Controllable productization method for tin refining sulfur slag

Abstract

The invention discloses a tin refining sulfur slag controllable productization method which comprises the following steps: S1, uniformly crushing tin refining sulfur slag, sampling and testing the contents of Cu, Sn, S and O elements in a tin refining sulfur slag raw material; s2, the adding amount of a vulcanizing agent is determined according to the set tin refining sulfur slag treatment product and the content of Cu, Sn, S and O elements; s3, the crushed tin refining sulfur slag and the vulcanizing agent with the determined adding amount in the step S2 are mixed to be uniform, then the mixture is put into a sealed container to be heated to 400-800 DEG C, heat preservation is conducted for 4-8 hours, after heat preservation is finished, the mixture is cooled to the room temperature, and then a vulcanized product is taken out; and S4, the sulfurized product obtained in the step S3 is placed in a vacuum distillation furnace to be separated, volatile matter on a condensing disc and residues in a crucible are collected, and a set tin refining sulfur slag treatment product is obtained. According to the method, the sulfur adding amount is accurately controlled, and short-process and high-recovery-rate tin refining sulfur slag treatment product controllability is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tin refining sulfur residue treatment, and particularly relates to a method for controllable productization of tin refining sulfur residue. BACKGROUND

[0002] The dross of copper removal by sulfur in the tin refining process contains 50-75% of tin, 10-35% of copper and 10-22% of sulfur. In the microstructure, the tin in the sulfur residue mainly exists in the form of metallic tin, tin sulfide (SnS, SnS2), copper-tin alloy and hydro-tin stone, and the copper mainly exists in the form of metallic copper and cuprous sulfide. The complex phase composition causes three technical problems in the sulfur residue treatment process:

[0003] (1) Difficult separation of metals: the existence of copper-tin alloy phase makes it difficult for traditional physical separation methods to work, even if it is finely ground to the micron level, it is also difficult to achieve effective dissociation;

[0004] (2) Great environmental pressure: sulfur is easily converted into SO2 in the fire treatment process, and the conventional roasting-acid leaching process needs to be matched with a complex flue gas purification system;

[0005] (3) Low recovery rate: the current diaphragm electrolysis method has a tin direct recovery rate of only 40-55%, and the current efficiency is about 55%, with poor economic benefits.

[0006] The current industrial sulfur residue treatment technology mainly includes fire smelting, roasting-acid leaching method, diaphragm electrolysis method and full wet process, each of which has its own characteristics but has obvious technical limitations.

[0007] The fire smelting process usually smelts the sulfur residue into a flux to generate a tin-copper alloy semi-product. Although this method has a relatively simple process, the sulfur element escapes in the form of SO2 during the smelting process, causing environmental pollution, and the generated alloy product contains a large amount of impurities, which is difficult to refine. More importantly, the fire smelting method cannot effectively separate tin and copper, the product has low added value, and the economic benefits are limited. The roasting-acid leaching method needs multi-stage roasting (to prevent the material from being stuck in the kiln), which has high energy consumption and produces a large amount of sulfur-containing waste gas; the diaphragm electrolysis method has low current efficiency (about 55%) and poor tin direct recovery rate (45-55%); and the full wet process faces the challenges of long process, large reagent consumption and serious equipment corrosion.

[0008] Vacuum metallurgy technology as a new method for treating sulfur slag has been widely concerned in recent years. CN114959277A discloses a method for separating and purifying tin and copper from tin refining sulfur slag. The tin refining sulfur slag is mixed with a sulfidizing agent and then pressed into a block. The block is then subjected to a sulfidation reaction in a vacuum atmosphere to obtain stannous sulfide and copper matte (mainly composed of cuprous sulfide). However, this method cannot achieve precise control of the tin refining sulfur slag treatment products. CN107619936A discloses a method for efficiently separating tin and copper by reacting Cu2S in sulfur slag with Sn to generate SnS and metallic copper under the conditions of a system pressure of 5-20 Pa and a temperature of 1173 K. SnS is completely volatilized under these conditions, while copper is enriched in the residue. However, the above-mentioned methods cannot achieve active control of the tin refining sulfur slag treatment products.

