Method for comprehensively utilizing high-carbonate bauxite

Abstract

The invention relates to the technical field of quality improvement and impurity removal of colored resources, in particular to a method for comprehensively utilizing high-carbonate bauxite. The high-carbonate bauxite comprises aluminum minerals, iron minerals and inorganic carbon-containing minerals, and the method comprises the following steps: carrying out first-stage crushing on the high-carbonate bauxite to obtain bauxite powder; the bauxite powder is subjected to first-stage screening and grading, and coarse-grain materials, medium-grain materials and fine-grain materials are obtained; carrying out second-stage crushing on the coarse-fraction material to obtain coarse-fraction mineral powder; the coarse-grained mineral powder is returned to the first-stage screening and grading for circular treatment; the heavy medium group and the medium-grain materials are subjected to segmented gravity separation, and second aluminum concentrate is obtained; the fine-fraction materials are subjected to second-stage screening and grading, and oversize materials and undersize materials are obtained; and the oversize material, the undersize material and the second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation, and an aluminum concentrate product and iron-containing tailings are obtained. According to the method, the targets of high inorganic carbon removal rate and high aluminum concentrate product yield are synchronously achieved through a closed-loop physical process of crushing, grading, reselection, ore grinding and magnetic separation.

Description

Technical Field

[0001] This application relates to the field of non-ferrous resource upgrading and impurity removal technology, and in particular to a method for comprehensive utilization of high carbonate bauxite. Background Technology

[0002] With the rapid development of the aluminum industry and the increasing scarcity of high-quality bauxite resources, the industry's dependence on imported bauxite has risen sharply. However, coal-fired bauxite reserves are currently abundant, possessing immense economic and strategic value. If coal-fired bauxite could replace imported bauxite, efficient utilization of complex bauxite resources could be achieved. However, current coal-fired bauxite contains high levels of carbonaceous impurities, making efficient utilization difficult. This means that the development and utilization of high-carbon bauxite resources in coal-fired bauxite remains in the exploratory stage, has not yet achieved large-scale production, and has not yet played a supporting role for the aluminum industry.

[0003] At present, the main processing technologies for high carbonates in coal-fired bauxite resources are: (1) Methods for simultaneously removing carbon and sulfur from high-sulfur and high-carbon bauxite. This method involves crushing the high-sulfur and high-carbon bauxite ore to obtain crushed products; then adding the crushed products to a ball mill for grinding to obtain slurry, and then transporting the slurry to a flotation cell for flotation: adding sulfuric acid as a pH adjuster to the slurry to adjust the pH of the slurry to the range of 4 to 7; then adding inhibitors (generally phosphoric acid or phosphoric acid derivatives) to the slurry; then adding hydrocarbon oil collectors, xanthate collectors and fatty acid anionic collectors to the prepared slurry in sequence for flotation operation to obtain desulfurized and decarbonized bauxite; (2) Industrial production methods for comprehensive utilization of high-sulfur and high-carbon complex bauxite. The process of this integrated industrial production method is as follows: First, high-sulfur, high-carbon bauxite is sequentially crushed, ground, and slurry-treated to obtain a slurry. Then, flotation reagents are used to perform a flotation process on the slurry (including roughing, cleaning, and scavenging). Through flotation, sulfides and aluminum minerals in the slurry are separated and enriched, thereby obtaining sulfur concentrate and aluminum concentrate. However, these processing techniques have low removal rates of inorganic carbon in coal-bearing bauxite and low aluminum concentrate yields, making it difficult to meet the requirements for efficient utilization. Summary of the Invention

[0004] This application provides a method for the comprehensive utilization of high-carbonate bauxite to solve the following technical problem: how to simultaneously improve the removal rate of inorganic carbon and the yield of aluminum concentrate in coal-fired bauxite resources.

[0005] In a first aspect, embodiments of this application provide a method for the comprehensive utilization of high-carbonate bauxite, wherein the high-carbonate bauxite includes aluminum minerals, iron minerals, and inorganic carbon-containing minerals, and the method includes: The high-carbonate bauxite is subjected to a primary crushing process to obtain bauxite powder; The bauxite powder is subjected to a first-stage screening and classification to obtain coarse-grained material, medium-grained material and fine-grained material. The coarse-grained material is subjected to two-stage crushing to obtain coarse-grained mineral powder. The coarse-grained mineral powder is returned to the first screening and grading stage for recycling. The heavy medium group and the medium-grained material are subjected to staged gravity separation to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material, thereby obtaining a second aluminum concentrate; The fine-particle material is subjected to two-stage screening and classification to obtain oversize material and undersize material. The oversize material, undersize material, and second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate product and iron-containing tailings.

[0006] Optionally, the heavy medium group and the medium-grained material are subjected to staged gravity separation to separate aluminum minerals, iron minerals, and inorganic carbon-containing minerals from the medium-grained material, obtaining a first iron tailings and a second aluminum concentrate, including the following steps: The first medium and the medium-grained material are subjected to a first-stage gravity separation to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material, thereby obtaining a first aluminum concentrate. The second medium and the first aluminum concentrate are subjected to two-stage gravity separation to separate aluminum minerals and iron minerals in the first aluminum concentrate, resulting in the first iron tailings and the second aluminum concentrate.

[0007] Optionally, the specific gravity of the first medium is 1.6 g / cm³. 3 Up to 2.0 g / cm 3 The feeding frequency of the reselection section is 24Hz to 28Hz.

[0008] Optionally, the specific gravity of the second medium is 2.2 g / cm³. 3 Up to 2.5g / cm 3 The feeding frequency of the two-stage reselection is 30Hz to 36Hz.

[0009] Optionally, the oversize material, the undersize material, and the second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate product and iron-containing tailings, including the following steps: The oversize material and the second aluminum concentrate are combined to obtain a first mixture. The first mixture is subjected to a grinding process to obtain a magnetic separation feed. The magnetically separated feed and the undersize material are combined to obtain a second mixture. The second mixture is subjected to a first-stage magnetic separation to obtain the third aluminum concentrate and the second iron tailings; The third aluminum concentrate is subjected to two-stage grinding to obtain a two-stage magnetic separation feed. The two-stage magnetic separation feed is subjected to two-stage magnetic separation to obtain aluminum concentrate and third iron tailings. The first iron tailings, the second iron tailings, and the third iron tailings are combined to obtain iron-bearing tailings.

[0010] Optionally, the first-stage magnetic separation feed includes a first-stage fine-particle magnetic separation feed, the mass of which is 70% to 80% of the total mass of the first-stage magnetic separation feed, and the particle size of which is ≤0.074 mm; and / or The two-stage magnetic separation feed includes two stages of fine-particle magnetic separation feed, the mass of which is 81% to 90% of the total mass of the two-stage magnetic separation feed, and the particle size of which is ≤0.074mm.

[0011] Optionally, the magnetic field strength of the first-stage magnetic separation is 0.4T to 0.6T, the first-stage magnetic separation is performed using pulsating water, and the pulsating water frequency of the first-stage magnetic separation is 20Hz to 25Hz; and / or The magnetic field strength of the two-stage magnetic separation is 0.7T to 0.9T, and the two-stage magnetic separation is carried out in the form of pulsating water with a pulse frequency of 18Hz to 22Hz.

[0012] Optionally, both the first-stage magnetic separation and the second-stage magnetic separation use cylindrical steel bars and rhomboid steel bars as composite magnetic media, wherein the filling rate of the composite magnetic media in the first-stage magnetic separation is 14% to 17%, and the filling rate of the composite magnetic media in the second-stage magnetic separation is 18% to 23%.

[0013] Optionally, in the composite magnetic medium of the magnetic separation section, the number of cylindrical steel bars S1 and the number of rhombic steel bars S2 satisfy: S1:S2 = (1 to 3):1; and / or In the composite magnetic medium of the two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhombic steel bars S2 satisfy: S1:S2=1:(2 to 3).

[0014] Optionally, the target particle size for the first stage of screening and grading includes a first particle size and a second particle size, wherein the first particle size is 4 mm to 7 mm and the second particle size is 0.1 mm to 0.5 mm; and / or The target particle size for the two-stage screening and grading is 0.038 mm to 0.074 mm.

