Desulfurization and desiliconization process for high-sulfur and high-silicon bauxite

Abstract

The invention relates to the technical field of ores, in particular to a desulfurization and desiliconization process for high-sulfur and high-silicon bauxite. Comprising the following steps: (1) washing and grinding ores; (2) a desulfurization activating agent, an inhibitor, a desulfurization collecting agent and a foaming agent are added for reverse flotation desulfurization, and sulfur concentrate and filter residues are obtained; (3) adding a desilicication collecting agent into the desulfurized filter residues for flotation desilicication to obtain aluminum concentrate and tailings; the desulfurization collecting agent is prepared from, by weight, 1-2 parts of modified thioether ethyl hydroximic acid and 4-7 parts of xanthate. According to the desulfurization and desiliconization process for the high-sulfur and high-silicon bauxite, the flotation recovery rate of minerals is remarkably increased, and the quality of flotation concentrate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of resource processing, and in particular to a process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite. Background Art

[0002] China is one of the countries with the most extensive distribution of bauxite resources in the world. However, due to environmental and safety issues, the market demand for bauxite is increasing, and the requirements for clean and energy-saving development of existing production are also increasing. The development and utilization of bauxite mainly depends on the grinding-flotation process, and its quality has a great influence on the flotation effect of the ore. Due to the mineral embedding particle size and intergrowth relationship between primary ore and weathered ore, as well as the differences in the occurrence environment of different ore bodies, after the bauxite is mined, its ore contains various components of pyrite compounds, resulting in a high sulfur load in the ore, which affects the grinding and flotation effects.

[0003] Chinese patent 201510594323.2 discloses a method for simultaneous desulfurization and desiliconization of bauxite by reverse flotation, wherein the high-sulfur and high-organic bauxite is ground and slurried, and then a regulator, an activator, a desulfurization collector, a deorganic collector, and a frother are added respectively for full mixing and mineralization, so that the gangue mineral pyrite and organic matter float up through the foam carrier, and the bauxite concentrate remains in the pulp. Chinese patent 201510593716.1 discloses a method for simultaneous flotation desulfurization and desiliconization of high-sulfur bauxite, wherein an inhibitor is added to the high-sulfur bauxite for grinding, and after slurrying, a desulfurization collector, a frother, an activator, and a desiliconization collector are added for simultaneous reverse flotation desulfurization and desiliconization, so that the sulfur-containing gangue minerals and the silicon gangue minerals float up as foam products, and the target aluminum minerals remain in the pulp, so that the simultaneous flotation desulfurization and desiliconization of the high-sulfur bauxite is achieved, and a bauxite flotation concentrate with a high aluminum-silicon ratio and a low sulfur content is obtained.

[0004] Flotation is an effective method for separating fine-grained minerals and desulfurizing high-sulfur bauxite. It can make comprehensive use of mineral resources and is an economical and feasible method. However, due to its small particle size, large specific surface area and unsaturated surface bond force, fine-grained high-sulfur bauxite is prone to slow flotation rate, low recovery rate, poor selectivity and high reagent consumption. It is difficult to achieve good results using conventional flotation reagents. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a high-sulfur and high-silicon bauxite desulfurization and desiliconization process. The desulfurization collector used in the process significantly improves the collection effect, increases the flotation recovery rate of the mineral, and improves the quality of the flotation concentrate.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A high-sulfur and high-silicon bauxite desulfurization and desiliconization process comprises the following steps:

[0008] (1) Washing and grinding: wash out the clay from the high-sulfur and high-silicon bauxite, and after the clay settles, crush and grind it;

[0009] (2) adding a desulfurization activator, an inhibitor, a desulfurization collector, and a frother to the ore after grinding in step (1) to perform reverse flotation desulfurization to obtain a sulfur concentrate and filter residue;

[0010] (3) adding a desiliconizing collector to the filter residue after desulfurization to carry out flotation desiliconization to obtain aluminum concentrate and tailings;

[0011] In step (2), the desulfurization collector is prepared by weight from 1-2 parts of modified thioether ethyl hydroxamic acid and 4-7 parts of xanthate;

