Process for desulfurization and desilication of high-sulfur and high-silicon bauxite

Abstract

The present application relates to the technical field of ore, and more particularly to a high-sulfur high-silicon bauxite desulfurization and desilication process, which comprises the following steps: (1) washing and grinding; (2) adding a desulfurization activator, an inhibitor, a desulfurization collector and a foaming agent for reverse flotation desulfurization to obtain sulfur concentrate and filter residue; (3) adding a desilication collector to the filter residue after desulfurization for flotation desilication to obtain aluminum concentrate and tailings; wherein the desulfurization collector is made of 1-2 parts of modified sulfide-based ethyl hydroxamic acid and 4-7 parts of xanthate by weight. The high-sulfur high-silicon bauxite desulfurization and desilication process provided by the present application significantly improves the flotation recovery rate of the mineral and improves the quality of the flotation concentrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resource processing, and particularly relates to a desulfurization and desilication process for high-sulfur and high-silicon bauxite. BACKGROUND

[0002] China is one of the countries with the most widely distributed bauxite resources in the world. However, due to the influence of environmental and safety problems, the market demand for bauxite is increasing, and the development of clean and energy-saving production is also becoming higher and higher. The development and utilization of bauxite mainly depends on the grinding-flotation process, and the quality of the bauxite has a great influence on the flotation effect of the ore. Due to the mineral dissemination size and intergrowth relationship of the primary ore and the weathered ore, and the difference of the different ore bodies, the bauxite contains various sulfur and iron compounds after being mined, which leads to a high sulfur load in the ore, thereby affecting the grinding and flotation effect.

[0003] Chinese patent 201510594323.2 discloses a method for synchronous desulfurization and removal of organic matter of bauxite reverse flotation, which grinds and slurries high-sulfur and high-organic bauxite, and then adds adjusting agent, activator, desulfurization collector, desilication collector and foaming agent for mixing and mineralization, so that the sulfur and iron minerals and organic matter are floated by the foam carrier, and the bauxite concentrate is left in the slurry. Chinese patent 201510593716.1 discloses a method for synchronous flotation desulfurization and desilication of high-sulfur bauxite, which grinds high-sulfur bauxite by adding inhibitor, and then adds desulfurization collector, foaming agent, activator and desilication collector for reverse flotation desulfurization and desilication, so that the sulfur and silicon gangue minerals are floated as foam products, and the target aluminum minerals are left in the slurry, thereby realizing synchronous flotation desulfurization and desilication of high-sulfur bauxite, and obtaining bauxite flotation concentrate with high aluminum-silicon ratio and low sulfur content.

[0004] The flotation method is an effective means for separating fine-grained minerals and an effective method for desulfurization of high-sulfur bauxite, which can comprehensively utilize mineral resources and is an economical and feasible method. However, due to the small particle size, large specific surface area and unsaturated surface bond of the micro-fine particle high-sulfur bauxite, it is easy to cause slow flotation rate, low recovery rate, poor selectivity and large reagent consumption, and it is difficult to achieve good results by using conventional flotation reagents. SUMMARY

[0005] In order to solve the above problems, the present application provides a desulfurization and desilication process for high-sulfur and high-silicon bauxite, which significantly improves the collection effect of the desulfurization collector, improves the flotation recovery rate of the mineral, and improves the quality of the flotation concentrate.

[0006] In order to achieve the above purpose, the following technical scheme is adopted in the present application.

[0007] A desulfurization and desilication process for high-sulfur and high-silicon bauxite, comprising the following steps:

[0008] (1) washing and grinding, the clay in the high-sulfur and high-silicon bauxite is washed out, after the clay is settled, crushing and grinding are carried out;

[0009] (2) adding a desulfurization activator, a depressant, a desulfurization collector and a foaming agent to the ore after grinding in step (1) to carry out reverse flotation desulfurization, and a sulfur concentrate and a filter residue are obtained;

[0010] (3) adding a desiliconization collector to the filter residue after desulfurization to carry out flotation desiliconization, and an aluminum concentrate and a tailing are obtained;