[0009] Therefore, there is a need for a precise sulfidation technology based on the physicochemical properties of sulfur slag to achieve controllable tin refining sulfur slag treatment products. SUMMARY

[0010] To solve the above problems, the present application provides a method for controllable productization of tin refining sulfur slag. The method uses tin refining sulfur slag produced by rough tin after deep removal of impurities such as lead, antimony, arsenic, and bismuth as raw material, controls the amount of sulfur added based on the physicochemical properties of the sulfur slag to obtain different final products, and forms a short process, high recovery rate, and clean production process.

[0011] The present application provides a method for controllable productization of tin refining sulfur slag, comprising:

[0012] Step S1: uniformly crushing the tin refining sulfur slag, and sampling and testing the Cu, Sn, S, and O element contents in the tin refining sulfur slag raw material;

[0013] Step S2: setting a tin refining sulfur slag treatment product, determining the amount of sulfidizing agent to be added according to the set treatment product and the Cu, Sn, S, and O element contents; the set tin refining sulfur slag treatment product includes any one of the following:

[0014] (1) SnS;

[0015] (2) SnS and Cu;

[0016] (3) SnS and Cu2S;

[0017] (4) Cu2S;

[0018] Step S3: uniformly mixing the crushed tin refining sulfur slag with the determined amount of sulfidizing agent in step S2, then placing it in a sealed container, heating to 400-800℃, and then holding for 4-8 hours. After holding, cool to room temperature and take out the sulfidation product;

[0019] Step S4: The sulfidation product obtained in step S3 is placed in a vacuum distillation furnace for separation, and the volatiles are collected on a condensing plate and the residue is collected in a crucible, to obtain the set tin refining sulfur residue treatment product.

[0020] Further, in step S2,

[0021] (1) When the set tin refining sulfur residue treatment product is SnS, the amount of sulfidation agent added is :

[0022]

[0023] (2) When the set tin refining sulfur residue treatment product is SnS and Cu, the amount of sulfidation agent added is :

[0024]

[0025] (3) When the set tin refining sulfur residue treatment product is SnS and Cu2S, the amount of sulfidation agent added is :

[0026]

[0027] (4) When the set tin refining sulfur residue treatment product is Cu2S, the amount of sulfidation agent added is :

[0028]

[0029] wherein m0 is the sulfur content in the tin refining sulfur residue; m1 is the amount of sulfur required for Sn to be converted into SnS; m2 is the amount of sulfur required for O to be converted into SO2; and m3 is the amount of sulfur required for Cu to be converted into Cu2S.

[0030]

[0031]

[0032]

[0033] M S is the molar mass of S, M Sn is the molar mass of Sn; M O is the molar mass of O; M Cu is the molar mass of Cu;

[0034] m Sn is the mass of Sn in the tin refining sulfur residue; m O is the mass of O in the tin refining sulfur residue; and m S is the mass of S in the tin refining sulfur residue.

[0035] Further, in step S3, the tin refining sulfur residue and the vulcanizing agent mixture have a particle size of no more than 3 mm.

[0036] Further, in step S2, the vulcanizing agent is added in an amount determined according to calculation, and no more than 1% of the amount of the vulcanizing agent is additionally added.

[0037] Further, step S4 comprises:

[0038] The pressure in the vacuum distillation furnace is kept constant at 10-100 Pa, the temperature is raised to 1100-1500 DEG C and kept for 2-8 h, then the temperature is lowered and air is introduced to normal pressure, and the volatiles on the condensing plate and the residues in the crucible are collected respectively.

[0039] Further, the holding time in the vacuum distillation furnace is 4-5 h.

[0040] Working mechanism:

[0041] The tin refining sulfur residue produced by the crude tin after deep removal of impurities such as lead, antimony, arsenic and bismuth by the vacuum method mainly contains Cu, Sn and S, and contains Sn, SnS and Cu2S. By precisely vulcanizing the sulfur residue and precisely controlling the amount of sulfur added to the sulfur residue, part of the tin is converted into stannous sulfide and copper is kept in the form of cuprous sulfide.

