A method for evaluating the potential of mineralized carbon sequestration in ore deposits

Abstract

The present invention discloses a method for evaluating the potential for mineralization and carbon fixation of a ore deposit, the method comprising: obtaining a plurality of mineral samples by prospecting a selected mine, recording the orientation information and elemental composition of the representative samples; randomly selecting 8-32 representative samples, experimentally determining the elemental composition, oxide composition, mineral composition and carbon fixation amount after accelerated carbonation of the representative samples, and determining the mutual conversion relationship between the parameters. The method of the present invention can predict the oxide composition, mineral composition and carbon fixation potential of the sample from the elemental composition of the sample, so that the carbon fixation potential of the ore deposit can be estimated according to the modeling of the drilling data, greatly reducing the manpower, material resources and financial resources of the experiment. The present invention is applicable to the field of mineral resource utilization.

Description

Technical Field

[0001] The invention belongs to the field of mineral resource utilization, and specifically relates to a method for evaluating the mineralization and carbon fixation potential of a ore deposit. Background Art

[0002] According to the China Environmental Statistical Yearbook released in 2019, the top three countries in the world in terms of annual carbon dioxide emissions in 2011 were China, the United States and India, with China ranking first with annual emissions of 9019.56 million tons, a year-on-year increase of 266.5% compared to 1990. The mining process has a wide range of carbon sources, and large-scale equipment such as drilling, rock drilling, and transportation consume a lot of energy. The explosive blasting process also releases a large amount of greenhouse gases. At the same time, mining also destroys the surrounding vegetation and reduces carbon sinks. Mining companies are facing huge pressure to reduce carbon emissions.

[0003] Nickel, diamond, platinum group element, asbestos and other deposits contain a large amount of silicate minerals required for CO2 mineralization storage technology, and have great carbon fixation potential. CO2 mineralization storage technology refers to the process of reacting silicates containing Ca, Mg, and Fe with CO2 to form carbonates under certain conditions to achieve permanent storage of CO2. Its simplified chemical reaction equation is shown below: (Ca, Mg, Fe) 2SiO4 + 2CO2 → 2 (Ca, Mg, Fe) CO3 + SiO2. This method has the advantages of large carbon dioxide storage capacity and permanent and stable carbon dioxide fixation without monitoring. However, so far, there is no method that can accurately evaluate the mineralization carbon fixation potential of a deposit, and this situation has greatly limited the in-depth research and utilization of CO2 mineralization storage technology by mining companies. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for evaluating the mineralization and carbon fixation potential of ore deposits. The method of the present invention can solve technical problems such as high cost of mineral carbonation experiments, anisotropy of mineral distribution in ore deposits, and low accuracy of estimation of carbon fixation potential of traditional ore deposits, thereby providing a feasible path for mining enterprises to achieve precise carbon fixation and reduce carbon emission pressure.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for evaluating the mineralization carbon sequestration potential of a ore deposit, the method comprising:

[0007] S1: Exploring the selected mine to obtain multiple mineral samples, recording the orientation information and elemental composition of the representative samples; randomly selecting 8-32 representative samples, experimentally determining the elemental composition, oxide composition and mineral composition of the representative samples, and determining the mutual conversion relationship between the components;

[0008] S2: performing mineral pretreatment and accelerating carbonation on the representative samples respectively to obtain the carbonation degree of the representative samples, and determining the carbonation reaction mechanism according to the carbonation degree;

[0009] S3: establishing a carbon fixation prediction model for the representative sample, and establishing a carbon fixation prediction database according to the calculation results of the carbon fixation prediction model, and then adding the carbon fixation prediction value to the drilling database test analysis table;

[0010] S4: Using 3D mining software, build a block model based on the ore body solid model, assign values ​​to predict carbon sequestration, perform reserve calculations, and derive the carbon sequestration potential of the deposit.

[0011] As an embodiment of the present invention, in step S1, the exploration method of the selected mine includes trenching or drilling;

[0012] The analysis methods of the element composition, oxide composition and mineral composition include one or more of ICP, X-ray fluorescence and X-ray diffraction.

[0013] As an embodiment of the present invention, in step S1, the elemental composition includes the content of one or more elements selected from the group consisting of Mo, Cu, Pb, Zn, Ag, Ni, Co, Mn, Fe, As, U, Au, Th, Sr, Cd, Sb, Bi, V, Ca, P, La, Cr, Mg, Ba, Ti, Al, Na, K, W, Zr, Sn, Y, Nb, Be, Sc and S;

[0014] The oxide composition includes: the content of one or more oxides selected from SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, MnO, TiO2, P2O5, Cr2O3 and BaO;

[0015] The mineral composition includes: the content of one or more minerals selected from olivine, serpentine, magnesium carbonate, quartz, diopside, brucite, magnetite, hematite, forsterite, troyite, siderite and clinochlore.

