Method for removing mud impurities in bauxite
Through the cascading application of dual-modal X-ray sorting technology, the problem of difficult removal of mud impurities in bauxite is solved, and efficient separation of combined ore mud and waste rock in bauxite is achieved, thereby improving the grade of bauxite and the yield of aluminum concentrate.
Patent Information
- Application Number
- CN202510491418.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-05-30
AI Technical Summary
The prior art is difficult to efficiently remove mud impurities in bauxite, especially combined with ore mud and waste stone, resulting in a decrease in bauxite grade and an increase in the difficulty of subsequent demining processes.
Cascade applications using dual-mode X-ray sorting technology, including X-ray transmission photoelectric sorting and X-ray fluorescence photoelectric sorting, and precisely separate the combined ore mud and waste rock in bauxite through dual energy spectrum imaging and fluorescence signal detection.
It realizes efficient removal of mud impurities in bauxite, improves the grade of bauxite and the yield of aluminum concentrate, and reduces the difficulty and cost of subsequent processes.
Smart Images
Figure CN120054883A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of bauxite processing, and particularly relates to a method for removing mud impurities from bauxite. Background Art
[0002] At present, the grades of bauxite ores are uneven, and the ores mainly consist of diaspore, while the gangue minerals mainly include kaolinite, illite, calcite and iron-containing minerals (such as hematite, pyrite); the aluminum-silicon ratio of this bauxite ore is relatively low, about 4 - 6. Since the raw bauxite ore is rich in a large amount of mud impurities, this will cause the grade of bauxite to be greatly reduced.
[0003] For bauxite rich in mud impurities, at present, washing is mainly used to remove these mud impurities. However, for some bauxite ores with more mud, the mud of the bauxite ore will become larger and larger in the washing machine during these washing processes, and finally form mud blocks that are difficult to wash. These mud blocks will increase the difficulty of the subsequent ore-breaking process. At present, these mud blocks can only be removed from the washing machine by manual cleaning, and this manual removal method not only has a high cost but also has a poor removal effect of the mud blocks. Summary of the Invention
[0004] This application provides a method for removing mud impurities from bauxite to solve the following technical problem: how to improve the removal effect of mud impurities in bauxite.
[0005] In a first aspect, an embodiment of this application provides a method for removing mud impurities from bauxite. The raw bauxite ore includes surface mud, combined mud and waste rock. The method includes:
[0006] Washing the raw bauxite ore to wash away the surface mud of the raw bauxite ore, and obtaining a bauxite washing mixture containing combined mud;
[0007] Screening the bauxite washing mixture containing combined mud to obtain a coarse-grained bauxite containing combined mud and waste rock;
[0008] Performing X-ray transmission photoelectric separation on the coarse-grained bauxite containing combined mud and waste rock to remove the combined mud of the coarse-grained bauxite, and obtaining a mixed bauxite containing waste rock;
[0009] Performing X-ray fluorescence photoelectric separation on the mixed bauxite containing waste rock to remove the waste rock of the mixed bauxite, and obtaining bauxite concentrate.
[0010] Optionally, the separation parameters of the X-ray transmission photoelectric separation include a first separation threshold f and a first standard threshold f x , the first separation threshold f and the first standard threshold f xSatisfy the following relationship: when f≥f x In this case, the target product of the X-ray transmission photoelectric separation is the combined slime;
[0011] When f<f x In this case, the target product of the X-ray transmission photoelectric separation is the mixed bauxite;
[0012] Among them, the value range of the first standard threshold f x is 5900 - 6100.
[0013] Optionally, the separation parameters of the X-ray fluorescence photoelectric separation include a second separation threshold H and a second standard threshold H x , and the second separation threshold H and the second standard threshold H x Satisfy the following relationship: when H≥H x In this case, the target product of the X-ray fluorescence photoelectric separation is the bauxite concentrate;
[0014] When H<H x In this case, the target product of the X-ray fluorescence photoelectric separation is the waste rock;
[0015] Among them, the value range of the second standard threshold H x is 1.5 - 2.5.
[0016] Optionally, the first acceleration voltage of the X-ray tube for the X-ray transmission photoelectric separation ≥80 kV, and the processing particle size for the X-ray transmission photoelectric separation ≥10 mm.
[0017] Optionally, the first acceleration voltage Q1 of the X-ray tube for the X-ray transmission photoelectric separation and the processing particle size D1 for the X-ray transmission photoelectric separation satisfy the relational expression: if 10 mm≤D1<50 mm, then Q1 satisfies 80 kV≤Q1<100 kV; and / or
[0018] if 50 mm≤D1<300 mm, then Q1 satisfies: 100 kV≤Q1<160 kV; and / or
[0019] if D1≥300 mm, then Q1≥160 kV.
[0020] Optionally, the second acceleration voltage of the X-ray tube for the X-ray fluorescence photoelectric separation ≥38 kV, and the processing particle size for the X-ray fluorescence photoelectric separation ≥10 mm.
[0021] Optionally, both the X-ray transmission photoelectric separation and the X-ray fluorescence photoelectric separation are carried out in a way of air blowing and removing or in a way of kick plate removing.
