Process for the direct oxidation of crude antimony to produce antimony white

Abstract

The present application belongs to the field of metallurgy, and relates to a method for producing antimony white by directly oxidizing crude antimony, comprising the following steps: S1, mixing crude antimony with crude antimony alloy, and reacting under an oxygen-containing atmosphere, to obtain oxidized slag and a melt after the reaction is completed; S2, adjusting the temperature of the melt, and then introducing compressed air to react, to produce antimony trioxide-containing flue gas, and to obtain antimony oxide slag after the reaction is completed. The present application makes full use of impurities such as sodium sulfide, sodium hydroxide and sodium thiosulfate contained in crude antimony, and innovatively uses these components for arsenic removal reaction, which not only avoids the cumbersome steps of adding various auxiliary materials in the traditional process, but also enables the original sodium sulfide, sodium hydroxide and sodium thiosulfate in the crude antimony to fully play a synergistic role, showing excellent performance in arsenic removal effect, thus simplifying the process flow, significantly reducing the production cost, and realizing the dual improvement of economic benefit and process efficiency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgy, and particularly relates to a method for producing antimony white by directly oxidizing crude antimony. BACKGROUND

[0002] In the non-ferrous metal smelting production process, lead anode mud is a by-product with important recycling value. After deep processing by converter reduction smelting process, a crude antimony alloy intermediate product can be obtained. However, due to the high-temperature fire reduction method used in the process, some impurity elements are inevitably introduced in the reduction process, among which the most common one is elemental arsenic and other harmful impurities. At the same time, antimony-containing gold concentrate can also effectively produce crude antimony products through the typical hydrometallurgical process route of alkali leaching and electrodeposition. In the electrodeposition process of the alkali sodium thioantimonite solution, the cathode region will undergo antimony deposition reaction, and the anode region will produce sodium sulfide by-product. It is worth noting that during the electrodeposition process, part of the sodium sulfide will undergo oxidation reaction with dissolved oxygen, and then be converted into sodium thiosulfate. Due to the presence of high concentrations of salts and alkalis in the electrolyte, the antimony product deposited on the cathode will be mechanically mixed with a large amount of sodium hydroxide, sodium sulfide and sodium thiosulfate and other impurities. The presence of these impurities will significantly affect the purity of the final product.

[0003] In the production process of antimony white, whether crude antimony alloy or crude antimony is used as raw material, the impurity removal process is an essential pretreatment link. For the impurity removal treatment of crude antimony alloy, the commonly used method is the chemical impurity removal process of adding alkali flux combined with oxidizing agent. Specifically, the alkali flux is usually sodium carbonate (Na2CO3) or sodium hydroxide (NaOH), and the oxidizing agent is usually sodium nitrate (NaNO3) or potassium nitrate (KNO3) and other chemical reagents. These additives will undergo complex oxidation-reduction reactions with arsenic elements in the alloy under high-temperature molten state, converting harmful arsenic into arsenate compounds. Since the density of arsenate is significantly less than that of molten antimony liquid, it will float to the surface of the melt as a dross and be enriched there. The preliminary separation of arsenic and antimony can be achieved by mechanical scraping. However, this method of removing arsenic has obvious defects. On the one hand, it consumes a large amount of chemical auxiliaries, resulting in high production cost. On the other hand, the efficiency of removing arsenic is limited, which cannot meet the requirements of high-quality antimony white production. As for the impurity removal of crude antimony raw material, the crushing-washing process combining physical and chemical methods is mainly used. This process first crushes the crude antimony to a suitable particle size, and then removes the mechanically mixed soluble impurities such as sodium hydroxide, sodium sulfide and sodium thiosulfate by water washing. However, this method produces a large amount of industrial wastewater containing sulfide components with high alkalinity. These wastewater not only has a very high pH value, but also contains a variety of harmful substances, which brings great difficulties to the subsequent wastewater treatment and significantly increases the environmental protection treatment cost. SUMMARY

[0004] In view of the deficiencies of the prior art, the application provides a method for producing antimony white by directly oxidizing crude antimony.

[0005] The specific technical scheme is as follows:

[0006] The method for producing antimony white by directly oxidizing crude antimony comprises the following steps:

[0007] S1, mixing crude antimony with crude antimony alloy and reacting under an oxygen-containing atmosphere, to obtain oxidation slag and a melt after the reaction is completed;

[0008] S2, adjusting the temperature of the melt, and then introducing compressed air to react, to generate antimony trioxide-containing flue gas, and to obtain antimony oxide slag after the reaction is completed.

