Preparation method of sulfur dispersing agent and application of sulfur dispersing agent in recovery of sulfur from high-sulfur slag

Abstract

The invention belongs to the field of comprehensive recycling of non-ferrous metal smelting waste residues, and relates to a preparation method of a sulfur dispersing agent and application of the sulfur dispersing agent to separation and recovery of sulfur from high-sulfur residues. Alkali lignin is subjected to hydroxymethylation, sulfonation and copolymerization and then is subjected to spray drying to prepare the sulfur dispersant. The dispersing agent can generate effective electrostatic repulsion and steric hindrance effects on different mineral particles, and has good dispersing performance. The method can be used for high-pressure decantation extraction of high-sulfur slag from different sources to obtain solid industrial sulfur with a sulfur product grade of grade B (sulfur purity gt; and the recovery rate of the sulfur is more than 95%. The prepared sulfur dispersing agent can be used for efficiently recovering sulfur from high-sulfur slag in the hydrometallurgy industry, the sulfur product reaches the B-grade sulfur standard in GB / T 2449-2021, and the sulfur dispersing agent has remarkable industrial application value.

Description

Technical Field

[0001] The present invention relates to a preparation method of a sulfur dispersant and its application in recovering sulfur from high-sulfur slag (sulfur extraction technology), and particularly relates to a method for preparing a sulfur dispersant and recovering sulfur from high-sulfur slag, belonging to the field of comprehensive recovery and utilization of non-ferrous metal smelting waste slag. Background Art

[0002] Sulfur is chemically active, showing various valence states from -2 to +6, and easily reacts with hydrogen, oxygen, and metals to form hydrogen sulfide, sulfur dioxide, and metal sulfides, widely participating in the formation of sulfide ores in nature. This polymorphism makes sulfur widely used in industry, covering fields such as medicine, fertilizers, chemicals, and biomedicine. During the smelting process of industrial minerals, a large amount of high-sulfur slag is generated. In China, about 600,000 tons of sulfur waste slag is produced annually from the zinc concentrate smelting process by the oxygen pressure leaching process.

[0003] High-sulfur slag refers to slag with a sulfur content higher than 60%. Traditional methods for recovering sulfur from high-sulfur slag mainly include flotation, sublimation, hot filtration, high-pressure rolling, solvent extraction, and the combined recovery of multiple of these methods.

[0004] In recent years, although many advanced technologies have been developed internationally, they all have the problems of strong solvent toxicity and high risk of secondary pollution. In particular, it is difficult to balance the purity and recovery rate of elemental sulfur products. For example, Chinese Patent CN 117735485A discloses a method for recovering high-purity sulfur products from sulfur slag in the wet zinc smelting process. This method combines high-pressure solvent thermal reaction and physical cutting and peeling to separate sulfur from metal impurities in the wet zinc smelting sulfur slag, obtaining high-purity sulfur products. However, this method still has the defects of low sulfur recovery rate (about 55% sulfur recovery rate) and the need for further treatment to peel off surface impurities after the hydrothermal reaction; a smelter in Shenzhen tried to add a dispersant (such as sodium lignosulfonate) during the reaction process to eliminate the occlusion effect and strengthen the impurity removal effect to achieve sulfur purification and synchronous recovery. However, sodium lignosulfonate shows poor dispersibility during application, and although the sulfur purity in the sulfur slag has increased, the effect is average, and there is an urgent need to develop a high-performance sulfur dispersant.

[0005] Therefore, there is an urgent need to develop a sulfur dispersant to simultaneously improve the sulfur purity and recovery rate of sulfur recovered from high-sulfur slag, and there is no need to perform secondary peeling of impurities on sulfur after the reaction.

[0006] Object of the Invention

[0007] Aiming at the deficiencies in the existing technology, the object of the present invention is to prepare a sulfur dispersant and use it to recover sulfur from high-sulfur slag, simultaneously improving the purity and recovery rate of sulfur, and achieving one-step purification of sulfur and synchronous recovery. Summary of the Invention

[0008] The object of the present invention is to provide a method for preparing a sulfur dispersant and its application in recovering sulfur from high-sulfur slag, so as to solve the problems existing in the above-mentioned prior art. This method can not only purify sulfur from high-sulfur slag in one step, but also ensure the recovery rate of sulfur.