[0012] The compound of xanthate and modified thioether ethyl hydroxamic acid is used as a collector, and the compound can play a synergistic collecting role. Xanthate has a good collecting ability for some sulfide ores, while modified thioether ethyl hydroxamic acid has a unique collecting effect on some difficult-to-select sulfide ores. The compound of the two can expand the collection range. The compound of the two agents can increase the adsorption amount and adsorption strength of the collector on the mineral surface. Their respective functional groups can interact with the active sites on the mineral surface in various ways, such as chemical bonding, hydrogen bonding, van der Waals force, etc., thereby forming a more stable adsorption layer, improving the hydrophobicity of the mineral surface, making the mineral more easily carried by bubbles, and thus improving the flotation recovery rate. Due to its good selectivity, the compound collector can reduce the content of impurity minerals in the concentrate and improve the quality of the concentrate. Xanthate may have insufficient stability under certain conditions and is prone to decomposition and failure. After the modified thioether ethyl hydroxamic acid is modified, its stability is improved. After the two are compounded, the modified thioether ethyl hydroxamic acid can improve the overall stability of the compound collector to a certain extent, so that it can maintain good collection performance under different flotation conditions, such as different pulp pH, temperature and other environments, reduce the decomposition and failure of the agent, and ensure the stability of the flotation effect.

[0013] The solubility and dispersibility of xanthate and modified thioether ethyl hydroxamic acid are different. After compounding, they can be adjusted to each other, so that the collector has better solubility and dispersibility in the slurry. This helps the collector to be evenly distributed in the slurry and fully contact with the mineral particles, improve the efficiency of the collector, and thus improve the flotation effect. The dosage of the compound collector is usually reduced compared to the use of xanthate or modified thioether ethyl hydroxamic acid alone, thereby reducing the cost of the reagent and improving the economic benefits of the flotation process.

[0014] Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows:

[0015] S1. Add thioether ethyl hydroxamic acid to water, stir evenly, and then perform ultrasonic treatment to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:40-70;

[0016] S2. Add formaldehyde to the above solution A, stir for 25-35 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 50-80°C, then add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 60-180 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 25%-35% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 5%-15% of the weight of thioether ethyl hydroxamic acid;

[0017] S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

[0018] During the reaction of thioether ethyl hydroxamic acid formaldehyde with aldehyde, the carbonyl group (-CO-) of formaldehyde can undergo addition reaction with the active hydrogen in thioether ethyl hydroxamic acid, and a hydroxymethyl group (-CH2OH) is introduced into the thioether ethyl hydroxamic acid molecule. This hydroxymethylation product increases the hydrophilicity and steric hindrance of the molecule, thereby improving its selectivity and collection capacity during the flotation process. At the same time, formaldehyde can also undergo condensation reaction with the hydroxyl group in the thioether ethyl hydroxamic acid molecule to form an acetal or ketal structure. The formation of this structure can increase the stability and rigidity of the molecule, making it less susceptible to interference from external factors such as acid, alkali, temperature and other changes in a complex flotation environment, thereby ensuring the stability of the agent performance. In addition, formaldehyde in the above reaction can also be used as a cross-linking agent to cause a cross-linking reaction between thioether ethyl hydroxamic acid molecules to form a three-dimensional network cross-linking structure. This cross-linked structure further improves the stability and rigidity of the molecule, making it less likely to be decomposed or destroyed in the slurry. It also increases the multi-point adsorption of the reagent molecules on the mineral surface, improves the firmness and selectivity of the adsorption, and is conducive to the effective separation of minerals.

[0019] Preferably, the xanthate is one or more of ethyl xanthate, butyl xanthate, isopropyl xanthate, isobutyl xanthate, pentyl xanthate, and hexyl xanthate.

[0020] Preferably, the preparation method of the desulfurization collector is as follows:

[0021] Step 1, adding xanthate into water, stirring and mixing, to prepare a xanthate aqueous solution;

[0022] Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the modified thioether ethyl hydroxamic acid addition time is 15-25min, and the stirring speed is 80-120 rpm to obtain a mixed solution C;

[0023] Step 3, allowing the mixed solution C to stand for 30-50 minutes, then filtering and washing to obtain a clean filter cake, and drying the filter cake to obtain a desulfurization collector.

[0024] Xanthate is usually a solid powder. If it is directly mixed with modified thioether ethyl hydroxamic acid, it is difficult to achieve a uniform mixing state in a short time due to the difference in physical state and properties between the two. However, dissolving the xanthate in water to make an aqueous solution, then adding modified thioether ethyl hydroxamic acid and mixing at a certain stirring speed can make the two components fully dispersed and contacted in the solution, which is more conducive to achieving uniform mixing and preventing agglomeration during the mixing process, thereby ensuring the performance stability and consistency of the desulfurization collector.