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

[0012] The xanthate and the modified sulfur ether group ethyl hydroxamic acid are compounded as the collector, and the compound can play a synergistic collecting effect. The xanthate has good collecting ability for some sulfide ores, and the modified sulfur ether group ethyl hydroxamic acid has unique collecting effect for some refractory sulfide ores, and the compound can expand the collecting range. The compound of the two reagents can increase the adsorption amount and adsorption strength of the collector on the mineral surface, and the functional groups of the two reagents can interact with the active sites on the mineral surface in various ways, such as chemical bonding, hydrogen bonding, van der Waals force, etc., so as to form a more stable adsorption layer, improve the hydrophobicity of the mineral surface, and make the mineral more easily carried by the bubbles to float, thereby 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. The xanthate may have the problem of insufficient stability under certain conditions and is prone to decomposition and failure. The modified sulfur ether group ethyl hydroxamic acid has improved stability after modification. The compound of the two reagents can improve the overall stability of the compound collector to some extent, so that it can maintain good collecting performance under different flotation conditions, such as different pulp acidities, temperatures, etc., reduce the decomposition and failure of the reagent, and ensure the stability of the flotation effect.

[0013] The solubility and dispersibility of the xanthate and the modified sulfur ether group ethyl hydroxamic acid are different, and the compound can adjust each other to have better solubility and dispersibility in the pulp. This helps the collector to be uniformly distributed in the pulp and fully contact with the mineral particles, improves the action efficiency of the collector, and further improves the flotation effect. The amount of the compound collector is usually reduced compared with the use of xanthate or modified sulfur ether group ethyl hydroxamic acid alone, thereby reducing the cost of the reagent and improving the economic benefit of the flotation process.

[0014] The preparation method of the modified sulfur ether group ethyl hydroxamic acid is as follows:

[0015] S1. The thioether group ethyl hydroxamic acid is added to water, stirred until uniform, and then ultrasonically treated to obtain solution A, wherein the mass ratio of thioether group ethyl hydroxamic acid to water is 1:40-70;

[0016] S2. Formaldehyde is added to the above solution A, stirred for 25-35 min, and sodium carbonate is added to adjust the pH to 8-10. Then activated carbon is added under stirring, heated to 50-80°C, and then sodium hydroxide is added to adjust the pH of the solution to 8-10. Continue stirring for 60-180 min to obtain a mixed solution B; wherein the amount of formaldehyde is 25%-35% of the weight of the thioether group ethyl hydroxamic acid, and the amount of activated carbon is 5%-15% of the weight of the thioether group ethyl hydroxamic acid;

[0017] S3. The modified thioether group ethyl hydroxamic acid is prepared by filtering and drying the mixed solution B.

[0018] During the reaction of thioether group ethyl hydroxamic acid methyl and aldehyde, the carbonyl group (-CO-) of formaldehyde can add to the active hydrogen in thioether group ethyl hydroxamic acid, introducing a hydroxymethyl group (-CH2OH) into the thioether group ethyl hydroxamic acid molecule. This hydroxymethylation product increases the hydrophilicity and steric hindrance of the molecule, improving its selectivity and collecting ability in the flotation process. At the same time, formaldehyde can also condense with the hydroxyl group in the thioether group 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 external factors such as changes in acid-base, temperature, etc. in the complex flotation environment, thereby ensuring the stability of the reagent performance. In addition, formaldehyde in the above reaction can also act as a crosslinking agent, causing crosslinking between thioether group ethyl hydroxamic acid molecules to form a three-dimensional network of crosslinked structures. This crosslinked structure further improves the stability and rigidity of the molecule, making it less likely to be decomposed or destroyed in the ore slurry, while also increasing the multi-point adsorption of the reagent molecule to the mineral surface, improving the firmness and selectivity of adsorption, and facilitating 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. Xanthate is added to water, stirred, and mixed to obtain a xanthate aqueous solution;

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

[0023] Step 3, the mixed solution C is left for 30-50 min, then filtered, washed to obtain clean filter cake, and the filter cake is dried to obtain the desulfurization collector.

[0024] The xanthate is usually a solid powder, and it is difficult to achieve uniform mixing with the modified sulfidic ethyl hydroxamic acid in a short time due to the difference in physical state and properties. Dissolving the xanthate in water to form an aqueous solution, then adding the modified sulfidic ethyl hydroxamic acid and mixing under a certain stirring speed can make the two components fully dispersed and contacted in the solution, which is more conducive to uniform mixing and prevents agglomeration during mixing, thereby ensuring the performance stability and consistency of the desulfurization collector.

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

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

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

[0028] Preferably, the desiliconization collector is one or more of oleic acid, linoleic acid, hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decyl benzyl ammonium chloride, and sodium dimethylamino decyl carboxylate.