[0022] Optionally, when the X-ray transmission photoelectric sorting or the X-ray fluorescence photoelectric sorting is carried out by means of air blowing and rejection, the air blowing pressure for air blowing and rejection ≥ 0.65 MPa.
[0023] Optionally, the particle size of the screening ≥ 30 mm.
[0024] Optionally, the screening of the bauxite washing mixture containing combined slime to obtain the bauxite with coarse particle size containing combined slime and waste rock includes the steps of:
[0025] Screening the bauxite washing mixture containing combined slime to obtain fine-particle-size bauxite and coarse-particle-size bauxite containing combined slime and waste rock;
[0026] After subjecting the mixed bauxite containing waste rock to X-ray fluorescence photoelectric sorting to remove the waste rock from the mixed bauxite and obtain bauxite concentrate, the following steps are included:
[0027] Mixing the bauxite concentrate and the coarse-particle-size bauxite to obtain bauxite concentrate product.
[0028] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:
[0029] A method for removing mud impurities in bauxite provided by an embodiment of the present application uses the bauxite raw ore containing surface slime, combined slime and waste rock as raw materials. The surface slime of the bauxite raw ore can be removed by washing, and then through screening, the bauxite with coarse particle size can be screened out. These coarse-grained bauxites contain a large amount of combined slime and waste rock. Through the X-ray transmission photoelectric sorting method, based on the characteristics of dual-energy spectrum imaging of X-ray transmission photoelectricity and the density difference between the combined slime and bauxite, the dual-energy spectrum imaging results of bauxite and combined slime with different density differences are quite different. According to this imaging difference, the combined slime and the coarse-grained bauxite can be accurately separated. Then, the mixed bauxite obtained by X-ray transmission photoelectric sorting is subjected to X-ray fluorescence photoelectric sorting. Based on X-ray fluorescence photoelectricity, the fluorescence threshold of specific elements of bauxite can be accurately measured, and the waste rock without specific elements has no obvious fluorescence signal intensity. Therefore, through X-ray fluorescence photoelectric sorting, the bauxite and the waste rock can be accurately separated. Compared with the traditional method for removing slime, this method is based on the composite sorting technology of X-ray transmission photoelectric sorting and X-ray fluorescence photoelectric sorting, and can fully separate the composition of the surface slime, combined slime and waste rock of the bauxite raw ore from the bauxite, thereby improving the removal effect of mud impurities in bauxite. Description of the Drawings
[0030] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application and, together with the specification, are used to explain the principles of this application.
[0031] In order to more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0032] Figure 1 It is a schematic flow chart of a method for removing mud impurities from bauxite provided by an embodiment of this application;
[0033] Figure 2 It is a detailed schematic flow chart of a method for removing mud impurities from bauxite provided by an embodiment of this application. Detailed implementation manners
[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts belong to the scope protected by this application.
[0035] The various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values within that range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within that range, such as 1, 2, 3, 4, 5, and 6, regardless of the range; in addition, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.
[0036] In this text, terms including "comprising" etc. mean "including but not limited to". Relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. "And / or", which describes the associated relationship of associated objects, indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone; where A and B can be singular or plural. "At least one" means one or more, and "multiple" means two or more; "at least one kind", "at least one of the following items" or similar expressions refer to any combination of these items, including any combination of single item or plural items; for example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively. "Part representation methods" such as parts by weight, parts by mass, etc. represent the proportional relationship between each component. In the proportional relationships involved in this text, the parameters that need to be described by proportion should be understood as the antecedents of the proportion formula in the order of description, and the proportional numbers should be understood as the consequents of the proportion formula. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substance A, substance B, and substance C should correspond one by one with the proportional numbers in the proportion formula in the order of description, that is, the mass of substance A: the mass of substance B: the mass of substance C = 1:2:3.
[0037] Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment, etc. used in this text can be obtained through market purchase or can be prepared by existing methods.
[0038] It should be noted that the ore mud impurities in bauxite include not only the easily detachable surface ore mud attached to the surface of the original ore, but also the combined ore mud firmly combined with the original ore. Part of these combined ore mud is carried by the waste rock in the original ore and adheres to a large amount in the bauxite of the original ore. Under the normal washing operation of the ore washer, most of these combined ore mud, surface ore mud, and waste rock will be removed from the original ore and precipitate in the ore washer, thus aggregating to form mud blocks.
[0039] Figure 1 Exemplarily shows a schematic flow chart of a method for removing mud impurities in bauxite provided by an embodiment of the present application;
[0040] As Figure 1 shown, a method for removing mud impurities in bauxite provided by an embodiment of the present application, the bauxite raw ore includes surface ore mud, combined ore mud, and waste rock, and the method includes:
[0041] S1. Wash the bauxite raw ore to remove the surface slime of the bauxite raw ore, and obtain a bauxite ore washing mixture containing combined slime.
[0042] S2. Screen the bauxite ore washing mixture containing combined slime to obtain coarse-grained bauxite containing combined slime and waste rock.