[0042] Possible core reactions in step S3 include:

[0043]

[0044] Possible core reactions in step S4 include:

[0045]

[0046]

[0047] In step S3 (vulcanization stage), reaction (1-2) does not occur, and the Gibbs free energy of reactions (1-3) and (1-4) is greater than that of reaction (1-1), so reaction (1-1) is more likely to occur. Sn reacts with S to form SnS, and reactions (1-5) and (1-6) can also occur. Cu reacts with S to form Cu2S. If sufficient sulfur is added, Sn is completely converted into SnS, and there is no elemental Sn in the system at this time. In step S4 (vacuum distillation stage), reaction (1-8) does not occur. If only part of the Sn reacts with the added sulfur, in the vacuum distillation stage, the remaining CuS decomposes to form Cu2S and S at high temperature, and Cu2S reacts with Sn, i.e. reaction (1-8) occurs.

[0048] Compared with the prior art, the present application has the following advantages:

[0049] (1) The tin refining sulfur residue can realize the accurate control of the product formed by tin and copper elements in the sulfur residue through the steps and the accurate control of sulfur addition of the application, can realize the conversion of copper element into elemental copper or cuprous sulfide, and tin can be converted into pure stannous sulfide, and the value of the elements in the slag can be maximized according to the demand; wherein the tin and sulfur elements are converted into stannous sulfide product, and the copper element is converted into copper which can be used as raw material for copper smelting, and the copper element is converted into Cu2S which can be used as a semiconductor material.

[0050] (2) The application realizes the productization of sulfur elements and new sulfur elements in the sulfur residue by accurately calculating and controlling the amount of sulfur addition, and solves the problem of sulfur dioxide emission in the traditional sulfur residue treatment process.

[0051] (3) The sulfurization process and vacuum distillation process of the application are carried out in a closed container, without three waste emissions, and the process is simple and clean. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 XRD characterization of volatiles and residues of 100g sulfur residue in Example 1 with 7.06g sulfur addition product, vacuum distillation at 1100℃ for 3h;

[0053] Figure 2 XRD characterization of volatiles and residues of 1kg sulfur residue in Example 2 with 100g sulfur addition product, vacuum distillation at 1200℃ for 3h;

[0054] Figure 3 XRD characterization of volatiles and residues of 10kg sulfur residue in Example 3 with 1.213kg sulfur addition product, vacuum distillation at 1300℃ for 5h;

[0055] Figure 4 XRD characterization of volatiles and residues of 100kg sulfur residue in Example 4 with 15kg sulfur addition product, vacuum distillation at 1500℃ for 8h. DETAILED DESCRIPTION

[0056] The application will be further described in detail through specific embodiments.

[0057] Example 1

[0058] The set tin refining sulfur residue treatment product is SnS and Cu:

[0059] Step S1: Cu, Sn, S, O element content in tin refining sulfur residue:

[0060]

[0061] Step S2: The set tin refining sulfur residue treatment product is SnS, and the sulfur residue composition can be calculated according to the following formula according to the sulfur residue raw material chemical composition in the above table:

[0062]

[0063] wherein , i.e. the amount of sulfur contained in 100 g of sulfur slag raw material .

[0064] The amount of sulfur required for the complete conversion of Sn to SnS is calculated as:

[0065]

[0066] The amount of sulfur required for the complete conversion of O to SO2 is calculated as:

[0067]

[0068] The amount of sulfur contained in Cu2S is:

[0069]

[0070] The amount of sulfur required for the treatment product SnS and Cu in 100 g of sulfur slag is:

[0071]

[0072] Step S3: 100 g of crushed tin refining sulfur slag is mixed with the determined amount (7.06 g) of sulfidizing agent in step S2 to obtain a mixture with a particle size of 1 mm. Then, the mixture is placed in a sealed container and heated to 400°C, and then kept for 4 hours. After cooling to room temperature, the sulfidation product is taken out;

[0073] Step S4: The sulfidation product obtained in step S3 is placed in a graphite crucible used in a high-temperature vacuum distillation furnace. The vacuum pump is started to extract the environment in the furnace to a vacuum state, and the pressure in the furnace is kept constant, with a vacuum degree of 10-50 Pa. The heating program is started, and the temperature is raised to 1100°C and kept for 3 hours. After the holding period, the temperature in the furnace is reduced to room temperature, air is introduced to the normal pressure state, and then the volatile SnS is collected on the condensing plate and the residual crude copper is collected in the crucible.

[0074] Referring to Figure 1 The XRD characterization results prove that the volatile obtained by vacuum distillation is pure SnS (PDF #75-2115), and the residue is Cu.