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

[0030] Preferably, the desulfurization process is as follows: adding ore into desulfurization activator, depressant, desulfurization collector and foaming agent to perform desulfurization roughing, the foam of roughing is subjected to first scavenging, and the underflow of roughing is subjected to desulfurization cleaning; the foam of first scavenging is subjected to second scavenging, the underflow of first scavenging is returned to roughing, the foam of second scavenging is treated to obtain sulfur concentrate, and the underflow of second scavenging is returned to first scavenging; the foam of desulfurization cleaning is returned to desulfurization roughing, and the underflow of desulfurization cleaning is concentrated and subjected to desiliconization.

[0031] Preferably, the desilication process is as follows: after the desulfurization cleaning underflow is concentrated, the filter residue is ground and classified, the qualified particle size slurry is added with a desilication collector and a depressor, desilication roughing is carried out, the foam of the roughing is subjected to first desilication cleaning, the underflow of the roughing is subjected to first desilication scavenging; the foam of the first desilication cleaning is subjected to second desilication cleaning, the underflow of the first desilication cleaning is returned to the desilication roughing; the foam of the second desilication cleaning is treated to obtain an aluminum concentrate; the underflow of the second desilication cleaning is returned to the first desilication cleaning; the foam of the first desilication scavenging is returned to the desilication roughing, the underflow of the first desilication scavenging is subjected to second desilication scavenging; the foam of the second desilication scavenging is returned to the first desilication scavenging, and the underflow of the second desilication scavenging is treated to obtain a tailing.

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

[0033] The high-sulfur high-silicon bauxite desulfurization and desilication process provided by the present application first modifies the thioether group ethyl hydroxamic acid, then modifies the thioether group ethyl hydroxamic acid and xanthate as a desulfurization collector, wherein the modified thioether group ethyl hydroxamic acid changes its molecular structure, making it more effective in interacting with the mineral surface, enhancing the collection capacity of the target mineral, and more firmly adsorbing on the mineral surface during the flotation process, thereby improving the flotation recovery rate of the mineral, especially for some difficult-to-flotate sulfur-containing minerals, the improvement of the collection effect is more significant. After modification, the selectivity of the thioether group ethyl hydroxamic acid 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 more accurately adsorb on the surface of the target mineral, improve the grade of the flotation concentrate, and obtain a sulfur concentrate with a sulfur content of ≥38%, an aluminum-silicon ratio of ≥6.1 in the aluminum concentrate, and a sulfur content of ≤0.28%, thereby better reducing the content of sulfur and silicon in the aluminum concentrate. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The high-sulfur high-silicon bauxite desulfurization and desilication process of the present application is shown in the flow chart of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0036] Embodiment 1

[0037] A high-sulfur high-silicon bauxite desulfurization and desilication process, comprising the following steps:

[0038] (1) Washing and grinding: the clay is washed out, after the clay is settled, the ore is crushed, the ore is first crushed by a jaw crusher, then crushed by a fine jaw crusher, and then crushed by a high-pressure roller, and then transported by a belt to a homogenizing bin. The homogenized ore is fed into a desulfurization grinding machine by an electronic belt scale, and then classified by a spiral classifier. The coarse particles are returned to the grinding machine for regrinding, forming a closed-circuit grinding. The overflow of the spiral classifier is classified by a cyclone, and the coarse particles are returned to the grinding machine for regrinding. The fine particles enter the desulfurization roughing.

[0039] (2) Desulfurization: the ore is added with a desulfurization activator, a depressant, a desulfurization collector and a frother, and desulfurization roughing is carried out. The froth of the roughing is subjected to first scavenging, and the underflow of the roughing is subjected to desulfurization cleaning. The froth of the first scavenging is subjected to second scavenging, and the underflow of the first scavenging is returned to the roughing. The froth of the second scavenging is treated to obtain a sulfur concentrate, and the underflow of the second scavenging is returned to the first scavenging. The froth of the desulfurization cleaning is returned to the desulfurization roughing, the underflow of the desulfurization cleaning is fed into a thickener, the underflow of the thickener after thickening is fed into a belt filter for dewatering, the overflow of the thickener and the filtrate of the belt filter are fed into a desulfurization circulating water pool and returned to the previous washing and grinding. The filter residue continues to be desiliconized.

