Beneficiation method for chlorite type bauxite

Abstract

A beneficiation method for chlorite type bauxite, comprising the following steps: performing selective dissociation, crushing, and grading on chlorite type bauxite to obtain coarse-fraction bauxite and fine-fraction bauxite; using a gravity separation process to desiliconize and desulfurize the coarse-fraction bauxite to obtain floating gravity separation concentrate containing aluminum mineral and sinking gravity separation tailings containing chlorite, pyrite and other impurity minerals; using a flotation process to desiliconize and desulfurize the fine-fraction bauxite to obtain flotation concentrate and flotation tailings; and combining the gravity separation concentrate and the flotation concentrate into aluminum concentrate, and combining the gravity separation tailings and the flotation tailings into tailings.

Description

A method for beneficiating chlorite-type bauxite

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410023884.6 filed on January 8, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of beneficiation of low-grade complex bauxite, and in particular to a beneficiation method for chlorite-type bauxite. Background Art

[0004] The rapid expansion of alumina production in my country has led to a sharp increase in the consumption of high-quality bauxite resources and a deterioration in ore quality. More and more alumina producers are being forced to use low-grade bauxite to produce alumina. The aluminum-silicon ratio of the bauxite feed in the Bayer process digestion system of some alumina producers has dropped below 4.0. The development and utilization of low-grade, high-sulfur bauxite is imperative.

[0005] Chlorite-type bauxite is composed of minerals such as diaspore, chlorite, kaolinite, pyrite, and rutile. Its chemical composition shows approximately 45% Al2O3, 14% SiO2, 28% Fe2O3, and 2% S. Research indicates that Si in this type of bauxite is primarily found in chlorite and kaolinite, Fe in chlorite and pyrite, and S in pyrite. Due to its high impurity content and low grade, chlorite-type bauxite cannot be directly incorporated into the alumina production process, resulting in low utilization rates.

[0006] At present, the most widely used method for beneficiation of low-grade bauxite is flotation. The chlorite content in chlorite-type bauxite is usually around 45%. The aggregates of chlorite are mostly microscopically scaly and often aggregate into flakes and irregular shapes. The aggregates of chlorite are associated with diaspore and pyrite, and the ore is easily muddied, which aggravates the deterioration of the flotation environment and increases the difficulty of its flotation separation.

[0007] Summary of the Invention

[0008] By utilizing one or more embodiments of the present disclosure, technical problems such as low beneficiation efficiency, great flotation difficulty, and high beneficiation cost of aluminum ore in existing chlorite-type bauxite are solved.

[0009] According to some embodiments of the present disclosure, a beneficiation method for chlorite-type bauxite comprises: selectively dissociating, crushing and classifying the chlorite-type bauxite to obtain coarse-grained bauxite and fine-grained bauxite; desiliconizing and desulfurizing the coarse-grained bauxite by a gravity separation process to obtain a gravity separation concentrate containing aluminum minerals that floats up and a gravity separation tailing containing impurity minerals that sinks; desiliconizing and desulfurizing the fine-grained bauxite by a flotation process to obtain a flotation concentrate and a flotation tailing; and, merging the gravity separation concentrate and the flotation concentrate into an aluminum concentrate, and merging the gravity separation tailings and the flotation tailings into tailings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0012] FIG1 shows a flow chart of a chlorite-type bauxite beneficiation method according to some embodiments of the present disclosure.

[0013] FIG2 shows a schematic diagram of the beneficiation principle of chlorite-type bauxite according to Example 1 of the present disclosure. DETAILED DESCRIPTION

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0015] Various embodiments of the present disclosure may be presented in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the present disclosure; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numbers within the range. For example, the description of a range from 1 to 6 should be considered to have 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., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0016] In this disclosure, unless otherwise stated, terms including "including" and "comprising" mean "including but not limited to". In this document, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this document, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. Wherein A and B can be singular or plural. In this document, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple, respectively.

[0017] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present disclosure can be purchased from the market or prepared by existing methods.

[0018] According to some embodiments of the present disclosure, a chlorite-type bauxite beneficiation method, as shown in FIG1 and FIG2 , comprises the following steps:

[0019] S1. selectively dissociating, crushing and classifying chlorite-type bauxite to obtain coarse-grained bauxite and fine-grained bauxite;

[0020] S2. The coarse-grained bauxite is desiliconized and desulfurized by gravity separation to obtain the floating aluminum-containing mineral concentrate and the sinking impurity-containing mineral tailings;

[0021] S3. Desiliconization and desulfurization of fine-grained bauxite by flotation process to obtain flotation concentrate and flotation tailings; and

[0022] S4. Combine the gravity separation concentrate and the flotation concentrate into aluminum concentrate, and combine the gravity separation tailings and the flotation tailings into tailings.