[0016] As an embodiment of the present invention, in step S1, the mutual conversion law between the various components refers to: through the law of conservation of elemental mass, respectively determining the conversion relationship between the elemental composition and the oxide composition, the conversion relationship between the oxide composition and the mineral composition, and the conversion relationship between the elemental composition and the mineral composition of the representative sample.

[0017] As an embodiment of the present invention, in step S2, the mineral pretreatment method includes: one or more of thermal activation, chemical activation and mechanical force activation;

[0018] The method for accelerating carbonation includes: one or more of direct dry carbonation, direct wet carbonation, indirect dry carbonation and indirect wet carbonation.

[0019] As an embodiment of the present invention, in step S2, the carbonation degree is calculated by using the CO2 storage reaction efficiency R X To represent; where R X The calculation method of is shown in the following formula (1):

[0020]

[0021] Among them, ε A is the percentage of carbonate in the total weight of the representative sample after all carbonateable metal cations in the representative sample are converted into carbonate; x CO2 is the weight percentage of CO2 in the representative sample after the accelerated carbonation; the ε A and x CO2 To accelerate the quantitative analysis of the mineral composition of the materials before and after carbonation;

[0022] Optionally, the carbonateable metal cation comprises Mg 2+ , Ca 2+ , Fe 2+ , K + 、Na + , Cu 2+ and Zn 2+ One or more of the following, preferably Mg 2+ , Ca 2+ and Fe 2+ .

[0023] As an embodiment of the present invention, in step S3, a carbon fixation prediction model of the representative sample is established, including: obtaining an oxide composition prediction value and a mineral composition prediction value of the representative sample according to the elemental composition and the conversion relationship, and then determining a carbon fixation prediction model MCP of the representative sample according to the carbonation reaction mechanism;

[0024] The calculation method of the carbon fixation prediction model MCP is shown in the following formula (2):

[0025]

[0026] Among them, R ij is the carbonation conversion rate of the jth mineral formed by the i-th carbonateable metal element, a ij is the mass percentage of the element in the jth mineral formed by the i-th carbonated metal element, k ij is the correction factor, determined by specific experiments;

[0027] Optionally, the carbonatable metal element includes one or more of Mg, Ca, Fe, K, Na, Cu and Zn, preferably includes Mg, Ca and Fe.

[0028] As an embodiment of the present invention, in step S4, the three-dimensional mining software includes one or more mining software with three-dimensional geological information modeling function among 3DMine, Dimine, Supac, Datamine, Mineplan and Vulcan.

[0029] As an embodiment of the present invention, in step S4, the ore body entity model is delineated based on the boundary grade of the primary mined mineral in the mine in the drilling database analysis table.

[0030] As an embodiment of the present invention, in step S4, the value assignment method includes one or more geostatistical models selected from the group consisting of the inverse distance power method, the ordinary kriging method and the universal kriging method;

[0031] The reserve calculation method includes: one or more of the section method, arithmetic mean method, geological block method and contour method.

[0032] The above technical solution provided by the present invention brings at least the following beneficial effects:

[0033] (1) The method of the present invention can predict the oxide composition, mineral composition and carbon fixation amount of the sample from its elemental composition, thereby estimating the carbon fixation potential of the ore deposit based on the drilling data, greatly reducing the manpower, material and financial resources of the experiment;

[0034] (2) The method of the present invention uses three-dimensional mining software to evaluate the carbon sequestration potential of mineral deposits, and obtains results based on modeling of massive exploration drilling data. The data source is reliable and the estimation results are accurate;

[0035] (3) The method of the present invention is based on ore grade estimation and reserve estimation, and can be quickly mastered by technicians in related industries and is easy to use;

[0036] (4) The method of the present invention can provide a reference for mining enterprises to make decisions on the adoption of CO2 mineralization technology by estimating the carbon sequestration potential of ore deposits. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is the technical roadmap of the present invention;

[0038] Figure 2 Comparison between the test value and the estimated value of MgO in the present invention;

[0039] Figure 3 The relationship between the consumption of olivine and the generation of magnesite in the present invention;

[0040] Figure 4 This is a cross-sectional view of the block model established by the present invention using the mining software Surpac. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below.