[0025] Preferably, in step 1, the weight volume ratio of xanthate to water is 1 g: 1000-2000 ml.

[0026] Preferably, the foaming agent is at least one of pine oil and methyl isobutyl carbinol.

[0027] Preferably, the inhibitor is sodium silicate or sodium fluorosilicate.

[0028] Preferably, the desiliconizing collector is one or more of oleic acid, linoleic acid, hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decylbenzyl ammonium chloride, and sodium dimethylaminodecyl carboxylate.

[0029] Preferably, per ton of ore, the amount of desulfurization activator is 50-100g, the amount of desulfurization collector is 250-1000g, the amount of foaming agent is 100-400g, the amount of inhibitor is 500-2000g, and the amount of desiliconization collector is 800-1200g.

[0030] Preferably, the desulfurization process is as follows: adding a desulfurization activator, an inhibitor, a desulfurization collector and a foaming agent to the ore to perform desulfurization roughing, the foam from the roughing is subjected to a first scavenging, and the bottom flow of the roughing is subjected to desulfurization concentration; the foam from the first scavenging is subjected to a second scavenging, the bottom flow of the first scavenging is returned to the roughing, the foam from the second scavenging is processed to obtain a sulfur concentrate, and the bottom flow of the second scavenging is returned to the first scavenging; the foam from the desulfurization concentration is returned to the desulfurization roughing, and the bottom flow of the desulfurization concentration is concentrated and then subjected to desiliconization.

[0031] Preferably, the desiliconization process is as follows: after the filter residue after the desulfurization and concentration bottom flow is concentrated and ground and classified, a desiliconization collector and an inhibitor are added to the slurry of qualified particle size to carry out desiliconization roughing, the foam of the roughing is subjected to the first desiliconization concentration, and the bottom flow of the roughing is subjected to the first desiliconization scavenging; the foam of the first desiliconization concentration is subjected to the second desiliconization concentration, and the bottom flow of the first desiliconization concentration is returned to the desiliconization roughing; the foam of the second desiliconization concentration is processed to obtain aluminum concentrate; the bottom flow of the second desiliconization concentration is returned to the first desiliconization concentration; the foam of the first desiliconization scavenging is returned to the desiliconization roughing, and the bottom flow of the first desiliconization scavenging is subjected to the second desiliconization scavenging; the foam of the second desiliconization scavenging is returned to the first desiliconization scavenging, and the bottom flow of the second desiliconization scavenging is processed to obtain tailings.

[0032] The present invention has the following beneficial effects:

[0033] The high-sulfur and high-silicon bauxite desulfurization and desiliconization process provided by the present invention first modifies the thioether ethyl hydroxamic acid, and then compounds the modified thioether ethyl hydroxamic acid with xanthate as a desulfurization collector, wherein the modified thioether ethyl hydroxamic acid has a changed molecular structure, so that it acts more effectively on the mineral surface, enhances the capture ability of the target mineral, and can be more firmly adsorbed on the mineral surface during the flotation process, thereby improving the flotation recovery rate of the mineral, especially for some sulfur-containing minerals that are difficult to float, the improvement of its capture effect is more significant. After the thioether ethyl hydroxamic acid is modified, its selectivity is improved, and after compounding with xanthate, the selective adsorption of the target mineral can be further optimized. During the flotation process, the compound collector can be more accurately adsorbed on the surface of the target mineral, improve the grade of the flotation concentrate, and the sulfur content of the obtained sulfur concentrate is ≥38%, the aluminum-silicon ratio in the aluminum concentrate is ≥6.1, and the sulfur is ≤0.28%, which better reduces the content of sulfur and silicon in the aluminum concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a process flow chart for desulfurization and desiliconization of high-sulfur and high-silicon bauxite according to Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] Example 1

[0037] A high-sulfur and high-silicon bauxite desulfurization and desiliconization process comprises the following steps:

[0038] (1) Ore washing and grinding: wash out the clay, wait for the clay to settle, and then crush the ore. The ore is first crushed by a jaw crusher, then crushed by a fine jaw crusher, and finally crushed by a high-pressure roller. The ore is then transported to a homogenizing bin by a belt. The homogenized ore is fed into a desulfurization mill through an electronic belt scale for grinding. After grinding, the ore is classified by the first stage of a spiral classifier, and the coarse particles are returned to the mill for further grinding, forming a closed-circuit grinding. The overflow of the spiral classifier is classified by a cyclone, and the coarse particles are returned to the mill for further grinding, and the fine particles enter the desulfurization roughing.

