A method for stage desulfurization of high-sulfur bauxite

Abstract

The application relates to the technical field of bauxite processing, and particularly relates to a stage desulfurization method for high-sulfur bauxite; the weight m1 of sulfur elements in the high-sulfur bauxite and the weight m2 of the high-sulfur bauxite satisfy the relationship m1:m2>=0.03; the stage desulfurization method comprises the following steps: grinding the high-sulfur bauxite to obtain high-sulfur bauxite powder; mixing an acid flotation reagent with the high-sulfur bauxite powder to obtain a primary ore pulp; performing primary flotation desulfurization on the primary ore pulp to obtain a primary middlings mixture; concentrating the primary middlings mixture to obtain a secondary middlings mixture; mixing a deep desulfurization reagent with the secondary middlings mixture, and then performing secondary flotation desulfurization on the secondary middlings mixture to obtain aluminum concentrate. The stage desulfurization method can increase the surface active sites of sulfur-containing particles in the high-sulfur bauxite by using an acid flotation desulfurization agent in cooperation with a deep desulfurization reagent, so that aluminum concentrate with a sulfur element weight content of less than or equal to 0.4% can be finally obtained.

Description

Technical Field

[0001] This application relates to the field of bauxite processing technology, and more particularly to a staged desulfurization method for high-sulfur bauxite. Background Technology

[0002] Bauxite is an important raw material for the production of alumina. However, the sulfur in bauxite has an adverse effect on the production process and product quality of alumina. Therefore, high-sulfur bauxite needs to be desulfurized before it is used as a raw material for alumina production.

[0003] Currently, most high-sulfur bauxite is desulfurized using flotation or a combination of gravity separation and flotation. However, high-sulfur bauxite has a high sulfur content and most of it has a high degree of pyrite oxidation. These characteristics can cause the surface active sites of sulfur-containing particles in high-sulfur bauxite to be covered by hydrophilic substances, which can affect the binding of the desulfurization collector to the surface active sites of sulfur-containing particles in high-sulfur bauxite, resulting in unsatisfactory desulfurization effect.

[0004] The current desulfurization technologies for high-sulfur bauxite include: (1) a flotation desulfurization method for high-sulfur bauxite, comprising the following steps: adding lime during the grinding process of the high-sulfur bauxite ore to control the pH of the high-sulfur bauxite slurry within the range of 6 to 8, and then adding activator, collector and frother to the high-sulfur bauxite slurry in sequence for flotation. (2) a desulfurization method for high-sulfur bauxite, comprising the following steps: obtaining high-sulfur bauxite; grinding the high-sulfur bauxite, and then mixing the ground material with water to obtain a slurry; adjusting the pH of the slurry to alkaline to obtain an adjusted slurry; mixing the adjusted slurry with dispersant, flocculant, collector and frother in sequence to obtain a mixed slurry; flotating the mixed slurry to obtain pre-alumina concentrate and sulfur concentrate; and mixing the pre-alumina concentrate with an oxidant to obtain alumina concentrate. (3) A method for combined gravity flotation desulfurization of high-sulfur bauxite, comprising grinding the high-sulfur bauxite slurry, and then separating pyrite and gravity-separated aluminum concentrate by gravity separation of the ground high-sulfur bauxite slurry; subjecting the obtained gravity-separated aluminum concentrate to flotation desulfurization, or subjecting the gravity-separated aluminum concentrate to coarse and fine fractionation and then subjecting it to flotation desulfurization separately to obtain froth product and underflow product respectively; combining the obtained froth product with pyrite to form a comprehensive sulfur concentrate, and the obtained underflow product is the aluminum concentrate. (4) A stepwise flotation desulfurization method for high-sulfur bauxite, comprising: firstly, performing desulfurization roughing to separate sulfide middlings and aluminum concentrate; secondly, subjecting the sulfide middlings from the first desulfurization roughing to desulfurization flotation to further separate sulfur rough concentrate and aluminum concentrate, and combining the two parts of aluminum concentrate to form a comprehensive aluminum concentrate. Summary of the Invention

[0005] This application provides a staged desulfurization method for high-sulfur bauxite to solve the following technical problem: how to increase the surface active sites of sulfur-containing particles in high-sulfur bauxite.

[0006] Firstly, this application provides a staged desulfurization method for high-sulfur bauxite, wherein the weight m1 of sulfur in the high-sulfur bauxite and the weight m2 of the high-sulfur bauxite satisfy the relationship: m1:m2≥0.03; the staged desulfurization method includes:

[0007] High-sulfur bauxite is ground to obtain high-sulfur bauxite powder;

[0008] The acidic flotation reagent is mixed with the high-sulfur bauxite powder to mineralize the high-sulfur bauxite powder and obtain a primary raw ore slurry.

[0009] The primary raw ore slurry is subjected to primary flotation desulfurization to obtain a primary middlings mixture;

[0010] The primary middlings mixture is concentrated to obtain a secondary middlings mixture;

[0011] The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate.

[0012] Optionally, the weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0013] m3:m4=(0.5:1000)~(5:1000).