[0040] (3) Desiliconization: the filter residue of the desulfurization cleaning after thickening is ground and classified, and the qualified particle size of the ore slurry is added with a desiliconization collector for desiliconization roughing. The froth of the roughing is subjected to first desiliconization cleaning, and the underflow of the roughing is subjected to first desiliconization scavenging. The froth of the first desiliconization cleaning is subjected to second desiliconization cleaning, and the underflow of the first desiliconization cleaning is returned to the desiliconization roughing. The froth of the second desiliconization cleaning is treated to obtain an aluminum concentrate. The underflow of the second desiliconization cleaning is returned to the first desiliconization cleaning. The froth of the first desiliconization scavenging is returned to the desiliconization roughing, and the underflow of the first desiliconization scavenging is subjected to second desiliconization scavenging. The froth of the second desiliconization scavenging is returned to the first desiliconization scavenging, and the underflow of the second desiliconization scavenging is treated to obtain a tailing.

[0041] In step (2), the desulfurization collector is prepared from 1.4 parts of modified sulfur ether-based ethyl hydroxamic acid and 6 parts of xanthate by weight. 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] The preparation method of the modified sulfur ether-based ethyl hydroxamic acid is as follows:

[0043] S1. Add sulfur ether-based ethyl hydroxamic acid into water, stir uniformly, and then ultrasonic treat for 30 min to obtain solution A, wherein the mass ratio of sulfur ether-based ethyl hydroxamic acid to water is 1:50.

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

[0045] S3. After filtering and drying the mixed solution B, modified thioether group ethyl hydroxamic acid is prepared.

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

[0047] Step 1: Add xanthate into water, stir and mix evenly to prepare xanthate aqueous solution; the weight-volume ratio of xanthate to water is 1g:1500ml;

[0048] Step 2: Under stirring, add modified thioether group ethyl hydroxamic acid into the xanthate aqueous solution, the feeding time of modified thioether group ethyl hydroxamic acid is 20 min, and the stirring speed is 100 revolutions per minute, to obtain mixed solution C;

[0049] Step 3: Let the mixed solution C stand for 40 min, then filter and wash to obtain clean filter cake, dry the filter cake to obtain the desulfurization collector.

[0050] The foaming agent is pinacol oil, the desiliconization 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. The amount of desulfurization activator, desulfurization collector, foaming agent, inhibitor, and desiliconization collector is 80g, 600g, 200g, 1500g, and 1000g per ton of ore, respectively.

[0051] Example 2

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

[0053] In step (2), the desulfurization collector is prepared from 1.5 parts of modified thioether group ethyl hydroxamic acid and 5 parts of xanthate by weight; 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] The preparation method of the modified thioether group ethyl hydroxamic acid is as follows:

[0055] S1. Add thioether group ethyl hydroxamic acid into water, stir until uniform, then ultrasonic treat for 25 min to obtain solution A; wherein the mass ratio of thioether group ethyl hydroxamic acid to water is 1:40;

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

[0057] S3. After filtering and drying the mixed solution B, modified thioether group ethyl hydroxamic acid is prepared.

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

[0059] Step 1: Add xanthate into water, stir and mix well to prepare a xanthate aqueous solution; the weight-volume ratio of xanthate to water is 1g:1000ml;

[0060] Step 2: Under stirring, add modified thioether group ethyl hydroxamic acid into the xanthate aqueous solution, the feeding time of modified thioether group ethyl hydroxamic acid is 15 min, and the stirring speed is 120 revolutions per minute, to obtain a mixed solution C;

[0061] Step 3: After the mixed solution C is placed for 30 min, filtering and washing are performed to obtain a clean filter cake, which is dried to obtain a desulfurization collector.

[0062] The foaming agent is methyl isobutyl carbinol, the desiliconization collector is a mixture of hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decyl benzyl ammonium chloride, and sodium dimethylamino decyl carboxylate in a ratio of 1:2:1:3, and the inhibitor is sodium silicate. For every 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 desiliconization collector is 800g.

[0063] Example 3

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

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

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

[0067] S1. The thioether group ethyl hydroxamic acid is added to water, stirred evenly, and then ultrasonic treatment is performed for 40 min to obtain solution A, wherein the mass ratio of thioether group ethyl hydroxamic acid to water is 1:70;

[0068] S2. Formaldehyde is added to the above solution A, stirred for 35 min, and the pH is adjusted to 8-10 with sodium carbonate. Then, activated carbon is added under stirring, heated to 50°C, and then sodium hydroxide is added to adjust the pH of the solution to 8-10. Stirring is continued for 180 min to obtain a mixed solution B. The amount of formaldehyde is 25% of the weight of the thioether group ethyl hydroxamic acid, and the amount of activated carbon is 5% of the weight of the thioether group ethyl hydroxamic acid.