[0039] (2) Desulfurization: Add desulfurization activator, inhibitor, desulfurization collector and frother to the ore for desulfurization roughing, the foam from the roughing is subjected to the first scavenging, and the underflow from the roughing is subjected to desulfurization fine selection; the foam from the first scavenging is subjected to the second scavenging, the underflow from the first scavenging is returned to the roughing, the foam from the second scavenging is processed to obtain sulfur concentrate, and the underflow from the second scavenging is returned to the first scavenging; the foam from the desulfurization fine selection is returned to the desulfurization roughing, the underflow from the desulfurization fine selection enters the thickener, and after the thickener is concentrated, the underflow enters the belt filter for dehydration, the overflow from the thickener and the filtrate from the belt filter enter the desulfurization circulating water pool, and return to the previous ore washing and grinding, and the filter residue continues to be desiliconized;

[0040] (3) Desiliconization: After the filter residue concentrated from the desulfurization and concentration bottom flow is ground and classified, a desiliconization collector is added to the qualified particle size pulp to carry out desiliconization roughing, and the foam of the roughing is subjected to the first desiliconization and concentration, and the bottom flow of the roughing is subjected to the first desiliconization scavenging; the foam of the first desiliconization and concentration is subjected to the second desiliconization and concentration, and the bottom flow of the first desiliconization and concentration is returned to the desiliconization roughing; the foam of the second desiliconization and concentration is processed to obtain aluminum concentrate; the bottom flow of the second desiliconization and concentration is returned to the first desiliconization and concentration; the foam of the first desiliconization scavenging is returned to the desiliconization roughing, and the bottom flow of the first desiliconization scavenging is subjected to the second desiliconization scavenging; the foam of the second desiliconization scavenging is returned to the first desiliconization scavenging, and the bottom flow of the second desiliconization scavenging is processed to obtain tailings.

[0041] In step (2), the desulfurization collector is prepared by weight from 1.4 parts of modified thioether ethyl hydroxamic acid and 6 parts of xanthate; the xanthate is butyl xanthate, isopropyl xanthate, isobutyl xanthate, and amyl xanthate, and the weight ratio of the four components is 1:2:1:3.

[0042] Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows:

[0043] S1. Add thioether ethyl hydroxamic acid into water, stir evenly, and then perform ultrasonic treatment for 30 minutes to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:50;

[0044] S2. Add formaldehyde to the above solution A, stir for 30 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 70°C, add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 120 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 30% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 10% of the weight of thioether ethyl hydroxamic acid;

[0045] S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

[0046] The preparation method of the desulfurization collector is as follows:

[0047] Step 1, adding xanthate to water, stirring and mixing, to prepare a xanthate aqueous solution; the weight volume ratio of xanthate to water is 1g:1500ml;

[0048] Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the modified thioether ethyl hydroxamic acid addition time is 20 minutes, the stirring speed is 100 revolutions per minute, and a mixed solution C is obtained;

[0049] Step 3, the mixed solution C is allowed to stand for 40 minutes, and then filtered and washed to obtain a clean filter cake, and the filter cake is dried to obtain a desulfurization collector.

[0050] The foaming agent is pine oil, the desiliconizing collector is a mixture of hexadecyl quaternary ammonium salt and tetradecyl quaternary ammonium salt in a ratio of 1:2, and the inhibitor is sodium silicate. Per ton of ore, the amount of desulfurization activator is 80g, the amount of desulfurization collector is 600g, the amount of foaming agent is 200g, the amount of inhibitor is 1500g, and the amount of desiliconizing collector is 1000g.

[0051] Example 2

[0052] A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, the process steps comprising: (1) ore washing and grinding; (2) desulfurization; and (3) desiliconization. The specific method is the same as that in Example 1.

[0053] In step (2), the desulfurization collector is prepared by weight from 1.5 parts of modified thioether ethyl hydroxamic acid and 5 parts of xanthate; the xanthate is butyl xanthate, isobutyl xanthate, amyl xanthate and hexyl xanthate, and the weight ratio of the four components is 1:1:2:3.