[0014] Optionally, the acidic flotation reagent includes an acid modifier, a first alkyl xanthate, and pinyl oil, wherein the acid modifier includes sulfuric acid and / or hydrochloric acid;

[0015] The first alkyl xanthate comprises at least one of the following:

[0016] Ethyl xanthate, butyl xanthate and pentyl xanthate.

[0017] Optionally, the weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0018] m5:m6=(2:1000)~(6:1000).

[0019] Optionally, the deep desulfurization agent includes an alkaline regulator, a second alkyl xanthate, and pinol oil, wherein the alkaline regulator includes sodium hydroxide and / or potassium hydroxide;

[0020] The second alkyl xanthate comprises at least one of the following:

[0021] Ethyl xanthate, butyl xanthate and pentyl xanthate.

[0022] Optionally, the weight m7 of the fine-grained material in the high-sulfur bauxite powder and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0023] m7:m4 = (0.75:1) to (0.90:1); the particle size of the fine-grained material is ≤0.074mm;

[0024] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0025] m8:m9=(0.20:1)~(0.30:1).

[0026] Optionally, the dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0027] m10:m11=(0.35:1)~(0.40:1).

[0028] Optionally, the time for the first flotation desulfurization is 8 min to 21 min;

[0029] The time for the secondary flotation desulfurization is 4 min to 12 min.

[0030] Optionally, the pH of the primary raw ore slurry is 2 to 6;

[0031] The pH of the secondary flotation desulfurization is 8-13.

[0032] Optionally, the staged desulfurization method further includes:

[0033] The primary raw ore slurry is subjected to primary flotation desulfurization to obtain a primary middlings mixture and a primary sulfur concentrate.

[0034] The primary middlings mixture is concentrated to obtain a secondary middlings mixture;

[0035] The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate and secondary sulfur concentrate, respectively.

[0036] The primary sulfur concentrate and the secondary sulfur concentrate are combined to obtain sulfur concentrate.

[0037] The technical solutions provided in this application have the following advantages compared with the prior art:

[0038] This application provides a staged desulfurization method for high-sulfur bauxite. Since the weight m1 of sulfur in high-sulfur bauxite and the weight m2 of the bauxite satisfy the relationship m1:m2≥0.03, this indicates that the high-sulfur bauxite contains a large amount of sulfur. High-sulfur bauxite with high sulfur content will form a large amount of hydrophilic substances on its surface. These hydrophilic substances adhere to the surface of the high-sulfur bauxite, reducing the surface active sites of sulfur-containing particles. This staged desulfurization method addresses this challenge by first using an acidic flotation desulfurizing agent to react with the hydrophilic alkaline... The substances undergo acid-base neutralization reactions to remove these hydrophilic alkaline substances from the surface of high-sulfur bauxite, thereby exposing the surface active sites of sulfur-containing particles in the bauxite. In addition, the use of deep desulfurization agents can remove some hydrophilic salts from the surface of sulfur-containing particles, exposing active sites, which helps the agents bind to sulfur-containing particles, thus facilitating the flotation of sulfur-containing substances in the secondary middlings mixture and further improving desulfurization efficiency. Therefore, this stage of desulfurization method, through acid flotation combined with deep desulfurization, can effectively increase the surface active sites of sulfur-containing particles in bauxite. Attached Figure Description

[0039] 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.

[0040] 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.

[0041] Figure 1 A schematic diagram of a staged desulfurization method for high-sulfur bauxite provided in this application embodiment;

[0042] Figure 2 This is a detailed flowchart illustrating a staged desulfurization method for high-sulfur bauxite, provided as an embodiment of this application. Detailed Implementation

[0043] 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.

[0044] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within 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 means including any referenced number (fraction or integer) within the indicated range.

[0045] In this document, terms including "comprising" and the like mean "including but not limited to". Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application are commercially available or can be prepared by existing methods.

[0046] It should be noted that, regarding the prior art (1), (2) and (3) described in the background art, the inventors have found that: high-sulfur bauxite has a high sulfur content and most high-sulfur bauxite has the characteristic of high pyrite oxidation. These characteristics will cause the surface active sites of sulfur-containing particles in high-sulfur bauxite to be covered by hydrophilic substances, which will affect the binding of the desulfurization collector to the surface active sites of sulfur-containing particles in high-sulfur bauxite, resulting in unsatisfactory desulfurization effect.

[0047] Figure 1 An exemplary schematic diagram of a staged desulfurization method for high-sulfur bauxite provided in an embodiment of this application is shown.

[0048] like Figure 1 As shown in the embodiment of this application, a staged desulfurization method for high-sulfur bauxite is provided, wherein the weight m1 of sulfur in the high-sulfur bauxite and the weight m2 of the high-sulfur bauxite satisfy the relationship: m1:m2≥0.03; the staged desulfurization method includes:

[0049] S1. Grind the high-sulfur bauxite to obtain high-sulfur bauxite powder;

[0050] S2. The acidic flotation reagent is mixed with the high-sulfur bauxite powder to mineralize the high-sulfur bauxite powder and obtain a primary raw ore slurry;

[0051] S3. Perform a first flotation desulfurization on the raw ore slurry to obtain a first middlings mixture;

[0052] S4. Concentrate the primary middlings mixture to obtain a secondary middlings mixture;

[0053] S5. The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate.

