Method for improving extraction of zinc oxide from metallurgical waste residues

Abstract

The invention relates to the technical field of metallurgical waste residue treatment, and discloses a method for improving zinc oxide extraction from metallurgical waste residues, which comprises the following steps: 1, waste residue pretreatment: crushing and grinding metallurgical waste residues to enable the granularity to reach 100-200 meshes, then carrying out magnetic separation to remove magnetic impurities in the metallurgical waste residues, and fully and uniformly mixing the metallurgical waste residues with a solvent according to a specific proportion to obtain a mixed solution; the waste residue particles are uniformly distributed in the solvent; and 2, roasting treatment: putting the uniformly mixed materials into a proper roasting furnace, and roasting under the conditions of specific temperature, time and atmosphere. By innovatively combining the advantages of a pyrogenic process and a wet process, firstly, a zinc compound is changed through pyrogenic roasting to improve reactivity, then, a roasted product is dissolved and separated through wet acid leaching to efficiently extract zinc, the pyrogenic process provides high-quality raw materials for the wet process, the wet process deepens zinc extraction and purification, and the pyrogenic process and the wet process are linked, coordinated, complemented and limited to jointly improve the zinc recovery efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical waste slag treatment, in particular to a method for improving the refining of zinc oxide from metallurgical waste slag. Background Art

[0002] Metallurgical slag is solid waste generated during the metal smelting process, usually containing a variety of metal elements and their oxides. With the development of metal resource mining and smelting technology, the amount of slag generated during the smelting process has increased year by year. Zinc oxide is an important inorganic compound and is widely used in rubber, coatings, cosmetics, and pharmaceutical fields.

[0003] In the production process of the metallurgical industry, a large amount of waste slag is generated. These waste slags usually contain valuable metal elements such as zinc. If they are not effectively recycled, it will not only be a waste of resources but also pollute the environment. However, among the existing methods for refining zinc oxide from metallurgical waste slag, the efficiency, purity and environmental protection effects of the method for refining zinc oxide are relatively poor. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for improving the refining of zinc oxide from metallurgical waste slag, which solves the problem that the efficiency, purity and environmental protection effects of the method for refining zinc oxide are relatively poor.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: A method for improving the extraction of zinc oxide from metallurgical waste slag, comprising:

[0006] Step 1: Waste slag pretreatment

[0007] The metallurgical waste slag is crushed and ground to a particle size of 100-200 mesh, and then magnetically separated to remove magnetic impurities, and the metallurgical waste slag and solvent are fully mixed in a specific ratio to ensure that the waste slag particles are evenly distributed in the solvent;

[0008] Step 2: Calcination treatment: Place the uniformly mixed materials in a suitable calcining furnace and calcine them under specific temperature, time and atmosphere conditions to cause physical and chemical changes in the zinc compounds in the waste slag to obtain a calcined product that is easy to subsequently process;

[0009] Step 3: Acid leaching process: Acid leaching is performed on the roasted product, and an appropriate amount of acidic substance is added thereto. By strictly controlling the type, concentration, temperature and reaction time of the acid, the dissolution, impurity removal, purification and purification are achieved, and the zinc element is directional precipitated in a specific form;

[0010] Step 4: solid-liquid separation: using solid-liquid separation technology to separate the zinc-containing precipitate product from the acid leaching solution, and then washing the zinc-containing precipitate product with deionized water for multiple times to remove residual impurities and acid;

[0011] Step 5: Calcination and cooling: The washed zinc-containing precipitate is placed in a calcination furnace and calcined at a specific temperature and air atmosphere. After a certain period of time, it is cooled to room temperature with the furnace to finally obtain a high-purity zinc oxide product.

[0012] Preferably, in the step 1 of pretreating the waste residue, the solvent is a mixed solution of ammonium chloride and sodium chloride, the mixing ratio of ammonium chloride to sodium chloride is 2:1, and the mass ratio of the solvent to the waste residue is 1:2.

[0013] Preferably, in the calcination treatment of step 2, the calcination temperature is 900° C., the calcination time is 4 hours, and the atmosphere condition is an oxidizing atmosphere.

