Tellurium fluxing agent TeR4 and preparation method and application thereof

Abstract

The application discloses a tellurium fluxing agent TeR4 and a preparation method and application thereof. The tellurium fluxing agent TeR4 is prepared from raw materials of soluble trivalent iron salt, chloride salt, organic carboxylate and nitrate. The tellurium fluxing agent TeR4 can be used in an acid leaching process of tellurium-containing refining slag, anode slime treatment slag and other tellurium-containing complex materials. Through the synergistic effect of iron salt oxidation, chloride complexation fluxing and organic carboxylate complexation stabilization in an acid system, the tellurium is promoted to transform from a state of difficult solubility, encapsulation or combination to a state of solubility, the tellurium leaching efficiency is improved, and conditions are provided for subsequent impurity removal and purification and reduction and tellurium precipitation recovery.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, specifically relating to a tellurium co-solvent TeR4, its preparation method, and its application. Background Technology

[0002] The core drawbacks of the solvents used in tellurium leaching are concentrated in their corrosiveness, consumption, and safety and environmental impact, as detailed below: Highly corrosive Common leaching solvents such as hydrochloric acid, sulfuric acid, and concentrated NaOH can severely corrode equipment under high temperature and high concentration conditions, necessitating the use of special acid / alkali resistant containers, which significantly increases equipment procurement and maintenance costs.

[0003] High solvent loss Traditional extraction solvents (such as the tributyl phosphate / kerosene system) have high loss rates and large solvent retention. The solvent loss of some traditional processes is more than 10 times that of centrifugal extraction processes, resulting in high long-term operating costs.

[0004] It can easily cause emulsification problems. When traditional extraction solvents come into contact with tellurium-containing feed solutions, emulsification is very likely to occur, making it difficult to separate the two phases, greatly reducing the separation efficiency, and causing a large amount of solvent to be carried away and lost.

[0005] High safety and environmental risks Organic extractants such as kerosene are flammable and explosive, posing significant safety hazards during storage and use. At the same time, the large amounts of production wastewater containing acids / alkalis and organic solvents are difficult to treat, easily causing environmental pollution and failing to meet the requirements of green production.

[0006] Insufficient selectivity Conventional leaching solvents cannot accurately distinguish between tellurium and the large number of coexisting impurity ions such as copper, lead, and selenium in the feed solution. A large number of impurities will enter the leaching solution at the same time, greatly increasing the burden of subsequent purification.

[0007] Poor adaptability to operating conditions For low-concentration tellurium solutions (0.05g / L-0.5g / L), the extraction efficiency of conventional solvents drops significantly, making them unsuitable for the efficient extraction of low-grade rare and dispersed metal raw materials.

[0008] Therefore, it is essential to develop a product and method that can solve the above-mentioned technical problems. Summary of the Invention

[0009] The first objective of this invention is to provide a tellurium co-solvent TeR4; the second objective is to provide a method for preparing the tellurium co-solvent TeR4; and the third objective is to provide applications of the tellurium co-solvent TeR4.

[0010] The first objective of this invention is achieved by preparing the tellurium cosolvent TeR4 from soluble ferric salts, chloride salts, organic carboxylic acid salts, and nitrate salts.

[0011] The second objective of this invention is achieved by including complexation and isothermal activation steps, specifically including: A. Complexation: Dissolve the soluble ferric salt and organic carboxylate in water according to the formula and stir to react to obtain material a; B. Constant temperature activation: 1) Add the chloride and nitrate salts in the formula ratio to material a, and adjust the pH value to 3.0~4.5 to obtain material b; 2) Material b is activated at a constant temperature of 50~70℃, and then dried, crushed or granulated to obtain the target product, tellurium cosolvent TeR4.