[0023] In some optional embodiments, the selective dissociation, crushing and grading comprises the following steps: performing a screening process on the chlorite-type bauxite to obtain an oversize and a first undersize, crushing the oversize again and repeating the screening process until both the chlorite-type bauxite and the oversize are screened once to obtain a second undersize; combining the first undersize and the second undersize to obtain an undersize, and subjecting the obtained undersize to a second screening to obtain coarse-grained bauxite and fine-grained bauxite.

[0024] According to the properties of bauxite, chlorite bauxite can be enriched in the coarse-grained bauxite after preliminary crushing.

[0025] From the above, it can be seen that through the "crushing-classification + coarse-grade gravity separation desiliconization and desulfurization + fine-grade flotation desiliconization and desulfurization" process, the extraction and recovery of aluminum-containing minerals in chlorite bauxite can be achieved, and the comprehensive utilization rate of low-grade chlorite bauxite can be improved. The obtained aluminum concentrate can directly enter the oxidation production system, thereby realizing the comprehensive utilization of chlorite bauxite.

[0026] In some optional embodiments, the chlorite in the chlorite-type bauxite may be one or more of oolitic chlorite, lepidolite, vermicular chlorite and ferromagnesian chlorite.

[0027] Since the chemical compositions of the above-mentioned various types of chlorite are similar, the density range of chlorite when coexisting with pyrite is controllable, and the density of chlorite is greater than that of diaspore, the gravity separation process can be used to achieve the separation of aluminum, silicon, iron and sulfur in chlorite-type bauxite.

[0028] In some optional embodiments, after the chlorite-type bauxite is subjected to selective dissociation, crushing and classification treatment, the particle size range of the obtained coarse-grained bauxite is +0.074 mm to -10 mm, and the particle size range of the obtained fine-grained bauxite is -0.074 mm.

[0029] The particle size range of coarse-grained bauxite is controlled to be +0.074mm to -10mm, and the particle size range of fine-grained bauxite is -0.074mm. The positive effect is that after the chlorite-type bauxite is selectively dissociated, crushed and classified, the coarse-grained bauxite obtained has a large number of diaspore aggregates, and the chlorite is mostly symbiotic with pyrite. After the gravity separation process, the aluminum and silicon, iron and sulfur in the coarse-grained bauxite can be separated. Since the gravity separation process has poor separation of fine-grained (-0.074mm) minerals, the overall particle size range of the fine-grained bauxite obtained by selective dissociation, crushing and classification is more suitable for desiliconization and desulfurization by flotation process. By using flotation process to desiliconize and desulfurize the fine-grained bauxite, the aluminum-containing minerals in the fine-grained bauxite can be further recovered.

[0030] In some optional embodiments, the gravity separation process is heavy liquid separation.

[0031] In some optional embodiments, the density of the heavy liquid is 3.5 g / cm 3 ~3.8g / cm 3 For example, you can choose 3.5g / cm 3 , 3.6g / cm 3 , 3.7g / cm 3 , 3.8g / cm 3 .

[0032] Control the density of the heavy liquid to 3.5g / cm 3 ~3.8g / cm 3 The positive effect is that the density of the heavy liquid is between the density of diaspore and the density of chlorite-pyrite intergrowth, so that the diaspore particles can be suspended in the upper layer of the heavy liquid, while the chlorite-pyrite intergrowth can sink to the lower layer of the heavy liquid, thereby achieving the purpose of separation.

[0033] In some optional embodiments, the weighting medium for heavy liquid separation is ferrosilicon.

[0034] Since the density of conventional heavy liquid is generally less than 3.3g / cm 3 , in order to make the density of the heavy liquid reach 3.5g / cm 3 ~3.8g / cm 3 The density of the heavy liquid can be adjusted by adding ferrosilicon to the heavy liquid, and the density of the heavy liquid can be changed by controlling the content of ferrosilicon as a weighting medium in the heavy liquid.

[0035] In some optional embodiments, the iron content in the ferrosilicon is greater than 80%.