[0009] A method for extracting sulfur using a sulfur dispersant, the method comprising the following steps:

[0010] 1) Add an acidic regulator and a part of formaldehyde to a reactor containing alkali lignin and a part of water, heat up to 40-100 °C, react for 1.0-3.0 h, then add a part of the sulfonating agent, raise the temperature to 60-130 °C, and react for 2.0-5.0 h to obtain hydroxymethylsulfonated lignin;

[0011] 2) Add the remaining water and the sulfonating agent to the reactor, stir evenly, heat up to 40-70 °C, react for 1.0-3.0 h, add acetone, continue to react for 1.0-2.0 h, slowly dropwise add the remaining formaldehyde, then add the hydroxymethylsulfonated lignin described in step 1), control the temperature at 70-120 °C, and carry out a polymerization reaction for 3.0-6.0 h. Cool down to 35-80 °C, introduce nitrogen, slowly dropwise add the graft monomer and the initiator, and carry out a polymerization reaction for 2.0-6.0 h, and then obtain a reddish-brown or brownish powder product through spray drying, with a relative molecular mass of 7000-90000, which is the sulfur dispersant described above;

[0012] Preferably, the raw material components and the mass parts of each component are: 11.5-20.0 parts of alkali lignin, 0.1-0.8 parts of acidic regulator, 4.9-10.0 parts of sulfonating agent, 4.5-10.0 parts of acetone, 5.4-13.5 parts of formaldehyde, 37.3-68.2 parts of water, 2.0-20.0 parts of graft monomer, and 0.01-0.6 parts of initiator;

[0013] Preferably, the alkali lignin is selected from one or more of bamboo, bagasse, rice straw, wheat straw, king grass, ash tree, oak, reed, poplar, eucalyptus, birch, masson pine, etc., and is obtained by preparing black liquor through an alkaline method or a sulfate method, and then obtaining alkali lignin through precipitation, separation, and extraction;

[0014] Preferably, the acidic regulator is a mixture of one or more of citric acid, phosphoric acid, salicylic acid, sulfuric acid, aminosulfonic acid, gluconic acid, tartaric acid, succinic acid, maleic acid, etc.;

[0015] Preferably, the sulfonating agent is a mixture of one or more of sodium metabisulfite, sodium bisulfite, sodium sulfite, etc.;

[0016] Preferably, the graft monomer includes one or a mixture of more than one of acrylic acid, acrylate, methacrylic acid, methacrylate, maleic anhydride, maleate, acrylamide, methallyl polyoxyethylene ether, 2-acrylamido-2-methylpropanesulfonic acid;

[0017] Preferably, the initiator includes one or a mixture of more than one of ammonium persulfate, potassium persulfate, sodium persulfate.

[0018] After washing / regulating the high-sulfur slag to a certain pH range, drying and granulating (particle size ≤ 150 μm), the treated high-sulfur slag, sulfur dispersant and water are stirred evenly in proportion, placed in a high-temperature and high-pressure reaction kettle, and kept warm for 0.1 - 2.0 h under the conditions of mechanical stirring at 800 - 1200 rpm, reaction temperature of 125 - 160 °C, and external pressure of 0 - 3.0 MPa, and then cooled to 40 - 65 °C to make the molten sulfur aggregate, separate from impurities, and obtain industrial sulfur and slag after sulfur extraction through sieving and drying. The mass ratio of the high-sulfur slag to water is 1:(1 - 10), and the addition amount of the sulfur dispersant is 0.1% - 20% of the mass of the high-sulfur slag.

[0019] Different from the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] (1) The present invention relates to the field of high-sulfur slag for sulfur recovery treatment, especially a preparation method of an efficient sulfur dispersant. This sulfur dispersant selectively adsorbs on the surface of mineral particles by using sulfonic acid groups and carboxylic acid groups, and the negative charges ionized produce an electrostatic effect. Through the macromolecular structure of lignin, the hydrophilic aliphatic long chain obtained by acetone sulfonation and copolymerization with formaldehyde, and the polycarboxylic acid long chain obtained by graft copolymerization, a steric hindrance effect synergistic with the electrostatic effect is generated, so that more impurities are dispersed in the water phase, reducing the contact between impurities and liquid sulfur, avoiding the occlusion effect of the molten sulfur re-wrapping impurities during the cooling process, and at the same time using high-temperature and high-pressure reaction to melt elemental sulfur into liquid sulfur, destroying the wrapping state between elemental sulfur and impurities, achieving the effect of efficient sulfur recovery.

[0021] (2) The sulfur dispersant prepared by the present invention has anchoring groups such as sulfonic acid groups and carboxylic acid groups, and provides different anchoring groups for different mineral particles in different high-sulfur slag mineral compositions and their complex occurrence states, overcoming the defects of a single anchoring group, and thus being applicable to all types of high-sulfur slag.