[0012] The specific steps are as follows: Weigh out soluble ferric salt and organic carboxylate according to the formula ratio, dissolve in water and stir to mix, so that the ferric ions and organic carboxylate groups undergo a complexation and stabilization reaction; then add chloride and nitrate, and continue stirring and mixing; under stirring conditions, slowly add an alkaline regulator to adjust the pH of the system to 3.0-4.5; then carry out a constant temperature activation reaction at 50-70℃ for 0.5-2 hours. After the reaction is completed, dry, pulverize or granulate to obtain tellurium cosolvent TeR4.

[0013] The third objective of this invention is achieved by the application of the tellurium co-solvent TeR4 in the leaching process of tellurium-containing materials.

[0014] The aforementioned tellurium co-solvent TeR4 can be used in the acid leaching process of tellurium-containing refining slag, anode mud treatment slag, and other complex tellurium-containing materials. In the acidic system, through the synergistic effect of iron salt oxidation, chlorine complexation for solubilization, and organic carboxylic acid complexation for stabilization, it promotes the transformation of tellurium from a sparingly soluble, encapsulated, or bound state to a soluble state, thereby improving tellurium leaching efficiency and providing conditions for subsequent impurity removal, purification, and reduction precipitation for tellurium recovery.

[0015] Preparation principle of tellurium cosolvent TeR4: The preparation of tellurium cosolvent TeR4 is an in-situ complexation and compounding process. Soluble ferric salts, chloride salts, organic carboxylate salts, and nitrate salts dissolve in aqueous solution, respectively providing Fe... 3+ Cl - Organic carboxylate ions and NO3 - Functional components; under the action of an alkaline regulator, the pH of the system is controlled at 3.0–4.5, so that Fe… 3+ It undergoes a complexation reaction with organic carboxylic acid ions to form a stable iron-organic carboxylic acid complex component, thus avoiding excessive hydrolysis and precipitation of iron ions.

[0016] At the same time, Cl- and NO3 - The components are uniformly distributed in the system, serving as the complexing and solubilizing components and the auxiliary oxidation components for tellurium in the subsequent acid leaching process. After an isothermal activation reaction at 50–70 °C, the functional components are further stabilized and combined. Subsequently, after drying, pulverizing, or granulation, solid tellurium solubilizer TeR4 is obtained.

[0017] The principle of TeR4 as a tellurium co-solubilizer: In acidic leaching systems, TeR4 primarily promotes the transformation of tellurium in refining slag from its insoluble, encapsulated, or bound states into a soluble state before it enters the leachate through the synergistic effects of oxidative dissociation, chloride complexation, and complexation stabilization. Specifically, the ferric and nitrate components in TeR4 enhance the system's oxidizing capacity, promoting the oxidative dissociation of elemental tellurium, low-valent tellurides, and tellurium-containing complex phases. Chloride ions can form soluble chloride-containing complexes with oxidized tellurium, improving its stability in acidic solutions. Organic carboxylic acid ions can complex with metal ions such as iron, copper, lead, and bismuth, reducing losses caused by impurity hydrolysis precipitation or tellurium encapsulation, thereby improving tellurium dissolution efficiency.

[0018] Its main equation is: Te 0 →Te 4+ +4e - Fe 3+ +e - →Fe 2+ Te 4+ +6Cl - →[TeCl6] 2- Its overall chemical equation is: TeO2+4H + +6Cl - →[TeCl6] 2- +2H2O Detailed Implementation

[0019] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0020] The tellurium cosolvent TeR4 described in this invention is prepared from soluble ferric salts, chloride salts, organic carboxylic acid salts, and nitrate salts.

[0021] The tellurium cosolvent TeR4 is prepared from raw materials consisting of 2-10 parts by weight of soluble ferric salt, 10-15 parts of chloride salt, 0.5-2 parts of organic carboxylic acid salt, and 2-15 parts of nitrate salt.