[0015] The technical solutions provided in this application have the following advantages compared with the prior art: This application provides a method for the comprehensive utilization of high-carbonate bauxite. This method employs a closed-loop physical process of "crushing + classification + gravity separation + grinding + magnetic separation" to precisely process high-carbonate bauxite into particle sizes. Based on the differences in specific gravity and magnetic properties between aluminum minerals, iron minerals, and carbonaceous impurities in high-carbonate bauxite, this process can achieve the technical goal of inhibiting and deeply removing carbonaceous impurities from the mud, while also reducing aluminum mineral loss and simultaneously improving the inorganic carbon removal rate and aluminum concentrate yield. The specific principle is as follows: First, through a first-stage crushing and a first-stage screening and classification, the high-carbonate bauxite is separated into coarse, medium, and fine particles. This facilitates targeted processing of each particle size, reduces the generation of secondary slime, helps maintain the liberated state of carbonaceous impurities, and prevents the loss of aluminum minerals, thus contributing to improved aluminum concentrate yield. Next, only the coarse particles undergo a second-stage crushing and a first-stage screening and classification cycle to prevent carbonaceous impurities from becoming muddy and difficult to separate, improving carbon removal rate. Simultaneously, it prevents the loss of aluminum minerals from the fine particles, ensuring aluminum concentrate yield. Subsequently, the medium particles undergo staged gravity separation. Utilizing the density differences between aluminum, iron, and carbonaceous impurities, aluminum minerals are separated in a gravity field to form a second aluminum concentrate. This staged separation... Gravity separation can quickly remove most of the inorganic carbon, directly improving the decarbonization rate, while enriching aluminum minerals and increasing the yield of aluminum concentrate. Furthermore, two-stage screening of fine materials optimizes particle size, preventing particle size mixing and excessive secondary slime generation during grinding, which could affect subsequent processes and facilitates the recovery of fine materials and removal of residual carbon. Finally, the second aluminum concentrate obtained from the staged gravity separation is combined with the oversize and undersize materials from the two-stage screening for multi-stage grinding and multi-stage magnetic separation. Multi-stage grinding ensures the complete dissociation of aluminum minerals from residual inorganic carbon and iron minerals, and reduces the generation of secondary slime during grinding, preventing these intergrowths from causing incomplete decarbonization and mineral loss in the aluminum concentrate. Multi-stage magnetic separation thoroughly removes the intergrowths of inorganic carbon and iron, improving the decarbonization rate and yield of the aluminum concentrate. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic flowchart of a method for comprehensive utilization of high-carbonate bauxite provided in this application embodiment; Figure 2A detailed flow chart illustrating a method for the comprehensive utilization of high-carbonate bauxite, provided in this application embodiment; Figure 3 for Figure 2 The continuation of. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] The range descriptions used in this application, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1~6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "comprising" and others used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships involved in this document, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained by purchasing from the market or by existing methods.

[0021] It should be noted that, regarding the prior art (1) described in the background art, the inventors have found that this method suffers from problems such as large flotation reagent dosage, difficulty in pH adjustment, difficulty in utilizing recycled water, low inorganic carbon removal rate, and severe loss of aluminum concentrate yield. Regarding the prior art (2) described in the background art, the inventors have found that this method suffers from problems such as large flotation reagent dosage, long overall process flow, difficulty in utilizing recycled water, low inorganic carbon removal rate, severe loss of aluminum concentrate yield, and the impact of aluminum concentrate reagents on subsequent alumina production.

[0022] Figure 1 An exemplary schematic diagram of a method for comprehensive utilization of high-carbonate bauxite provided in an embodiment of this application is shown. like Figure 1As shown in the embodiments of this application, a method for the comprehensive utilization of high-carbonate bauxite is provided. The high-carbonate bauxite includes aluminum minerals, iron minerals, and inorganic carbon-containing minerals. The method includes: S1. The high-carbonate bauxite is subjected to a first-stage crushing process to obtain bauxite powder; S2. The bauxite powder is subjected to a first-stage screening and classification to obtain coarse-grained material, medium-grained material and fine-grained material; S3. The coarse-grained material is subjected to two-stage crushing to obtain coarse-grained mineral powder; S4. The coarse-grained mineral powder is returned to the first-stage screening and grading process for recycling; S5. Perform segmented gravity separation on the heavy medium group and the medium-grained material to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material to obtain a second aluminum concentrate; S6. Perform two-stage screening and classification on the fine-particle material to obtain oversize material and undersize material; S7. The oversize material, the undersize material, and the second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate product and iron-containing tailings.

[0023] It should be noted that the total carbon content in this high-carbonate bauxite is ≥1.00% by mass, and the inorganic carbon accounts for more than 90.00% of the total carbon mass. The inorganic carbon mainly exists in the form of dolomite, calcite, and siderite; among them, the dolomite and calcite have relatively coarse particle sizes, generally ranging from 0.1 mm to 5.0 mm; while the siderite exists in a non-uniform form, generally ranging from 0.02 mm to 2.00 mm. By refining the total carbon content, inorganic carbon percentage, inorganic carbon form, and inorganic carbon particle size range in the high-carbonate bauxite, the raw material range of the high-carbonate bauxite is further defined, thereby enabling the comprehensive utilization of the high-carbonate bauxite and ultimately obtaining high-quality aluminum concentrate, calcite tailings, and iron-bearing tailings. This demonstrates the wide applicability and feasibility of the method provided in this application's embodiments. If the total carbon content and inorganic carbon percentage of the high-carbonate bauxite are too low, the advanced nature of this method cannot be highlighted. If the total carbon content of high-carbonate bauxite is too high, it indicates that the high-carbonate bauxite has no development or utilization value.

[0024] It should be noted that the primary and secondary crushing stages can utilize either a crushing layer compression process or a multi-cylinder hydraulic cone crusher. Combining primary and secondary crushing stages allows for better selective crushing, reduces secondary slime production during the crushing process, improves decarbonization efficiency in high-carbonate bauxite, and increases the yield and grade of high-quality aluminum concentrate.

[0025] It should be noted that the method for comprehensive utilization of high-carbonate bauxite provided in this application embodiment employs a comprehensive physical process involving graded and segmented processing, staged crushing, staged grinding, combined gravity and magnetic separation, and heavy media recycling. This method addresses the characteristics of high-carbonate bauxite, such as uneven particle size distribution of carbon impurity minerals (dolomite / calcite), low hardness leading to easy mud formation, and significant differences in mineral specific gravity and magnetic properties. It simultaneously improves both inorganic carbon removal rate and bauxite concentrate yield from three core dimensions: reducing mineral mud formation loss, enhancing precise carbon-aluminum separation, and efficient fractional recovery. The specific mechanism is as follows: I. Stage crushing + graded recycling process: Reduce mud formation from the source and lay a solid foundation for efficient sorting.

[0026] The dolomite and calcite in high-carbonate bauxite have low Mohs hardness, and traditional single crushing or grinding methods easily generate a large amount of secondary slime. This not only causes the loss of aluminum minerals due to entrainment but also covers the surface of high-carbonate bauxite, worsening the decarburization effect. This method addresses this problem at its source through staged crushing and graded recycling: 1. First stage crushing + first stage screening and grading: The high carbonate bauxite is first crushed and then screened and graded to separate the material into three grades: coarse, medium and fine particles. This achieves stratification by particle size and avoids sorting disorder caused by mixing minerals of different particle sizes. 2. Two-stage crushing of coarse materials + return recycling: After secondary crushing, the coarse materials are returned to screening and grading. Only coarse materials are crushed in a targeted manner, which prevents the over-crushing of fine minerals and greatly reduces the occurrence of mud formation in dolomite or calcite. 3. Effects: It reduces the amount of secondary slime, which not only prevents aluminum minerals from being carried away by slime (ensuring the yield of aluminum concentrate products), but also keeps carbonate impurities in a clear embedded state, creating a clean separation environment for gravity separation and significantly improving the removal rate of inorganic carbon in high carbonate bauxite.

[0027] II. Medium-grained fractional gravity separation: Utilizing the difference in specific gravity for deep decarbonization, rapidly enriching aluminum minerals.

[0028] Medium-sized materials are those in which carbon, aluminum, and iron minerals are relatively fully liberated and whose particle size is most suitable for gravity separation. The method provided in this application introduces staged gravity separation using heavy media, utilizing the specific gravity differences of the three types of minerals to achieve preliminary separation: 1. In the heavy medium separation system, inorganic carbon minerals (dolomite or calcite) have a low specific gravity, aluminum minerals have a medium specific gravity, and iron minerals have a high specific gravity, achieving stratification of the three in a gravitational field; 2. Directly separate the first iron tailings (removing most of the iron minerals) and the second aluminum concentrate (preliminarily enriching aluminum minerals and removing a large amount of inorganic carbon); 3. Effects: It quickly and efficiently removes most of the inorganic carbon from medium-sized materials, while directly recovering high-grade aluminum minerals. This not only significantly improves the removal rate of inorganic carbon but also directly contributes to the yield of aluminum concentrate products, achieving the simultaneous completion of "decarbonization + production increase".