[0022] (3) The present invention utilizes a sulfur dispersant to recover sulfur from high-sulfur slag, achieving sulfur extraction in one step. The purity of the produced sulfur is as high as over 99.5%, and the product quality grade can meet the requirements of Class B solid industrial sulfur. There is no need for extraction, refining, and sublimation purification, and the sulfur recovery rate can reach over 95%. At the same time, the amount of slag is significantly reduced after sulfur separation, reducing inventory, and the enrichment rate of valuable metals is high, which is conducive to further recovering valuable metals in the slag and greatly improving the slag treatment efficiency.

[0023] (4) The present invention helps to greatly simplify the sulfur separation process flow, provides a breakthrough solution for the treatment and disposal of high-sulfur slag, effectively realizes the comprehensive utilization of resources and the resourceization of solid waste. While achieving the high-value utilization of lignin, it also provides a solution to the environmental hidden danger problems caused by the large accumulation of high-sulfur slag, and has good economic benefits and application prospects.

[0024] In summary, the present invention provides a preparation method of a sulfur dispersant and its application in recovering sulfur from high-sulfur slag. Sulfur is separated and purified by the one-step method of the sulfur dispersant and recovered synchronously. The produced sulfur can directly obtain sulfur products after simple drying treatment, and the sulfur recovery rate is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 For the comparison of the sulfur forms recovered in the examples and comparative examples; among them, (a) is Comparative Example 1, and (b) is Example 1. SPECIFIC EMBODIMENTS

[0026] To deepen the understanding of the present invention, the following detailed description is made in combination with the examples, but they should not be construed as limiting the protection scope of the present invention.

[0027] Example 1

[0028] Take the bottom sulfur slag (≤100μm) with a sulfur content of 67.2% after zinc recovery in a zinc concentrate smelter as the target for sulfur recovery treatment.

[0029] The preparation method of the sulfur dispersant is as follows:

[0030] 1) Add 0.6 kg of citric acid and 2.0 kg of formaldehyde to a reactor containing 13.4 kg of straw alkali lignin and 35.0 kg of water, heat up to 40°C, after reacting for 3.0 h, then add 2.7 kg of sodium metabisulfite, raise the temperature to 95°C, and react for 5.0 h to obtain hydroxymethylsulfonated lignin;

[0031] 2) Add 27.2 kg of water and 5.3 kg of sodium sulfite to the reactor. After stirring evenly, heat up to 45 °C. After reacting for 3.0 h, add 4.0 kg of acetone, continue to react for 2.0 h, slowly dropwise add 6.0 kg of formaldehyde, then add the hydroxymethylsulfonated lignin from step 1). Control the temperature at 75 °C. After the polymerization reaction for 3.0 h, cool down to 60 °C, introduce nitrogen, slowly dropwise add 12.1 kg of sodium acrylate and 0.11 kg of sodium persulfate. After the polymerization reaction for 2.0 h, obtain a reddish-brown or brownish powder product through spray drying, with an average relative molecular mass of 80,000, which is the sulfur dispersant mentioned above.

[0032] Wash the high-sulfur slag (bottom-sulfur slag) with water until the pH > 3.0 and then dry it. Stir the dried high-sulfur slag, sulfur dispersant, and water evenly at a ratio of 1:0.1:6, place it in a high-temperature and high-pressure reaction kettle, keep it warm for 0.4 h under the conditions of mechanical stirring at 900 rpm, reaction temperature of 130 °C, and external pressure of 1.2 MPa, then cool down to 45 °C to make the molten sulfur aggregate, separate it from impurities, and obtain industrial sulfur and the slag after sulfur extraction through sieving and drying.

[0033] Determine the grade of the obtained industrial sulfur as 99.72% according to the determination method of sulfur mass fraction in "GB / T 2449.1 - 2021: Industrial Sulfur - Part 1: Solid Products", and the recovery rate of sulfur is 96.03%.

[0034] Example 2

[0035] Use the high-sulfur slag (≤150 μm) with a sulfur content of 67.2% after zinc recovery in a certain zinc concentrate smelter as the target for sulfur recovery treatment.

[0036] The preparation method of the sulfur dispersant is as follows:

[0037] 1) Add 0.7 kg of salicylic acid and 3.3 kg of formaldehyde to a reactor containing 16.0 kg of eucalyptus alkali lignin and 15.0 kg of water. Heat up to 95 °C. After reacting for 1.0 h, then add 3.3 kg of sodium sulfite. Lower the temperature to 80 °C. After reacting for 3.0 h, obtain hydroxymethylsulfonated lignin.