[0009] The crude antimony is obtained from a product produced by alkali leaching-electrodeposition process of antimony-containing gold concentrate, and mainly comprises: Sb content of 85wt% or more, NaOH content of 3.0wt%-6.0wt%, Na2S content of 3.0wt%-6.0wt%, and Na2S2O3 content of 1.0wt%-3.0wt%.

[0010] The crude antimony alloy is obtained from a product produced by high-temperature reduction of lead anode slime, and mainly comprises: Sb content of 85wt% or more, Au content of 0.5wt% or less, Ag content of 0.5wt% or less, As content of 5.0wt% or less, Te content of 0.1wt% or less, Se content of 0.1wt% or less, and Bi content of 0.1wt% or less.

[0011] The reaction mechanism of the application is as follows:

[0012] The impurities in the crude antimony mainly include sodium sulfide, sodium hydroxide and sodium thiosulfate, and the impurities in the crude antimony alloy mainly include arsenic, and the crude antimony and the crude antimony alloy are used to play a synergistic effect under the oxygen-containing atmosphere, so that the impurities in the two are mutually converted to form slag phases, and the effective separation and removal of the impurities and the antimony are realized.

[0013] In step S1, the sodium sulfide, sodium hydroxide and sodium thiosulfate in the crude antimony and the arsenic in the crude antimony alloy react to generate oxidation slag under the oxygen-containing atmosphere, and the separation of the impurities and the antimony is realized. The main reactions are as follows:

[0014] 4As+Na2S+7O2+4NaOH→4NaAsO3+Na2SO4+2H2O↑;

[0015] 4As+Na2S2O3+7O2+6NaOH→4NaAsO3+2Na2SO4+3H2O↑;

[0016] Na2S+2O2→Na2SO4;

[0017] 2Na2S2O3+3O2→2Na2SO4+2SO2↑;

[0018] Na2S2O3 + 2O2 + 2NaOH → 2Na2SO4 + H2O↑.

[0019] Further, in step S1, before mixing, the crude antimony and the crude antimony alloy are crushed to a particle size of ≤5 cm.

[0020] Further, in step S1, the mass ratio of the crude antimony to the crude antimony alloy is (1.5-2):1.

[0021] Further, in step S1, the oxygen-containing atmosphere is air.

[0022] Further, in step S1, the specific process of the reaction is as follows: the temperature is increased to 650-700℃, and after the crude antimony and the crude antimony alloy are completely melted, the temperature is kept constant for 1-3 h.

[0023] Preferably, in step S1, after the reaction is completed, the oxidized slag is removed by means of slagging.

[0024] In step S2, the antimony in the melt fully reacts with the oxygen in the compressed air to generate antimony trioxide-containing flue gas. The main reaction is:

[0025] 4Sb + 3O2 → 2Sb2O3↑.

[0026] Further, in step S2, the temperature of the melt is adjusted to 630-650℃, and the reaction time is 4-8 h.

[0027] Further, in step S2, the compressed air has a wind pressure of 0.1-0.3 MPa and a gas flow rate of 5000-7000 Nm 3 / h.

[0028] Further, in step S2, the flue gas obtained in step S2 is cooled to below 350℃ to collect antimony white; the antimony white meets the grade requirements of Sb2O399.90 in GB / T 4062-2013.

[0029] Preferably, in step S2, the antimony oxide slag is returned to the anode slime treatment system to recover valuable metals therefrom.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] The application takes full advantage of impurity components such as sodium sulfide, sodium hydroxide and sodium thiosulfate contained in the crude antimony, innovatively uses these components for arsenic removal reaction, avoids the cumbersome steps of adding various auxiliary materials in the traditional process, and the original sodium sulfide, sodium hydroxide and sodium thiosulfate in the crude antimony can fully play a synergistic role, showing excellent performance in arsenic removal effect; at the same time, without additional auxiliary materials, not only simplifies the process flow, but also significantly reduces the production cost, realizes the double improvement of economic benefit and process efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The process flow chart of the method for directly oxidizing the crude antimony to produce antimony white in the specific embodiment. DETAILED DESCRIPTION

[0033] The embodiments of the application will be further described in detail below in conjunction with the drawings and examples. The following examples are used to illustrate the application, but cannot be used to limit the scope of the application. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents and the like used in the following examples can be obtained from commercial channels unless otherwise specified.