[0029] III. Two-stage screening of fine-grained materials + multi-stage grinding + multi-stage magnetic separation: fine decomposition and deep removal of residual carbon and iron components.

[0030] Fine-grained materials are small in size and easily turn into mud, requiring a finer treatment process consisting of two-stage screening, multi-stage grinding, and multi-stage magnetic separation to compensate for the shortcomings of gravity separation in separating fine-grained minerals. 1. Two-stage screening of fine materials: The fine materials are divided into oversize and undersize materials to further optimize the particle size distribution of the fine materials and avoid particle size mixing from affecting grinding and separation; 2. Multi-stage grinding: Combined grinding of fine-grained materials and second aluminum concentrate allows aluminum minerals to be fully dissociated from residual carbon impurities and iron minerals, avoiding incomplete carbon removal and aluminum mineral loss caused by intergrowth; 3. Multi-stage magnetic separation: Utilizing the difference in magnetic susceptibility among carbon impurity minerals, aluminum minerals, and iron minerals, residual iron-containing minerals and carbon-containing minerals are removed in a magnetic field, ultimately yielding high-quality aluminum concentrate and iron-containing tailings; 4. Effects: It completely removes residual inorganic carbon from fine-grained materials, while recovering all recoverable aluminum minerals from the fine-grained materials, reducing the loss of aluminum minerals from the fine-grained materials, further improving the total yield of aluminum concentrate products, and completing the final step of deep removal of inorganic carbon.

[0031] IV. Heavy media circulation + physical combined process: stabilizes sorting indicators and maximizes aluminum ore recovery rate.

[0032] 1. Heavy media recycling: The heavy media used in multi-stage heavy separation can be recycled and reused, ensuring that the carbon removal process of heavy separation is stable and efficient, avoiding the decline in carbon removal rate due to the failure of heavy media, and continuously maintaining high inorganic carbon removal index. 2. Pure physical process without reagent entrainment: The use of fatty acid decarbonization collectors, which easily lead to the loss of aluminum mineral inclusions, is eliminated. The entire process relies on physical separation by gravity and magnetic force to avoid harmful impurity minerals being entrained in the flotation foam, thus reducing the carbon impurity removal rate. This maximizes the quality of aluminum concentrate products and the carbon impurity removal rate, and does not produce difficult-to-treat flotation backwater.

[0033] 3. Complementary "gravity separation + magnetic separation" by particle size: Gravity separation for rapid decarbonization of medium-sized materials and magnetic separation for deep purification of fine-sized materials. The two processes work together to cover different particle size ranges, achieving thorough carbon removal and complete aluminum mineral recovery.

[0034] V. Overall Results: Collaboration across the entire process achieves dual improvements.

[0035] The core logic behind this method, which combines the above processes, to simultaneously improve both inorganic carbon removal rate and aluminum concentrate yield, is as follows: 1. Grading and segmentation: Adapt to the characteristics of minerals with different particle sizes to avoid loss of aluminum minerals and incomplete carbon removal caused by "one-size-fits-all" sorting; 2. Suppress mud formation: Reduce mud formation of dolomite and calcite, thereby reducing the loss of aluminum minerals and improving the separation efficiency of carbon impurity minerals. 3. Gravity and magnetic combined deep separation: Utilizing the dual differences in specific gravity and magnetism, inorganic carbon can be removed in stages and deeply, while aluminum minerals can be recovered in stages and fully recovered. 4. Green physical process: No pollutants or reagents are involved. While ensuring low cost and high environmental protection, it can stably produce high-quality aluminum concentrate products, achieving triple optimization of resource utilization rate, carbon removal rate and aluminum concentrate product yield.

[0036] Ultimately, this method, through a closed-loop physical process of "crushing + classification + gravity separation + grinding + magnetic separation," not only solves the technical pain points of severe mud formation and difficult decarbonation in high-carbonate bauxite, but also achieves efficient removal of inorganic carbon and maximum recovery of aluminum minerals, simultaneously achieving the goals of high inorganic carbon removal rate and high aluminum concentrate yield.

[0037] In some optional embodiments, the heavy medium group and the medium-grained material are subjected to staged gravity separation to separate aluminum minerals, iron minerals, and inorganic carbon-containing minerals from the medium-grained material, obtaining a first iron tailings and a second aluminum concentrate, including the following steps: S501. Perform a first-stage gravity separation on the first medium and the medium-particle material to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-particle material to obtain a first aluminum concentrate; S502. Perform two-stage gravity separation on the second medium and the first aluminum concentrate to separate aluminum minerals and iron minerals in the first aluminum concentrate, and obtain the first iron tailings and the second aluminum concentrate.

[0038] In these implementations, the medium-sized material is first subjected to primary gravity separation using a first-stage medium, and then the first aluminum concentrate is subjected to secondary gravity separation using a second-stage medium. Based on the characteristics of low specific gravity of inorganic carbon minerals (dolomite or calcite), medium specific gravity of aluminum minerals, and high specific gravity of iron minerals, the three materials can be separated into layers in the gravity fields of the primary and secondary gravity separations. This allows for the rapid and efficient removal of most of the inorganic carbon from the medium-sized material, while high-grade aluminum minerals are directly recovered.

[0039] It should be noted that in addition to obtaining the first aluminum concentrate, this stage of re-selection can also yield calcite tailings.

[0040] It should be noted that after the first stage of re-selection, in addition to obtaining the corresponding first aluminum concentrate, a corresponding first-stage medium is also obtained, which can be recycled back to the first stage of re-selection. Furthermore, after the second stage of re-selection, in addition to obtaining the corresponding first iron tailings and second aluminum concentrate, a corresponding second-stage medium is also obtained, which can be recycled back to the second stage of re-selection.

[0041] In some alternative embodiments, the specific gravity of the first medium is 1.6 g / cm³. 3 Up to 2.0 g / cm 3 The feeding frequency of the reselection section is 24Hz to 28Hz.

[0042] In these embodiments, the specific gravity is 1.6 g / cm³. 3 Up to 2.0 g / cm 3 The first-stage medium and the first-stage gravity separation with a feeding frequency of 24Hz to 28Hz can quickly and efficiently remove most of the inorganic carbon from medium-sized materials by combining the first-stage medium and the feeding frequency, based on the characteristics of low proportion of inorganic carbon minerals (dolomite or calcite), medium proportion of aluminum minerals and high proportion of iron minerals. At the same time, high-grade aluminum minerals can be directly recovered.

[0043] The specific gravity of this first medium can be 1.6 g / cm³. 3 1.65g / cm 3 1.7g / cm 3 1.75g / cm 3 1.8g / cm 3 1.85g / cm 3 1.9g / cm 3 1.95g / cm 3 Or 2.0g / cm 3 .

[0044] The feeding frequency for this reselection stage can be 24Hz, 24.5Hz, 25Hz, 25.5Hz, 26Hz, 26.5Hz, 27Hz, 27.5Hz, or 28Hz.

[0045] It should be noted that the specific gravity of the first medium is greater than 2.0 g / cm³. 3 In such cases, some aluminum concentrate is lost in the calcite and dolomite tailings, reducing the recovery rate of high-quality aluminum concentrate products. When the specific gravity of the first medium is less than 1.6 g / cm³... 3 In this case, the already dissociated calcite and dolomite cannot be separated from the medium-grained material, resulting in an increase in the carbon content in the aluminum concentrate product and failing to achieve the effect of gravity separation and decarbonization.

[0046] It should be noted that when the feed frequency of the first-stage gravity separation is greater than 28Hz, the centrifugal force is too high, causing some aluminum minerals in the medium-grained material to be lost in the calcite and dolomite tailings, reducing the recovery rate of high-quality aluminum concentrate. When the feed frequency of the first-stage gravity separation is less than 24Hz, the centrifugal force is insufficient, preventing the already liberated calcite and dolomite in the medium-grained material from separating from the aluminum concentrate, resulting in an increased carbon content in the aluminum concentrate and failing to achieve the desired decarbonization effect.

[0047] In some alternative embodiments, the specific gravity of the second medium is 2.2 g / cm³. 3 Up to 2.5g / cm 3 The feeding frequency of the two-stage reselection is 30Hz to 36Hz.