[0054] It should be noted that this mineralization process can be carried out by stirring, which can improve the contact between the acidic flotation reagent and the high-sulfur bauxite powder.

[0055] It should be noted that after concentration, the primary middlings mixture will not only yield a secondary middlings mixture, but also a supernatant, which can be used as a wetting agent for grinding.

[0056] In some optional embodiments, the weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0057] m3:m4=(0.5:1000)~(5:1000);

[0058] In these embodiments, the weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder can satisfy the relationship: m3:m4 = (0.5:1000) ~ (5:1000). This can ensure that there is a sufficient amount of acidic flotation reagent added to the high-sulfur bauxite powder. The sufficient amount of acidic flotation reagent will undergo an acid-base neutralization reaction with the hydrophilic alkaline substances on the surface of the high-sulfur bauxite, so that these hydrophilic alkaline substances will detach from the surface of the high-sulfur bauxite, thereby exposing the surface active sites of sulfur-containing particles in the high-sulfur bauxite.

[0059] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder can satisfy the following relationship: m3:m4 = (0.5:1000), (1:1000), (1.5:1000), (2.5:1000), (3:1000), (3.5:1000), (4:1000), (4.5:1000) or (5:1000).

[0060] In some optional embodiments, the acidic flotation reagent includes an acid modifier, a first alkyl xanthate, and pinyl oil, wherein the acid modifier includes sulfuric acid and / or hydrochloric acid;

[0061] The first alkyl xanthate comprises at least one of the following:

[0062] Ethyl xanthate, butyl xanthate, and pentyl xanthate;

[0063] In these embodiments, the acid flotation reagent may include an acid modifier, alkyl xanthate, and pine oil. In addition, the acid modifier may include sulfuric acid and / or hydrochloric acid; and the alkyl xanthate may include at least one of ethyl xanthate, butyl xanthate, and pentyl xanthate. By the acid-base neutralization reaction between the acid modifier in the acid flotation reagent and the hydrophilic alkaline substances on the surface of the high-sulfur bauxite, the surface active sites of sulfur-containing particles in the high-sulfur bauxite can be exposed, and then the alkyl xanthate and pine oil are used to float these sulfur-containing particles.

[0064] It should be noted that the acidic flotation reagent may also include copper sulfate and / or ferrous sulfate and / or sodium hexametaphosphate.

[0065] In some optional embodiments, the weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0066] m5:m6=(2:1000)~(6:1000);

[0067] In these embodiments, the weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture can satisfy the relationship: m5:m6=(2:1000)~(6:1000), which can ensure that there is a sufficient amount of deep desulfurization agent in the secondary middlings mixture. The sufficient amount of deep desulfurization agent can expose the surface active sites of sulfur-containing particles and adsorb them, thereby promoting the flotation of sulfur-containing substances in the secondary middlings mixture.

[0068] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture can satisfy the following relationship: m5:m6 = (2:1000), (2.5:1000), (3:1000), (3.5:1000), (4:1000), (4.5:1000), (5:1000), (5.5:1000) or (6:1000).

[0069] In some optional embodiments, the deep desulfurization agent includes an alkaline regulator, a second alkyl xanthate, and pinol oil, wherein the alkaline regulator includes sodium hydroxide and / or potassium hydroxide;

[0070] The second alkyl xanthate comprises at least one of the following:

[0071] Ethyl xanthate, butyl xanthate, and pentyl xanthate;

[0072] In these embodiments, the deep desulfurization agent may include an alkaline regulator, a second alkyl xanthate, and pine oil. The alkaline regulator may include sodium hydroxide and / or potassium hydroxide, and the second alkyl xanthate may include at least one of ethyl xanthate, butyl xanthate, and pentyl xanthate. The deep desulfurization agent can expose and adsorb the surface active sites of sulfur-containing particles to further improve desulfurization efficiency.

[0073] It should be noted that the alkalinity regulator may also include sodium carbonate and potassium carbonate.

[0074] In some optional embodiments, the weight m7 of the fine-grained material in the high-sulfur bauxite powder and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0075] m7:m4 = (0.75:1) to (0.90:1); the particle size of the fine-grained material is ≤0.074mm;

[0076] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0077] m8:m9=(0.20:1)~(0.30:1);

[0078] In these embodiments, the weight m7 of fine-grained material and the total weight m4 of high-sulfur bauxite powder can satisfy the relationship: m7:m4 = (0.75:1) to (0.90:1), and the particle size of the fine-grained material is ≤0.074mm. This ensures that there is a sufficient amount of fine-grained material in the high-sulfur bauxite powder, which allows for sufficient contact between the fine-grained material and the acidic flotation reagent, thereby promoting the contact between the acidic flotation reagent and the surface of the high-sulfur bauxite. The hydrophilic substances undergo sufficient acid-base neutralization reactions, allowing them to detach from the surface of the high-sulfur bauxite and expose the surface active sites of the sulfur-containing particles in the high-sulfur bauxite. In addition, the dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry can satisfy the relationship: m8:m9=(0.20:1)~(0.30:1), which promotes the acid flotation reagent to fully desulfurize the high-sulfur bauxite, thereby improving the grade of the aluminum concentrate.