[0042] Example 1

[0043] like Figure 1 As shown, the method of the present invention is used to evaluate the mineralization carbon fixation potential of the ore deposit, and the specific method is as follows:

[0044] S1: Taking a selected nickel mine as an example, multiple mineral samples were obtained by drilling exploration, and the orientation information of the mineral samples and the elemental composition of Mo, Cu, Pb, Zn, Ag, Co, Mn, Ni, Fe, As, Sr, Cd, Sb, Bi, V, Ca, P, Cr, Mg, Ti, Al, Na, K, W, S, Au, Pt, Pd, etc. were recorded; it was found that the deposit was a polymetallic deposit, and the main valuable metals were: Ni, Co, Fe. The deposit contained a large amount of Mg, which is suitable for carbon fixation;

[0045] 16 representative samples were randomly selected from the mineral samples, and the elemental composition, oxide composition and mineral composition were determined by ICP, X-ray fluorescence, X-ray diffraction and other methods: the elemental composition test contents include: Mo, Cu, Pb, Zn, Ag, Ni, Co, Mn, Fe, As, U, Au, Th, Sr, Cd, Sb, Bi, V, Ca, P, La, Cr, Mg, Ba, Ti, Al, Na, K, W, Zr, Sn, Y, Nb, Be, Sc, S, etc.; the oxide composition test contents include: SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, MnO, TiO2, P2O5, Cr2O3, BaO, etc.; in addition, the ignition loss, total carbon and total sulfur content were also tested. The mineral types in the mineral composition test results include: olivine, serpentine, magnesium carbonate, quartz, diopside, brucite, magnetite, hematite, forsterite, troyite, siderite, clinochlore, etc. Among them, the experimental measured values ​​of the elemental composition are compared with the measured values ​​in the drilling database. The average test error of the main element Mg is 8%, and the average test error of Fe is 7%.

[0046] S2: Determine the mutual conversion relationship between the element composition, oxide composition and mineral composition in step S1 by the law of conservation of element mass; compare the oxide estimation result with the test result, and the estimation error is within 5% (such as Figure 2); Comparison of mineral composition estimation results with test results: the estimation error of olivine is 12%, and the estimation error of serpentine is 11%;

[0047] The representative sample in step S2 is subjected to mechanical activation pretreatment by a high-energy pulverizer, and then accelerated carbonation is performed by direct wet carbonation; the carbonation reaction is carried out in an autoclave at a reaction temperature of 180° C., a CO2 partial pressure of 6.5 MPa, a solid content of 30%, and a reaction time of 3 hours;

[0048] The carbonation degree of representative samples was calculated using the following formula (1):

[0049]

[0050] Among them, ε A is the percentage of carbonate in the total weight of the representative sample after all carbonate-able metal cations in the representative sample are converted into carbonates, wherein the carbonate-able metal cations mainly include Mg 2+ , Ca 2+ and Fe 2+ ;x CO2 is the weight percentage of CO2 in the surface sample after the accelerated carbonation; the ε A and x CO2 To accelerate the quantitative analysis of the mineral composition of the material before and after carbonation; representative sample R of the case mine x Values ​​range from 5-45%.

[0051] The carbonation reaction mechanism determined according to the carbonation degree is: olivine is the main carbonated mineral, and serpentine promotes the carbonation of olivine. The relationship between the consumption of olivine and the generation of magnesite is shown in FIG3 .

[0052] S3: The sample carbon fixation prediction model is based on the elemental composition of Mg, Ca, Fe, K, Na, Cu and Zn in the mine borehole and the conversion relationship obtained in step S1, and the oxide composition prediction value and mineral composition prediction value of the representative sample are obtained. Then, according to the carbonation reaction mechanism of the sample, the carbon fixation prediction model MCP of the representative sample is determined; wherein, the calculation method of the carbon fixation prediction model MCP is shown in the following formula (2):

[0053]

[0054] Among them, R ij is the carbonation conversion rate of the jth mineral formed by the ith metal element, a ij is the mass percentage of the element in the jth mineral formed by the i-th metal element, k ijis the correction coefficient, which is determined by specific experiments; after comparison, the MCP prediction value calculated by formula (2) is consistent with the test value (x CO2 )The error is within 5%.