[0069] S3. The modified thioether group ethyl hydroxamic acid is prepared by filtering and drying the mixed solution B.

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

[0071] Step 1. The xanthate is added to water, stirred, and mixed evenly to obtain a xanthate aqueous solution. The weight-volume ratio of xanthate to water is 1g:2000ml.

[0072] Step 2. The modified thioether group ethyl hydroxamic acid is added to the xanthate aqueous solution under stirring. The feeding time of the modified thioether group ethyl hydroxamic acid is 25 min, and the stirring speed is 80 revolutions per minute to obtain a mixed solution C.

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

[0074] The foaming agent is a mixture of pinol oil and methyl isobutyl carbinol in a mass ratio of 1:3. The desiliconization collector is a mixture of hexadecyl quaternary ammonium salt, decyl benzyl ammonium chloride, and dimethyl amino decyl sodium carboxylate in a ratio of 1:3:2. The inhibitor is sodium fluorosilicate. The amount of desulfurization activator used per ton of ore is 100g, the amount of desulfurization collector used is 1000g, the amount of foaming agent used is 100g, the amount of inhibitor used is 500g, and the amount of desiliconization collector used is 1200g.

[0075] Example 4

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

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

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

[0079] S1. The thioether group ethyl hydroxamic acid is added to water, stirred uniformly, and then ultrasonically treated for 35 min to obtain solution A, wherein the mass ratio of the thioether group ethyl hydroxamic acid to water is 1:60;

[0080] S2. Formaldehyde is added to the above solution A, stirred for 32 min, and then sodium carbonate is added to adjust the pH to 8-10. Then activated carbon is added under stirring, heated to 80℃, and then sodium hydroxide is added to adjust the pH of the solution to 8-10. Continue to stir for 100 min to obtain a mixed solution B. The amount of formaldehyde is 28% of the weight of the thioether group ethyl hydroxamic acid, and the amount of activated carbon is 12% of the weight of the thioether group ethyl hydroxamic acid.

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

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

[0083] Step 1. The xanthate is added to water, stirred, and mixed uniformly to obtain a xanthate aqueous solution. The weight-volume ratio of xanthate to water is 1g:1700ml.

[0084] Step 2. The modified thioether group ethyl hydroxamic acid is added to the xanthate aqueous solution under stirring. The feeding time of the modified thioether group ethyl hydroxamic acid is 22 min, 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 min, and then filtered and washed to obtain a clean filter cake. The filter cake is dried to obtain the desulfurization collector.

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

[0087] Comparative Example 1

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

[0089] Comparative Example 2

[0090] A high-sulfur high-silicon bauxite desulfurization and desilication process, wherein in step (2), the desulfurization collector is prepared from unmodified sulfide-based ethyl hydroxamic acid 1.5 parts and xanthate 5 parts by weight fraction; the desilication collector is dodecyl ammonium chloride:dodecyl trimethyl ammonium chloride 1:1, and the rest is the same as example 2.

[0091] Comparative example 3

[0092] The preparation method of the desulfurization collector is to directly stir xanthate and modified sulfide-based ethyl hydroxamic acid for 30 min, and mix, the desilication collector is dodecyl ammonium chloride:dodecyl trimethyl ammonium chloride:dodecyl trimethyl ammonium chloride 2:1:3, and the rest is the same as example 1.

[0093] Comparative example 4

[0094] The preparation method of the desulfurization collector is to directly stir xanthate and modified sulfide-based ethyl hydroxamic acid for 30 min, and mix, the desilication collector is dodecyl ammonium chloride:dodecyl trimethyl ammonium chloride:dodecyl trimethyl ammonium chloride 2:1:3, and the rest is the same as example 2.

[0095] Results detection:

[0096] The sulfur concentrate, aluminum concentrate and tailings obtained by the high-sulfur high-silicon bauxite desulfurization and desilication process provided by examples 1-4 and comparative examples 1-4 are detected, and the results are shown in table 1.

[0097] Table 1. Experimental results

[0098]

[0099]

[0100] As can be seen from table 1, using the desulfurization and desilication process of examples 1-4 of the present application, the sulfur content of the sulfur concentrate obtained is ≥37%, the aluminum-silicon ratio in the aluminum concentrate is ≥6.1, and the sulfur is ≤0.28%, which are all better than comparative examples 1-4. Using the process of the present application, the collection efficiency is higher, the desulfurization and desilication efficiency is higher, and the cost is also reduced. The sulfur concentrate can be sold as a product for producing sulfuric acid, the aluminum concentrate can be used for producing alumina, and the tailings can be used for producing non-burning bricks, which better realizes the comprehensive utilization of resources.