[0048] In these embodiments, the specific gravity is 2.2 g / cm³. 3 Up to 2.5g / cm 3 The second medium and the two-stage gravity separation with a feeding frequency of 30Hz to 36Hz can quickly and efficiently remove most of the inorganic carbon from the first aluminum concentrate product by combining the second medium and the feeding frequency, based on the characteristics of low proportion of inorganic carbon minerals (dolomite or calcite), medium proportion of aluminum minerals and high proportion of iron minerals. At the same time, high-grade aluminum minerals can be directly recovered.

[0049] The specific gravity of this second medium can be 2.2 g / cm³. 3 2.25g / cm 3 2.3g / cm 3 2.35g / cm 3 2.4g / cm 3 2.45g / cm 3 Or 2.5g / cm 3 .

[0050] The feeding frequency for this two-stage reselection can be 30Hz, 30.5Hz, 31Hz, 31.5Hz, 32Hz, 32.5Hz, 33Hz, 33.5Hz, 34Hz, 34.5Hz, 35Hz, 35.5Hz, or 36Hz.

[0051] It should be noted that the specific gravity of the second medium is greater than 2.5 g / cm³. 3 In this case, some of the first iron tailings (usually siderite) from the first aluminum concentrate enters the second aluminum concentrate, affecting the grade of the aluminum concentrate product and increasing the carbon content in the aluminum concentrate product. When the specific gravity of the second medium is less than 2.2 g / cm³... 3In this situation, the already dissociated aluminum minerals cannot be separated from the first aluminum concentrate, resulting in the loss of some aluminum minerals in the first iron tailings. This not only fails to achieve the effect of gravity separation and decarbonization but also reduces the recovery rate of the aluminum concentrate product.

[0052] It should be noted that when the feed frequency of the second-stage gravity separation is greater than 36Hz, the centrifugal force is too high, causing some of the liberated first iron tailings from the first aluminum concentrate to enter the second aluminum concentrate, reducing the recovery rate of high-quality aluminum concentrate products. When the feed frequency of the second-stage gravity separation is less than 30Hz, the centrifugal force is also too high, preventing the already liberated aluminum minerals from separating from the first aluminum concentrate. This results in a simultaneous decrease in the yield and recovery rate of the second aluminum concentrate, leading to poor removal of the first iron tailings in the second-stage gravity separation.

[0053] In some optional embodiments, the oversize material, the undersize material, and the second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate product and iron-containing tailings, including the following steps: S701. Combine the oversize material and the second aluminum concentrate to obtain a first mixture; S702. The first mixture is subjected to a first-stage grinding process to obtain a first-stage magnetic separation feed; S703. Combine the first-stage magnetic separation feed and the undersize material to obtain a second mixture; S704. The second mixture is subjected to a first-stage magnetic separation to obtain a third aluminum concentrate and a second iron tailings; S705. The third aluminum concentrate is subjected to two-stage grinding to obtain a two-stage magnetic separation feed; S706. The two-stage magnetic separation feed is subjected to two-stage magnetic separation to obtain aluminum concentrate and third iron tailings; S707. The first iron tailings, the second iron tailings and the third iron tailings are combined to obtain iron-bearing tailings.

[0054] In these embodiments, the oversize material and the second aluminum concentrate are combined and ground in a single stage to ensure thorough mixing. Then, the undersize material is added and combined to form a uniformly dispersed second mixture with a finer particle size. This facilitates the subsequent screening of the strongly magnetic second iron tailings in the second mixture through a single stage of magnetic separation, thereby improving the grade of the third aluminum concentrate. The third aluminum concentrate is then subjected to a second stage of grinding to refine it and expose some weakly magnetic third iron tailings. Subsequent second-stage magnetic separation can remove residual iron-containing minerals from the feed material of the second stage magnetic separation, forming third iron minerals, which helps to improve the grade and recovery rate of the aluminum concentrate product.

[0055] In some optional embodiments, the first-stage magnetic separation feed includes a first-stage fine-particle magnetic separation feed, the mass of which is 70% to 80% of the total mass of the first-stage magnetic separation feed, and the particle size of which is ≤0.074 mm; and / or The two-stage magnetic separation feed includes two stages of fine-particle magnetic separation feed, the mass of which is 81% to 90% of the total mass of the two-stage magnetic separation feed, and the particle size of which is ≤0.074mm.

[0056] In these embodiments, the primary fine-grained magnetic separation feed, comprising 70% to 80% of the primary magnetic separation feed mass and having a particle size ≤0.074 mm, indicates that after the primary grinding process, the coarse-grained siderite in the primary magnetic separation feed is completely liberated, which is beneficial for obtaining a higher-grade and higher-recovery third-stage aluminum concentrate through subsequent primary magnetic separation. Furthermore, the secondary fine-grained magnetic separation feed, comprising 81% to 90% of the secondary magnetic separation feed mass and having a particle size ≤0.074 mm, indicates that after the secondary grinding process, the fine-grained siderite in the secondary fine-grained magnetic separation feed is completely liberated, which is beneficial for obtaining a higher-grade and higher-recovery aluminum concentrate product through subsequent secondary magnetic separation.

[0057] The mass of the fine-particle magnetic separation feed can be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80% of the mass of the magnetic separation feed.

[0058] The mass of the feed material for the two-stage fine-particle magnetic separation can be 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90% of the mass of the feed material for the two-stage magnetic separation.

[0059] It should be noted that if the mass of the fine-particle magnetic separation feed in the first stage is greater than 80% of the total feed mass, this indicates over-grinding of the first mixture during the first-stage grinding process. This increases energy consumption in the first-stage grinding, leading to poorer separation efficiency and higher grinding costs. Conversely, if the mass of the fine-particle magnetic separation feed in the first stage is less than 70% of the total feed mass, this will affect the liberation degree of the coarse-particle siderite in the subsequent first-stage magnetic separation, resulting in the loss of some aluminum minerals in the second iron tailings and reducing the yield and recovery rate of the third aluminum concentrate.

[0060] It should be noted that when the mass of the feed material for the second-stage fine-grained magnetic separation is greater than 90% of the total mass of the feed material for the second-stage magnetic separation, this indicates over-grinding of the third-stage aluminum concentrate during the second-stage grinding process. Furthermore, the increased energy consumption of the second-stage grinding leads to a decrease in the separation efficiency of the second-stage magnetic separation and an increase in grinding costs. When the mass of the feed material for the second-stage fine-grained magnetic separation is less than 81% of the total mass of the feed material for the second-stage magnetic separation, this affects the degree of liberation of the fine-grained siderite embedded in the second-stage magnetic separation, causing some aluminum concentrate to be lost in the third-stage iron tailings, thus reducing the yield and recovery rate of the aluminum concentrate product.

[0061] In some optional embodiments, the magnetic field strength of the first-stage magnetic separation is 0.4T to 0.6T, the first-stage magnetic separation is performed in the form of pulsating water, and the pulsating water frequency of the first-stage magnetic separation is 20Hz to 25Hz; and / or The magnetic field strength of the two-stage magnetic separation is 0.7T to 0.9T, and the two-stage magnetic separation is carried out in the form of pulsating water with a pulse frequency of 18Hz to 22Hz.

[0062] In these embodiments, a first-stage magnetic separation with a magnetic field strength of 0.4T to 0.6T and a pulsed water flow rate of 20Hz to 25Hz can screen out carbon impurity minerals and iron minerals from the second mixture based on the difference in the specific magnetic susceptibility of carbon impurity minerals, aluminum minerals, and iron minerals, resulting in a third aluminum concentrate with higher grade and recovery rate. Additionally, a second-stage magnetic separation with a magnetic field strength of 0.7T to 0.9T and a pulsed water flow rate of 18Hz to 22Hz can screen out carbon impurity minerals and iron minerals from the second-stage magnetic separation feed based on the difference in the specific magnetic susceptibility of carbon impurity minerals, aluminum minerals, and iron minerals, resulting in a high-grade aluminum concentrate product with high recovery rate.

[0063] The magnetic field strength of this section of magnetic separation can be 0.4T, 0.41T, 0.42T, 0.43T, 0.44T, 0.45T, 0.50T, 0.55T or 0.60T.

[0064] The frequency of the pulsating water jets in this magnetic separation section can be 20Hz, 21Hz, 22Hz, 23Hz, 24Hz, or 25Hz.

[0065] The magnetic field strength of the two-stage magnetic separation can be 0.7T, 0.75T, 0.8T, 0.85T or 0.9T.

[0066] The pulsating water jet frequency of the two-stage magnetic separation can be 18Hz, 18.5Hz, 19Hz, 19.5Hz, 20Hz, 20.5Hz, 21Hz, 21.5Hz, or 22Hz.