[0034] Example 1

[0035] The method for directly oxidizing the crude antimony to produce antimony white, wherein,

[0036] The crude antimony comes from the product produced by alkali leaching-electrodeposition process of antimony-containing gold concentrate, and the main components are: Sb content 85.36wt%, NaOH content 5.86wt%, Na2S content 5.91wt%, Na2S2O3 content 2.84wt%;

[0037] The crude antimony alloy comes from the product produced by high-temperature reduction of lead anode mud, and the main components are: Sb content 94.38wt%, Au content 0.11wt%, Ag content 0.14wt%, As content 1.34wt%, Te content 0.02wt%, Se content 0.02wt%, Bi content 0.05wt%.

[0038] The method steps are as follows:

[0039] S1, the crude antimony and the crude antimony alloy are crushed to a particle size of ≤5cm, then mixed in the oxidation pot according to the mass ratio of the crude antimony to the crude antimony alloy of 2:1, the temperature is raised to 700℃ under air atmosphere, the temperature is kept unchanged after the crude antimony and the crude antimony alloy are completely melted at 700℃ for 1.5h, and the oxidation slag and the melt are obtained after the reaction is completed, and the oxidation slag on the upper layer of the melt is removed by scraping;

[0040] S2, the temperature of the melt is adjusted to 650℃, then 7000Nm 3The crude antimony and the crude antimony alloy are crushed to a particle size of ≤5 cm, and then mixed in an oxidation pot at a mass ratio of 1.5:1, and the temperature is increased to 650°C under an air atmosphere. After the crude antimony and the crude antimony alloy are completely melted at 650°C, the temperature is kept unchanged for 3 hours. After the reaction is completed, oxidation slag and a melt are obtained, and the oxidation slag on the upper layer of the melt is removed by raking.

[0041] Example 2

[0042] A method for producing antimony white by direct oxidation of crude antimony, wherein

[0043] The crude antimony is obtained from a product produced by an alkali leaching-cathodic deposition process of an antimony-containing gold concentrate, and the main components are: Sb content of 92.34wt%, NaOH content of 3.21wt%, Na2S content of 3.28wt%, and Na2S2O3 content of 1.32wt%.

[0044] The crude antimony alloy is obtained from a product produced by high-temperature reduction of lead anode slime, and the main components are: Sb content of 85.27wt%, Au content of 0.21wt%, Ag content of 0.45wt%, As content of 4.92wt%, Te content of 0.03wt%, Se content of 0.05wt%, and Bi content of 0.08wt%.

[0045] The method steps are as follows:

[0046] S1 The crude antimony and the crude antimony alloy are crushed to a particle size of ≤5 cm, and then mixed in an oxidation pot at a mass ratio of 1.5:1, and the temperature is increased to 650°C under an air atmosphere. After the crude antimony and the crude antimony alloy are completely melted at 650°C, the temperature is kept unchanged for 3 hours. After the reaction is completed, oxidation slag and a melt are obtained, and the oxidation slag on the upper layer of the melt is removed by raking.

[0047] S2 The temperature of the melt is adjusted to 640°C, and then 6000Nm 3 / h of compressed air at a wind pressure of 0.2MPa is introduced, and the reaction is carried out at this temperature for 8 hours to produce antimony trioxide-containing flue gas. After the reaction is completed, antimony oxide slag is obtained, and the flue gas is cooled to 300°C to collect antimony white. The antimony oxide slag is returned to the anode slime treatment system to recover valuable metals such as antimony white, gold ingot, silver ingot, selenium dioxide, copper matte, and tellurium ingot. The purity of the antimony white is 99.92wt%, and the antimony recovery rate is 93.08%.

[0048] Example 3

[0049] A method for producing antimony white by direct oxidation of crude antimony, wherein

[0050] The crude antimony comes from the product produced by alkali leaching-electrodeposition process of antimony-containing gold concentrate, and the main components are: Sb content of 88.36wt%, NaOH content of 4.95wt%, Na2S content of 5.14wt%, and Na2S2O3 content of 2.98wt%.

[0051] The crude antimony alloy comes from the product produced by high-temperature reduction of lead anode slime, and the main components are: Sb content of 87.25wt%, Au content of 0.10wt%, Ag content of 0.34wt%, As content of 3.21wt%, Te content of 0.08wt%, Se content of 0.05wt%, and Bi content of 0.06wt%.