[0014] Preferably, in the physical and chemical changes of the zinc compound in the waste slag in step 2, the zinc compound in the metallurgical waste slag undergoes an oxidation reaction, and zinc sulfide is oxidized to zinc oxide, and there will be some complex phase transformations and structural reorganizations:

[0015] The physical changes: the particle size of the waste residue will change, and the porosity will increase, which is beneficial to the subsequent acid leaching treatment;

[0016] The chemical changes: Some impurity components will be oxidized or converted into forms that are easily removed during the acid leaching process.

[0017] Preferably, in the step three, when performing the acid leaching operation, the roasted product is placed in an acid-resistant container, and the acidic substance is slowly added while stirring to ensure that the material is fully in contact with the acid, the acid is sulfuric acid, the acid concentration is 3 mol / L, the temperature is 80°C, and the reaction time is 3 hours.

[0018] Preferably, the solid-liquid separation in step 4 comprises the following specific steps:

[0019] Step 1: First, prepare a suitable filtering device, such as a filter press or centrifuge, and slowly pour the acid-leached mixture into the filtering device;

[0020] Step 2: Start the filter press, apply pressure to make the liquid pass through the filter cloth, and the solid is trapped on the filter cloth to form a filter cake;

[0021] Step 3: After separation, carefully take out the Zn-containing precipitate product, collect the filtrate, and further process and detect the separated Zn-containing precipitate product.

[0022] Preferably, in step 4, washing the zinc-containing precipitate product with deionized water multiple times comprises the following specific steps:

[0023] Step 1: Place the separated zinc-containing precipitate product in a beaker or a washing tank, and add an appropriate amount of deionized water to completely immerse the precipitate product;

[0024] Step 2: Stir or shake the container to fully mix the precipitated product with deionized water, soak for 10 to 30 minutes, dissolve and remove impurity ions adsorbed on the surface, and perform solid-liquid separation;

[0025] Step 3: Repeat the above steps and wash multiple times, usually 3 to 5 times, until the pH value of the washing liquid is close to neutral and no obvious impurity ions can be detected. After each washing, the washing liquid can be tested to analyze the zinc ion concentration and impurity content to determine whether the washing effect meets the requirements.

[0026] Preferably, in step five, the specific temperature for calcination and cooling can be 600-800°C.

[0027] The present invention provides a method for improving the extraction of zinc oxide from metallurgical waste slag. It has the following beneficial effects:

[0028] 1. The present invention innovatively combines the advantages of pyrometallurgical process and hydrometallurgical process. The zinc compound is first changed by pyrometallurgical roasting to improve reactivity, and then the roasting product is dissolved and separated by wet acid leaching to efficiently extract zinc. The pyrometallurgical process provides high-quality raw materials for the wet process, and the wet process deepens the extraction and purification of zinc. The two are connected and coordinated, complementing each other's limitations, and jointly improve the zinc recovery efficiency.

[0029] 2. The present invention uses an optimized process flow and precise parameter control to strictly control temperature, atmosphere and time during roasting to convert zinc compounds and remove impurities. During acid leaching, the acid type is carefully selected, the acid concentration is controlled, the temperature and time are controlled to allow zinc to dissolve while impurities to dissolve less. High-efficiency technology is used for solid-liquid separation to wash away residual impurities. The temperature and atmosphere are precisely controlled during calcination to remove impurities and obtain high-purity zinc oxide, thereby improving purity.

[0030] 3. The whole process of the present invention pays attention to environmental protection from many aspects to reduce secondary pollution. By precisely controlling the conditions, the disorderly emission of harmful gases is reduced, and suitable and less polluting acidic substances are selected and the dosage is precisely controlled to reduce the generation of waste liquid. Effective and environmentally friendly technologies and materials are used to reduce wastewater discharge and control waste gas emissions. The wastewater, waste gas and waste residue generated in the whole process are reasonably treated and disposed of to minimize their harm to the environment, thereby effectively reducing secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flow chart of a method for improving the refining of zinc oxide from metallurgical waste slag. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Example:

[0034] Please see attached Figure 1 The embodiment of the present invention provides a method for improving the refining of zinc oxide from metallurgical waste slag, comprising:

[0035] Step 1: Waste slag pretreatment

[0036] The metallurgical waste slag is crushed and ground to a particle size of 100-200 mesh, and then magnetically separated to remove magnetic impurities, and the metallurgical waste slag and solvent are fully mixed in a specific ratio to ensure that the waste slag particles are evenly distributed in the solvent;