[0079] The weight m7 of the fine-grained material and the total weight m4 of the high-sulfur bauxite powder can satisfy the following relationship: m7:m4 = 0.75:1, 0.80:1, 0.85:1 or 0.90:1.

[0080] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry can satisfy the following relationship: m8:m9 = 0.20:1, 0.21:1, 0.22:1, 0.23:1, 0.24:1, 0.25:1, 0.26:1, 0.27:1, 0.28:1, 0.29:1 or 0.30:1.

[0081] It should be noted that when the dry weight m8 of the primary raw ore pulp and the total weight m9 of the primary raw ore pulp satisfy the relationship m8:m9 < 0.20:1, the efficiency of primary flotation desulfurization will be reduced; when the dry weight m8 of the primary raw ore pulp and the total weight m9 of the primary raw ore pulp satisfy the relationship m8:m9 > 0.30:1, the amount of inclusions in the desulfurization foam will be increased, thereby reducing the grade of the final sulfur concentrate.

[0082] In some optional embodiments, the dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0083] m10:m11=(0.35:1)~(0.40:1);

[0084] In these embodiments, the dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture can satisfy the relationship: m10:m11=(0.35:1)~(0.40:1), indicating that the secondary middlings mixture contains sufficient desulfurized high-sulfur bauxite powder to promote sufficient secondary desulfurization and increase the mass concentration of secondary middlings in the secondary middlings mixture, thereby promoting the flotation of sulfur-containing substances in the secondary middlings mixture.

[0085] The dry weight m10 and the total weight m11 of the secondary middlings mixture can satisfy the following relationship: m9:m10 = 0.35:1, 0.36:1, 0.37:1, 0.38:1, 0.39:1 or 0.40:1.

[0086] It should be noted that when the dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the relationship m10:m11 < 0.35:1, the weight content of desulfurized high-sulfur bauxite powder in the secondary middlings mixture is too low, which will reduce the efficiency of secondary flotation desulfurization. When the dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the relationship m10:m11 > 0.40:1, the weight content of desulfurized high-sulfur bauxite powder in the secondary middlings mixture is too high. Excessive desulfurized high-sulfur bauxite powder will increase the amount of inclusions in the desulfurization foam during the secondary flotation desulfurization process, thereby reducing the grade of the final sulfur concentrate.

[0087] In some optional embodiments, the time for the first flotation desulfurization is 8 min to 21 min;

[0088] The secondary flotation desulfurization time is 4 min to 12 min;

[0089] In these embodiments, the primary flotation desulfurization time can be 8 min to 21 min, which can ensure that the primary flotation desulfurization is carried out sufficiently, so as to promote the acid flotation reagent to fully neutralize the hydrophilic alkaline substances on the surface of high-sulfur bauxite. This can promote the removal of these hydrophilic alkaline substances from the surface of high-sulfur bauxite, thereby exposing the surface active sites of sulfur-containing particles in high-sulfur bauxite. In addition, the secondary flotation desulfurization time can be 4 min to 12 min, which can ensure that the secondary flotation desulfurization is carried out sufficiently. This can improve the flotation of sulfur-containing substances in the secondary middlings mixture by using a deep desulfurizing agent, thereby further improving the desulfurization efficiency.

[0090] The time for one flotation desulfurization can be 8 min, 10 min, 12 min, 14 min, 16 min, 18 min or 21 min.

[0091] The time for the secondary flotation desulfurization can be 4 min, 6 min, 8 min, 10 min or 12 min.

[0092] In some optional embodiments, the pH of the primary raw ore slurry is 2 to 6;

[0093] The pH of the secondary flotation desulfurization is 8-13.

[0094] In these embodiments, the pH of the primary raw ore slurry can be 2 to 6. Within this pH range, the acidic flotation reagents can fully neutralize the hydrophilic substances on the surface of the high-sulfur bauxite, thereby causing these hydrophilic substances to detach from the surface of the high-sulfur bauxite and exposing the surface active sites of sulfur-containing particles in the high-sulfur bauxite. In addition, the pH of the secondary flotation desulfurization can be 8 to 13, which can promote the deep desulfurization reagents to fully expose the surface active sites of sulfur-containing particles and adsorb onto these exposed surface active sites, thereby improving the flotation of sulfur-containing substances in the secondary middlings mixture and further improving the desulfurization efficiency.

[0095] The pH of the primary ore slurry can be 2, 3, 4, 5 or 6.

[0096] The pH of the secondary flotation desulfurization can be 8, 9, 10, 11, 12 or 13.

[0097] It should be noted that when the pH of the primary raw ore pulp is less than 2, the excessively low pH of the primary raw ore pulp will corrode the flotation desulfurization equipment, increasing the cost of primary flotation desulfurization. When the pH of the primary raw ore pulp is greater than 6, the excessively high pH of the primary raw ore pulp will make it difficult to improve the surface properties of the high-sulfur bauxite powder in the primary raw ore pulp, thus failing to promote sufficient acid-base neutralization reaction between the acidic flotation reagents and the hydrophilic substances on the surface of the high-sulfur bauxite, and consequently failing to expose the surface active sites of sulfur-containing particles in the high-sulfur bauxite.