[0022] The preparation method of the tellurium cosolvent TeR4 according to the present invention includes complexation and isothermal activation steps, specifically including: A. Complexation: Dissolve the soluble ferric salt and organic carboxylate in water according to the formula and stir to react to obtain material a; B. Constant temperature activation: 1) Add the chloride and nitrate salts in the formula ratio to material a, and adjust the pH value to 3.0~4.5 to obtain material b; 2) Material b is activated at a constant temperature of 50~70℃, and then dried, crushed or granulated to obtain the target product, tellurium cosolvent TeR4.

[0023] In step A, the temperature of the stirring reaction is 80~100℃, and the time is 2~8h.

[0024] The application of the tellurium co-solvent TeR4 described in this invention refers to its application in the leaching process of tellurium-containing materials.

[0025] The present invention will be further described below with reference to specific embodiments: Example 1

[0026] The tellurium co-solvent TeR4 used in this embodiment was prepared from the following raw materials in parts by weight: 2 parts soluble ferric salt, 10 parts chloride salt, 0.5 parts organic carboxylate salt, and 2 parts nitrate salt. The soluble ferric salt is ferric sulfate, the chloride salt is sodium chloride, the organic carboxylate salt is sodium citrate, and the nitrate salt is sodium nitrate.

[0027] According to the above weight ratio, weigh out 20g of ferric sulfate, 100g of sodium chloride, 5g of sodium citrate and 20g of sodium nitrate respectively.

[0028] Ferric sulfate and sodium citrate were added to 300 mL of deionized water and stirred at 300 r / min for 2 h at 80 °C to allow ferric ions to complex with organic carboxylate ions, yielding material a. Sodium chloride and sodium nitrate were added to material a, and stirring continued until dissolved. The pH of the system was adjusted to 3.0 using dilute hydrochloric acid or sodium hydroxide solution to obtain material b. Material b was activated at 50 °C for 2 h. After activation, it was dried at 80 °C to constant weight, pulverized, and passed through a 100-mesh sieve to obtain powdered tellurium co-solvent TeR4-1.

[0029] The prepared TeR4-1 was used for leaching tellurium-containing refining slag. The Te content in the tellurium-containing refining slag was 15.19%. 100g of tellurium-containing refining slag was weighed, 800mL of leaching agent was added, and 2.0g of TeR4-1 was added. Leaching was carried out at 90℃ and a stirring speed of 400r / min for 3 hours. After leaching, solid-liquid separation was performed, and the tellurium content in the leachate and leaching slag was determined.

[0030] The results showed that after adding TeR4-1, the tellurium leaching rate was 86.37%, and the Te content in the leaching residue was 3.18%; under the same conditions and without adding TeR4-1, the tellurium leaching rate was 71.26%. The addition of TeR4-1 increased the tellurium leaching rate by 15.11 percentage points, indicating that the tellurium co-solvent prepared according to the formulation range of this invention can significantly promote the dissociation and leaching of the tellurium-containing phase.

[0031] Example 2

[0032] The tellurium co-solvent TeR4 used in this embodiment was prepared from the following raw materials in parts by weight: 4 parts soluble ferric salt, 11 parts chloride salt, 1 part organic carboxylate salt, and 5 parts nitrate salt. The soluble ferric salt is ferric chloride, the chloride salt is sodium chloride, the organic carboxylate salt is sodium tartrate, and the nitrate salt is potassium nitrate.

[0033] According to the above weight ratio, weigh out 40g of ferric chloride, 110g of sodium chloride, 10g of sodium tartrate and 50g of potassium nitrate respectively.

[0034] Ferric chloride and sodium tartrate were added to 400 mL of deionized water and reacted at 85 °C with stirring at 300 r / min for 3 h to obtain material a. Sodium chloride and potassium nitrate were added to material a and stirred until completely dissolved. The pH of the system was adjusted to 3.3 to obtain material b. Material b was activated at 55 °C for 3 h, dried at 80 °C, pulverized, and passed through a 100-mesh sieve to obtain tellurium co-solvent TeR4-2.