[0067] It should be noted that when the magnetic field strength of the first-stage magnetic separation exceeds 0.60T, the excessively high magnetic field strength causes some aluminum minerals to mix with strongly magnetic iron minerals, reducing the yield and recovery rate of the third-stage aluminum concentrate. Conversely, when the magnetic field strength of the first-stage magnetic separation is below 0.4T, the magnetic field collection capacity is insufficient, resulting in the incomplete removal of liberated siderite and an increase in the carbon content of the third-stage aluminum concentrate.

[0068] It should be noted that when the pulsating water flow rate in the first-stage magnetic separation is greater than 25Hz, although the high-frequency pulsating water flow can improve the mechanical inclusion problem in the first-stage magnetic separation process and increase the carbon content and total iron (TFe) content in the second iron tailings, it will lead to an increase in the carbon impurity content of the aluminum concentrate and a decrease in the carbon removal rate. When the pulsating water flow rate in the first-stage magnetic separation is less than 20Hz, the frequency of the pulsating water flow is too low, reducing the dispersion of the feed material in the first-stage magnetic separation, resulting in severe mechanical inclusion in the first-stage magnetic separation process and reducing the yield of the third aluminum concentrate.

[0069] It should be noted that when the magnetic field strength of the second-stage magnetic separation exceeds 0.9T, the excessively high magnetic field strength causes some aluminum minerals to enter the weakly magnetic iron minerals, reducing the yield and recovery rate of the aluminum concentrate obtained from the second-stage magnetic separation. When the magnetic field strength of the second-stage magnetic separation is below 0.7T, the magnetic field collection capacity is insufficient, resulting in the incomplete removal of liberated siderite and an increase in the carbon content of the aluminum concentrate.

[0070] It should be noted that when the pulsating water flow rate in the second-stage magnetic separation is greater than 22Hz, although the high-frequency pulsating water flow can improve the mechanical inclusion problem in the second-stage magnetic separation process and increase the carbon content and total iron (TFe) content in the third-stage iron tailings, it will lead to an increase in the carbon impurity content of the aluminum concentrate and a decrease in the carbon impurity removal rate. When the pulsating water flow rate in the second-stage magnetic separation is less than 18Hz, the frequency of the pulsating water flow is too low, reducing the dispersion of the feed to the second-stage magnetic separation, resulting in severe mechanical inclusion during the second-stage magnetic separation process and reducing the yield of aluminum concentrate.

[0071] In some optional embodiments, both the first-stage magnetic separation and the second-stage magnetic separation use cylindrical steel bars and rhomboid steel bars as composite magnetic media, wherein the filling rate of the composite magnetic media in the first-stage magnetic separation is 14% to 17%, and the filling rate of the composite magnetic media in the second-stage magnetic separation is 18% to 23%.

[0072] In these embodiments, cylindrical steel bars and rhomboid steel bars are used as composite magnetic media in the first-stage and second-stage magnetic separation processes. The filling rate of the composite magnetic media in the first-stage magnetic separation is controlled to be 14% to 17%, and the filling rate of the composite magnetic media in the second-stage magnetic separation is controlled to be 18% to 23%. This ensures that the magnetic field strength of the first-stage and second-stage magnetic separations is within the preset magnetic field strength range, thereby satisfying the separation capacity of the first-stage and second-stage magnetic separations.

[0073] The filling rate of the composite magnetic medium in this magnetic separation section can be 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, or 17%.

[0074] The filling rate of the composite magnetic medium in the two-stage magnetic separation can be 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, 22%, 22.5% or 23%.

[0075] It should be noted that the diameter of the cylindrical steel bar and the rhomboid steel bar can be 2mm.

[0076] It should be noted that when the filling rate of the composite magnetic medium in the first-stage magnetic separation exceeds 17%, the magnetic field strength is too high, causing some aluminum minerals to mix with the strongly magnetic iron minerals, thus reducing the yield and recovery rate of the third-stage aluminum concentrate. Conversely, when the filling rate of the composite magnetic medium in the first-stage magnetic separation is less than 14%, the magnetic field's collecting capacity is insufficient, resulting in the incomplete removal of liberated siderite and an increase in the carbon content of the third-stage aluminum concentrate.

[0077] It should be noted that when the filling rate of the composite magnetic medium in the second-stage magnetic separation exceeds 23%, the magnetic field strength is too high, causing some aluminum minerals to enter the weakly magnetic iron minerals, reducing the yield and recovery rate of the aluminum concentrate obtained from the second-stage magnetic separation. Simultaneously, excessively high magnetic field strength in the second-stage magnetic separation also reduces the processing capacity of the equipment. Conversely, when the filling rate of the composite magnetic medium in the second-stage magnetic separation is less than 18%, the magnetic field collection capacity is insufficient, resulting in the incomplete removal of liberated siderite and an increase in the carbon content of the aluminum concentrate.

[0078] In some optional embodiments, in the composite magnetic medium of the magnetic separation section, the number S1 of the cylindrical steel bars and the number S2 of the rhombic steel bars satisfy: S1:S2 = (1 to 3):1; and / or In the composite magnetic medium of the two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhombic steel bars S2 satisfy: S1:S2=1:(2 to 3).

[0079] In these embodiments, in the composite magnetic media of the first-stage magnetic separation, the use of cylindrical and rhombic steel bars in a ratio of (1 to 3):1 allows the magnetic field strength of the first-stage magnetic separation to match the collecting capacity. Based on the difference in the specific magnetic susceptibility of carbon impurity minerals, aluminum minerals, and iron minerals, carbon impurity minerals and iron minerals in the second mixture are screened out, resulting in a third aluminum concentrate with higher grade and recovery rate. Furthermore, in the composite magnetic media of the second-stage magnetic separation, the use of cylindrical and rhombic steel bars in a ratio of 1:(2 to 3) allows the magnetic field strength of the second-stage magnetic separation to match the collecting capacity. Based on the difference in the specific magnetic susceptibility of carbon impurity minerals, aluminum minerals, and iron minerals, carbon impurity minerals and iron minerals in the second-stage magnetic separation feed are screened out, resulting in a high-grade aluminum concentrate product with high recovery rate.

[0080] In a composite magnetic medium with a single magnetic separation, the number of cylindrical steel bars S1 can be 1, 1.5, 2, 2.5 or 3.

[0081] In the composite magnetic medium of two-stage magnetic separation, the number S2 of the rhomboid steel rods can be 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0.

[0082] It should be noted that in the composite magnetic media of a first-stage magnetic separation, if the ratio of cylindrical steel bars S1 to rhombic steel bars S2 satisfies S1:S2 > 3:1, the magnetic field strength generated by the composite magnetic media will be uneven. This will result in insufficient collection capacity in the first-stage magnetic separation, causing some coarse-grained iron minerals to enter the third-stage aluminum concentrate. Consequently, the already liberated siderite cannot be completely removed, leading to an increase in the carbon content of the third-stage aluminum concentrate. Conversely, if the ratio of cylindrical steel bars S1 to rhombic steel bars S2 satisfies S1:S2 < 1:1, the magnetic field strength generated by the composite magnetic media will be excessively high, resulting in severe mechanical inclusions. This will cause some aluminum minerals to mix with strongly magnetic iron minerals, reducing the yield and recovery rate of the third-stage aluminum concentrate obtained from the first-stage magnetic separation.

[0083] It should be noted that in the composite magnetic media of the two-stage magnetic separation, if the ratio of cylindrical steel bars S1 to rhombic steel bars S2 satisfies S1:S2 > 1:2, the magnetic field strength generated by the composite magnetic media will be uneven, resulting in insufficient collection capacity in the two-stage magnetic separation. This allows some fine-grained embedded iron minerals to enter the aluminum concentrate product, preventing the complete removal of liberated siderite and increasing the carbon content in the aluminum concentrate product. Conversely, if the ratio of cylindrical steel bars S1 to rhombic steel bars S2 satisfies S1:S2 < 1:3, the magnetic field strength generated by the composite magnetic media will be excessively high, leading to severe mechanical inclusions. This causes some aluminum minerals to mix with strongly magnetic iron minerals, reducing the yield and recovery rate of the aluminum concentrate product obtained from the first-stage magnetic separation.

[0084] In some optional embodiments, the target particle size for the first stage of sieving and grading includes a first particle size and a second particle size, wherein the first particle size is 4 mm to 7 mm and the second particle size is 0.1 mm to 0.5 mm; and / or The target particle size for the two-stage screening and grading is 0.038 mm to 0.074 mm.