[0043] S3. Perform X-ray transmission photoelectric separation on the coarse-grained bauxite containing combined slime and waste rock to remove the combined slime of the coarse-grained bauxite and obtain mixed bauxite containing waste rock.
[0044] S4. Perform X-ray fluorescence photoelectric separation on the mixed bauxite containing waste rock to remove the waste rock of the mixed bauxite and obtain bauxite concentrate.
[0045] It should be noted that the washing can be carried out by means of high-pressure water flushing, and auxiliary equipment can be used during the washing process; the types of these auxiliary equipment mainly include vibrating screens, rotary vibrating screens, spiral ore washing machines, drum ore washing machines, etc. However, for some slimes with relatively high viscosity, these slimes will become larger and larger in the vibrating screen or drum ore washing machine, and finally form large-volume mud blocks. These large-volume mud blocks cannot pass through the screen or the screen surface of the drum ore washing machine, so that these mud blocks will enter the subsequent crushing process of bauxite together with the bauxite, resulting in an increase in the aluminum-silicon ratio of the ore and a decrease in the ore grade.
[0046] It should be noted that the material transmission speed of X-ray transmission photoelectric separation can be 3m / s - 5m / s. Under this speed condition, the coarse-grained bauxite can pass through the X-ray transmission photoelectric separation at a uniform speed to ensure the full progress of the X-ray transmission photoelectric separation process and achieve the full separation of bauxite and combined slime.
[0047] It should be noted that the principle of X-ray transmission photoelectric separation technology is: when X-rays penetrate the ore and slime-containing impurities of the coarse-grained bauxite, based on the density differences of different bauxite and slime-containing impurities, the attenuation degree of X-rays is different. According to the attenuation degree of X-rays, the ore of bauxite and the combined slime can be clearly screened.
[0048] It should be noted that bauxite generally contains metal elements such as aluminum and iron. Bauxite mainly consists of diaspore and goethite, while waste rock mainly consists of calcite, and some waste rock also contains a small amount of quartz. Through X-ray fluorescence photoelectric separation, there will be a large difference between the fluorescence signals presented by aluminum and iron in bauxite and the fluorescence signal presented by silicon in waste rock. Based on this difference point, bauxite and waste rock can be effectively separated.
[0049] It should be noted that the X-ray fluorescence photoelectric sorting can use a chute as the driving device to make the bauxite slide in the chute to complete the X-ray fluorescence photoelectric sorting; the number of the chutes is generally ≥1, and the number of the chutes is 4 to 6 under normal processing conditions.
[0050] It should be noted that a method for removing mud impurities in bauxite provided by an embodiment of the present application realizes the efficient separation of surface mud, combined mud and waste rock through a multi-stage collaborative sorting technology. The core innovation lies in the cascaded application of the dual-modal X-ray sorting technology and the targeted treatment of the occurrence state of the mud. The specific principle of this method is as follows:
[0051] 1. Sorting mechanism and technological innovation:
[0052] (1) Control of mud dissociation in X-ray transmission photoelectric sorting (XRT): Dual-energy spectrum imaging: The X-ray transmission photoelectric sorting can use an 80kV low-energy spectrum and a 140kV high-energy spectrum dual-channel imaging system. Through the difference in the attenuation coefficient of X-rays by substances {the attenuation coefficient of bauxite (Al 2 O 3 ·H 2 O) is generally 0.35 cm 2 / g, and the mud (SiO 2 + clay) is generally 0.15 cm 2 / g}, a three-dimensional density distribution map with an accuracy of ±0.05 g / cm 3 can be constructed. The combined mud and bauxite will show different gray level differences in the image due to the density difference, and accurate rejection can be achieved through a threshold segmentation algorithm (such as the Otsu adaptive algorithm).
[0053] (2) Optimization of waste rock identification in X-ray fluorescence sorting (XRF): 1) Element fingerprint recognition technology: Aiming at the fluorescence characteristic spectrum differences between Al (Kα line 1.49 keV) or iron in bauxite and Si (Kα line 1.74 keV) in waste rock, a silicon drift detector (SDD, energy resolution <130 eV) is used to capture element signals in real time. Combining Monte Carlo simulation to establish an Al / Si abundance ratio threshold model (the threshold is set as Al / Si > 3:1), so that the waste rock rejection accuracy rate > 97%. 2) High-speed sorting execution system: Using an integrated high-frame-rate CMOS camera (500 frames per second) in combination with high-pressure air blowing or a cylinder kick plate method, the waste rock or bauxite can be sorted online at the millimeter-level particles (5 mm to 50 mm).
[0054] 2. Process flow strengthening design:
[0055] (1) Optimization in the pretreatment stage: Using auxiliary equipment in combination with a washing machine to remove the surface mud of bauxite, and the removal rate of these surface muds can be as high as more than 95%.
[0056] (2) Coordinated control of the sorting process: Cascade sorting of XRT and XRF: Coarse-grained bauxite passes through XRT (removing combined slime) and XRF (removing waste rock) in sequence, and the sorting thresholds of the two are dynamically linked to effectively remove combined slime and waste rock.