[0098] It should be noted that when the pH of secondary flotation desulfurization is less than 8, excessively low pH secondary flotation desulfurization will make it difficult for the deep desulfurization agent to expose the surface active sites of sulfur-containing particles, thus making it difficult to improve the flotation of sulfur-containing substances in the secondary middlings mixture through the deep desulfurization agent; when the pH of secondary flotation desulfurization is greater than 13, excessively high pH secondary flotation desulfurization ash will increase the cost of secondary flotation desulfurization.

[0099] Figure 2 An exemplary schematic diagram of a staged desulfurization method for high-sulfur bauxite provided in an embodiment of this application is shown.

[0100] In some alternative implementations, such as Figure 2 As shown, the staged desulfurization method further includes:

[0101] S301. The primary raw ore slurry is subjected to primary flotation desulfurization to obtain a primary middlings mixture and a primary sulfur concentrate;

[0102] S401. Concentrate the primary middlings mixture to obtain a secondary middlings mixture;

[0103] S501. The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate and secondary sulfur concentrate respectively.

[0104] S601. Combine the primary sulfur concentrate and the secondary sulfur concentrate to obtain sulfur concentrate;

[0105] In these embodiments, the primary sulfur concentrate obtained from one flotation desulfurization and the secondary sulfur concentrate obtained from two flotations are combined to recover sulfur from high-sulfur bauxite and obtain a higher-grade sulfur concentrate product.

[0106] 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 industry standards; if no corresponding industry standard exists, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0107] Example 1

[0108] like Figure 2 As shown, a staged desulfurization method for high-sulfur bauxite is described, wherein the weight m1 of sulfur in the high-sulfur bauxite and the weight m2 of the high-sulfur bauxite satisfy the relationship: m1:m2=0.0833; the staged desulfurization method includes:

[0109] S1. Grind the high-sulfur bauxite to obtain high-sulfur bauxite powder;

[0110] S2. Mix the acidic flotation reagent with the high-sulfur bauxite powder to mineralize the high-sulfur bauxite powder and obtain a primary raw ore slurry;

[0111] S301. The raw ore slurry is subjected to flotation desulfurization to obtain a middlings mixture and a sulfur concentrate.

[0112] S401. Concentrate the primary middlings liquor to obtain a secondary middlings liquor;

[0113] S501. The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate and secondary sulfur concentrate respectively.

[0114] S601. Combine primary sulfur concentrate and secondary sulfur concentrate to obtain sulfur concentrate.

[0115] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0116] m3:m4 = 4.71:1000.

[0117] The types and proportions of acidic flotation reagents are as follows:

[0118] Sulfuric acid:copper sulfate:sodium hexametaphosphate:butyl xanthate:pine oil = 40:1:0.8:4:1.3.

[0119] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0120] m5:m6 = 5.77:1000.

[0121] The types and proportions of deep desulfurization agents are as follows:

[0122] Sodium hydroxide:sodium carbonate:butyl xanthate:pine oil = 35:20:2:0.7.

[0123] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0124] m7:m4 = 0.90:1; particle size of fine-grained materials ≤ 0.074 mm;

[0125] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0126] m8:m9 = 0.2018:1.

[0127] The dry weight m10 and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0128] m10:m11 = 0.3715:1.

[0129] The time for one flotation desulfurization process is 21 minutes;

[0130] The time for secondary flotation desulfurization is 12 minutes.

[0131] The pH of the primary raw ore slurry is 2;

[0132] The pH of the secondary flotation desulfurization is 13.

[0133] Example 2

[0134] Based on the content disclosed in Example 1, the following modifications are made:

[0135] The weight m1 of sulfur in high-sulfur bauxite and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0607.

[0136] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0137] m3:m4 = 3.53:1000.

[0138] The types and proportions of acidic flotation reagents are as follows:

[0139] Sulfuric acid:copper sulfate:sodium hexametaphosphate:butyl xanthate:pine oil = 30:0.8:0.5:3:1.

[0140] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0141] m5:m6 = 3.77:1000.

[0142] The types and proportions of deep desulfurization agents are as follows:

[0143] Potassium hydroxide:potassium carbonate:butyl xanthate:pine oil = 20:15:2:0.7.

[0144] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0145] m7:m4 = 0.8632:1; the particle size of fine-grained materials is ≤0.074mm;

[0146] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0147] m8:m9 = 0.2369:1.

[0148] The dry weight m10 and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0149] m10:m11 = 0.3598:1.

[0150] The time for one flotation desulfurization operation is 12 minutes;

[0151] The time for secondary flotation desulfurization is 6 minutes.

[0152] The pH of the primary raw ore slurry is 3;

[0153] The pH of the secondary flotation desulfurization process is 10.5.

[0154] Example 3

[0155] Based on the content disclosed in Example 1, the following modifications are made:

[0156] The weight m1 of sulfur in high-sulfur bauxite and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0680.