[0085] In these embodiments, a first-stage screening and grading process is performed to separate the material into a first particle size and a second particle size, with the first particle size controlled to be 4 mm to 7 mm and the second particle size controlled to be 0.1 mm to 0.5 mm. This first-stage screening and grading process can screen out intergrowths containing inorganic carbon and iron such as dolomite, calcite, and siderite, and separate bauxite powder into coarse, medium, and fine particles, which is beneficial for the subsequent two-stage lattice crushing of the medium particles to achieve sufficient individual particle dissociation. In addition, the second-stage screening and grading process with a target particle size of 0.038 mm to 0.074 mm can screen out undissociated siderite containing fine particles, thereby obtaining undersize material with a better degree of dissociation, which is beneficial for subsequent first-stage and second-stage magnetic separation.

[0086] The first particle size can be 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm or 7mm.

[0087] The second particle size can be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm.

[0088] The target particle size for the two-stage screening and grading can be 0.038mm, 0.039mm, 0.040mm, 0.042mm, 0.044mm, 0.046mm, 0.048mm, 0.050mm, 0.052mm, 0.054mm, 0.056mm, 0.058mm, 0.060mm, 0.062mm, 0.064mm, 0.066mm, 0.068mm, 0.070mm, 0.072mm, or 0.074mm.

[0089] It should be noted that when the initial particle size is greater than 7mm, the medium-sized material contains more inorganic carbon and iron intergrowths such as dolomite, calcite, and siderite, resulting in a higher carbon content in the subsequent aluminum concentrate product. When the initial particle size is less than 4mm, a large amount of fine-grained impurities (such as secondary slime) will be generated, thereby deteriorating the carbon removal effect in subsequent multi-stage gravity separation and multi-stage magnetic separation processes.

[0090] It should be noted that when the second particle size is greater than 0.5 mm, some undissociated siderite-containing material in the bauxite powder will directly enter the first-stage magnetic separation process, resulting in the loss of some aluminum minerals in the iron tailings and reducing the recovery rate of aluminum concentrate. When the second particle size is less than 0.1 mm, the already dissociated minerals in the bauxite powder will re-enter the first-stage grinding stage, increasing grinding energy consumption and generating a large amount of secondary slime, reducing the magnetic separation effect of the first-stage magnetic separation and the grade of aluminum concentrate, thus affecting the classification effect of the magnetic separation equipment.

[0091] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0092] Example 1 A high-carbonate bauxite deposit was selected from a region in Henan Province. The aluminum minerals in this high-carbonate bauxite deposit, calculated as alumina, have an alumina content of 55.39% by mass. The total iron (TFe) content in this high-carbonate bauxite deposit is 8.69% by mass, the total carbon (TC) content is 1.56% by mass, and the total organic carbon content is 0.12% by mass.

[0093] The main useful mineral in this high-carbonate bauxite is diaspore, while the gangue minerals are mainly kaolinite, illite, and chlorite. Carbon mainly exists in the form of calcite, dolomite, and siderite. Among them, the dolomite and calcite have a relatively coarse grain size, generally ranging from 0.1 mm to 2.0 mm; the siderite has an uneven grain size, generally ranging from 0.065 mm to 0.500 mm.

[0094] like Figure 2 and Figure 3 As shown, a method for the comprehensive utilization of high-carbonate bauxite is described. The high-carbonate bauxite includes aluminum minerals, iron minerals, and inorganic carbon-containing minerals, including: S1. The high-carbonate bauxite is crushed in one stage to obtain bauxite powder; S2. The bauxite powder is subjected to a first-stage screening and classification to obtain coarse, medium and fine particles. S3. The coarse-grained material is subjected to two-stage crushing to obtain coarse-grained mineral powder; S4. Return the coarse-grained mineral powder to the first-stage screening and classification process for recycling; S501. Perform a first-stage gravity separation on the first medium and the medium-grained material to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material to obtain the first aluminum concentrate; S502. The second medium and the first aluminum concentrate are subjected to two-stage gravity separation to separate aluminum minerals and iron minerals in the first aluminum concentrate, and obtain the first iron tailings and the second aluminum concentrate. S6. Perform two-stage screening and classification on the fine-particle material to obtain the oversize material and the undersize material. S701. Combine the oversize material and the second aluminum concentrate to obtain the first mixture; S702. The first mixture is subjected to a first-stage grinding process to obtain a first-stage magnetic separation feed; S703. Combine the first-stage magnetic separation feed and the undersize material to obtain a second mixture; S704. The second mixture is subjected to a first-stage magnetic separation to obtain the third aluminum concentrate and the second iron tailings; S705. The third aluminum concentrate is subjected to two-stage grinding to obtain a two-stage magnetic separation feed; S706. The second-stage magnetic separation feed is subjected to second-stage magnetic separation to obtain aluminum concentrate and third-stage iron tailings; S707. The first iron tailings, the second iron tailings and the third iron tailings are combined to obtain iron-bearing tailings.

[0095] The specific gravity of the first medium is 1.75 g / cm³. 3 The feed frequency for the first reselection is 26Hz.

[0096] The specific gravity of the second medium is 2.25 g / cm³. 3 The feeding frequency for the second-stage reselection is 31.50 Hz.

[0097] The first stage of magnetic separation feed includes a first stage of fine-particle magnetic separation feed, the mass of which is 70.47% of the total mass of the first stage of magnetic separation feed, and the particle size of which is ≤0.074mm. The two-stage magnetic separation feed includes a two-stage fine-particle magnetic separation feed, the mass of which is 83.37% of the total mass of the two-stage magnetic separation feed, and the particle size of the two-stage fine-particle magnetic separation feed is ≤0.074mm.

[0098] The magnetic field strength of the first-stage magnetic separation is 0.45T, and the separation is carried out in the form of pulsating water with a pulse frequency of 23.5Hz. The magnetic field strength of the two-stage magnetic separation is 0.75T. The two-stage magnetic separation is carried out in the form of pulsating water, and the pulsating water pulse frequency of the two-stage magnetic separation is 19.50Hz.

[0099] Both the first-stage and second-stage magnetic separation use cylindrical steel bars and rhomboid steel bars as composite magnetic media. The filling rate of the composite magnetic media in the first-stage magnetic separation is 14.50%, and the filling rate of the composite magnetic media in the second-stage magnetic separation is 18.25%.

[0100] In a composite magnetic medium with magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=3:1; In a composite magnetic medium with two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=1:2.

[0101] The target particle size for a first-stage screening and grading process includes a first particle size and a second particle size, where the first particle size is 5 mm and the second particle size is 0.15 mm. The target particle size for the two-stage screening and grading is 0.044 mm.

[0102] Example 2 Compared to Example 1, the differences in this example are as follows, while the rest are the same: A high-carbonate bauxite deposit was selected from a region in Guangxi. The aluminum minerals in this high-carbonate bauxite deposit, calculated as alumina, have an alumina content of 52.08% by mass. The total iron (TFe) content in this high-carbonate bauxite deposit is 9.39% by mass, the total carbon (TC) content is 2.48% by mass, and the total organic carbon content is 0.21% by mass.

[0103] The main useful mineral in this high-carbonate bauxite is diaspore, while the gangue minerals are mainly kaolinite, illite, chlorite, and quartz. Carbon mainly exists in the form of calcite, dolomite, and siderite. Among them, the dolomite and calcite have a relatively coarse grain size, generally ranging from 0.2 mm to 3.0 mm; the siderite has an uneven grain size, generally ranging from 0.035 mm to 0.600 mm.

[0104] The specific gravity of the first medium is 1.8 g / cm³. 3 The feed frequency for the first reselection is 27Hz.

[0105] The specific gravity of the second medium is 2.3 g / cm³. 3 The feeding frequency for the second-stage reselection is 30.50 Hz.

[0106] The mass of the fine-particle magnetic separation feed is 75.07% of the mass of the first-stage magnetic separation feed, and the particle size of the fine-particle magnetic separation feed is ≤0.074mm; The mass of the feed material for the second-stage fine-particle magnetic separation is 85.31% of the mass of the feed material for the second-stage fine-particle magnetic separation, and the particle size of the feed material for the second-stage fine-particle magnetic separation is ≤0.074mm.

[0107] The magnetic field strength of the first-stage magnetic separation is 0.5T, and the pulsating water jet frequency of the first-stage magnetic separation is 21.50Hz; The magnetic field strength of the two-stage magnetic separation is 0.85T, and the pulsating water jet frequency of the two-stage magnetic separation is 20Hz.

[0108] The filling rate of the composite magnetic medium in the first stage of magnetic separation is 15.50%, and the filling rate of the composite magnetic medium in the second stage of magnetic separation is 19.47%.