[0036] The use of ferrosilicon with an iron content greater than 80% can increase the density of the heavy liquid, thereby configuring a density of 3.5g / cm 3 ~3.8g / cm 3of heavy liquid.

[0037] In some optional embodiments, the floating aluminum-containing mineral gravity separation concentrate is the useful aluminum-containing mineral to be separated, and the floating impurity-containing mineral gravity separation tailings is the impurity-containing mineral tailings to be removed.

[0038] Since the density of chlorite-pyrite conjoints is greater than that of diaspore, the mineral that floats up during heavy liquid separation is diaspore (aluminum-containing mineral), and the mineral that sinks is the tailings containing impurities such as chlorite-pyrite, thereby obtaining a heavy separation concentrate that is a useful aluminum-containing mineral.

[0039] In some optional embodiments, the flotation process used for fine-grained bauxite is a positive flotation simultaneous desulfurization and desiliconization process, and the collector of the positive flotation simultaneous desulfurization and desiliconization process is one or more of oleic acid, sodium oleate, sodium dodecyl sulfonate and sodium dodecyl sulfate.

[0040] The fine-grained bauxite adopts the direct flotation simultaneous desulfurization and desiliconization process, which can inhibit the floating of sulfur-containing minerals and silicon-containing minerals. By adding one or more of oleic acid, sodium oleate, sodium dodecyl sulfonate and sodium dodecyl sulfate as a collector for diaspore, diaspore can be floated, thereby achieving the simultaneous removal of sulfur and silicon in fine-grained bauxite.

[0041] In some optional embodiments, the number of concentration stages in the flotation process of fine-sized bauxite is two or more.

[0042] By controlling the number of concentration stages in the flotation process of fine-grained bauxite to more than two stages, the Al2O3 content in the aluminum concentrate can be increased as much as possible through repeated concentration processes, while the impurity SiO2 and S content can be fully reduced, thereby obtaining high-quality aluminum concentrate.

[0043] The technical solutions of the present disclosure are further described below in conjunction with specific examples. It should be understood that these examples are intended only to illustrate the present disclosure and are not intended to limit the scope of the present disclosure. Experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national standards. If there are no corresponding national standards, the methods are carried out in accordance with commonly used international standards, conventional conditions, or conditions recommended by the manufacturer.

[0044] Example 1

[0045] This embodiment discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0046] A chlorite-type bauxite is selected. The chemical composition of the chlorite-type bauxite is as follows: Al2O3: 44.90%, SiO2: 14.45%, and S: 2.47%, calculated by mass fraction. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is mainly chlorite. The gangue minerals in the chlorite-type bauxite also contain small amounts of pyrite and anatase. As shown in FIG2 , the mineral processing steps of this embodiment are as follows:

[0047] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -10mm. The crushed product is classified into a particle size of 0.074mm to obtain coarse-grained bauxite and fine-grained bauxite. The coarse-grained bauxite with a particle size of +0.074mm to -10mm is mixed with ferrosilicon as a weighting medium to prepare a heavy liquid with a density of 3.5g / cm 3 Heavy liquid separation is carried out under the conditions of to obtain the floating gravity separation concentrate containing aluminum minerals and the sinking gravity separation tailings containing impurity minerals; the fine-grained bauxite with a particle size of -0.074mm is subjected to direct flotation synchronous desulfurization and desiliconization, and the direct flotation synchronous desulfurization and desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0048] Example 2

[0049] This embodiment discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0050] A chlorite-type bauxite is selected. The chemical composition of the chlorite-type bauxite is as follows: Al2O3: 44.90%, SiO2: 14.45%, and S: 2.47%, calculated by mass fraction. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is mainly chlorite. The gangue minerals in the chlorite-type bauxite also contain small amounts of pyrite and anatase. As shown in FIG2 , the mineral processing steps of this embodiment are as follows:

[0051] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -5mm. The crushed product is classified into a particle size of 0.074mm to obtain coarse-grained bauxite and fine-grained bauxite. The coarse-grained bauxite with a particle size of +0.074mm to -5mm is mixed with ferrosilicon as a weighting medium to prepare a heavy liquid with a density of 3.5g / cm 3Heavy liquid separation is carried out under the conditions of to obtain the floating gravity separation concentrate containing aluminum minerals and the sinking gravity separation tailings containing impurity minerals; the fine-grained bauxite with a particle size of -0.074mm is subjected to direct flotation synchronous desulfurization and desiliconization, and the direct flotation synchronous desulfurization and desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0052] Example 3