[0157] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0158] m3:m4 = 3.27:1000.

[0159] The types and proportions of acidic flotation reagents are as follows:

[0160] Hydrochloric acid: ferrous sulfate: sodium hexametaphosphate: ethyl xanthate: pentyl xanthate: pine oil = 20:5:1:2:3:1.7.

[0161] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0162] m5:m6 = 3.83:1000.

[0163] The types and proportions of deep desulfurization agents are as follows:

[0164] Sodium hydroxide:sodium carbonate:ethyl xanthate:pentyl xanthate:pine oil = 15:20:0.5:2:0.8

[0165] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0166] m7:m4 = 0.8213:1; the particle size of fine-grained materials is ≤0.074mm;

[0167] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0168] m8:m9 = 0.2458:1.

[0169] The dry weight m10 and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0170] m10:m11 = 0.3818:1.

[0171] The time for one flotation desulfurization operation is 18 minutes;

[0172] The time for secondary flotation desulfurization is 9 minutes.

[0173] The pH of the primary raw ore slurry is 4;

[0174] The pH of the secondary flotation desulfurization is 10.

[0175] Example 4

[0176] Based on the content disclosed in Example 1, the following modifications are made:

[0177] The weight m1 of sulfur in high-sulfur bauxite and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0402.

[0178] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0179] m3:m4 = 1.5:1000.

[0180] The types and proportions of acidic flotation reagents are as follows:

[0181] Sulfuric acid: hydrochloric acid: ferrous sulfate: sodium hexametaphosphate: butyl xanthate: pine oil = 2:3:0.5:1:3:1.

[0182] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0183] m5:m6 = 2.07:1000.

[0184] The types and proportions of deep desulfurization agents are as follows:

[0185] Potassium hydroxide:potassium carbonate:butyl xanthate:pine oil = 4:10:5:1.7.

[0186] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0187] m7:m4 = 0.7869:1; the particle size of fine-grained materials is ≤0.074mm;

[0188] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0189] m8:m9 = 0.2756:1.

[0190] The dry weight m10 and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0191] m10:m11 = 0.3921:1.

[0192] The time for one flotation desulfurization operation is 10 minutes;

[0193] The time for secondary flotation desulfurization is 4 minutes.

[0194] The pH of the primary raw ore slurry is 5;

[0195] The pH of the secondary flotation desulfurization is 9.

[0196] Example 5

[0197] Based on the content disclosed in Example 1, the following modifications are made:

[0198] The weight m1 of sulfur in high-sulfur bauxite and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0366.

[0199] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0200] m3:m4 = 0.73:1000.

[0201] The types and proportions of acidic flotation reagents are as follows:

[0202] Sulfuric acid:copper sulfate:sodium hexametaphosphate:butyl xanthate:pine oil = 3:0.5:0.5:2.5:0.8.

[0203] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0204] m5:m6 = 2.55:1000.

[0205] The types and proportions of deep desulfurization agents are as follows:

[0206] Sodium hydroxide:sodium carbonate:butyl xanthate:pine oil = 2.8:20:2:0.7.

[0207] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0208] m7:m4 = 0.7869:1; the particle size of fine-grained materials is ≤0.074mm;

[0209] The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship:

[0210] m8:m9 = 0.2756:1.

[0211] The dry weight m10 and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0212] m10:m11 = 0.3921:1.

[0213] The time for one flotation desulfurization is 8 minutes;

[0214] The time for secondary flotation desulfurization is 4 minutes.

[0215] The pH of the primary raw ore slurry is 6;

[0216] The pH of the secondary flotation desulfurization is 8.

[0217] Comparative Example 1

[0218] Based on the content disclosed in Example 1, the following modifications are made:

[0219] Using the prior art (1) described in the background art, a high-sulfur bauxite is processed in which the weight m1 of sulfur and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0833.

[0220] High-sulfur bauxite is ground, and lime is added during the grinding process to obtain the grinding product. The weight m11 of the fine particles in the grinding product and the total weight m12 of the grinding product satisfy the relationship: m11:m12=0.83:1. The pH of the grinding product is 8. The particle size of the fine particles is ≤0.074mm.

[0221] The grinding product is then subjected to closed-circuit flotation desulfurization using a "one roughing, three scavenging, and three cleaning" process to obtain aluminum concentrate and sulfur concentrate, respectively.

[0222] Comparative Example 2

[0223] Based on the content disclosed in Example 1, the following modifications are made:

[0224] Using the prior art (2) described in the background art, a high-sulfur bauxite is processed in which the weight m1 of sulfur and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0833.

[0225] The high-sulfur bauxite is ground until the particle size of the ground high-sulfur bauxite powder is ≤400 mesh. Then the high-sulfur bauxite powder is mixed with water to obtain a slurry with a weight concentration of 10%.

[0226] The pH of the slurry was adjusted to 9 using CaO to obtain the adjusted slurry.