[0057] In some alternative embodiments, the sorting parameters of the X-ray transmission photoelectric sorting include a first sorting threshold f and a first standard threshold f x , the first sorting threshold f and the first standard threshold f x satisfy the following relationship: When f ≥ f x , the target product of the X-ray transmission photoelectric sorting is the combined slime;
[0058] When f < f x , the target product of the X-ray transmission photoelectric sorting is the mixed bauxite;
[0059] Among them, the value of the first standard threshold f x is 5900 - 6100.
[0060] In these embodiments, the sorting parameters of the X-ray transmission photoelectric sorting include a first sorting threshold f and a first standard threshold f x , and the first sorting threshold f and the first standard threshold f x satisfy the following relationship: When f ≥ f x , the target product of the X-ray transmission photoelectric sorting can be the combined slime; additionally, when f < f x , the target product of the X-ray transmission photoelectric sorting can be the mixed bauxite. Based on the first sorting threshold f and the first standard threshold f x , through the dual-energy spectrum imaging of the X-ray transmission light technology, combined with the density difference between bauxite and combined slime, the difference between bauxite and combined slime can be clearly reflected in the imaging result. Through this imaging result, bauxite and combined slime can be accurately screened out.
[0061] It should be noted that the value of the first standard threshold f x can be in the range of 5900 - 6100, and the specific standard value needs to be confirmed according to the actual demand of bauxite.
[0062] In some alternative embodiments, the sorting parameters of the X-ray fluorescence photoelectric sorting include a second sorting threshold H and a second standard threshold H x , the second sorting threshold H and the second standard threshold H x satisfy the following relationship: When H ≥ H xIn the case where [condition], the target product of the X-ray fluorescence photoelectric sorting is the bauxite concentrate;
[0063] When H < H x In the case where [condition], the target product of the X-ray fluorescence photoelectric sorting is the waste rock;
[0064] Wherein, the second standard threshold H x has a value range of 1.5 to 2.5.
[0065] In these embodiments, the sorting parameters of the X-ray fluorescence photoelectric sorting may include the second sorting threshold H and the second standard threshold H x , and the second sorting threshold H and the second standard threshold H x satisfy the following relationship: When H ≥ H x In the case where [condition], the target product of the X-ray fluorescence photoelectric sorting can be the bauxite concentrate; additionally, when H < H x In the case where [condition], the target product of the X-ray fluorescence photoelectric sorting can be the waste rock. Based on the sorting threshold H and the second standard threshold H x as a reference, the value of H x can be set to 1.5 to 2.5. Through the fluorescence signal detection of the X-ray fluorescence technology and the fluorescence signal intensity difference between the mixed bauxite and the waste rock, the bauxite concentrate and the waste rock can be directly and accurately separated.
[0066] It should be noted that the second sorting threshold H and the second standard threshold H x are both threshold parameters for iron elements in bauxite.
[0067] It should be noted that the value of the second standard threshold H x can be in the range of 1.5 to 2.5, and the specific standard value needs to be confirmed according to the actual requirements of bauxite.
[0068] The sorting threshold H of the X-ray fluorescence photoelectric sorting can be 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5.
[0069] In some alternative embodiments, the first acceleration voltage of the X-ray tube for the X-ray transmission photoelectric sorting ≥ 80 kV, and the processing particle size of the X-ray transmission photoelectric sorting ≥ 10 mm.
[0070] In these embodiments, the first acceleration voltage of the X-ray tube for X-ray transmission photoelectric sorting is ≥80 kV, and the processing particle size of the X-ray transmission photoelectric sorting is ≥10 mm, so that the X-ray transmission photoelectric sorting has sufficient X-ray tube acceleration voltage. The X-ray transmission photoelectric sorting with sufficient X-ray tube acceleration voltage can effectively penetrate bauxite, thereby improving the accuracy of the X-ray transmission photoelectric sorting.
[0071] It should be noted that the acceleration voltage of the X-ray tube can accelerate the movement of free electrons and give energy to the free electrons, enabling the free electrons to penetrate the ore. The magnitude of the X-ray energy determines the energy of the free electrons and also determines the particle size of the ore that the X-ray can penetrate.
[0072] It should be noted that the device model used for this X-ray transmission photoelectric sorting is (LPNC), and the power of the X-ray tube of this X-ray transmission photoelectric sorting is ≥200 W.
[0073] In some alternative embodiments, the first acceleration voltage Q1 of the X-ray tube of the X-ray transmission photoelectric sorting and the processing particle size D1 of the X-ray transmission photoelectric sorting satisfy the relationship: if 10 mm ≤ D1 < 50 mm, then Q1 satisfies 80 kV ≤ Q1 < 100 kV; and / or
[0074] if 50 mm ≤ D1 < 300 mm, then Q1 satisfies: 100 kV ≤ Q1 < 160 kV; and / or
[0075] if D1 ≥ 300 mm, then Q1 ≥ 160 kV.