[0109] In a composite magnetic medium with magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=2:1; In a composite magnetic medium with two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=1:2.

[0110] The first particle size is 6mm, and the second particle size is 0.2mm; The target particle size for the two-stage screening and grading is 0.050 mm.

[0111] Example 3 Compared to Example 1, the differences in this example are as follows, while the rest are the same: A high-carbonate bauxite deposit was selected from a region in Yunnan Province. The aluminum minerals in this high-carbonate bauxite deposit, calculated as alumina, have an alumina content of 53.58% by mass. The total iron (TFe) content in this high-carbonate bauxite deposit is 8.54% by mass, the total carbon (TC) content is 1.95% by mass, and the total organic carbon content is 0.11% by mass.

[0112] The main useful minerals in this high-carbonate bauxite are diaspore and a small amount of boehmite. The gangue minerals are mainly kaolinite, chlorite and quartz. Carbon mainly exists in the form of calcite, dolomite and siderite. Among them, the grain size of dolomite and calcite is relatively coarse, generally ranging from 0.35 mm to 4.0 mm; the grain size of siderite is uneven, generally ranging from 0.055 mm to 0.700 mm.

[0113] The specific gravity of the first medium is 1.7 g / cm³. 3 The feed frequency for the first reselection is 28Hz.

[0114] The specific gravity of the second medium is 2.21 g / cm³. 3 The feeding frequency for the second-stage reselection is 32.50Hz.

[0115] The mass of the fine-particle magnetic separation feed in the first stage is 76.22% of the mass of the first-stage magnetic separation feed, and the particle size of the fine-particle magnetic separation feed in the first stage is ≤0.074mm; The mass of the feed material for the second-stage fine-particle magnetic separation is 89.51% of the mass of the feed material for the second-stage fine-particle magnetic separation, and the particle size of the feed material for the second-stage fine-particle magnetic separation is ≤0.074mm.

[0116] The magnetic field strength of the first-stage magnetic separation is 0.56T, and the pulsating water jet frequency of the first-stage magnetic separation is 23Hz; The magnetic field strength of the two-stage magnetic separation is 0.73T, and the pulsating water jet frequency of the two-stage magnetic separation is 21.50Hz.

[0117] The filling rate of the composite magnetic medium in the first stage of magnetic separation is 15.75%, and the filling rate of the composite magnetic medium in the second stage of magnetic separation is 20.57%.

[0118] In a composite magnetic medium with magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=3:1; In a composite magnetic medium with two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=1:2.5.

[0119] The first particle size is 5mm, and the second particle size is 0.28mm; The target particle size for the two-stage screening and grading is 0.045 mm.

[0120] Example 4 Compared to Example 1, the differences in this example are as follows, while the rest are the same: A high-carbonate bauxite deposit was selected from a region in Guizhou Province. The aluminum minerals in this high-carbonate bauxite deposit, calculated as alumina, have an alumina content of 50.06% by mass. The total iron (TFe) content in this high-carbonate bauxite deposit is 10.35% by mass, the total carbon (TC) content is 3.07% by mass, and the total organic carbon content is 0.25% by mass.

[0121] The main useful mineral in this high-carbonate bauxite is diaspore, while the gangue minerals are mainly kaolinite, chlorite, hematite, and quartz. Carbon mainly exists in the form of calcite, dolomite, and siderite. Among them, the dolomite and calcite have a relatively coarse grain size, generally ranging from 0.21 mm to 4.5 mm; the siderite has an uneven grain size, generally ranging from 0.025 mm to 1.000 mm.

[0122] The specific gravity of the first medium is 1.85 g / cm³. 3 The feed frequency for the first reselection is 24.50Hz.

[0123] The specific gravity of the second medium is 2.45 g / cm³. 3 The feeding frequency for the second-stage reselection is 30.50 Hz.

[0124] The mass of the fine-particle magnetic separation feed is 75.08% of the mass of the first-stage magnetic separation feed, and the particle size of the fine-particle magnetic separation feed is ≤0.074mm; The mass of the feed material for the second-stage fine-particle magnetic separation is 89.57% of the mass of the feed material for the second-stage fine-particle magnetic separation, and the particle size of the feed material for the second-stage fine-particle magnetic separation is ≤0.074mm.

[0125] The magnetic field strength of the first-stage magnetic separator is 0.45T, and the pulsating water jet frequency of the first-stage magnetic separator is 24.50Hz. The magnetic field strength of the two-stage magnetic separation is 0.80T, and the pulsating water jet frequency of the two-stage magnetic separation is 22.00Hz.

[0126] The filling rate of the composite magnetic medium in the first stage of magnetic separation is 16.25%, and the filling rate of the composite magnetic medium in the second stage of magnetic separation is 18.57%.

[0127] In a composite magnetic medium with magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=2:1; In a composite magnetic medium with two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=1:2.

[0128] The first particle size is 4.5 mm, and the second particle size is 0.15 mm; The target particle size for the two-stage screening and grading is 0.060 mm.

[0129] Example 5 Compared to Example 1, the differences in this example are as follows, while the rest are the same: A high-carbonate bauxite deposit was selected from a region in Shanxi Province. The aluminum minerals in this high-carbonate bauxite deposit, calculated as alumina, have an alumina content of 41.57% by mass. The total iron (TFe) content in this high-carbonate bauxite deposit is 13.57% by mass, the total carbon (TC) content is 5.48% by mass, and the total organic carbon content is 0.39% by mass.

[0130] The main useful minerals in this high-carbonate bauxite are diaspore and a small amount of boehmite. The gangue minerals are mainly illite, goethite, hematite, chlorite, and quartz. Carbon mainly exists in the form of calcite, dolomite, and siderite. Among them, the grain size of dolomite and calcite is relatively coarse, generally ranging from 0.10 mm to 5.0 mm; the grain size of siderite is uneven, generally ranging from 0.025 mm to 0.10 mm.

[0131] The specific gravity of the first medium is 1.75 g / cm³. 3 The feed frequency for the first reselection is 28Hz.

[0132] The specific gravity of the second medium is 2.4 g / cm³. 3 The feeding frequency for the second-stage reselection is 30.50 Hz.

[0133] The mass of the fine-particle magnetic separation feed is 79.05% of the mass of the first-stage magnetic separation feed, and the particle size of the fine-particle magnetic separation feed is ≤0.074mm; The mass of the feed material for the second-stage fine-particle magnetic separation is 89.52% of the mass of the feed material for the second-stage fine-particle magnetic separation, and the particle size of the feed material for the second-stage fine-particle magnetic separation is ≤0.074mm.

[0134] The magnetic field strength of the first-stage magnetic separation is 0.5T, and the pulsating water jet frequency of the first-stage magnetic separation is 20.50Hz; The magnetic field strength of the two-stage magnetic separation is 0.75T, and the pulsating water jet frequency of the two-stage magnetic separation is 21Hz.

[0135] The filling rate of the composite magnetic medium in the first stage of magnetic separation is 16.20%, and the filling rate of the composite magnetic medium in the second stage of magnetic separation is 21%.

[0136] In a composite magnetic medium with magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=2.5:1; In a composite magnetic medium with two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhomboid steel bars S2 satisfy: S1:S2=1:3.

[0137] The first particle size is 6mm, and the second particle size is 0.1mm; The target particle size for the two-stage screening and grading is 0.038 mm.

[0138] Comparative Example 1 Compared to Example 1, the differences in this comparative example are as follows, while the rest are the same: The prior art (1) in the background art is used for processing.

[0139] Comparative Example 2 Compared to Example 2, the differences in this comparative example are as follows, while the rest are the same: The prior art (1) in the background art is used for processing.

[0140] Comparative Example 3 Compared to Example 3, the differences in this comparative example are as follows, while the rest are the same: The prior art (1) in the background art is used for processing.

[0141] Comparative Example 4 Compared to Example 4, the differences in this comparative example are as follows, while the rest are the same: The prior art (1) in the background art is used for processing.

[0142] Comparative Example 5 Compared to Example 5, the differences in this comparative example are as follows, while the rest are the same: The prior art (1) in the background art is used for processing.

[0143] Relevant experimental and effect data: 1. The aluminum concentrate products and various iron tailings obtained from the examples and comparative examples were statistically analyzed, and the results are shown in Table 1 and... Figure 2 As shown.