[0035] Weigh 100g of the tellurium-containing refining residue identical to that in Example 1, add 800mL of leaching agent and 3.0g of TeR4-2, and leach for 3h at 90℃ and 400r / min. After leaching, perform solid-liquid separation and test the tellurium content in the leachate and leaching residue respectively.

[0036] The results showed that the tellurium leaching rate was 89.64%, and the Te content in the leaching residue was 2.46%. Compared with the result without the addition of tellurium co-solvent, the tellurium leaching rate increased by 18.38 percentage points. These results indicate that TeR4-2, prepared using ferric chloride, sodium chloride, sodium tartrate, and potassium nitrate, also has a significant solubilizing effect on tellurium-containing refining residue.

[0037] Example 3

[0038] The tellurium co-solvent TeR4 used in this embodiment was prepared from the following raw materials in parts by weight: 6 parts soluble ferric salt, 12 parts chloride salt, 1.2 parts organic carboxylate salt, and 8 parts nitrate salt. The soluble ferric salt is ferric sulfate, the chloride salt is potassium chloride, the organic carboxylate salt is sodium citrate, and the nitrate salt is sodium nitrate.

[0039] According to the above weight ratio, weigh out 60g of ferric sulfate, 120g of potassium chloride, 12g of sodium citrate and 80g of sodium nitrate respectively.

[0040] Ferric sulfate and sodium citrate were added to 500 mL of deionized water and stirred at 350 r / min for 5 h at 90 °C to allow the ferric ions to fully complex with the citrate ions, yielding material a. Potassium chloride and sodium nitrate were added to material a sequentially, and stirring continued until dissolved. The pH of the system was adjusted to 3.8 to obtain material b. Material b was activated at 60 °C for 4 h, then dried at 80 °C to constant weight. After pulverizing and passing through a 100-mesh sieve, tellurium co-solvent TeR4-3 was obtained.

[0041] Weigh 100g of tellurium-containing refining residue, add 800mL of leaching agent and 5.0g of TeR4-3, and leach for 3h at 90℃ and 400r / min. After leaching, perform solid-liquid separation and detect the tellurium content in the liquid and solid phases.

[0042] The results showed that the tellurium leaching rate reached 94.32%, and the Te content in the leaching residue decreased to 1.34%, which was 23.06 percentage points higher than the blank test without TeR4. The tellurium concentration in the leachate was significantly increased, and no obvious gelation or local precipitation was observed during the leaching process.

[0043] Example 4

[0044] The tellurium co-solvent TeR4 used in this embodiment was prepared from the following raw materials in parts by weight: 8 parts of soluble ferric salt, 14 parts of chloride salt, 1.5 parts of organic carboxylate salt, and 12 parts of nitrate salt. The soluble ferric salt is ferric nitrate, the chloride salt is sodium chloride, the organic carboxylate salt is sodium acetate, and the nitrate salt is potassium nitrate.

[0045] According to the above weight ratio, weigh out 80g of ferric nitrate, 140g of sodium chloride, 15g of sodium acetate and 120g of potassium nitrate respectively.

[0046] Ferric nitrate and sodium acetate were added to 600 mL of deionized water and reacted at 95 °C with stirring at 350 r / min for 6 h to obtain material a. Sodium chloride and potassium nitrate were added to material a and stirred until dissolved. The pH of the system was adjusted to 4.2 to obtain material b. Material b was activated at 65 °C for 5 h, dried, pulverized, and passed through a 100-mesh sieve to obtain tellurium co-solvent TeR4-4.

[0047] TeR4-4 was used for leaching tellurium-containing alloy dust. The tellurium-containing alloy dust contained 1.39% Te and 35.51% Se. 100g of tellurium-containing alloy dust was weighed, 300mL of leaching agent was added, and 5.0g of TeR4-4 was added. Leaching was carried out at 85℃ and 400r / min for 2h. After leaching, solid-liquid separation was performed, and the tellurium content in the leachate and leaching residue was measured separately.