[0037] Step 2: Calcination treatment: Place the uniformly mixed materials in a suitable calcining furnace and calcine them under specific temperature, time and atmosphere conditions to cause physical and chemical changes in the zinc compounds in the waste slag to obtain a calcined product that is easy to subsequently process;

[0038] Step 3: Acid leaching process: Acid leaching is performed on the roasted product, and an appropriate amount of acidic substance is added thereto. By strictly controlling the type, concentration, temperature and reaction time of the acid, the dissolution, impurity removal, purification and purification are achieved, and the zinc element is directional precipitated in a specific form;

[0039] Step 4: solid-liquid separation: using solid-liquid separation technology to separate the zinc-containing precipitate product from the acid leaching solution, and then washing the zinc-containing precipitate product with deionized water for multiple times to remove residual impurities and acid;

[0040] Step 5: Calcination and cooling: The washed zinc-containing precipitate is placed in a calcination furnace and calcined at a specific temperature and air atmosphere. After a certain period of time, it is cooled to room temperature with the furnace to finally obtain a high-purity zinc oxide product.

[0041] In the step 1, in the waste residue pretreatment, the solvent is a mixed solution of ammonium chloride and sodium chloride, the mixing ratio of ammonium chloride to sodium chloride is 2:1, and the mass ratio of the solvent to the waste residue is 1:2.

[0042] In the calcination treatment of step 2, the calcination temperature is 900° C., the calcination time is 4 hours, and the atmosphere condition is an oxidizing atmosphere.

[0043] Step 2: During the physical and chemical changes of the zinc compounds in the waste slag, the zinc compounds in the metallurgical waste slag will undergo an oxidation reaction, and zinc sulfide will be oxidized to zinc oxide. At the same time, there will be some complex phase transitions and structural reorganizations:

[0044] Physical changes: The particle size of the waste residue will change and the porosity will increase, which is beneficial for subsequent acid leaching treatment;

[0045] Chemical changes: Some impurity components will be oxidized or converted into forms that can be easily removed during the acid leaching process.

[0046] In step three, during the acid leaching operation, the roasted product is placed in an acid-resistant container, and the acidic substance is slowly added while stirring to ensure that the material is fully in contact with the acid. The acid is sulfuric acid, the acid concentration is 3 mol / L, the temperature is 80°C, and the reaction time is 3 hours.

[0047] The solid-liquid separation in step 4 includes the following specific steps:

[0048] Step 1: First, prepare a suitable filtering device, such as a filter press or centrifuge, and slowly pour the acid-leached mixture into the filtering device;

[0049] Step 2: Start the filter press, apply pressure to make the liquid pass through the filter cloth, and the solid is trapped on the filter cloth to form a filter cake;

[0050] Step 3: After separation, carefully take out the Zn-containing precipitate product, collect the filtrate, and further process and detect the separated Zn-containing precipitate product.

[0051] In step 4, washing the zinc-containing precipitate product with deionized water for multiple times comprises the following specific steps:

[0052] Step 1: Place the separated zinc-containing precipitate product in a beaker or a washing tank, and add an appropriate amount of deionized water to completely immerse the precipitate product;

[0053] Step 2: Stir or shake the container to fully mix the precipitated product with deionized water, soak for 10 to 30 minutes, dissolve and remove impurity ions adsorbed on the surface, and perform solid-liquid separation;

[0054] Step 3: Repeat the above steps and wash multiple times, usually 3 to 5 times, until the pH value of the washing liquid is close to neutral and no obvious impurity ions can be detected. After each washing, the washing liquid can be tested to analyze the zinc ion concentration and impurity content to determine whether the washing effect meets the requirements.

[0055] In step five, the specific temperature for calcination and cooling can be 600-800°C.

[0056] The following is an introduction in conjunction with specific embodiments:

[0057] Embodiment 1:

[0058] The waste residue is pretreated to a particle size of 100 mesh and then subjected to magnetic separation.

[0059] Wash the zinc-containing precipitate several times with deionized water:

[0060] The precipitated product was fully mixed with deionized water and soaked for 10 minutes, and the above steps were repeated for multiple washings, and the washing was performed 3 times.

[0061] The specific temperature for calcination and cooling can be 600℃

[0062] Embodiment 2:

[0063] The waste residue is pretreated to a particle size of 200 mesh and then subjected to magnetic separation.