[0076] In these embodiments, the first acceleration voltage Q1 of the X-ray tube of the X-ray transmission photoelectric sorting and the processing particle size D1 of the X-ray transmission photoelectric sorting can satisfy the relationship: if 10 mm ≤ D1 < 50 mm, then Q1 satisfies 80 kV ≤ Q1 < 100 kV, or if 50 mm ≤ D1 < 300 mm, then Q1 satisfies: 100 kV ≤ Q1 < 160 kV, or if D1 ≥ 300 mm, then Q1 ≥ 160 kV, so that the first acceleration voltage of the X-ray tube of the X-ray transmission photoelectric sorting can meet the requirements of different processing particle sizes, so that the X-ray of the X-ray transmission photoelectric sorting has sufficient energy to penetrate bauxite and improve the accuracy of the X-ray transmission photoelectric sorting.
[0077] In some alternative embodiments, the second acceleration voltage of the X-ray tube of the X-ray fluorescence photoelectric sorting is ≥38 kV, and the processing particle size of the X-ray fluorescence photoelectric sorting is ≥10 mm.
[0078] In these embodiments, the second acceleration voltage of the X-ray tube for X-ray fluorescence photoelectric sorting is ≥38 kV, and the processing particle size of X-ray fluorescence photoelectric sorting is ≥10 mm, so that X-ray fluorescence photoelectric sorting has sufficient energy to distinguish waste rock and bauxite concentrate in the mixed bauxite through X-ray fluorescence photoelectric sorting.
[0079] It should be noted that the device model used for this X-ray fluorescence photoelectric sorting is (LPPC), and the power of the X-ray tube for this X-ray fluorescence photoelectric sorting is ≥10 W.
[0080] In some alternative embodiments, both the X-ray transmission photoelectric sorting and the X-ray fluorescence photoelectric sorting are performed by means of air blowing rejection or kick plate rejection.
[0081] In these embodiments, both the X-ray transmission photoelectric sorting and the X-ray fluorescence photoelectric sorting can be performed by means of air blowing rejection or kick plate rejection. Through air blowing rejection or kick plate rejection, the combined slime or waste rock can be effectively separated from the bauxite.
[0082] In some alternative embodiments, when the X-ray transmission photoelectric sorting or the X-ray fluorescence photoelectric sorting is performed by means of air blowing rejection, the blowing pressure of the air blowing rejection is ≥0.65 MPa.
[0083] In these embodiments, when the X-ray transmission photoelectric sorting or the X-ray fluorescence photoelectric sorting is performed by means of air blowing rejection, the blowing pressure of the air blowing rejection can be ≥0.65 MPa, so that the air blowing rejection has a strong enough blowing pressure to effectively separate the bauxite from the combined slime or waste rock.
[0084] It should be noted that, according to the hardness of the bauxite, air blowing rejection or kick plate rejection can be selectively used. For example, when the hardness of the bauxite is small, using the kick plate rejection method will break the bauxite and affect the subsequent X-ray fluorescence photoelectric sorting process; when the hardness of the bauxite is large, using air blowing rejection cannot effectively separate the bauxite.
[0085] In some alternative embodiments, the particle size of the screening is ≥30 mm.
[0086] In these embodiments, the particle size of the screening can be ≥30 mm, and the coarse particle size bauxite containing combined slime and waste rock in the bauxite can be screened out.
[0087] Figure 2 Exemplarily, a detailed flow schematic diagram of a method for removing mud impurities in bauxite provided by an embodiment of the present application is shown;
[0088] In some alternative embodiments, such as Figure 2 shown, screening the bauxite ore washing mixture containing combined slime to obtain coarse-grained bauxite ore containing combined slime and waste rock includes the steps of:
[0089] S201. Screening the bauxite ore washing mixture containing combined slime to obtain fine-grained bauxite ore and coarse-grained bauxite ore containing combined slime and waste rock;
[0090] For the X-ray fluorescence photoelectric separation of the mixed bauxite ore containing waste rock to remove the waste rock from the mixed bauxite ore to obtain bauxite concentrate, the subsequent steps include:
[0091] S5. Mixing the bauxite concentrate and the coarse-grained bauxite ore to obtain bauxite concentrate product.
[0092] In these embodiments, mixing the fine-grained bauxite ore obtained by screening and the bauxite concentrate obtained by X-ray fluorescence photoelectric separation can effectively recover pure bauxite concentrate, and these bauxite concentrates can be directly used as raw materials for producing alumina after being crushed and ground.
[0093] The present application will be further described below in conjunction with specific embodiments. For the experimental methods without specific conditions indicated in the following embodiments, they are generally determined according to national standards / industry standards; if there are no corresponding national standards / industry standards, they are carried out according to general international standards, conventional conditions or the conditions recommended by the manufacturer.
[0094] Example 1
[0095] Using the bauxite ore raw material from a certain mine in Guangxi, which mainly consists of bauxite ore, waste rock, surface slime and combined slime. The chemical element composition of this raw ore is shown in Table 1.