[0075] Example 2

[0076] The volatile in the tin refining sulfur slag treatment product is set to be pure SnS, and the residue is a mixture of Cu and Cu2S.

[0077] Step S1: Cu, Sn, S, O element content in tin refining sulfur residue:

[0078]

[0079] Step S2: Set 1 kg of tin refining sulfur residue treatment product as SnS, calculate the sulfur required for 1 kg of sulfur residue treatment product as SnS as 100 g;

[0080] Step S3: Mix 1 kg of crushed tin refining sulfur residue with the determined amount (10 g) of sulfurizing agent in step S2 uniformly, and the particle size of the mixture is 2 mm. Then put it into a sealed container and heat to 500℃, then keep it for 5 hours. After cooling to room temperature, take out the vulcanized product;

[0081] Step S4: Put the vulcanized product obtained in step S3 into a graphite crucible used in a high-temperature vacuum distillation furnace, start the vacuum pump to extract the environment in the furnace to a vacuum state, keep the pressure in the furnace constant, and the vacuum degree is kept in the range of 20~60 Pa. Start the heating program, heat to 1200℃ and keep for 3 hours. After the heat preservation is over, the temperature in the furnace drops to room temperature, air is introduced to the normal pressure state, and then the volatile SnS on the condensing plate and the residue in the crucible are collected respectively.

[0082] Referring to Figure 2 , the XRD characterization results prove that the volatile obtained by vacuum distillation is pure SnS (PDF #75-2115), and the residue is a mixture of Cu and Cu2S.

[0083] Example 3

[0084] The set tin refining sulfur residue treatment product is pure SnS, and the residue is Cu2S.

[0085] Step S1: Cu, Sn, S, O element content in tin refining sulfur residue:

[0086]

[0087] Step S2: Set 10 kg of tin refining sulfur residue treatment product as SnS and Cu2S, and the required sulfur addition calculated according to the chemical composition of the sulfur residue raw material in the above table is 1.213 kg;

[0088] Step S3: Mix 10 kg of crushed tin refining sulfur residue with the determined amount (1.213 kg) of sulfurizing agent in step S2 uniformly, and the particle size of the mixture is 3 mm. Then put it into a sealed container and heat to 600℃, then keep it for 6 hours. After the heat preservation is over, cool to room temperature, and take out the vulcanized product;

[0089] Step S4: Put the sulfidation product obtained in step S3 into a graphite crucible used in a high-temperature vacuum distillation furnace, start the vacuum pump to extract the environment in the furnace to a vacuum state, keep the pressure in the furnace constant, and keep the vacuum degree in the range of 30-80 Pa. Start the heating program, heat to 1300℃ and keep for 5 hours. After the holding period ends, the temperature in the furnace is reduced to room temperature, air is introduced to the normal pressure state, and then the volatile SnS and the residue Cu2S in the crucible are collected on the condensing plate, respectively.

[0090] Referring to Figure 3 , the XRD characterization results prove that the volatile obtained by vacuum distillation is pure SnS (PDF #75-2115), and the residue is Cu2S.

[0091] Example 4

[0092] The volatile in the set tin refining sulfur residue treatment product is a mixture of SnS and S, and the residue is Cu2S.

[0093] Step S1: Cu, Sn, S, O element content in tin refining sulfur residue:

[0094]

[0095] Step S2: The set 100 kg tin refining sulfur residue treatment product is Cu2S, and the required sulfur addition calculated according to the chemical composition of the sulfur residue raw material in the above table should be greater than 12.13 kg. In this embodiment, the sulfur addition is 15 kg;

[0096] Step S3: Mix 100 kg of crushed tin refining sulfur residue with the determined amount of sulfurizing agent (15 kg) in step S2 uniformly, and the particle size of the mixture is 3 mm. Then put it into a sealed container and heat to 800℃ and keep for 8 hours. After the holding period ends, cool to room temperature and take out the sulfidation product;

[0097] Step S4: Put the sulfidation product obtained in step S3 into a graphite crucible used in a high-temperature vacuum distillation furnace, start the vacuum pump to extract the environment in the furnace to a vacuum state, keep the pressure in the furnace constant, and keep the vacuum degree in the range of 50-100 Pa. Start the heating program, heat to 1500℃ and keep for 8 hours. After the holding period ends, the temperature in the furnace is reduced to room temperature, air is introduced to the normal pressure state, and then the volatile SnS, S and the residue Cu2S in the crucible are collected on the condensing plate, respectively.