[0064] Wash the zinc-containing precipitate several times with deionized water:

[0065] The precipitated product was fully mixed with deionized water and soaked for 30 minutes, and the above steps were repeated for multiple washings, for a total of 5 times.

[0066] The specific temperature for calcination and cooling can be 800℃

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving the extraction of zinc oxide from metallurgical waste slag, characterized in that: include: Step 1: Waste slag pretreatment The metallurgical waste slag is crushed and ground to a particle size of 100-200 mesh, and then magnetically separated to remove magnetic impurities, and the metallurgical waste slag and solvent are fully mixed in a specific ratio to ensure that the waste slag particles are evenly distributed in the solvent; Step 2: Calcination The uniformly mixed materials are placed in a suitable roasting furnace and roasted under specific temperature, time and atmosphere conditions to cause the zinc compound in the waste slag to undergo physical and chemical changes, thereby obtaining a roasted product that is easy to subsequently process; Step 3: Acid leaching process The roasted product is subjected to acid leaching operation, and an appropriate amount of acidic substance is added thereto. By strictly controlling the type, concentration, temperature and reaction time of the acid, the dissolution, impurity removal, purification and refining are achieved, and the zinc element is precipitated in a specific form; Step 4: Solid-liquid separation The zinc-containing precipitate product is separated from the acid leaching solution by using solid-liquid separation technology, and then the zinc-containing precipitate product is washed multiple times with deionized water to remove residual impurities and acid solution; Step 5: Calcination and Cooling The washed zinc-containing precipitate product is placed in a calcining furnace and calcined at a specific temperature and air atmosphere. After a certain period of time, it is cooled to room temperature along with the furnace to finally obtain a high-purity zinc oxide product.

2. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the step 1 of waste residue pretreatment, the solvent is a mixed solution of ammonium chloride and sodium chloride, the mixing ratio of ammonium chloride to sodium chloride is 2:1, and the mass ratio of the solvent to the waste residue is 1:

2.

3. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the calcination treatment of step 2, the calcination temperature is 900° C., the calcination time is 4 hours, and the atmosphere condition is an oxidizing atmosphere.

4. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the physical and chemical changes of the zinc compounds in the waste slag in step 2, the zinc compounds in the metallurgical waste slag will undergo an oxidation reaction, and zinc sulfide will be oxidized to zinc oxide. At the same time, there will be some complex phase transformations and structural reorganizations: The physical changes: the particle size of the waste residue will change, and the porosity will increase, which is beneficial to the subsequent acid leaching treatment; The chemical changes: Some impurity components will be oxidized or converted into forms that are easily removed during the acid leaching process.

5. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the step three, during the acid leaching operation, the roasted product is placed in an acid-resistant container, and an acidic substance is slowly added while stirring to ensure that the material is fully in contact with the acid. The acid is sulfuric acid, the concentration of the acid is 3 mol / L, the temperature is 80° C., and the reaction time is 3 hours.

6. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: The solid-liquid separation in step 4 includes the following specific steps: Step 1: First, prepare a suitable filtering device, such as a filter press or centrifuge, and slowly pour the acid-leached mixture into the filtering device; Step 2: Start the filter press, apply pressure to make the liquid pass through the filter cloth, and the solid is trapped on the filter cloth to form a filter cake; Step 3: After separation, carefully take out the Zn-containing precipitate product, collect the filtrate, and further process and detect the separated Zn-containing precipitate product.

7. A method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the step 4, washing the zinc-containing precipitate product with deionized water for multiple times comprises the following specific steps: Step 1: Place the separated zinc-containing precipitate product in a beaker or a washing tank, and add an appropriate amount of deionized water to completely immerse the precipitate product; Step 2: Stir or shake the container to fully mix the precipitated product with deionized water, soak for 10 to 30 minutes, dissolve and remove impurity ions adsorbed on the surface, and perform solid-liquid separation; Step 3: Repeat the above steps and wash multiple times, usually 3 to 5 times, until the pH value of the washing liquid is close to neutral and no obvious impurity ions can be detected. After each washing, the washing liquid can be tested to analyze the zinc ion concentration and impurity content to determine whether the washing effect meets the requirements.

8. The method for improving the extraction of zinc oxide from metallurgical waste slag according to claim 1, characterized in that: In the step 5, the specific temperature of calcination and cooling can be 600-800°C.

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