[0048] The results showed that the tellurium leaching rate reached 78.65% after the addition of TeR4-4; under the same leaching conditions but without the addition of TeR4-4, the tellurium leaching rate was 55.56%. The addition of TeR4-4 increased the tellurium leaching rate by 23.09 percentage points. Meanwhile, the selenium leaching rate did not show a significant decrease, indicating that TeR4-4 can enhance the dissolution of tellurium from tellurium-containing alloy dust and has good adaptability to this type of complex selenium- and tellurium-containing materials.

[0049] Example 5

[0050] The tellurium co-solvent TeR4 used in this embodiment was prepared from the following raw materials in parts by weight: 10 parts of soluble ferric salt, 15 parts of chloride salt, 2 parts of organic carboxylate salt, and 15 parts of nitrate salt. The soluble ferric salt is ferric sulfate, the chloride salt is potassium chloride, the organic carboxylate salt is potassium citrate, and the nitrate salt is sodium nitrate.

[0051] According to the above weight ratio, weigh out 100g of ferric sulfate, 150g of potassium chloride, 20g of potassium citrate and 150g of sodium nitrate respectively.

[0052] Ferric sulfate and potassium citrate were added to 800 mL of deionized water and stirred at 400 r / min for 8 h at 100 °C to obtain material a. Potassium chloride and sodium nitrate were added to material a, and stirring was continued until completely dissolved. The pH of the system was adjusted to 4.5 to obtain material b. Material b was activated at 70 °C for 6 h. After activation, it was dried and granulated to obtain granular tellurium co-solvent TeR4-5 with a particle size of 0.5–2.0 mm.

[0053] Weigh 100g of tellurium-containing refining residue, add 800mL of leaching agent at a liquid-to-solid ratio of 8:1, and add 8.0g of TeR4-5. Leach for 3 hours at 90℃ and 400r / min. After leaching, perform solid-liquid separation and determine the tellurium leaching rate.

[0054] The results showed that the tellurium leaching rate was 93.87%, and the Te content in the leaching residue was 1.46%, which was 22.61 percentage points higher than that without the addition of tellurium co-solvent. Compared with Example 3, further increasing the ratio of raw materials and the amount of TeR4 did not significantly increase the tellurium leaching rate, indicating that the tellurium leaching effect gradually stabilizes after the amount of tellurium co-solvent reaches a certain level. Considering the tellurium leaching rate, co-solvent consumption, and production cost, the raw material ratio and TeR4 amount used in Example 3 are more suitable.

Claims

1. A tellurium co-solvent, TeR4, characterized in that, The tellurium cosolvent TeR4 is prepared from soluble ferric salts, chloride salts, organic carboxylic acid salts, and nitrate salts.

2. The tellurium co-solvent TeR4 according to claim 1, characterized in that, The tellurium cosolvent TeR4 is prepared from raw materials consisting of 2-10 parts by weight of soluble ferric salt, 10-15 parts of chloride salt, 0.5-2 parts of organic carboxylic acid salt, and 2-15 parts of nitrate salt.

3. A method for preparing the tellurium co-solvent TeR4 as described in claim 1 or 2, characterized in that, The process includes complexation and isothermal activation steps, specifically including: A. Complexation: Dissolve the soluble ferric salt and organic carboxylate in water according to the formula and stir to react to obtain material a; B. Constant temperature activation: 1) Add the chloride and nitrate salts in the formula ratio to material a, and adjust the pH value to 3.0~4.5 to obtain material b; 2) Material b is activated at a constant temperature of 50~70℃, and then dried, crushed or granulated to obtain the target product, tellurium cosolvent TeR4.

4. The preparation method according to claim 3, characterized in that, In step A, the temperature of the stirring reaction is 80~100℃, and the time is 2~8h.

5. An application of the tellurium co-solvent TeR4 as described in claim 1 or 2, characterized in that, The application of the tellurium co-solvent TeR4 in the leaching process of tellurium-containing materials.