[0038] 2) Add 41.2 kg of water and 63.5 kg of sodium sulfite to the reactor. After stirring evenly, heat up to 65 °C. After reacting for 1.0 h, add 4.5 kg of acetone, continue to react for 2.0 h, slowly dropwise add 10.2 kg of formaldehyde, then add the hydroxymethylsulfonated lignin from step 1). Control the temperature at 75 °C. After the polymerization reaction for 6.0 h, introduce nitrogen, slowly dropwise add 10.9 kg of sodium acrylate and 0.21 kg of potassium persulfate. After the polymerization reaction for 4.0 h, obtain a reddish-brown or brownish powder product through spray drying, with an average relative molecular mass of 84,000, which is the sulfur dispersant mentioned above.

[0039] Wash the high-sulfur slag (bottom-sulfur slag) with water until the pH > 3.0, then dry it. Stir the dried high-sulfur slag, sulfur dispersant, and water evenly in a ratio of 1:0.1:6, place it in a high-temperature and high-pressure reactor, keep it warm for 0.4 h under the conditions of mechanical stirring at 900 rpm, reaction temperature of 130 °C, and external pressure of 1.2 MPa, then cool it to 45 °C to make the molten sulfur aggregate, separate it from impurities, and obtain industrial sulfur and the slag after sulfur extraction through sieving and drying.

[0040] Determine the grade of the obtained industrial sulfur as 99.76% and the recovery rate of sulfur as 95.81% according to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products".

[0041] Example 3

[0042] Take the anode slime produced from nickel electrolysis in a certain nickel smelter as the target for sulfur recovery treatment (sulfur content is 89.6%, particle size ≤ 150 μm).

[0043] The preparation method of the sulfur dispersant is as follows:

[0044] 1) Add 0.3 kg of sulfuric acid and 2.0 kg of formaldehyde to a reactor containing 11.5 kg of willow alkali lignin and 20.0 kg of water, heat up to 55 °C, react for 2.0 h, then add 2.3 kg of sodium bisulfite, raise the temperature to 100 °C, and obtain hydroxymethylsulfonated lignin after reacting for 2 h.

[0045] 2) Add 47.2 kg of water and 4.6 kg of sodium sulfite to the reactor, stir evenly, heat up to 55 °C, react for 3.0 h, add 5.7 kg of acetone, continue to react for 2.0 h, slowly dropwise add 6.6 kg of formaldehyde, then add the hydroxymethylsulfonated lignin from step 1), control the temperature at 105 °C, carry out a polymerization reaction for 4 h, then cool down to 40 °C, introduce nitrogen, slowly dropwise add 3.1 kg of acrylic acid, 16.2 kg of ammonium acrylate, and 0.31 kg of sodium persulfate, carry out a polymerization reaction for 5.0 h, and obtain a reddish-brown or brownish-black powdery product through spray drying, with an average relative molecular mass of 12,000, which is the sulfur dispersant mentioned above.

[0046] Stir the high-sulfur slag (nickel electrolysis anode slime), sulfur dispersant, and water evenly in a ratio of 1:0.05:5, place it in a high-temperature and high-pressure reactor, keep it warm for 1.0 h under the conditions of mechanical stirring at 1000 rpm, reaction temperature of 140 °C, and external pressure of 0 MPa, then cool it to 45 °C to make the molten sulfur aggregate, separate it from impurities, and obtain industrial sulfur and the slag after sulfur extraction through sieving and drying.

[0047] The grade of the industrial sulfur obtained by measuring according to the sulfur mass fraction measurement method in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products" is 99.82%, and the sulfur recovery rate is 98.22%.

[0048] Example 4

[0049] The anode slime produced from nickel electrolysis in a certain nickel smelter is used as the target for sulfur recovery treatment after drying (sulfur content is 82.6%).

[0050] The preparation method of the sulfur dispersant is as follows:

[0051] 1) Add 0.5 kg of phosphoric acid and 3.8 kg of formaldehyde to a reactor containing 18.0 kg of reed alkali lignin and 17.0 kg of water. Heat up to 75 °C, react for 1.5 h, then add 3.5 kg of sodium bisulfite, raise the temperature to 100 °C, and react for 4.0 h to obtain hydroxymethylsulfonated lignin.

[0052] 2) Add 30.3 kg of water and 6.0 kg of sodium sulfite to the reactor, stir evenly, heat up to 95 °C, react for 1.0 h, add 10.0 kg of acetone, continue to react for 1.0 h, slowly dropwise add 11.2 kg of formaldehyde, then add the hydroxymethylsulfonated lignin from step 1). Control the temperature at 80 °C, carry out polymerization reaction for 6.0 h, then cool down to 60 °C, introduce nitrogen, slowly dropwise add 8.7 kg of maleic anhydride, 8.7 kg of potassium acrylate and 0.23 kg of ammonium persulfate, carry out polymerization reaction for 6.0 h, and obtain a reddish-brown or brownish-black powdery product through spray drying, with an average relative molecular mass of 45000, which is the said sulfur dispersant.