[0055] S4: Surpac was used for 3D geological information modeling. The ore body model was delineated based on the Ni cut-off grade of 0.2% in the drilling data. The block model predicted carbon fixation value was assigned using conventional Kriging. The block model profile after assignment is shown in the figure below. Figure 4 Finally, the reserve calculation adopts the geological block method, and the carbon sequestration capacity of the deposit is 45×10 6 tCO2.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating the mineralization carbon sequestration potential of a ore deposit, characterized in that: The method comprises: S1: Exploring the selected mine to obtain multiple mineral samples, recording the orientation information and elemental composition of the representative samples; randomly selecting 8-32 representative samples, experimentally determining the elemental composition, oxide composition and mineral composition of the representative samples, and determining the mutual conversion relationship between the components; In step S1, the mutual conversion relationship between the various components refers to: determining the conversion relationship between the element composition and the oxide composition, the conversion relationship between the oxide composition and the mineral composition, and the conversion relationship between the element composition and the mineral composition of the representative sample respectively through the law of conservation of element mass; S2: performing mineral pretreatment and accelerating carbonation on the representative samples respectively to obtain the carbonation degree of the representative samples, and determining the carbonation reaction mechanism according to the carbonation degree; S3: establishing a carbon fixation prediction model for the representative sample, and establishing a carbon fixation prediction database according to the calculation results of the carbon fixation prediction model, and then adding the carbon fixation prediction value to the drilling database test analysis table; In step S3, a carbon fixation prediction model of the representative sample is established, including: obtaining an oxide composition prediction value and a mineral composition prediction value of the representative sample according to the elemental composition and the conversion relationship, and then determining a carbon fixation prediction model MCP of the representative sample according to the carbonation reaction mechanism; The calculation method of the carbon fixation prediction model MCP is shown in the following formula (2): Among them, R ij is the carbonation conversion rate of the jth mineral formed by the i-th carbonateable metal element, a ij is the mass percentage of the element in the jth mineral formed by the i-th carbonated metal element, k ij is the correction factor, determined by specific experiments; The carbonatable metal element includes one or more of Mg, Ca, Fe, K, Na, Cu and Zn; S4: Using 3D mining software, build a block model based on the ore body solid model, assign values ​​to predict carbon sequestration, perform reserve calculations, and derive the carbon sequestration potential of the deposit.

2. The method according to claim 1, characterized in that In step S1, the exploration method of the selected mine includes trenching or drilling; The analysis methods of the element composition, oxide composition and mineral composition include one or more of ICP, X-ray fluorescence and X-ray diffraction.

3. The method according to claim 1, characterized in that In step S1, the elemental composition includes the content of one or more elements selected from the group consisting of Mo, Cu, Pb, Zn, Ag, Ni, Co, Mn, Fe, As, U, Au, Th, Sr, Cd, Sb, Bi, V, Ca, P, La, Cr, Mg, Ba, Ti, Al, Na, K, W, Zr, Sn, Y, Nb, Be, Sc and S; The oxide composition includes: the content of one or more oxides selected from SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, MnO, TiO2, P2O5, Cr2O3 and BaO; The mineral composition includes: the content of one or more minerals selected from olivine, serpentine, magnesium carbonate, quartz, diopside, brucite, magnetite, hematite, forsterite, troyite, siderite and clinochlore.

4. The method according to claim 1, characterized in that: In step S2, the mineral pretreatment method includes: one or more of thermal activation, chemical activation and mechanical force activation; The method for accelerating carbonation includes: one or more of direct dry carbonation, direct wet carbonation, indirect dry carbonation and indirect wet carbonation.

5. The method according to claim 1, characterized in that: In step S2, the carbonation degree is calculated by using the CO2 storage reaction efficiency R X To represent; where R X The calculation method of is shown in the following formula (1): Among them, ε A is the percentage of carbonate in the total weight of the representative sample after all carbonateable metal cations in the representative sample are converted into carbonate; x CO2 is the weight percentage of CO2 in the representative sample after the accelerated carbonation; the ε A and x CO2 To accelerate the quantitative analysis of the mineral composition of the materials before and after carbonation; The carbonateable metal cations include Mg 2+ , Ca 2+ , Fe 2+ , K + 、Na + , Cu 2+ and Zn 2+ One or more of the .

6. The method according to claim 5, characterized in that In step S2, the carbonatable metal cation includes Mg 2+ , Ca 2+ and Fe 2+ .

7. The method according to claim 1, characterized in that In step S3, the carbonatable metal elements include Mg, Ca and Fe.

8. The method according to claim 1, characterized in that In step S4, the three-dimensional mining software includes one or more mining software with three-dimensional geological information modeling function among 3DMine, Dimine, Supac, Datamine, Mineplan and Vulcan.

9. The method according to claim 1, characterized in that: In step S4, the ore body entity model is delineated based on the boundary grade of the primary mining mineral in the mine in the drilling database analysis table.

10. The method according to claim 1, characterized in that In step S4, the value assignment method includes one or more geostatistical models selected from the group consisting of the inverse distance power method, the ordinary kriging method, and the universal kriging method; The reserve calculation method includes one or more of the following: cross-section method, arithmetic mean method, geological block method and contour line method.

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