A method for recovering tellurium from antimony smelting waste residues

Abstract

A method for recovering tellurium from antimony smelting waste residue, comprising the following steps: (1) ball milling roasting: after ball milling antimony smelting waste residue, uniformly mixing with sodium hydroxide and sodium nitrate in a certain proportion, and then roasting the uniformly mixed material; (2) leaching: adding the roasted material into hot water and adding hydrogen peroxide, and leaching under ultrasonic wave condition, and filtering to obtain filtrate I; (3) impurity removal: adding dilute sulfuric acid to the filtrate I for neutralization, adjusting the pH value to 3-3.5, filtering the precipitate to obtain filtrate II; (4) reduction: after adjusting the pH value of the filtrate II to 6-7, adding a reducing agent to obtain a tellurium dioxide product. The present application is simple in operation and low in cost, and the recovery rate of tellurium can reach more than 98%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrometallurgy, and particularly relates to a method for recovering tellurium from antimony smelting waste residues. BACKGROUND

[0002] Tellurium belongs to rare and dispersed metal elements and is praised as "vitamin of modern industry, national defense and cutting-edge technology", and is a support material for new materials in modern high technology. This is because the demand for rare and dispersed metals including tellurium in the fields of spaceflight, atomic energy and electronic industry is increasing day by day, so that tellurium has become a support material for new materials required by electronic computers, communication and spaceflight development, energy and medical treatment. Tellurium is mainly associated with copper, lead, antimony and other minerals, so that the production of tellurium is mainly comprehensive recovery in the smelting process of heavy metals such as copper, lead and antimony.

[0003] The antimony resources in China are very rich, and the proven reserves account for more than half of the total reserves in the world. With the continuous development and application of antimony ore resources, a large amount of antimony smelting waste residues is discharged. It is understood that due to various reasons, the production enterprises basically do not treat the antimony-containing waste residues, but directly stack them in mountains and ravines, which not only pollutes the environment, but also causes the loss of valuable resources. How to comprehensively utilize these waste residues, recover rare and dispersed metals therein, increase the economic benefits of enterprises and reduce environmental pollution has become a problem to be solved in the antimony smelting industry.

[0004] The antimony smelting waste residues are relatively complex, mainly containing metals such as antimony, lead, iron, gold and silver, non-metals such as arsenic, carbon and sulfur, and oxide complex systems of rare and dispersed metals such as selenium and tellurium. Although the chemical composition of the antimony smelting waste residues is quite different due to different production places and production processes, the rare and dispersed metals such as selenium and tellurium contained therein are quite considerable, and many antimony smelting waste residues contain dozens of grams or even hundreds of grams of rare and dispersed tellurium per ton, so they have high development and utilization value. At present, copper powder is generally used to reduce and precipitate tellurium in industry, and copper tellurium slag mainly containing copper telluride is obtained, so that the copper tellurium slag needs to be leached and separated again, the process is complex, the cost is high, and 2-3 tons of copper powder are consumed for precipitating 1 ton of tellurium. SUMMARY

[0005] The purpose of the present application is to solve the above technical problems, and provide a method for recovering tellurium from antimony smelting waste residues with low cost and high recovery rate.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A method for recovering tellurium from antimony smelting waste residues, comprising the following steps:

[0008] Ball milling and roasting: after ball milling the antimony smelting waste residues, uniformly mixing the antimony smelting waste residues with sodium hydroxide and sodium nitrate in a certain proportion, and then roasting the uniformly mixed materials;

[0009] Leaching: the roasted material is added into hot water and hydrogen peroxide, and leaching is carried out under ultrasonic condition, and filtration is carried out to obtain filtrate I;

[0010] Impurity removal: the filtrate I is added into dilute sulfuric acid for neutralization, and the pH value is adjusted to 3-3.5, and filtration is carried out to obtain filtrate II;

[0011] Reduction: after the pH value of the filtrate II is adjusted to 6-7, a reducing agent is added to obtain a tellurium dioxide product.

[0012] As a further technical solution, the mass fraction of the antimony smelting waste residue, sodium hydroxide and sodium nitrate is 100: (60-80): (10-20), the roasting time is 1-1.5 hours, and the roasting temperature is 750-850 DEG C.

[0013] As a further technical solution, the solid-liquid ratio of the roasted material and hot water is 1g: (2-3) ml, the hydrogen peroxide addition amount is 3%-5% of the total volume, the temperature of the hot water is 60-80 DEG C, the ultrasonic oscillation frequency is 40-50 KHz, and the leaching time is 1-1.5 hours.

[0014] As a further technical solution, the concentration of the dilute sulfuric acid is 150-300 g / l.

[0015] As a further technical solution, the reducing agent is sulfur dioxide and sodium sulfite, the sulfur dioxide is introduced for 10-20 min, the sulfur dioxide gas supply amount is 0.05 L / min, and the sodium sulfite amount is 3-5 times of the theoretical mass of tellurium.