[0053] This embodiment discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0054] A chlorite-type bauxite is selected. The chemical composition of the chlorite-type bauxite is calculated by mass fraction as follows: Al2O3: 47.37%, SiO2: 14.71%, and S: 2.34%. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is mainly chlorite. The gangue minerals in the chlorite-type bauxite also contain small amounts of kaolinite, pyrite, and anatase. As shown in Figure 2, the mineral processing steps of this embodiment are as follows:

[0055] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -10mm. The crushed product is classified into a particle size of 0.074mm to obtain coarse-grained bauxite and fine-grained bauxite. The coarse-grained bauxite with a particle size of +0.074mm to -10mm is mixed with ferrosilicon as a weighting medium to prepare a heavy liquid with a density of 3.8g / cm 3 Heavy liquid separation is carried out under the conditions of to obtain the floating gravity separation concentrate containing aluminum minerals and the sinking gravity separation tailings containing impurity minerals; the fine-grained bauxite with a particle size of -0.074mm is subjected to direct flotation synchronous desulfurization and desiliconization, and the direct flotation synchronous desulfurization and desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0056] Example 4

[0057] This embodiment discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0058] A chlorite-type bauxite is selected. The chemical composition of the chlorite-type bauxite is calculated by mass fraction as follows: Al2O3: 47.37%, SiO2: 14.71%, and S: 2.34%. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is mainly chlorite. The gangue minerals in the chlorite-type bauxite also contain a small amount of kaolinite, pyrite, and anatase. As shown in Figure 2, the mineral processing steps of this embodiment are as follows:

[0059] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -6mm. The crushed product is classified into a particle size of 0.074mm to obtain coarse-grained bauxite and fine-grained bauxite. The coarse-grained bauxite with a particle size of +0.074mm to -6mm is mixed with ferrosilicon as a weighting medium to prepare a heavy liquid with a density of 3.8g / cm 3 Heavy liquid separation is carried out under the conditions of to obtain the floating gravity separation concentrate containing aluminum minerals and the sinking gravity separation tailings containing impurity minerals; the fine-grained bauxite with a particle size of -0.074mm is subjected to direct flotation synchronous desulfurization and desiliconization, and the direct flotation synchronous desulfurization and desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0060] Example 5

[0061] This embodiment discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0062] A chlorite-type bauxite is selected. The chemical composition of the chlorite-type bauxite is calculated by mass fraction as follows: Al2O3: 40.23%, SiO2: 15.09%, and S: 2.51%. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is mainly chlorite. The gangue minerals in the chlorite-type bauxite also contain small amounts of kaolinite, illite, pyrite, and anatase. As shown in Figure 2, the mineral processing steps of this embodiment are as follows:

[0063] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -5mm. The crushed product is classified into a particle size of 0.074mm to obtain coarse-grained bauxite and fine-grained bauxite. The coarse-grained bauxite with a particle size of +0.074mm to -5mm is mixed with ferrosilicon as a weighting medium to prepare a heavy liquid with a density of 3.8g / cm 3Heavy liquid separation is carried out under the conditions of to obtain the floating gravity separation concentrate containing aluminum minerals and the sinking gravity separation tailings containing impurity minerals; the fine-grained bauxite with a particle size of -0.074mm is subjected to direct flotation synchronous desulfurization and desiliconization, and the direct flotation synchronous desulfurization and desiliconization process adopts three concentrations to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0064] Comparative Example 1

[0065] This comparative example discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0066] This comparative example uses the same chlorite bauxite as in Example 1. The chemical composition of the chlorite bauxite, calculated by mass fraction, includes: Al2O3: 44.90%, SiO2: 14.45%, and S: 2.47%. The useful mineral in the chlorite bauxite is diaspore, and the gangue mineral in the chlorite bauxite is mainly chlorite. The gangue minerals in the chlorite bauxite also contain small amounts of pyrite and anatase. The beneficiation steps of this comparative example are as follows:

[0067] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -10mm. The crushed product is classified into 1mm particle size. The particle size of the crushed and classified products with a particle size of +1mm to -10mm is prepared with a heavy liquid density of 3.5g / cm2 by using ferrosilicon as a weighting medium. 3 Heavy liquid separation is carried out under the conditions of to obtain gravity separation concentrate and gravity separation tailings; the particle size product with a particle size of -1mm obtained by crushing and classification is subjected to flotation desiliconization, and the flotation desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0068] Comparative Example 2