[0054] Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows:

[0055] S1. Add thioether ethyl hydroxamic acid into water, stir evenly, and then perform ultrasonic treatment for 25 minutes to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:40;

[0056] S2. Add formaldehyde to the above solution A, stir for 25 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 65°C, add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 60 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 35% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 15% of the weight of thioether ethyl hydroxamic acid;

[0057] S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

[0058] The preparation method of the desulfurization collector is as follows:

[0059] Step 1, adding xanthate to water, stirring and mixing, to prepare a xanthate aqueous solution; the weight volume ratio of xanthate to water is 1g:1000ml;

[0060] Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the addition time of the modified thioether ethyl hydroxamic acid is 15 minutes, and the stirring speed is 120 revolutions per minute to obtain a mixed solution C;

[0061] Step 3, the mixed solution C is allowed to stand for 30 minutes, and then filtered and washed to obtain a clean filter cake, and the filter cake is dried to obtain a desulfurization collector.

[0062] The foaming agent is methyl isobutyl carbinol, the desiliconizing collector is a mixture of hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decyl benzyl ammonium chloride, and sodium dimethylaminodecyl carboxylate in a ratio of 1:2:1:3, and the inhibitor is sodium silicate. For each ton of ore, the amount of desulfurization activator is 50g, the amount of desulfurization collector is 250g, the amount of foaming agent is 320g, the amount of inhibitor is 1200g, and the amount of desiliconizing collector is 800g.

[0063] Example 3

[0064] A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, the process steps comprising: (1) ore washing and grinding; (2) desulfurization; and (3) desiliconization. The specific method is the same as that in Example 1.

[0065] In step (2), the desulfurization collector is prepared by weight from 1 part of modified thioether ethyl hydroxamic acid and 7 parts of xanthate; the xanthate is ethyl xanthate, butyl xanthate and hexyl xanthate, and the weight ratio of the three components is 1:1:4.

[0066] Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows:

[0067] S1. Add thioether ethyl hydroxamic acid into water, stir evenly, and then perform ultrasonic treatment for 40 minutes to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:70;

[0068] S2. Add formaldehyde to the above solution A, stir for 35 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 50°C, add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 180 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 25% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 5% of the weight of thioether ethyl hydroxamic acid;

[0069] S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

[0070] The preparation method of the desulfurization collector is as follows:

[0071] Step 1, adding xanthate to water, stirring and mixing, to prepare a xanthate aqueous solution; the weight volume ratio of xanthate to water is 1g:2000ml;

[0072] Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the addition time of the modified thioether ethyl hydroxamic acid is 25 min, the stirring speed is 80 rpm, and a mixed solution C is obtained;

[0073] Step 3, the mixed solution C is allowed to stand for 50 minutes, and then filtered and washed to obtain a clean filter cake, and the filter cake is dried to obtain a desulfurization collector.

[0074] The foaming agent is a mixture of pine oil and methyl isobutyl carbinol in a mass ratio of 1:3, the desiliconization collector is a mixture of hexadecyl quaternary ammonium salt, decylbenzyl ammonium chloride, and sodium dimethylaminodecyl carboxylate in a mass ratio of 1:3:2, and the inhibitor is sodium fluorosilicate. For each ton of ore, the amount of desulfurization activator is 100g, the amount of desulfurization collector is 1000g, the amount of foaming agent is 100g, the amount of inhibitor is 500g, and the amount of desiliconization collector is 1200g.

[0075] Example 4

[0076] A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, the process steps comprising: (1) ore washing and grinding; (2) desulfurization; and (3) desiliconization. The specific method is the same as that in Example 1.

[0077] In step (2), the desulfurization collector is prepared by weight from 2 parts of modified thioether ethyl hydroxamic acid and 4 parts of xanthate; the xanthate is ethyl xanthate, isobutyl xanthate, amyl xanthate and hexyl xanthate, and the weight ratio of the four components is 1:1:4:1.