[0053] Mix the high-sulfur slag (nickel electrolysis anode slime), sulfur dispersant and water evenly at a ratio of 1:0.05:5, place them in a high-temperature and high-pressure reaction kettle, keep warm for 1 h under the conditions of mechanical stirring at 1000 rpm, reaction temperature of 140 °C and external pressure of 0 MPa, then cool down to 45 °C to make the molten sulfur aggregate, separate from impurities, and obtain industrial sulfur and slag after sulfur extraction through sieving and drying.

[0054] The grade of the industrial sulfur obtained by measuring according to the sulfur mass fraction measurement method in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products" is 99.85%, and the sulfur recovery rate is 98.02%.

[0055] Example 5

[0056] The high-sulfur slag produced from copper flotation in a certain copper smelter is used as the target for sulfur recovery treatment after drying (sulfur content is 72.6%).

[0057] The preparation method of the sulfur dispersant is as follows:

[0058] 1) Add 0.6 kg of tartaric acid and 2.0 kg of formaldehyde to a reactor containing 13.8 kg of manchurian ash lignin and 17.0 kg of water. Heat up to 65 °C and react for 2.0 h. Then add 2.7 kg of sodium bisulfite and raise the temperature to 100 °C. After reacting for 3 h, hydroxymethylsulfonated lignin is obtained.

[0059] 2) Add 47.0 kg of water and 6.08 kg of sodium metabisulfite to the reactor. After stirring evenly, heat up to 70 °C and react for 1 h. Then add 5.7 kg of acetone and continue to react for 2 h. Slowly dropwise add 5.6 kg of formaldehyde, and then add the hydroxymethylsulfonated lignin from step 1). Control the temperature at 105 °C and carry out the polymerization reaction for 4.5 h. Then cool down to 60 °C, introduce nitrogen, slowly dropwise add 3.1 kg of ammonium acrylate and 0.05 kg of ammonium persulfate, and carry out the polymerization reaction for 2 h. After stirring evenly, discharge the material. After spray drying, a reddish-brown or brownish powder product with an average relative molecular mass of 9000 is obtained, which is the sulfur dispersant mentioned above.

[0060] Stir evenly the high-sulfur slag, sulfur dispersant and water in a ratio of 1:0.1:7, place them in a high-temperature and high-pressure reaction kettle, keep warm for 1.5 h under the conditions of mechanical stirring at 1000 rpm, reaction temperature of 145 °C and external pressure of 1 MPa, then cool down to 55 °C to make the molten sulfur aggregate and separate from impurities. After sieving and drying, industrial sulfur and slag after sulfur extraction are obtained.

[0061] Determine the grade of the obtained industrial sulfur as 99.79% according to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products", and the recovery rate of sulfur is 97.37%.

[0062] Example 6

[0063] Take the high-sulfur slag produced by copper flotation in a certain copper smelter, and after drying, use it as the target for sulfur recovery treatment (sulfur content is 72.6%).

[0064] The preparation method of the sulfur dispersant is as follows:

[0065] 1) Add 0.6 kg of maleic acid and 1.8 kg of formaldehyde to a reactor containing 16.6 kg of alkali lignin and 27.8 kg of water. Heat up to 55 °C and react for 3.0 h. Then add 2.3 kg of sodium bisulfite and raise the temperature to 90 °C. After reacting for 2 h, hydroxymethylsulfonated lignin is obtained.

[0066] 2) Add 32.0 kg of water and 4.7 kg of sodium metabisulfite into the reactor. After stirring evenly, heat up to 65 °C. After reacting for 2.0 h, add 6.4 kg of acetone, continue reacting for 2.0 h, slowly dropwise add 3.6 kg of formaldehyde, then add the hydroxymethylsulfonated lignin from step 1). Control the temperature at 110 °C. After polymerizing for 4.0 h, cool down to 60 °C, introduce nitrogen, slowly dropwise add 14.1 kg of ammonium acrylate and 0.15 kg of ammonium persulfate. After polymerizing for 6.0 h, obtain a reddish-brown or brownish powder product through spray drying, with an average relative molecular mass of 15,000, which is the sulfur dispersant mentioned above.