[0096] Table 1 Chemical element analysis of the raw ore
[0097] Mineral name <![CDATA[Al 2 O 3 > <![CDATA[SiO 2 > <![CDATA[Fe 2 O 3 > <![CDATA[TiO 2 > <![CDATA[K 2 O]]> <![CDATA[Sodium 2 O]]> CaO MgO Loss on ignition A / S Bauxite 46.47 11.52 12.27 1.97 0.38 0.14 7.95 0.31 17.48 4.03
[0098] As Figure 2 shown, a method for removing slime impurities from bauxite ore, where the bauxite ore raw material contains surface slime, combined slime and waste rock, includes:
[0099] S1. Washing the bauxite ore raw material to wash away the surface slime of the bauxite ore raw material to obtain a bauxite ore washing mixture containing combined slime;
[0100] S201. Screening the bauxite ore washing mixture containing combined slime to obtain fine-grained bauxite ore and coarse-grained bauxite ore containing combined slime and waste rock;
[0101] S3. Perform X-ray transmission photoelectric separation on the coarse-grained bauxite containing combined slime and waste rock to remove the combined slime from the coarse-grained bauxite, obtaining mixed bauxite containing waste rock;
[0102] S4. Perform X-ray fluorescence photoelectric separation on the mixed bauxite containing waste rock to remove the waste rock from the mixed bauxite, obtaining bauxite concentrate;
[0103] S5. Mix the bauxite concentrate and the coarse-grained bauxite to obtain bauxite concentrate product.
[0104] The separation parameters of the X-ray transmission photoelectric separation include a separation threshold f, and the separation threshold f satisfies the following relationship: when f ≥ f x in this case, the target product of the X-ray transmission photoelectric separation is combined slime;
[0105] when f < f x in this case, the target product of the X-ray transmission photoelectric separation is mixed bauxite;
[0106] wherein, the value of f x is 6000.
[0107] The separation parameters of the X-ray fluorescence photoelectric separation include a separation threshold H, and the separation threshold H satisfies the following relationship: when H ≥ H x in this case, the target product of the X-ray fluorescence photoelectric separation is bauxite concentrate;
[0108] when H < H x in this case, the target product of the X-ray fluorescence photoelectric separation is waste rock;
[0109] wherein, the value of H x is 2.0.
[0110] The first acceleration voltage of the X-ray tube for the X-ray transmission photoelectric separation is 80 kV, and the processing particle size of the X-ray transmission photoelectric separation is 30 mm.
[0111] The second acceleration voltage of the X-ray tube for the X-ray fluorescence photoelectric separation is 38 kV, and the processing particle size of the X-ray fluorescence photoelectric separation ≥ 10 mm.
[0112] The X-ray transmission photoelectric separation is carried out in the way of air blowing and rejection. The air blowing pressure for air blowing and rejection is generated by a supporting air compressor. The power of this air compressor is 35 kW, and the generated air blowing pressure is 0.65 MPa.
[0113] While the X-ray fluorescence photoelectric separation is carried out in the way of cylinder kick plate rejection. The working voltage of the supporting cylinder of the cylinder kick plate is 160 kV, and the generated pressure is 0.65 MPa.
[0114] The material transmission speed of X-ray transmission photoelectric sorting is 3 m / s.
[0115] The particle size of screening is 30 mm.
[0116] Example 2
[0117] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0118] f x The value of is 6050.
[0119] H x The value of is 2.2.
[0120] Example 3
[0121] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0122] f x The value of is 6000.
[0123] H x The value of is 2.0.
[0124] The first acceleration voltage of the X-ray tube for X-ray transmission photoelectric sorting is 165 kV, and the processing particle size of X-ray transmission photoelectric sorting is 300 mm.
[0125] The acceleration voltage of the X-ray tube for X-ray fluorescence photoelectric sorting is 38 kV, and the processing particle size of X-ray fluorescence photoelectric sorting ≥ 10 mm.
[0126] X-ray transmission photoelectric sorting is carried out by means of air blowing and rejection. The air blowing pressure for air blowing and rejection is generated by a supporting air compressor. The power of this air compressor is 35 kW, and the generated air blowing pressure is 0.7 MPa.
[0127] The material transmission speed of X-ray transmission photoelectric sorting is 4 m / s.
[0128] Example 4
[0129] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0130] f x The value of is 6000.
[0131] H x The value of is 2.0.
[0132] The first acceleration voltage of the X-ray tube for X-ray transmission photoelectric sorting is 165 kV, and the processing particle size of X-ray transmission photoelectric sorting is 300 mm.
[0133] Example 5
[0134] Based on the content disclosed in Example 1, the following further modifications are made:
[0135] The second acceleration voltage of the X-ray tube for X-ray fluorescence photoelectric sorting is 40 kV, and the processing particle size of X-ray fluorescence photoelectric sorting is ≥ 10 mm.
[0136] Example 6
[0137] Based on the content disclosed in Example 1, the following further modifications are made:
[0138] f x takes a value of 5900.
[0139] H x takes a value of 2.0.
[0140] Comparative Example 1
[0141] Based on the content disclosed in Example 1, the following further modifications are made:
[0142] Use a traditional ore washing machine for ore washing, without performing X-ray transmission photoelectric sorting and X-ray fluorescence photoelectric sorting.
