re content determination by the low-temperature semi-closed isotope dilution method.

[0124] Re element is chemically stable and not easy to volatilize relative to Os element. In order to further improve the efficiency of Re content determination, the embodiment proposes a low-temperature semi-closed isotope dilution method for sample digestion of black rock series samples. The specific process of step S150 can be as follows:

[0125] First, the ultra-finely crushed black rock series sample is weighed in a plastic centrifuge tube. Specifically, 0.1g-0.2g of the ultra-finely crushed black rock series sample is weighed in a plastic centrifuge tube by using a high-precision electronic analytical balance. Preferably, in the embodiment, 0.1g of the ultra-finely crushed black rock series sample is weighed in a 15mL plastic centrifuge tube.

[0126] Secondly, HCl, HNO3 and Re diluent are 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 the Re diluent is determined. 1mL-2mL of 12mol / L HCl, 1.5mL-2mL of 16mol / L HNO3 and 185 Re diluent are added to the plastic centrifuge tube. Specifically, in the embodiment, 1ml of 12mol / L HCl and 1.5ml of 16mol / L HNO3 are added.

[0128] Thirdly, the plastic centrifuge tube is covered with a bottle cap and ultrasonically shaken for 0.5h-0.6h. Preferably, in the embodiment, ultrasonic shaking is performed for 0.5h.

[0129] Fourthly, the plastic centrifuge tube after shaking is placed in an oven at 105℃-110℃ and heated for 12h-15h. Specifically, the plastic centrifuge tube after shaking is placed in an oven at 105℃ and heated for 12h.

[0130] Then, after the 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 revolutions per minute for 10 minutes.

[0131] Finally, the supernatant is diluted and then the Re content is determined quickly and accurately by MC-ICP-MS. Specifically, 0.1 mL of the supernatant is diluted 10 times and then tested on the machine.

[0132] The Re content is directly analyzed and determined by a Neptune Plus type MC-ICP-MS produced by Thermo Fisher Company. The multi-reception inductively coupled plasma mass spectrometer in the Re-Os Key Laboratory of the National Geological Experimental Test Center uses both energy and mass focusing methods, is equipped with dynamic zoom technology that can improve the ion mass dispersion by 17%, and is equipped with 7 Faraday cups receivers with a fixed center channel ion counter receiver in the middle. In addition to the center cup, 4 electric motors are used to drive accurate position changes on both sides of the high and low mass numbers. A electron multiplier is configured behind the center cup, and 4 ion counters are configured outside the lowest mass number cup. Faraday cup static simultaneous reception measurement and ion counter once peak quasi-static measurement can be realized. High-sensitivity JET type sampling cones and X type intercepting cones are selected, which significantly improve the sensitivity by about 2 times, the instrument measurement internal precision is less than 0.05% (Re content is greater than 1 ng / g), and the sensitivity of 1 pg Re sample can reach 60000 cps (1 mV). For Re element, static Faraday mode is used to simultaneously determine 185 Re and 187 Re.

[0133] As shown in Table 2, the Re content data determined by the low-temperature semi-closed isotope dilution method in the present embodiment and the traditional high-temperature Teflon closed digestion tank dissolution method are compared.

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

[0135] Sample Type Sample Number Original Sample Name Re Content (ppb) Test Method Black Shale 240128-1 B54 26.1 Low Temperature Semi-Closed Black Shale 240128-2 B54 26.2 Low Temperature Semi-Closed Black Shale 240128-3 DRe-1 95.5 Low Temperature Semi-Closed Black Shale 240129-4 DRe-1 98.4 Low Temperature Semi-Closed Black Shale 240201-1 B54 26.9 High Temperature Closed Black Shale 240201-2 B54 26.2 High Temperature Closed Black Shale 240201-3 DRe-1 96.2 High Temperature Closed Black Shale 240201-4 DRe-1 97.7 High Temperature Closed