[0067] Stir evenly the high-sulfur slag, sulfur dispersant and water in a ratio of 1:0.1:7, place them in a high-temperature and high-pressure reaction kettle, keep warm for 1.5 h under the conditions of mechanical stirring at 1000 rpm, reaction temperature of 145 °C and external pressure of 1.0 MPa, then cool down to 55 °C to make the molten sulfur aggregate, separate from impurities, and obtain industrial sulfur and desulfurized slag after sieving and drying.

[0068] Determine the grade of the obtained industrial sulfur as 99.79% and the sulfur recovery rate as 97.37% according to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products".

[0069] Comparative Example 1

[0070] Use the bottom sulfur slag (≤100 μm) with a sulfur content of 67.2% after zinc recovery in a certain zinc concentrate smelter as the target for sulfur recovery treatment.

[0071] Wash the high-sulfur slag (bottom sulfur slag) with water until the pH > 3 and then dry it. Stir evenly the dried high-sulfur slag and water in a ratio of 1:6, place them in a high-temperature and high-pressure reaction kettle, keep warm for 0.4 h under the conditions of mechanical stirring at 900 rpm, reaction temperature of 130 °C and external pressure of 1.2 MPa, then cool down to 45 °C to make the molten sulfur aggregate, separate from impurities, and obtain industrial sulfur and desulfurized slag after sieving and drying.

[0072] Determine the sulfur grade of the obtained sulfur as 78.32% and the sulfur recovery rate as 91.03% according to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products". The sulfur purity is far lower than the requirements for industrial sulfur purity in the national standard, and the sulfur recovery fails.

[0073] Conduct semi-quantitative component detection and measurement on the high-sulfur slag, sulfur recovered in Comparative Example 1, and sulfur recovered in Example 1 respectively. The detection data are shown in Table 1 below.

[0074] Table 1

[0075]

[0076] Comparative Example 1 is different from Example 1 in that no dispersant was added in the sulfur recovery in Comparative Example 1, and the purity of the recovered sulfur decreased by 21.4% compared with that when the sulfur dispersant of the present invention was added, and it only played the role of sulfur enrichment (as shown in the attached Figure 1 ).

[0077] Comparative Example 2

[0078] Taking the bottom sulfur slag (≤100μm) with a sulfur content of 67.2% after zinc recovery in a certain zinc concentrate smelter as the target for sulfur recovery treatment.

[0079] The preparation method of the sulfur dispersant is as follows:

[0080] Add 22.0 kg of water and 4.9 kg of sodium metabisulfite into the reactor. After stirring evenly, heat up to 55°C. After reacting for 2.0 h, add 9.4 kg of acetone, continue to react for 2.5 h, slowly dropwise add 3.7 kg of formaldehyde, control the temperature at 100°C, after polymerization reaction for 6.0 h, cool down to 60°C, introduce nitrogen, slowly dropwise add 12.1 kg of sodium acrylate and 0.11 kg of sodium persulfate, after polymerization reaction for 2.0 h, stir evenly and discharge. After spray drying, a reddish-brown or brownish powder product is obtained, which is the sulfur dispersant.

[0081] Wash the high-sulfur slag (bottom sulfur slag) with water until the pH > 3 and then dry it. Stir the dried high-sulfur slag, sulfur dispersant and water evenly according to the ratio of 1:0.1:6, place it in a high-temperature and high-pressure reaction kettle, keep it warm for 0.4 h under the conditions of mechanical stirring at 900 rpm, reaction temperature of 130°C and external pressure of 1.2 MPa, then cool it to 45°C to make the molten sulfur aggregate, separate it from the impurities, and obtain industrial sulfur and slag after sulfur extraction after sieving and drying.

[0082] According to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products", the sulfur grade of the obtained sulfur is 92.32%, and the recovery rate of sulfur is 75.13%. The sulfur purity is much lower than the requirements for industrial sulfur purity in the national standard, and the recovery rate of sulfur is relatively low.

[0083] Conduct semi-quantitative component detection and measurement on the high-sulfur slag, sulfur recovered in Comparative Example 2, and sulfur recovered in Example 1 respectively. The detection data are shown in Table 2 below.

[0084] Table 2

[0085]

[0086] Comparative Example 2 is different from Example 1 in that hydroxymethylsulfonated lignin is missing in the preparation process of the sulfur dispersant in Comparative Example 2. The purity of the recovered sulfur is 7.4% lower and the recovery rate is 20.9% lower than that when adding the sulfur dispersant of the present invention, and the sulfur recovery effect is poor. This not only fails to achieve one-step purification of sulfur, but also is not conducive to the maximization of sulfur resource utilization.