[0143] Comparative Example 2
[0144] Based on the content disclosed in Example 1, the following further modifications are made:
[0145] Use a traditional ore washing machine for ore washing, only perform X-ray transmission photoelectric sorting and not perform X-ray fluorescence photoelectric sorting.
[0146] Comparative Example 3
[0147] Based on the content disclosed in Example 1, the following further modifications are made:
[0148] Use a traditional ore washing machine for ore washing, without performing X-ray transmission photoelectric sorting and only perform X-ray fluorescence photoelectric sorting.
[0149] Comparative Example 4
[0150] Based on the content disclosed in Example 1, the following further modifications are made:
[0151] f x takes a value of 7000.
[0152] H x takes a value ≥ 2.0.
[0153] Comparative Example 5
[0154] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0155] f x takes a value of 5500.
[0156] H x takes a value ≥ 2.0.
[0157] Comparative Example 6
[0158] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0159] H x takes a value of 1.
[0160] Comparative Example 7
[0161] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0162] H x takes a value of 4.
[0163] Comparative Example 8
[0164] On the basis of the content disclosed in Example 1, the following further modifications are made:
[0165] The first acceleration voltage of the X-ray tube for X-ray transmission photoelectric sorting is 130 kV.
[0166] Related experiments and effect data:
[0167] The yields and specific compositions of the aluminum concentrate, waste rock, and muddy impurities (surface slime and combined slime) obtained in each example and comparative example were respectively counted, and the results are shown in Table 2.
[0168] Table 2 Product yield and specific composition distribution table of each example and comparative example
[0169]
[0170]
[0171]
[0172] As can be seen from Table 1, a method for removing mud impurities from bauxite provided by an embodiment of the present application is based on the cascaded application of dual-mode X-ray sorting technology and targeted treatment of the occurrence state of ore mud. Through multi-stage collaborative sorting technology, efficient separation of surface ore mud, combined ore mud, and waste rock is achieved; this method enables the yield of the final bauxite concentrate to be above 85%, the alumina content of the bauxite concentrate to be above 55%, and the aluminum-silicon ratio of the bauxite concentrate to be above 4.6. Compared with the parameters of the embodiment, in Comparative Example 1, two X-ray sorting technologies are not used, while in Comparative Example 2 and Comparative Example 3, two X-ray sorting technologies are partially used, and the yield of the screened bauxite is unstable, and the purity of each bauxite product is not high; in addition, compared with the parameters of the embodiment, in Comparative Example 4, a higher first standard threshold f x is used. Although this increases the output of the bauxite concentrate, the silica content of the bauxite concentrate also increases significantly, and the aluminum-silicon ratio A / S also decreases. This is because X-ray transmission photoelectric sorting mainly presents different gray values according to the differences in different densities, and the too high first standard threshold f x will result in a low gray value, causing some combined ore mud to be judged as bauxite by X-ray transmission photoelectric sorting, and these combined ore mud will enter the bauxite concentrate, resulting in an increase in the silica content of the bauxite concentrate and a decrease in the aluminum-silicon ratio. In Comparative Example 5, a lower first standard threshold f x is used. This will undoubtedly reduce the output of the bauxite concentrate and will judge some bauxite concentrate as ore mud, and this part of the bauxite concentrate will enter the combined ore mud, causing losses of the bauxite concentrate.
[0173] Compared with the parameters of the embodiment, in Comparative Example 6, a lower second standard threshold H x is used. Although this increases the output of the bauxite concentrate, the silica content of the bauxite concentrate also increases significantly, and the aluminum-silicon ratio A / S also decreases. This is because the too low second standard threshold H x will cause some waste rock to be judged as bauxite concentrate, enabling these waste rock to enter the bauxite concentrate, resulting in an increase in the silica content of the bauxite concentrate and a decrease in the aluminum-silicon ratio. In Comparative Example 7, a higher second standard threshold H x is used. This will undoubtedly reduce the output of the bauxite concentrate and will judge some bauxite concentrate as waste rock, and this part of the bauxite concentrate will enter the waste rock, causing losses of the bauxite concentrate.
[0174] Compared with the parameters of the embodiment, in Comparative Example 8, a lower first acceleration voltage of the X-ray tube for X-ray transmission photoelectric sorting is used, which makes the energy of the X-rays for X-ray transmission photoelectric sorting lower, making the X-rays unable to effectively penetrate the bauxite, causing some bauxite to be judged as bauxite concentrate, thus resulting in an increase in the yield of the bauxite concentrate. Since the silicon content of the bauxite is relatively high, this leads to an increase in the silica content of the bauxite concentrate separated by X-ray transmission photoelectric sorting, and ultimately results in a decrease in the aluminum-silicon ratio A / S of the separated bauxite concentrate.
[0175] In summary, a method for removing mud impurities from bauxite provided by an embodiment of the present application is based on the cascaded application of dual-mode X-ray sorting technology and the targeted treatment of the occurrence state of ore mud. Through multi-stage collaborative sorting technology, efficient separation of surface ore mud, combined ore mud and waste rock is achieved, such that the yield of the final bauxite concentrate is above 85%, the alumina content of the bauxite concentrate is above 55%, and the aluminum-silicon ratio of the bauxite concentrate is above 4.6.