[0144] Table 1. Composition of aluminum concentrate and various iron tailings in the examples

[0145] Table 2. Composition of aluminum concentrate and iron tailings in comparative examples

[0146] As shown in Tables 1 and 2, the method for comprehensive utilization of high-carbonate bauxite provided in this application embodiment employs a comprehensive physical process involving graded and segmented processing, staged crushing, staged grinding, combined gravity and magnetic separation, and heavy media recycling. This method addresses the characteristics of high-carbonate bauxite, such as uneven particle size distribution of carbon impurity minerals (dolomite / calcite), low hardness leading to easy mud formation, and significant differences in mineral specific gravity and magnetic properties. It simultaneously improves both inorganic carbon removal rate and aluminum concentrate yield by focusing on three core dimensions: reducing mineral mud formation loss, enhancing precise carbon-aluminum separation, and efficient fractional recovery. Ultimately, a high-quality aluminum concentrate product with a total carbon content ≤0.37%, a sulfur content ≤0.20%, and an Al2O3 increase ≥7.18% can be obtained.

[0147] Compared to the example, the comparative method using existing technology for sorting resulted in a lower quality aluminum concentrate product.

[0148] In summary, the embodiments of this application provide a method for the comprehensive utilization of high-carbonate bauxite. This method, through a closed-loop physical process of "crushing + classification + gravity separation + grinding + magnetic separation", not only solves the technical pain points of severe mudification and difficult decarbonation of high-carbonate bauxite, but also achieves efficient removal of inorganic carbon and maximum recovery of aluminum minerals, simultaneously achieving the goals of high inorganic carbon removal rate and high aluminum concentrate product yield.

[0149] In addition, the method for comprehensive utilization of high-carbonate bauxite provided in this application embodiment has the following advantages: (1) This method improves the problem of severe mud formation in dolomite and calcite caused by uneven particle size distribution of carbon impurities in high-carbonate bauxite and low Mohs hardness of dolomite and calcite in carbon impurities through a combination of "stage crushing + stage grinding". This avoids the generation of a large amount of secondary mud during the crushing or grinding stage and reduces the cost of the crushing and grinding stages. This method solves the current technical problem of easy mud formation of dolomite and calcite during the grinding stage, thereby improving the effect of subsequent gravity separation and decarbonization. (2) This method uses a combined process of “stage crushing + stage grinding + gravity and magnetic combination + heavy medium reuse” to achieve deep removal of carbon impurity minerals (such as dolomite, calcite and siderite) in a gravity field and a magnetic field based on the difference in the specific magnetic susceptibility of carbon impurity minerals, aluminum minerals and iron minerals. This overcomes a series of problems in the existing technology, such as the serious inclusion of fatty acid decarbonization collectors in aluminum concentrate, low inorganic carbon removal rate, difficulty in water recycling and high cost. (3) This method, through a combination of multi-stage crushing, gravity separation and magnetic separation, can not only achieve deep removal of carbon impurity minerals, but also sell the separated calcite tailings and iron-bearing tailings (siderite) as building materials, realizing the comprehensive utilization of high carbonate bauxite. At the same time, the high-quality aluminum concentrate produced can alleviate the supply pressure of alumina enterprises. (4) This method only requires physical combined processes and does not require the use of chemical reagents. Therefore, no pollutants are generated as a whole. It has the advantages of low cost, high economic benefits, good quality of aluminum concentrate, high recovery rate, high resource utilization rate, mature and stable process, and environmental friendliness.

[0150] Furthermore, this application provides a method for the comprehensive utilization of high-carbonate bauxite. This method, through a closed-loop physical process of "crushing + grading + gravity separation + grinding + magnetic separation," can activate high-carbon bauxite resources beneath coal seams, enabling large-scale development and utilization of bauxite resources. It can directly provide stable raw materials for alumina and electrolytic aluminum enterprises, reduce the cost of imported bauxite resources, and enhance the competitiveness of aluminum processing-related enterprises. Simultaneously, this method can improve the self-sufficiency of aluminum processing-related enterprises, reduce their dependence on external bauxite resources, and provide crucial support for the security and stability of their supply chains.

[0151] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for comprehensive utilization of high-carbonate bauxite, characterized in that, The high-carbonate bauxite includes aluminum minerals, iron minerals, and inorganic carbon-containing minerals; the method includes: The high-carbonate bauxite is subjected to a primary crushing process to obtain bauxite powder; The bauxite powder is subjected to a first-stage screening and classification to obtain coarse-grained material, medium-grained material and fine-grained material. The coarse-grained material is subjected to two-stage crushing to obtain coarse-grained mineral powder. The coarse-grained mineral powder is returned to the first screening and grading stage for recycling. The heavy medium group and the medium-grained material are subjected to staged gravity separation to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material, thereby obtaining a second aluminum concentrate; The fine-particle material is subjected to two-stage screening and classification to obtain oversize material and undersize material. The oversize material, undersize material, and second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate and iron-containing tailings.

2. The method according to claim 1, characterized in that, The heavy medium group and the medium-grained material are subjected to staged gravity separation to separate aluminum minerals, iron minerals, and inorganic carbon-containing minerals from the medium-grained material, yielding a first iron tailings and a second aluminum concentrate. The process includes the following steps: The first medium and the medium-grained material are subjected to a first-stage gravity separation to separate aluminum minerals, iron minerals and inorganic carbon-containing minerals from the medium-grained material, thereby obtaining a first aluminum concentrate. The second medium and the first aluminum concentrate are subjected to two-stage gravity separation to separate aluminum minerals and iron minerals in the first aluminum concentrate, resulting in the first iron tailings and the second aluminum concentrate.

3. The method according to claim 2, characterized in that, The specific gravity of the first medium is 1.6 g / cm³. 3 Up to 2.0 g / cm 3 The feeding frequency of the reselection section is 24Hz to 28Hz.

4. The method according to claim 2, characterized in that, The specific gravity of the second medium is 2.2 g / cm³. 3 Up to 2.5g / cm 3 The feeding frequency of the two-stage reselection is 30Hz to 36Hz.

5. The method according to claim 2, characterized in that, The oversize material, undersize material, and second aluminum concentrate are subjected to multi-stage grinding and multi-stage magnetic separation to obtain aluminum concentrate product and iron-containing tailings, including the following steps: The oversize material and the second aluminum concentrate are combined to obtain a first mixture. The first mixture is subjected to a grinding process to obtain a magnetic separation feed. The magnetically separated feed and the undersize material are combined to obtain a second mixture. The second mixture is subjected to a first-stage magnetic separation to obtain the third aluminum concentrate and the second iron tailings; The third aluminum concentrate is subjected to two-stage grinding to obtain a two-stage magnetic separation feed. The two-stage magnetic separation feed is subjected to two-stage magnetic separation to obtain aluminum concentrate and third iron tailings. The first iron tailings, the second iron tailings, and the third iron tailings are combined to obtain iron-bearing tailings.

6. The method according to claim 5, characterized in that, The first-stage magnetic separation feed includes a first-stage fine-particle magnetic separation feed, the mass of which is 70% to 80% of the total mass of the first-stage magnetic separation feed, and the particle size of which is ≤0.074 mm; and / or The two-stage magnetic separation feed includes two stages of fine-particle magnetic separation feed, the mass of which is 81% to 90% of the total mass of the two-stage magnetic separation feed, and the particle size of which is ≤0.074mm.

7. The method according to claim 5, characterized in that, The magnetic field strength of the first-stage magnetic separation is 0.4T to 0.6T, and the separation is performed using pulsating water with a pulse frequency of 20Hz to 25Hz; and / or The magnetic field strength of the two-stage magnetic separation is 0.7T to 0.9T, and the two-stage magnetic separation is carried out in the form of pulsating water with a pulse frequency of 18Hz to 22Hz.

8. The method according to claim 5, characterized in that, Both the first-stage and second-stage magnetic separation use cylindrical and rhomboid steel bars as composite magnetic media. The filling rate of the composite magnetic media in the first-stage magnetic separation is 14% to 17%, and the filling rate of the composite magnetic media in the second-stage magnetic separation is 18% to 23%.

9. The method according to claim 8, characterized in that, In the composite magnetic medium of the aforementioned magnetic separation section, the number of cylindrical steel bars S1 and the number of rhombic steel bars S2 satisfy: S1:S2 = (1 to 3):1; and / or In the composite magnetic medium of the two-stage magnetic separation, the number of cylindrical steel bars S1 and the number of rhombic steel bars S2 satisfy: S1:S2=1:(2 to 3).

10. The method according to claim 1, characterized in that, The target particle size for the first stage of screening and grading includes a first particle size and a second particle size, wherein the first particle size is 4 mm to 7 mm and the second particle size is 0.1 mm to 0.5 mm; and / or The target particle size for the two-stage screening and grading is 0.038 mm to 0.074 mm.

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