[0078] Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows:

[0079] S1. Add thioether ethyl hydroxamic acid into water, stir evenly, and then perform ultrasonic treatment for 35 minutes to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:60;

[0080] S2. Add formaldehyde to the above solution A, stir for 32 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 80°C, add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 100 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 28% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 12% of the weight of thioether ethyl hydroxamic acid;

[0081] S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

[0082] The preparation method of the desulfurization collector is as follows:

[0083] Step 1, adding xanthate to water, stirring and mixing, to prepare a xanthate aqueous solution; the weight volume ratio of xanthate to water is 1g:1700ml;

[0084] Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the addition time of the modified thioether ethyl hydroxamic acid is 22 minutes, and the stirring speed is 110 revolutions per minute to obtain a mixed solution C;

[0085] Step 3, the mixed solution C is allowed to stand for 45 minutes, and then filtered and washed to obtain a clean filter cake, and the filter cake is dried to obtain a desulfurization collector.

[0086] The foaming agent is a mixture of pine oil and methyl isobutyl carbinol in a mass ratio of 2:1, the desiliconization collector is a mixture of hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decyl benzyl ammonium chloride, and sodium dimethylaminodecyl carboxylate in a mass ratio of 1:2:1:1, and the inhibitor is sodium fluorosilicate. For each ton of ore, the amount of desulfurization activator is 75g, the amount of desulfurization collector is 800g, the amount of foaming agent is 400g, the amount of inhibitor is 2000g, and the amount of desiliconization collector is 900g.

[0087] Comparative Example 1

[0088] A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, wherein in step (2), the desulfurization collector is prepared by weight from 1.4 parts of unmodified thioether ethyl hydroxamic acid and 6 parts of xanthate; the desiliconization collector is dodecyl ammonium chloride: dodecyl trimethyl ammonium chloride in a ratio of 1:1, and the rest is the same as in Example 1.

[0089] Comparative Example 2

[0090] A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, wherein in step (2), the desulfurization collector is prepared by weight from 1.5 parts of unmodified thioether ethyl hydroxamic acid and 5 parts of xanthate; the desiliconization collector is dodecyl ammonium chloride: dodecyl trimethyl ammonium chloride in a ratio of 1:1, and the rest is the same as in Example 2.

[0091] Comparative Example 3

[0092] The preparation method of the desulfurization collector is to directly stir xanthate and modified thioether ethyl hydroxamic acid for 30 minutes to mix, the desiliconization collector is dodecyl ammonium chloride: dodecyl trimethyl ammonium chloride: sodium dimethylamino tetradecyl carboxylate in a ratio of 2:1:3, and the rest is the same as in Example 1.

[0093] Comparative Example 4

[0094] The preparation method of the desulfurization collector is to directly stir xanthate and modified thioether ethyl hydroxamic acid for 30 minutes to mix, the desiliconization collector is dodecyl ammonium chloride: dodecyl trimethyl ammonium chloride: sodium dimethylamino tetradecyl carboxylate in a ratio of 2:1:3, and the rest is the same as in Example 2.

[0095] Results test:

[0096] The sulfur concentrate, aluminum concentrate and tailings obtained by the high-sulfur and high-silicon bauxite desulfurization and desiliconization process provided in Examples 1-4 and Comparative Examples 1-4 were tested, and the results are shown in Table 1.

[0097] Table 1. Experimental results

[0098]

[0099]

[0100] As can be seen from Table 1, by using the desulfurization and desiliconization process of Examples 1-4 of the present invention, the sulfur content of the obtained sulfur concentrate is ≥37%, the aluminum-silicon ratio in the aluminum concentrate is ≥6.1, and the sulfur is ≤0.28%, which are all better than those of Comparative Examples 1-4. By using the process of the present invention, the capture efficiency is higher, the desulfurization and desiliconization efficiency is higher, and the cost is also reduced. The sulfur concentrate can be sold as a product for the production of sulfuric acid, the aluminum concentrate can be used for the production of alumina, and the tailings can be used for the production of unburned bricks, thereby better realizing the comprehensive utilization of resources.