[0227] The slurry was first stirred and mixed with sodium hexametaphosphate, then the mixture obtained from the first stirring and mixing was second stirred and mixed with aluminum sulfate, then the mixture obtained from the second stirring and mixing was third stirred and mixed with butyl xanthate, and then the mixture obtained from the third stirring and mixing was fourth stirred and mixed with pine oil to obtain a mixed slurry; wherein, the first stirring speed was 2400 rpm and the first stirring time was 5 min; the second stirring speed was 1000 rpm and the second stirring time was 12 min.

[0228] The mixed slurry was subjected to flotation to obtain pre-alumina concentrate and sulfur concentrate; the flotation stirring rate was 1000 rpm and the flotation stirring time was 12 min. The pre-alumina concentrate was mixed with O3 and desulfurized for 180 min to obtain alumina concentrate.

[0229] Comparative Example 3

[0230] Based on the content disclosed in Example 1, the following modifications are made:

[0231] Using the prior art (3) described in the background art, a high-sulfur bauxite is processed in which the weight m1 of sulfur and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0833.

[0232] High-sulfur bauxite is ground to obtain grinding products; wherein, the weight m11 of fine particles in the grinding products and the total weight m12 of the grinding products satisfy the relationship: m11:m12=0.82:1; the particle size of fine particles is ≤0.074mm;

[0233] The grinding product is then mixed with water to obtain a high-sulfur bauxite slurry;

[0234] A shaking table was used to desulfurize high-sulfur bauxite slurry by gravity separation, yielding gravity-separated aluminum concentrate and gravity-separated pyrite. The shaking table was set with a table inclination angle of 1.5°, a stroke of 14 mm, and a washing frequency of 300 times / min.

[0235] Flotation desulfurization of gravity-separated aluminum concentrate is carried out using a flotation machine. The flotation desulfurization process includes one roughing, three cleaning, and three scavenging processes to obtain flotation aluminum concentrate and flotation sulfur concentrate. The obtained flotation aluminum concentrate is the final aluminum concentrate. The flotation sulfur concentrate obtained by flotation and the gravity-separated pyrite obtained by gravity separation are combined into a comprehensive sulfur concentrate.

[0236] Comparative Example 4

[0237] Based on the content disclosed in Example 1, the following modifications are made:

[0238] Using the prior art (4) described in the background art, a high-sulfur bauxite is processed in which the weight m1 of sulfur and the weight m2 of high-sulfur bauxite satisfy the relationship: m1:m2=0.0833.

[0239] High-sulfur bauxite is ground to a fineness of 75%, and then subjected to a first desulfurization roughing process (I). During this first desulfurization roughing process, 300 g / t of butyl xanthate and 100 g / t of frother pine oil are added to remove sulfide middlings. The remaining product in the flotation cell of the first desulfurization roughing process (I) is bauxite middlings. The bauxite middlings are then subjected to a first desulfurization roughing process (II), to which 100 g / t of butyl xanthate and 30 g / t of frother pine oil are added again. Pine oil is used to separate sulfide middlings II and aluminum concentrate 2. Then, sulfide middlings II undergo a second-step desulfurization flotation: sulfide middlings I from the first-step desulfurization roughing I and sulfide middlings II from the first-step desulfurization roughing I are combined, and then 200g / t water glass and 50g / t butyl xanthate are added respectively to further separate sulfide rough concentrate and aluminum concentrate 2. Then, the aluminum concentrate 2 obtained from the second-step desulfurization flotation is combined with the aluminum concentrate 2 obtained from the first-step flotation to form a composite aluminum concentrate.

[0240] Comparative Example 5

[0241] Based on the content disclosed in Example 1, the following modifications are made:

[0242] No deep desulfurization agents are added and no secondary flotation desulfurization is performed.

[0243] Comparative Example 6

[0244] Based on the content disclosed in Example 1, the following modifications are made:

[0245] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0246] m3:m4 = 0.43:1000.

[0247] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0248] m5:m6 = 1.9:1000.

[0249] Comparative Example 7

[0250] Based on the content disclosed in Example 1, the following modifications are made:

[0251] The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship:

[0252] m3:m4 = 5.01:1000.

[0253] The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship:

[0254] m5:m6 = 6.17:1000.

[0255] Comparative Example 8

[0256] Based on the content disclosed in Example 1, the following modifications are made:

[0257] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0258] m7:m4 = 0.70:1.

[0259] Comparative Example 9

[0260] Based on the content disclosed in Example 1, the following modifications are made:

[0261] The weight m7 of fine-grained material in high-sulfur bauxite powder and the total weight m4 of high-sulfur bauxite powder satisfy the following relationship:

[0262] m7:m4 = 1.0:1.

[0263] Comparative Example 10

[0264] Based on the content disclosed in Example 1, the following modifications are made:

[0265] The dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0266] m10:m11 = 0.30:1.

[0267] Comparative Example 11

[0268] Based on the content disclosed in Example 1, the following modifications are made:

[0269] The dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the following relationship:

[0270] m10:m11 = 0.50:1.

[0271] Relevant experimental and effect data:

[0272] The weight content of sulfur in the high-sulfur bauxite used in each embodiment and comparative example was statistically analyzed, and the performance parameters of the obtained aluminum concentrate and sulfur concentrate were also statistically analyzed. The results are shown in Table 1.