[0098] Referring to Figure 4 , the XRD characterization results prove that the volatile obtained by vacuum distillation is a mixture of SnS and S, and the residue is Cu2S.

[0099] The above application of specific examples to the present application is described, is only used to help understand the present application, and does not limit the present application. For the skilled in the art to which the present application belongs, according to the idea of the present application, a number of simple deductions, deformations or substitutions can be made. The above application of specific examples to the present application is described, is only used to help understand the present application, and does not limit the present application. For the skilled in the art to which the present application belongs, according to the idea of the present application, a number of simple deductions, deformations or substitutions can be made.

Claims

1. A method for controllable commercialization of tin refined sulfur slag, characterized in that: include: Step S1: uniformly crushing the tin refined sulfur slag, sampling and testing the content of Cu, Sn, S, and O elements in the tin refined sulfur slag raw material; Step S2: Setting the treated product of tin refined sulfur slag, and determining the amount of sulfiding agent to be added according to the set treated product and the content of Cu, Sn, S, and O elements; the set treated product of tin refined sulfur slag includes any one of the following: (1) SnS; (2) SnS and Cu; (3) SnS and Cu2S; (4) Cu2S; Step S3: Evenly mix the crushed tin refined sulfur slag with the amount of sulfurizing agent determined in step S2, then place in a sealed container, heat to 400-800°C, and then keep warm for 4-8 hours. After the heat preservation is completed, cool to room temperature and take out the sulfurized product; Step S4: placing the sulfurized product obtained in step S3 in a vacuum distillation furnace for separation, collecting the volatiles on the condensation tray and the residue in the crucible, and obtaining the predetermined tin refined sulfur slag treatment product.

2. The method for controllable commercialization of tin refined sulfur slag according to claim 1, characterized in that: In step S2, (1) When the product of tin refined sulfur slag treatment is SnS, the amount of sulfurizing agent added is for: ， (2) When the products of tin refined sulfur slag treatment are SnS and Cu, the amount of sulfurizing agent added is for: ， (3) When the products of tin refined sulfur slag treatment are SnS and Cu2S, the amount of sulfiding agent added is for: ， (4) When the product of tin refined sulfur slag treatment is Cu2S, the amount of sulfiding agent added is for: ， Among them, m0 is the sulfur content in the tin refining sulfur slag; m1 is the sulfur content required for Sn to be converted into SnS; m2 is the sulfur content required for O to be converted into SO2; m3 is the sulfur content required for Cu to be converted into Cu2S.

3. The method for controllable commercialization of tin refined sulfur slag according to claim 2, characterized in that: ， ， ， M S is the molar mass of S, M Sn is the molar mass of Sn; M O is the molar mass of O; M Cu is the molar mass of Cu; m Sn is the mass of Sn in the sulfur slag from tin refining; m O is the mass of O in the sulfur slag from tin refining; m S is the mass of S in the sulfur slag from tin refining.

4. The method for controllably producing tin refined sulfur slag as claimed in claim 1, characterized in that: In step S3, the particle size of the mixture of tin refined sulfur slag and sulfurizing agent is not greater than 3 mm.

5. The method for controllably producing tin refined sulfur slag as claimed in claim 1, characterized in that: In step S2, the vulcanizing agent is added according to the calculated amount of the vulcanizing agent, and an additional amount of the vulcanizing agent not exceeding 1% of the amount of the vulcanizing agent is added.

6. The method for controllably producing tin refined sulfur slag as claimed in claim 1, characterized in that: Step S4 includes: The pressure in the vacuum distillation furnace is kept constant at 10-100 Pa, and the temperature is raised to 1100-1500℃ and kept for 2-8 hours. After the insulation is completed, the temperature is lowered and air is introduced to normal pressure. The volatiles on the condensation tray and the residues in the crucible are collected separately.

7. The method for controllably producing tin refined sulfur slag as claimed in claim 6, characterized in that: The holding time in the vacuum distillation furnace is 4-5h.

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