[0052] The method steps are as follows:

[0053] S1: The crude antimony and the crude antimony alloy are crushed to a particle size of ≤5cm, and then mixed in an oxidizing pot according to a mass ratio of 1.8:1. In an air atmosphere, the temperature is raised to 680℃, and after the crude antimony and the crude antimony alloy are completely melted at 680℃, the temperature is kept unchanged for 1h. After the reaction is completed, the oxidized slag and the melt are obtained, and the oxidized slag on the upper layer of the melt is removed by scraping.

[0054] S2: The temperature of the melt is adjusted to 630℃, and then 5000Nm 3 / h of compressed air with a wind pressure of 0.1MPa is introduced. The reaction is carried out at this temperature for 6h to produce antimony trioxide-containing flue gas. After the reaction is completed, the antimony oxide slag is obtained, and the flue gas is cooled to 350℃ to collect antimony white. The antimony oxide slag is returned to the anode slime treatment system to recover valuable metals such as antimony white, gold ingot, silver ingot, selenium dioxide, copper matte, and tellurium ingot. The purity of the antimony white is 99.91wt%, and the antimony recovery rate is 92.18%.

[0055] Test

[0056] The arsenic content in the oxidized slag and the melt obtained in step S1 of Examples 1-3 is detected, and the results are shown in Table 1.

[0057] The determination of arsenic content in the melt is carried out according to “Chemical Analysis Method for Crude Antimony Part 3: Determination of Arsenic, Lead, Copper, Selenium and Iron Content Inductively Coupled Plasma Atomic Emission Spectrometry (YS / T 1582.3-2022)”, and the determination of arsenic content in the oxidized slag is carried out according to “Chemical Analysis Method for Lead Smelting Silver Separation Slag Part 7: Determination of Arsenic Content Inductively Coupled Plasma Atomic Emission Spectrometry (YS / T 1348.7-2021)”.

[0058] Table 1 Arsenic content in the oxidized slag and the melt

[0059]

[0060] As shown in Table 1, the arsenic content in the melt is less than 0.02wt%, which indicates that the effect of dearsenication by mixing and smelting of crude antimony and crude antimony alloy is good. The antimony white produced in Examples 1-3 all meets the grade requirement of Sb2O399.90 in GB / T 4062-2013.

[0061] The above description is merely preferred embodiments of the present application, and not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. Process for the direct oxidation of crude antimony to produce antimony white, characterized in that, The method comprises the following steps: S1. mixing crude antimony with crude antimony alloy, reacting under an oxygen-containing atmosphere, and obtaining oxidized slag and a melt after the reaction is completed; S2. adjusting the temperature of the melt, and then introducing compressed air to react, generating antimony trioxide-containing flue gas, and obtaining antimony trioxide slag after the reaction is completed; In step S1, the mass ratio of crude antimony to crude antimony alloy is (1.5-2):1; The crude antimony is obtained from a product produced by alkali leaching-electrodeposition process of antimony-containing gold concentrate, and the main components are as follows: Sb content ≥ 85wt%, NaOH content 3.0wt%-6.0wt%, Na2S content 3.0wt%-6.0wt%, and Na2S2O3 content 1.0wt%-3.0wt%; The crude antimony alloy is obtained from a product produced by high-temperature reduction of lead anode slime, and the main components are as follows: Sb content ≥ 85wt%, Au content ≤ 0.5wt%, Ag content ≤ 0.5wt%, As content ≤ 5.0wt%, Te content ≤ 0.1wt%, Se content ≤ 0.1wt%, and Bi content ≤ 0.1wt%; In step S1, the specific process of the reaction is as follows: the temperature is increased to 650-700℃, and after the crude antimony and the crude antimony alloy are completely melted, the temperature is kept unchanged for 1-3h. In step S2, the temperature of the melt is adjusted to 630-650℃, and the reaction time is 4-8h.

2. The method of claim 1, wherein, In step S1, before mixing, the crude antimony and the crude antimony alloy are crushed to a particle size ≤ 5cm.

3. The method of claim 1, wherein, In step S1, the oxygen-containing atmosphere is air.

4. The method of claim 1, wherein, In step S1, after the reaction is completed, the oxidized slag is removed by raking.

5. The method of claim 1, wherein, In step S2, the compressed air has a wind pressure of 0.1-0.3 MPa and a gas flow rate of 5000-7000 Nm 3 / h.

6. The method of claim 1, wherein, In step S2, the flue gas obtained in step S2 is cooled to below 350℃ to collect antimony white.

7. The method of claim 1, wherein, In step S2, the antimony trioxide slag is returned to the anode slime treatment system.

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