[0136] From Table 2, the same B54 and DRe-1 samples were tested and analyzed by low-temperature semi-closed rapid digestion method and high-temperature Teflon closed digestion tank method respectively, and the results are shown in Table 3.5. From the table, the Re content in B54 sample measured by low-temperature semi-closed method is 26.1 ppb and 26.2 ppb respectively, and the Re content in DRe-1 sample is 95.5 ppb and 98.4 ppb respectively; the Re content in B54 sample measured by high-temperature Teflon closed digestion tank method is 26.9 ppb and 26.2 ppb respectively, and the Re content in DRe-1 sample is 96.2 ppb and 97.7 ppb respectively. The two test results are basically consistent, indicating that under the condition of 105℃, 12h, most of the Re in the sample has been basically dissolved. In addition, the low-temperature semi-closed method requires less time, the material is easier to obtain, and the experimental operation is simpler.

[0137] As shown in Table 3, the low-temperature semi-closed rapid Re test results are compared with the standard recommended values. From Table 3, the test value (26.15±0.07 ppb) of B54 sample is completely consistent with the standard recommended value (26.71±0.07 ppb), and the relative error is only 0.2%. The test value (96.95±2.05 ppb) of DRe-1 sample is about 5% higher than the value measured by the traditional Carius tube method. The reason is that the uniformity of DRe-1 sample is not as good as that of black rock series candidate standard material B54, and there is a "chunk gold effect", but the result is still acceptable within the error range. In summary, the above results are basically consistent with the recommended values within the error range, which proves the accuracy and reliability of the low-temperature semi-closed rapid Re test method established in this embodiment.

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

[0139]

[0140] In this embodiment, the Re content is rapidly and accurately measured by low-temperature semi-closed isotope dilution method. During the mass spectrometry process 187 Os will interfere with 187 Re, Re element is chemically stable and not easy to volatilize. By using low-temperature semi-closed sample dissolution method, firstly, low temperature can ensure that Re is not easy to volatilize and lose, affecting the accuracy of measurement; secondly, in semi-closed environment, interfering element Os can be volatilized completely and cannot interfere with the measurement, improving the accuracy of Re content measurement. In addition, there is no need to distill Os separately, saving time and cost; the whole precision measurement process can be completed in one day, significantly improving the single sample analysis efficiency by more than 5 times; and only low-cost plastic centrifugal tubes are used. Under the premise of ensuring ppt-ppb level analysis accuracy, the detection cost is reduced by 70%.

[0141] In summary, the method for rapidly and accurately determining the Re content of the black rock series according to the present application preliminarily determines the Re content of the Re sample target by using a laser in-situ analysis method on the Re standard target, and rapidly and accurately determines the Re content by using a low-temperature semi-closed isotope dilution method, wherein the isotope dilution method and multi-receiving inductively coupled plasma mass spectrometry are combined to determine the Re content, which can rapidly and accurately determine the Re content in the pg-ng level, and ensures the accuracy of the determination of the Re content of the black rock series; the entire preliminary and accurate determination process of the Re content only needs two days, which greatly shortens the time compared with the traditional 10 days, and the single sample analysis efficiency is improved by more than 5 times; at the same time, the use amount of chemical reagents and experimental vessels is small during the rapid and accurate determination of the Re content of the black rock series, and the detection cost is reduced by 70%, which saves the cost; the method can be used to determine the Re content of the black rock series, which is accurate, fast and low in cost, and can provide strong technical support for the rapid screening of Re resources in a large number of black rock series samples.