[0069] This comparative example discloses a beneficiation method for chlorite-type bauxite, comprising the following steps:

[0070] This comparative example uses the same chlorite bauxite as in Example 3. The chemical composition of the chlorite bauxite, calculated by mass fraction, includes: Al2O3: 47.37%, SiO2: 14.71%, and S: 2.34%. The useful mineral in the chlorite bauxite is diaspore, and the gangue mineral in the chlorite bauxite is mainly chlorite. The gangue minerals in the chlorite bauxite also contain small amounts of kaolinite, pyrite, and anatase. The mineral processing steps of this comparative example are as follows:

[0071] The chlorite bauxite ore is processed by crushing-classification process to obtain a crushed product with a particle size of -10mm. The crushed product is classified into a particle size of 0.074mm. The particle size of the crushed and classified products with a particle size of +0.074mm to -10mm is prepared with a heavy liquid density of 3.3g / cm2 by using ferrosilicon as a weighting medium. 3 Heavy liquid separation is carried out under the conditions of to obtain gravity separation concentrate and gravity separation tailings; the particle size product with a particle size of -0.074mm obtained by crushing and classification is subjected to flotation desiliconization, and the flotation desiliconization process adopts secondary concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0072] Comparative Example 3

[0073] This comparative example discloses a method for separating chlorite-type bauxite, comprising the following steps:

[0074] This comparative example uses the same chlorite-type bauxite as in Example 5. The chemical composition of the chlorite-type bauxite, measured by mass, includes: Al2O3: 40.23%, SiO2: 15.09%, and S: 2.51%. The useful mineral in the chlorite-type bauxite is diaspore, and the gangue mineral in the chlorite-type bauxite is primarily chlorite. The gangue minerals in the chlorite-type bauxite also contain small amounts of kaolinite, illite, pyrite, and anatase. The beneficiation steps for the comparative example are as follows:

[0075] The chlorite bauxite ore was processed by crushing-classification process to obtain a crushed product with a particle size of -5mm. The crushed product was classified into a particle size of 0.074mm. The particle size of the crushed and classified products with a particle size of +0.074mm to -5mm was prepared with a heavy liquid density of 3.8g / cm2 using ferrosilicon as a weighting medium. 3 Heavy liquid separation is carried out under the conditions of to obtain gravity separation concentrate and gravity separation tailings; the particle size product with a particle size of -0.074mm obtained by crushing and classification is subjected to flotation desiliconization, and the flotation desiliconization process adopts one-time concentration to obtain flotation concentrate and flotation tailings; the flotation concentrate obtained by flotation and the gravity separation concentrate obtained by heavy liquid separation are combined into aluminum concentrate, and the flotation tailings obtained by flotation and the gravity separation tailings obtained by heavy liquid separation are combined into tailings.

[0076] The products obtained from Examples 1-5 and Comparative Examples 1-3 were compared and analyzed, and the results are shown in Table 1 below:

[0077] Table 1 Data analysis of Examples 1-5 and Comparative Examples 1-3

[0078] From the comparison of the data in Example 1 and Comparative Example 1, it can be seen that increasing the crushing particle size, increasing the gravity separation and flotation particle size will directly affect the final sorting index. This is mainly because the aluminum-containing minerals in the chlorite-type bauxite are co-existing with silicon minerals and sulfur minerals. Under coarse particle size conditions, the various minerals are not fully dissociated. During the sorting process, the aluminum-silicon ratio of the tailings is relatively high, and the aluminum-silicon ratio of the aluminum concentrate is relatively low and the sulfur content is high, which directly affects the sorting effect.

[0079] From the comparison of the data in Example 3 and Comparative Example 2, it can be seen that reducing the heavy liquid density in heavy liquid separation will also directly affect the sorting indicators. This is mainly because under the condition of lower heavy liquid density, diaspore and silicate minerals and sulfur minerals are not fully dissociated, resulting in silicate minerals, sulfur minerals and other minerals remaining in the aluminum concentrate, resulting in a low grade of the aluminum concentrate.

[0080] From the comparison of the data in Example 5 and Comparative Example 3, it can be seen that although reducing the number of concentration stages can increase the yield of aluminum concentrate, the silicon and sulfur contents in the aluminum concentrate increase, and it is impossible to better separate the aluminum-containing minerals from other impurity minerals.