[0087] Comparative Example 3

[0088] Take the bottom sulfur slag (≤100μm) with a sulfur content of 67.2% after zinc recovery in a certain zinc concentrate smelter as the target for sulfur recovery treatment.

[0089] The preparation method of the sulfur dispersant is as follows:

[0090] Add 0.3 kg of aminosulfonic acid and 2.6 kg of formaldehyde to a reactor containing 13.6 kg of pine kraft lignin and 27.3 kg of water, heat up to 45°C, after reacting for 1.0 h, then add 4.2 kg of sodium metabisulfite, raise the temperature to 80°C, after reacting for 2.5 h, hydroxymethylsulfonated lignin is obtained, cool down to 60°C, introduce nitrogen, slowly dropwise add 12.1 kg of sodium acrylate and 0.11 kg of sodium persulfate, after polymerization reaction for 2.0 h, a reddish-brown or brownish powder product is obtained by spray drying, which is the described sulfur dispersant.

[0091] Wash the high-sulfur slag (bottom sulfur slag) with water until the pH > 3 and then dry it. Stir the dried high-sulfur slag, sulfur dispersant and water evenly at a ratio of 1:0.1:6, place it in a high-temperature and high-pressure reactor, keep it warm for 0.4 h under the conditions of mechanical stirring at 900 rpm, reaction temperature of 130°C and external pressure of 1.2 MPa, then cool it to 45°C to make the molten sulfur aggregate, separate from impurities, and obtain industrial sulfur and desulfurized slag after sieving and drying.

[0092] Conduct semi-quantitative composition detection and measurement on the high-sulfur slag, the sulfur recovered in Comparative Example 3, and the sulfur recovered in Example 1 respectively. The detection data are shown in Table 3 below.

[0093] Table 3

[0094]

[0095] The sulfur grade of the obtained sulfur is 93.62% and the recovery rate of sulfur is 83.02% determined according to the determination method of sulfur mass fraction in "GB / T 2449.1-2021: Industrial Sulfur - Part 1: Solid Products". The purity of sulfur is lower than the requirements for the purity of industrial sulfur in the national standard, and the recovery rate of sulfur is relatively low.

[0096] Comparative Example 3 is different from Example 1 in that the introduction of the aliphatic long chain is missing in the preparation process of the sulfur dispersant in Comparative Example 3. The purity of the recovered sulfur is reduced by 6.1% and the recovery rate is reduced by 13.01% compared with when the sulfur dispersant of the present invention is added. The sulfur recovery effect is poor, neither achieving one-step purification of sulfur nor being conducive to the maximization of sulfur resource utilization.

[0097] Comparative Example 4

[0098] The bottom sulfur slag (≤100μm) with a sulfur content of 67.2% after zinc recovery in a certain zinc concentrate smelter is used as the sulfur recovery target 1; the high-sulfur slag produced by copper flotation in a certain copper smelter is dried and used as the sulfur recovery treatment target 2 (sulfur content is 72.6%); the anode mud with a sulfur content of 89.6% and a particle size ≤150μm produced by nickel electrolysis in a certain nickel smelter is used as the sulfur recovery treatment target 3.

[0099] The preparation method of the sulfur dispersant is as follows:

[0100] 1) Add 0.8 kg of succinic acid and 4.8 kg of formaldehyde to a reactor containing 18.6 kg of wheat straw alkali lignin and 47.8 kg of water, heat up to 65°C, after reacting for 3.0 h, then add 1.1 kg of sodium bisulfite and 1.2 kg of sodium metabisulfite, raise the temperature to 93°C, and obtain hydroxymethylsulfonated lignin after reacting for 3.5 h;

[0101] 2) Add 22.0 kg of water and 4.9 kg of sodium metabisulfite to the reactor, stir evenly, heat up to 55°C, after reacting for 2.0 h, add 9.4 kg of acetone, continue to react for 2.5 h, slowly dropwise add 3.7 kg of formaldehyde, then add the hydroxymethylsulfonated lignin in step 1), control the temperature at 100°C, after the polymerization reaction for 6.0 h, cool and discharge, and obtain a reddish-brown or brownish powder product through spray drying, which is the sulfur dispersant.

[0102] The three high-sulfur slags, sulfur dispersant and water are stirred evenly in a ratio of 1:0.2:5, placed in a high-temperature and high-pressure reactor, and kept warm for 5.5 h under the conditions of mechanical stirring at 1100 rpm, reaction temperature of 145°C, and external pressure of 2.0 MPa, then cooled to 55°C to make the molten sulfur aggregate, separated from impurities, and after sieving and drying, sulfur blocks and slag after sulfur extraction are obtained. The sulfur purity and sulfur recovery rate are respectively counted as shown in Table 4 below.