[0142] It can be understood that the above embodiments are only exemplary embodiments for illustrating the principles of the present application, but the present application is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A rapid and accurate method for determining the Re content in black rock formations, characterized in that, The method includes: Samples of the black rock formation were collected and subjected to ultrafine grinding. Prepare Re standard powder material with the same lithology as the black rock series sample; To prepare Re sample targets and Re standard targets, ultrafine pulverized black rock samples and the Re standard powder were respectively compressed into pellets. Specifically, this involved using a sample powder pelleting device for in-situ micro-area analysis. The pelleting device included a base, a fixing ring, splicing plates, a pressing column, an insert rod, a plastic ring, and a polyethylene powder filler. Multiple splicing plates were included, all of which were slidably connected to the upper surface of the base. The fixing ring was slidably connected to the outer wall of the base. Each splicing plate had... First limiting surface; during tablet pressing, multiple splicing plates slide and splice on the base, and multiple first limiting surfaces combine to form a groove. The fixing ring is sleeved on the outer periphery of the spliced ​​multiple splicing plates. The insertion rod passes through the fixing ring and is inserted into the base. The pressure column is inserted into the groove. The plastic ring is disposed in the groove. The plastic ring 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 inside the plastic ring and the outer side of the plastic ring. Based on the Re standard target, the whole-rock Re content of the Re sample target was preliminarily determined by laser in-situ analysis, and preliminary whole-rock Re content data of the black rock series sample were obtained. Based on the preliminary whole-rock Re content of the black rock series samples, the addition ratio of Re diluent was determined, and the Re content was rapidly and accurately determined using a low-temperature semi-closed isotope dilution method.

2. The method according to claim 1, characterized in that, The method for rapid and accurate determination of Re content using a semi-closed isotope dilution method includes: Weigh the ultrafine pulverized black rock sample into a plastic centrifuge tube; Add HCl, HNO3, and Re diluent to the plastic centrifuge tube; The plastic centrifuge tube was capped and subjected to ultrasonic vibration. Heat in an oven at 105℃~110℃; After heating is complete, the plastic centrifuge tubes are placed in a centrifuge for centrifugation; After diluting the supernatant, the Re content was rapidly and accurately determined using MC-ICP-MS.

3. The method according to claim 2, characterized in that, Weigh 0.1 g to 0.2 g of ultrafinely pulverized 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; sonicate 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 tablet pressing device further includes: The base has a vertical sliding groove on its side wall. The fixing ring includes a ring body and a vertical slider. The vertical slider is provided on the inner side wall of the ring body. The ring body is sleeved on the base, and the vertical slider is slidably connected in the vertical sliding groove.

5. The method according to any one of claims 1 to 3, characterized in that, The tablet pressing device further includes: The top wall of the base is provided with multiple horizontal sliding grooves. Each splicing plate includes a plate body and a first horizontal slider. The first horizontal slider is provided on one side of the plate body. When pressing the plate, the first horizontal slider is slidably connected in the horizontal sliding groove. The end face inside the plate body is the first limiting surface. The splicing plate also includes a second horizontal slider, which is provided on the other side of the plate body. When the sample after pressing is taken out, the second horizontal slider can be slidably connected in the horizontal groove.

6. The method according to any one of claims 1 to 3, characterized in that, The preliminary determination of whole-rock Re content in the Re sample target using laser in-situ analysis based on the Re standard target yields preliminary whole-rock Re content data for the black rock series sample, including: Under the same laser and mass spectrometry experimental conditions, laser spot ablation was used to sequentially perform laser spot analysis on the Re standard target and the Re sample target, respectively. The preliminary whole-rock Re content of the black rock series sample is obtained according to the following formula; C2 = (A2 / A1) × C1, Wherein, C2 represents the preliminary whole-rock Re content of the black rock series 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.

7. The method according to claim 6, characterized in that, The laser spot size used is 70 μm to 80 μm, and the dwell time of the dots is 0.4 s to 0.5 s.

8. The method according to any one of claims 1 to 3, characterized in that, Preparation of Re standard powder materials with the same lithology as the black rock series samples, including: Collect alternative standard materials with the same lithology as the black rock series samples; The candidate standard substances are pulverized and ground to a fineness of less than 200 mesh. The crushed candidate standard substances were dispensed into multiple wide-mouth bottles and mixed evenly; The homogeneity, stability, and normality of the setpoint data of the candidate standard substances were tested respectively.

9. The method according to any one of claims 1 to 3, characterized in that, The collection and ultrafine grinding of black rock samples includes: Collect samples of the black rock formations and clean them with deionized water; The black rock samples were ultra-finely ground and pulverized using a planetary ball mill to a mesh size of less than 200. The ultra-finely ground black rock samples were then mixed evenly to increase the uniformity of the samples.

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