[0176] In addition, a method for removing mud impurities from bauxite provided by an embodiment of the present application combines ore washing, X-ray transmission photoelectric sorting and X-ray fluorescence photoelectric sorting. The overall process flow is short and the operation is simple; the X-ray transmission photoelectric sorting and X-ray fluorescence photoelectric sorting used in this method can achieve automatic removal of combined ore mud and waste rock in bauxite, and the overall method has a high degree of automation. Compared with the traditional manual selection and removal, this method not only avoids heavy manual operation steps, but also can avoid safety accidents; the overall method has a high safety factor, and the efficiency of removing muddy impurities is high, which can improve the quality of bauxite concentrate products.
[0177] In addition, a method for removing mud impurities from bauxite provided by an embodiment of the present application can further extract metal elements from the separated surface ore mud and combined ore mud and recycle them as waste sludge; the separated bauxite concentrate can be recycled as a production raw material for alumina; the separated waste rock can be used as sand and gravel aggregate in the construction field.
[0178] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined in the present application can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown in the present application, but will conform to the widest scope consistent with the principles and novel features claimed in the present application.
Claims
1. A method for removing mud impurities from bauxite, wherein the bauxite ore contains surface mud, combined mud and waste rock, the method comprising: Washing the raw bauxite ore to remove the surface mud of the raw bauxite ore, and obtaining a bauxite washing mixture containing bound mud; Screening the bauxite washing mixture containing bound sludge to obtain coarse-grained bauxite containing bound sludge and waste rock; The coarse-grained bauxite containing bound ore slime and waste rock is subjected to X-ray transmission photoelectric separation to remove bound ore slime from the coarse-grained bauxite to obtain mixed bauxite containing waste rock; The mixed bauxite containing waste rock is subjected to X-ray fluorescence photoelectric separation to remove the waste rock from the mixed bauxite to obtain bauxite concentrate.
2. The method according to claim 1, wherein the sorting parameters of the X-ray transmission photoelectric sorting include a first sorting threshold value f and a first standard threshold value f x , the first sorting threshold f and the first standard threshold f x The following relationship is satisfied: when f≥f x In the case of , the target product of the X-ray transmission photoelectric sorting is the combined sludge; When f<f x In the case of , the target product of the X-ray transmission photoelectric sorting is the mixed bauxite; in, The first standard threshold value f x The value ranges from 5900 to 6100.
3. The method according to claim 1, wherein the sorting parameters of the X-ray fluorescence photoelectric sorting include a second sorting threshold H and a second standard threshold H x , the second sorting threshold H and the second standard threshold H x The following relationship is satisfied: x In the case of , the target product of the X-ray fluorescence photoelectric sorting is the bauxite concentrate; When H<H x In the case of , the target product of the X-ray fluorescence photoelectric sorting is the waste rock; in, The second standard threshold H x The value is 1.5~2.
5.
4. The method according to claim 1, wherein the first acceleration voltage of the X-ray tube of the X-ray transmission photoelectric sorting is ≥80 kV, and the processing particle size of the X-ray transmission photoelectric sorting is ≥10 mm.
5. The method according to claim 1 or 4, wherein the first acceleration voltage Q1 of the X-ray tube of the X-ray transmission photoelectric sorting and the processing particle size D1 of the X-ray transmission photoelectric sorting satisfy the relationship: if 10 mm ≤ D1 < 50 mm, then Q1 satisfies 80 kV ≤ Q1 < 100 kV; and / or If 50mm≤D1<300mm, then Q1 satisfies: 100kV≤Q1<160kV; and / or If D1≥300mm, then Q1≥160kV.
6. The method according to claim 1, wherein the second acceleration voltage of the X-ray tube of the X-ray fluorescence photoelectric sorting is ≥38 kV, and the processing particle size of the X-ray fluorescence photoelectric sorting is ≥10 mm.
7. The method according to claim 1, wherein the X-ray transmission photoelectric sorting and the X-ray fluorescence photoelectric sorting are both carried out by air blowing removal or by kick plate removal.
8. The method according to claim 7, when the X-ray transmission photoelectric sorting or the X-ray fluorescence photoelectric sorting is carried out in the form of air blowing rejection, the blowing pressure of the air blowing rejection is ≥0.65MPa.
9. The method according to claim 1, wherein the particle size of the sieved particles is ≥ 30 mm.
10. The method according to claim 1, wherein the bauxite washing mixture containing bound ore slime is screened to obtain coarse-grained bauxite containing bound ore slime and waste rock, comprising the steps of: Screening the bauxite washing mixture containing bound sludge to obtain fine-grained bauxite and coarse-grained bauxite containing bound sludge and waste rock; The mixed bauxite containing waste rock is subjected to X-ray fluorescence photoelectric sorting to remove the waste rock from the mixed bauxite to obtain bauxite concentrate, and then the steps include: The bauxite concentrate and the coarse-grained bauxite are mixed to obtain an aluminum concentrate product.