[0101] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0102] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A process for desulfurization and desiliconization of high-sulfur and high-silicon bauxite, characterized in that: The following steps are involved: (1) Washing and grinding: wash out the clay from the high-sulfur and high-silicon bauxite, and after the clay settles, crush and grind it; (2) adding a desulfurization activator, an inhibitor, a desulfurization collector, and a frother to the ore after grinding in step (1) to perform reverse flotation desulfurization to obtain a sulfur concentrate and filter residue; (3) adding a desiliconizing collector to the filter residue after desulfurization to carry out flotation desiliconization to obtain aluminum concentrate and tailings; In step (2), the desulfurization collector is prepared by weight from 1-2 parts of modified thioether ethyl hydroxamic acid and 4-7 parts of xanthate; Wherein, the preparation method of the modified thioether ethyl hydroxamic acid is as follows: S1. Add thioether ethyl hydroxamic acid to water, stir evenly, and then perform ultrasonic treatment to obtain solution A, wherein the mass ratio of thioether ethyl hydroxamic acid to water is 1:40-70; S2. Add formaldehyde to the above solution A, stir for 25-35 minutes, adjust the pH to 8-10 with sodium carbonate, then add activated carbon under stirring, heat to 50-80°C, then add sodium hydroxide to adjust the pH of the solution to 8-10, continue stirring for 60-180 minutes, and obtain a mixed solution B; wherein the amount of formaldehyde is 25%-35% of the weight of thioether ethyl hydroxamic acid, and the amount of activated carbon is 5%-15% of the weight of thioether ethyl hydroxamic acid; S3. The mixed solution B is filtered and dried to obtain modified thioether ethyl hydroxamic acid.

2. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1 is characterized in that: The xanthate is one or more of ethyl xanthate, butyl xanthate, isopropyl xanthate, isobutyl xanthate, pentyl xanthate, and hexyl xanthate.

3. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The preparation method of the desulfurization collector is as follows: Step 1, adding xanthate into water, stirring and mixing, to prepare a xanthate aqueous solution; Step 2, adding the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution under stirring, the modified thioether ethyl hydroxamic acid addition time is 15-25min, and the stirring speed is 80-120 rpm to obtain a mixed solution C; Step 3, allowing the mixed solution C to stand for 30-50 minutes, then filtering and washing to obtain a clean filter cake, and drying the filter cake to obtain a desulfurization collector.

4. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 3 is characterized in that: In the step 1, the weight volume ratio of xanthate to water is 1g:1000-2000ml.

5. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The foaming agent is at least one of pine oil and methyl isobutyl carbinol.

6. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The inhibitor is sodium silicate or sodium fluorosilicate.

7. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The desiliconizing collector is one or more of oleic acid, linoleic acid, hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decylbenzyl ammonium chloride, and sodium dimethylaminodecyl carboxylate.

8. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: For every ton of ore, the dosage of desulfurization activator is 50-100g, the dosage of desulfurization collector is 250-1000g, the dosage of foaming agent is 100-400g, the dosage of inhibitor is 500-2000g, and the dosage of desiliconization collector is 800-1200g.

9. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The desulfurization process is as follows: adding a desulfurization activator, an inhibitor, a desulfurization collector and a frother to the ore to carry out a desulfurization roughing selection, the foam from the roughing selection is subjected to a first scavenging selection, and the roughing underflow is subjected to a desulfurization concentrating selection; the foam from the first scavenging selection is subjected to a second scavenging selection, and the underflow of the first scavenging selection is returned to the roughing selection, the foam from the second scavenging selection is processed to obtain a sulfur concentrate, and the underflow of the second scavenging selection is returned to the first scavenging selection; the foam from the desulfurization concentrating selection is returned to the desulfurization roughing selection, and the underflow of the desulfurization concentrating selection is concentrated and then desiliconized.

10. The high-sulfur and high-silicon bauxite desulfurization and desiliconization process according to claim 1, characterized in that: The desiliconization process is as follows: after the filter residue after the desulfurization and concentration bottom flow is concentrated, it is ground and classified, and a desiliconization collector is added to the qualified particle size pulp to carry out desiliconization roughing, the foam of the roughing is subjected to the first desiliconization and concentration, and the bottom flow of the roughing is subjected to the first desiliconization scavenging; the foam of the first desiliconization and concentration is subjected to the second desiliconization and concentration, and the bottom flow of the first desiliconization and concentration is returned to the desiliconization roughing; the foam of the second desiliconization and concentration is processed to obtain aluminum concentrate; the bottom flow of the second desiliconization and concentration is returned to the first desiliconization and concentration; the foam of the first desiliconization scavenging is returned to the desiliconization roughing, and the bottom flow of the first desiliconization scavenging is subjected to the second desiliconization scavenging; the foam of the second desiliconization scavenging is returned to the first desiliconization scavenging, and the bottom flow of the second desiliconization scavenging is processed to obtain tailings.

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