[0101] It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0102] While embodiments of the present application have been shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application. The scope of the application is thus defined by the appended claims and their equivalents.

Claims

1. A desulfurization and desiliconization process for high-sulfur, high-silicon bauxite, characterized in that, Includes the following steps: (1) Washing and grinding: wash out the clay from the high-sulfur and high-silica bauxite, and after the clay settles, crush and grind it. (2) Add desulfurization activator, inhibitor, desulfurization collector and frother to the ore after grinding in step (1) and carry out reverse flotation desulfurization to obtain sulfur concentrate and filter residue; (3) The desulfurized filter residue is added to a desiliconizing collector for flotation desiliconization to obtain aluminum concentrate and tailings; In step (2), the desulfurization collector is prepared by weight parts of 1-2 parts of modified thioether ethyl hydroxamic acid and 4-7 parts of xanthate; The preparation method of the modified thioether-based ethyl hydroxamic acid is as follows: S1. Add thioether ethyl hydroxamic acid to water, stir until homogeneous, and then sonicate 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 while stirring, heat to 50-80℃, then add sodium hydroxide to adjust the pH to 8-10, and continue stirring for 60-180 minutes to obtain mixture 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. After filtering and drying the mixture B, modified thioether-based ethyl hydroxamic acid is obtained; The preparation method of the desulfurization collector is as follows: Step 1: Add the yellow medicine to water, stir and mix well to obtain a yellow medicine aqueous solution; Step 2: Under stirring, add the modified thioether ethyl hydroxamic acid to the xanthate aqueous solution. The addition time of the modified thioether ethyl hydroxamic acid is 15-25 min, and the stirring speed is 80-120 rpm to obtain mixture C. Step 3: Let the mixture C stand for 30-50 minutes, then filter and wash to obtain a clean filter cake. Dry the filter cake to obtain the desulfurization collector. In step 1, the weight-to-volume ratio of xanthate to water is 1g:1000-2000ml; The desulfurization process is as follows: The ore is added to a desulfurization activator, an inhibitor, a desulfurization collector, and a frother for desulfurization roughing. The froth from the roughing process is then subjected to a first scavenging process, and the underflow from the roughing process is subjected to a desulfurization cleaning process. The froth from the first scavenging process is then subjected to a second scavenging process, and the underflow from the first scavenging process is returned to the roughing process. The froth from the second scavenging process is processed to obtain a sulfur concentrate, and the underflow from the second scavenging process is returned to the first scavenging process. The froth from the desulfurization cleaning process is returned to the desulfurization roughing process, and the underflow from the desulfurization cleaning process is concentrated and then subjected to desilication. The desilication process is as follows: After grinding and classifying the filter residue from the concentrated desulfurization and beneficiation underflow, a desilication collector is added to the qualified particle size slurry for desilication roughing. The froth from the roughing process undergoes a first desilication cleaning, and the underflow from the roughing process undergoes a first desilication scavenging. The froth from the first desilication cleaning undergoes a second desilication cleaning, and the underflow from the first desilication cleaning is returned to the desilication roughing process. The froth from the second desilication cleaning is processed to obtain aluminum concentrate. The underflow from the second desilication cleaning is returned to the first desilication cleaning. The froth from the first desilication scavenging is returned to the desilication roughing process, and the underflow from the first desilication scavenging undergoes a second desilication scavenging. The froth from the second desilication scavenging is returned to the first desilication scavenging, and the underflow from the second desilication scavenging is processed to obtain tailings.

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

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

5. The desulfurization and desiliconization process for high-sulfur and high-silicon bauxite according to claim 1, characterized in that, The desilication collector is one or more of oleic acid, linoleic acid, hexadecyl quaternary ammonium salt, tetradecyl quaternary ammonium salt, decylbenzylammonium chloride, and sodium dimethylaminodecylcarboxylate.

6. The desulfurization and desiliconization process for high-sulfur and high-silicon bauxite according to claim 1, characterized in that, For each ton of ore, the dosage of desulfurization activator is 50-100g, the dosage of desulfurization collector is 250-1000g, the dosage of frother is 100-400g, the dosage of inhibitor is 500-2000g, and the dosage of desilication collector is 800-1200g.

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