[0273] Table 1. Performance parameters of high-sulfur bauxite raw materials, bauxite concentrate, and sulfur concentrate for each embodiment and comparative example.

[0274]

[0275]

[0276] As shown in Table 1, the staged desulfurization method for high-sulfur bauxite provided in this application embodiment effectively increases the surface active sites of sulfur-containing particles in high-sulfur bauxite by using an acidic flotation desulfurizing agent in combination with a deep desulfurizing agent, so as to finally obtain aluminum concentrate with a sulfur element weight content ≤0.4% and sulfur concentrate with a sulfur element weight content ≥36%. However, according to the prior art of Comparative Examples 1 to 4, for high-sulfur bauxite with high sulfur content, the prior art cannot reduce the sulfur content of aluminum concentrate to below 0.4%. The main reason for this is that high-sulfur bauxite is severely oxidized, and there are hydrophilic substances on the surface of pyrite in high-sulfur bauxite, which is not conducive to the adhesion of collectors in flotation desulfurization.

[0277] In summary, the present application provides a staged desulfurization method for high-sulfur bauxite. This method first grinds the high-sulfur bauxite and then performs a primary flotation desulfurization using an acidic flotation desulfurizing agent to obtain primary middlings and primary sulfur concentrate. However, the sulfur content of the primary middlings is still high at this stage. Therefore, a deep desulfurization agent is subsequently added to expose and bind to the active sites of sulfur-containing substances in the secondary middlings mixture. This facilitates the flotation of sulfur-containing minerals in the secondary middlings mixture, thereby promoting secondary desulfurization and obtaining aluminum concentrate and secondary sulfur concentrate. The obtained aluminum concentrate can be used as a qualified production raw material for alumina enterprises. Then, the primary and secondary sulfur concentrates are combined into a sulfur concentrate, which can be used as a raw material for sulfuric acid production, thus achieving comprehensive utilization of high-sulfur bauxite resources.

[0278] 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 staged desulfurization method for high-sulfur bauxite, characterized in that, The weight m1 of sulfur in the high-sulfur bauxite and the weight m2 of the high-sulfur bauxite satisfy the relationship: m1:m2≥0.03; the staged desulfurization method includes: High-sulfur bauxite is ground to obtain high-sulfur bauxite powder; The acidic flotation reagent is mixed with the high-sulfur bauxite powder to mineralize the high-sulfur bauxite powder and obtain a primary raw ore slurry with a pH of 2 to 6. The primary raw ore slurry is subjected to primary flotation desulfurization to obtain a primary middlings mixture; The primary middlings mixture is concentrated to obtain a secondary middlings mixture; The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate. The pH of the secondary flotation desulfurization is 8-13, and the sulfur content in the aluminum concentrate is ≤0.4% by weight. The time for primary flotation desulfurization is 8 min to 21 min; the time for secondary flotation desulfurization is 4 min to 12 min. The weight m3 of the acidic flotation reagent and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship: m3:m4=(0.5:1000)~(5:1000); The weight m5 of the deep desulfurization agent and the dry weight m6 of the secondary middlings mixture satisfy the following relationship: m5:m6=(2: 1000)~(6: 1000); The dry weight m10 of the secondary middlings mixture and the total weight m11 of the secondary middlings mixture satisfy the following relationship: m10: m11 = (0.35:1) ~ (0.40:1). The acidic flotation reagent consists of an acid modifier, a first alkyl xanthate, and pine oil; The deep desulfurization agent consists of an alkaline regulator, a second alkyl xanthate, and pine oil.

2. The staged desulfurization method according to claim 1, characterized in that, The acid regulator includes sulfuric acid and / or hydrochloric acid; the first alkyl xanthate includes at least one of the following: ethyl xanthate, butyl xanthate, and pentyl xanthate.

3. The staged desulfurization method according to claim 1, characterized in that, The alkalinity regulator includes sodium hydroxide and / or potassium hydroxide; the second alkyl xanthate includes at least one of the following: ethyl xanthate, butyl xanthate, and pentyl xanthate.

4. The staged desulfurization method according to claim 1, characterized in that, The weight m7 of the fine-grained material in the high-sulfur bauxite powder and the total weight m4 of the high-sulfur bauxite powder satisfy the following relationship: m7:m4 = (0.75:1) ~ (0.90:1); the particle size of the fine-grained material is ≤0.074mm; The dry weight m8 of the primary raw ore slurry and the total weight m9 of the primary raw ore slurry satisfy the following relationship: m8:m9=(0.20:1)~(0.30:1).

5. The staged desulfurization method according to claim 1, characterized in that, The staged desulfurization method also includes: The primary raw ore slurry is subjected to primary flotation desulfurization to obtain a primary middlings mixture and a primary sulfur concentrate. The primary middlings mixture is concentrated to obtain a secondary middlings mixture; The deep desulfurization agent is mixed with the secondary middlings mixture, and then the secondary middlings mixture is subjected to secondary flotation desulfurization to obtain aluminum concentrate and secondary sulfur concentrate, respectively. The primary sulfur concentrate and the secondary sulfur concentrate are combined to obtain sulfur concentrate.

Images