[0103] Table 4

[0104]

[0105] When the polycarboxylic acid long chain is not introduced, the effect of the sulfur dispersant on sulfur recovery from different high-sulfur slags is unstable and it is difficult to adapt to the sulfur recovery of different high-sulfur slags.

[0106] Through the data analysis of the above examples and comparative examples, the results prove that: the process of the present invention fully possesses high efficiency, economy, and environmental friendliness.

[0107] The above are only the preferred embodiments of the present invention and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the protection scope of the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of a sulfur dispersant, characterized in that The method includes the following steps: 1) Add an acidic regulator and formaldehyde into a reactor containing alkali lignin and water, heat up to 40 - 100 °C, after reacting for 1.0 - 3.0 h, then add a sulfonating agent, raise the temperature to 60 - 130 °C, and obtain hydroxymethylsulfonated lignin after reacting for 2.0 - 5.0 h; 2) Add water and a sulfonating agent into the reactor, stir evenly, heat up to 40 - 70 °C, after reacting for 1.0 - 3.0 h, add acetone, continue to react for 1.0 - 2.0 h, slowly dropwise add formaldehyde, then add the hydroxymethylsulfonated lignin described in step 1), control the temperature at 70 - 120 °C, carry out a polymerization reaction for 3.0 - 6.0 h, cool down to 30 - 80 °C, introduce nitrogen, slowly dropwise add a graft monomer and an initiator, and discharge the product after a polymerization reaction for 2.0 - 6.0 h, and obtain a reddish-brown or brown powdery product through spray drying, with a relative molecular mass of 7000 - 90000, which is the sulfur dispersant described above.

2. The preparation method of the sulfur dispersant according to claim 1, wherein The mass parts of each component of the raw materials are as follows: 11.5 - 20.0 parts of alkali lignin, 0.1 - 0.8 parts of acidic regulator, 4.9 - 10.0 parts of sulfonating agent, 4.5 - 10.0 parts of acetone, 5.4 - 13.5 parts of formaldehyde, 37.3 - 68.2 parts of water, 2.0 - 20.0 parts of graft monomer, and 0.01 - 0.6 parts of initiator.

3. The preparation method of the sulfur dispersant according to any one of claims 1 or 2, characterized in that, The alkali lignin includes alkali lignin obtained by preparing black liquor from one or more of bamboo, bagasse, rice straw, wheat straw, king grass, Manchurian ash, oak, reed, poplar, eucalyptus, birch, masson pine through an alkali method, sulfite method or sulfate method, and through precipitation, separation and extraction.

4. The preparation method of the sulfur dispersant according to any one of claims 1 or 2, characterized in that, The acidic regulator includes a mixture of one or more of citric acid, phosphoric acid, salicylic acid, sulfuric acid, sulfamic acid, gluconic acid, tartaric acid, succinic acid, maleic acid.

5. The preparation method of the sulfur dispersant according to any one of claims 1 or 2, characterized in that, The sulfonating agent is a mixture of one or more of sodium metabisulfite, sodium bisulfite, sodium sulfite.

6. The preparation method of the sulfur dispersant according to any one of claims 1 or 2, characterized in that, The graft monomer includes a mixture of one or more of acrylic acid, acrylate, methacrylic acid, methacrylate, maleic anhydride, maleate, acrylamide, methallyl polyoxyethylene ether, 2-acrylamido-2-methylpropanesulfonic acid.

7. The preparation method of the sulfur dispersant according to any one of claims 1 or 2, characterized in that The initiator includes a mixture of one or more of ammonium persulfate, potassium persulfate, sodium persulfate.

8. Use of a sulfur dispersant prepared by the method according to claim 1 in the recovery of sulfur, characterized in that, It includes the following steps: Stir evenly high-sulfur slag, sulfur dispersant and water in proportion, place them in a high-temperature and high-pressure reaction kettle, keep warm for 0.1 - 14.0 h under the conditions of mechanical stirring at 800 - 1200 rpm, reaction temperature of 125 - 160 °C, and external pressure of 0 - 3.0 MPa, then cool down to 25 - 65 °C, make the molten sulfur aggregate, separate from impurities, and directly obtain industrial-grade sulfur and the slag after sulfur extraction through sieving and drying, where the mass ratio of high-sulfur slag to water is 1:(1 - 10), and the addition amount of the sulfur dispersant is 0.1% - 20% of the mass of the high-sulfur slag.

9. The application according to claim 8, wherein The high-sulfur slag is a slag with a native sulfur content higher than 50%.

Images