[0016] Compared with the prior art, the present application has the following beneficial effects: firstly, the sodium hydroxide and sodium nitrate are mixed with the antimony smelting waste residue, and the antimony smelting waste residue is alkali-fused at high temperature, so that the tellurium in the antimony-tellurium alloy in the antimony smelting waste residue is melted into Na2TeO4 which is easily soluble in water, the reaction equation is Sb2Te+2O2=2SbO+TeO2, NaOH+TeO2+NaNO3=Na2TeO4+NO2↑, then the sound pressure of the ultrasonic wave is changed greatly when the ultrasonic wave propagates in the liquid, so that the liquid is strongly cavitated and emulsified, and millions of micro cavitation bubbles are generated per second, the bubbles are rapidly and massively generated under the action of the sound pressure, and continuously and violently burst, so that a strong impact force and negative pressure suction force are generated, and the tellurium element is separated from the waste residue; then the pH value is adjusted by the dilute sulfuric acid, so that the tin, antimony, copper, zinc, magnesium and other impurities are precipitated in the slag, and the tellurium is effectively separated by simple operation; finally, the Na2TeO4 in the solution is reduced into tellurium dioxide by the sulfur dioxide reduction atmosphere and sodium sulfite. The present application has the advantages of simple operation, low cost, and the tellurium recovery rate can reach more than 98%. DETAILED DESCRIPTION

[0017] The application will be further described in conjunction with the following examples, but the embodiments of the application are not limited to the scope indicated by the examples.

[0018] The mass content of tellurium in the antimony smelting waste residue in the embodiments of the application is 0.8%. Example 1

[0019] Put 3 kg of antimony smelting waste residue into a ball mill and ball mill to a particle size of 200 mesh. Mix the ball-milled material with 1.8 kg of sodium hydroxide and 0.3 kg of sodium nitrate. Then put the mixed material into a muffle furnace and roast at 750°C for 1 hour. Put the roasted waste residue into a 40 KHz ultrasonic oscillator and immerse in 10 liters of hot water with 0.3 liters of hydrogen peroxide at 60°C for 1 hour. Filter and separate. Neutralize the obtained filtrate with 150 g / l dilute sulfuric acid to pH 3. Filter. Adjust the pH value of the filtered filtrate to 6 with 150 g / l dilute sulfuric acid. Pass in sulfur dioxide for 10 min. Add 72 g of sodium sulfite. Obtain 29.4 g of tellurium dioxide. The recovery rate of tellurium is 98%. Example 2

[0020] Put 3 kg of antimony smelting waste residue into a ball mill and ball mill to a particle size of 250 mesh. Mix the ball-milled material with 2.1 kg of sodium hydroxide and 0.45 kg of sodium nitrate. Then put the mixed material into a muffle furnace and roast at 800°C for 1.25 hours. Put the roasted waste residue into a 45 KHz ultrasonic oscillator and immerse in 14 liters of hot water with 0.55 liters of hydrogen peroxide at 70°C for 1.25 hours. Filter and separate. Neutralize the obtained filtrate with 250 g / l dilute sulfuric acid to pH 3.3. Filter. Adjust the pH value of the filtered filtrate to 6.5 with 250 g / l dilute sulfuric acid. Pass in sulfur dioxide for 15 min. Add 96 g of sodium sulfite. Obtain 29.6 g of tellurium dioxide. The recovery rate of tellurium is 98.7%. Example 3

[0021] Put 3 kg of antimony smelting waste residue into a ball mill and ball mill to a particle size of 300 mesh. Mix the ball-milled material with 2.4 kg of sodium hydroxide and 0.6 kg of sodium nitrate. Then put the mixed material into a muffle furnace and roast at 850°C for 1.5 hours. Put the roasted waste residue into a 50 KHz ultrasonic oscillator and immerse in 18 liters of hot water with 0.9 liters of hydrogen peroxide at 80°C for 1.5 hours. Filter and separate. Neutralize the obtained filtrate with 300 g / l dilute sulfuric acid to pH 3.5. Filter. Adjust the pH value of the filtered filtrate to 7 with 300 g / l dilute sulfuric acid. Pass in sulfur dioxide for 20 min. Add 120 g of sodium sulfite. Obtain 29.8 g of tellurium dioxide. The recovery rate of tellurium is 99.3%.

[0022] The above examples are only specific examples for further detailing the purposes, technical solutions and beneficial effects of the present application, and the present application is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the scope disclosed in the present application is included in the protection scope of the present application.

Claims

1. A method for recovering tellurium from antimony smelting waste residue, characterized by, The method comprises the following steps: ball milling roasting: after the antimony smelting waste residue is ball milled, the residue is mixed with sodium hydroxide and sodium nitrate in a certain proportion, and then the mixed material is roasted; leaching: the roasted material is added into hot water and hydrogen peroxide, and then leached under ultrasonic condition, and filtered to obtain filtrate I; impurity removal: the filtrate I is neutralized by adding dilute sulfuric acid, and the pH value is adjusted to 3-3.5, and then the precipitate is filtered to obtain filtrate II; reduction: after the pH value of the filtrate II is adjusted to 6-7, a reducing agent is added to obtain a tellurium dioxide product; the mass ratio of the antimony smelting waste residue, sodium hydroxide and sodium nitrate is 100:(60-80):(10-20), the roasting time is 1-1.5 hours, and the roasting temperature is 750-850℃; the solid-liquid ratio of the roasted material to hot water is 1g:(2-3)ml, the hydrogen peroxide addition amount is 3%-5% of the total volume, the temperature of the hot water is 60-80℃, the ultrasonic oscillation frequency is 40-50KHz, and the leaching time is 1-1.5 hours; the reducing agent is sulfur dioxide and sodium sulfite, the sulfur dioxide is introduced for 10-20min, the sulfur dioxide gas supply amount is 0.05L / min, and the sodium sulfite amount is 3-5 times of the theoretical mass of tellurium; the mass content of tellurium in the antimony smelting waste residue is 0.8%.

2. The method according to claim 1, wherein the method is characterized by: the concentration of the dilute sulfuric acid is 150-300g / l.