[0081] In summary, according to one or more embodiments of the present disclosure, there are at least the following technical effects or advantages:

[0082] According to some embodiments of the present disclosure, the beneficiation method of chlorite-type bauxite can realize the extraction and recovery of aluminum-containing minerals in chlorite-type bauxite through the process of "crushing-classification + coarse-particle gravity separation desiliconization and desulfurization + fine-particle flotation desiliconization and desulfurization", and improve the comprehensive utilization rate of low-grade bauxite without requiring too high grinding fineness. Therefore, it overcomes the problem of fine-particle ore mud polluting the sorting environment and deteriorating the floatability of the ore during the flotation process, and has the characteristics of low grinding energy consumption, low production cost, strong process adaptability, etc.

[0083] According to some embodiments of the present disclosure, the beneficiation method for chlorite-type bauxite first undergoes a crushing, grinding, and classification process to produce coarse-grained bauxite and fine-grained bauxite. In the coarse-grained bauxite, chlorite is often associated with pyrite, and the density of chlorite containing pyrite is greater than that of diaspore. Therefore, chlorite and pyrite can be initially removed by gravity separation. The fine-grained bauxite is then subjected to flotation to remove the chlorite, thereby obtaining a pure aluminum concentrate. The "crushing-classification" process, followed by desiliconization and desulfurization of the coarse-grained bauxite by gravity separation and desiliconization and desulfurization of the fine-grained bauxite by flotation, allows the extraction and recovery of aluminum-containing minerals from the chlorite-type bauxite, while improving the comprehensive utilization rate of low-grade bauxite. This process eliminates the need for excessively high grinding fineness, thereby overcoming the problem of fine-grained slime contaminating the separation environment and deteriorating the floatability of the ore during flotation. The process features low grinding energy consumption, low production costs, and strong process adaptability.

[0084] The foregoing description is intended only to provide specific embodiments of the present disclosure, which will enable those skilled in the art to understand and implement the present disclosure. 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 the present disclosure. Therefore, the present disclosure is not intended to be limited to the embodiments shown herein, but rather to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A beneficiation method for chlorite-type bauxite, comprising: selectively dissociating, crushing and classifying the chlorite-type bauxite to obtain coarse-grained bauxite and fine-grained bauxite; desiliconizing and desulfurizing the coarse-grained bauxite by a gravity separation process to obtain a gravity separation concentrate containing aluminum minerals floating upward and a gravity separation tailing containing impurity minerals sinking downward; desiliconizing and desulfurizing the fine-grained bauxite by a flotation process to obtain a flotation concentrate and a flotation tailing; and combining the gravity separation concentrate and the flotation concentrate into a bauxite concentrate, and combining the gravity separation tailing and the flotation tailing into a tailing.

2. The beneficiation method of chlorite-type bauxite according to claim 1, wherein, The chlorite in the chlorite-type bauxite is one or more of oolitic chlorite, scale chlorite, vermicular chlorite and ferro-magnesium chlorite.

3. The beneficiation method of chlorite-type bauxite according to claim 1, wherein, The particle size range of the coarse-grained bauxite is +0.074 mm to -10 mm, and the particle size range of the fine-grained bauxite is -0.074 mm.

4. The beneficiation method of chlorite-type bauxite according to claim 1, wherein, The gravity separation process is heavy liquid separation.

5. The beneficiation method of chlorite-type bauxite according to claim 4, wherein, The density of the heavy liquid for heavy liquid separation is 3.5 g / cm 3 ~3.8g / cm 3 .

6. The beneficiation method of chlorite-type bauxite according to claim 4, wherein, The heavy medium for the heavy liquid separation is ferrosilicon.

7. The beneficiation method of chlorite-type bauxite according to claim 6, wherein, The iron content in the ferrosilicon is greater than 80%.

8. The beneficiation method of chlorite-type bauxite according to claim 1, wherein, The impurity minerals in the gravity separation tailing include at least one of chlorite, pyrite, anatase, illite and kaolinite.

9. The beneficiation method of chlorite-type bauxite according to claim 1, wherein, The flotation process is a positive flotation synchronous desiliconization and desulfurization process, and the collector for the positive flotation synchronous desiliconization and desulfurization process is one or more of oleic acid, sodium oleate, sodium dodecyl sulfonate and sodium dodecyl sulfate.

10. The beneficiation method of chlorite-type bauxite according to claim 9, wherein, The number of cleaning stages in the flotation process is not less than two.

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