Method for removing iron from spodumene smelting slag

Abstract

The invention discloses a method for removing iron from spodumene smelting slag, and belongs to the technical field of solid waste harmless treatment. The method provided by the invention comprises the following steps: S1, carrying out slurrying treatment on spodumene smelting slag and water, and then carrying out magnetic separation treatment to obtain slurry; s2, adding an acid into the slurry, stirring, then adding an oxidant, stirring, carrying out an oxidation acid leaching reaction, then carrying out solid-liquid separation, and carrying out separation and washing to obtain an aluminum-silicon mixture and a filtrate; the pH value of the acid is 1.5-5.5; the mass ratio of the acid to the spodumene smelting slag is (0.01-0.05): 1; s3, the aluminum-silicon mixture is subjected to vacuum drying treatment, and aluminum-silicon powder is obtained; and returning the filtrate to the step S1 for cyclic utilization. According to the method, the iron content in the spodumene smelting slag can be effectively reduced, the cost is low, and the economic benefit of the whole process can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of harmless treatment of solid waste, and specifically relates to a method for removing iron from spodumene smelting slag. Background Art

[0002] Lithium is widely used in new energy vehicles, aerospace, glass and ceramics, nuclear industry, medicine, petrochemical industry and other fields. It is known as "new energy metal", "aerospace alloy metal" and "industrial MSG" and is an important element in promoting scientific and technological progress and development in the 21st century.

[0003] Currently, lithium ores such as spodumene are the primary raw material sources for lithium extraction in my country. According to statistics, over 70% of domestic lithium salt production comes from lithium ore extraction. However, during the spodumene smelting process, every ton of lithium carbonate produced generates approximately 8-10 tons of spodumene slag. Currently, my country's annual lithium smelting slag production exceeds 12 million tons. This slag is rich in SiO2 and Al2O3, making it a high-quality raw material for the production of functional materials such as pyrophyllite, glass fiber, and glass-ceramics. However, spodumene slag has a complex composition, often containing various impurities such as iron, sodium, and potassium. The presence of iron in spodumene slag severely restricts its subsequent resource utilization. The large amount of lithium smelting slag stored in large quantities creates significant ecological and environmental pressures, hindering the high-quality, green development of the lithium battery industry. Therefore, the thorough removal of iron from spodumene slag can help reduce the amount of spodumene slag at its source and promote the high-quality, green development of the lithium battery industry.

[0004] Currently, the technology for removing iron from spodumene smelting slag has problems such as limited iron removal efficiency, high cost, and large reagent consumption, making it difficult to meet the requirements of large-scale industrial applications.

[0005] Therefore, there is an urgent need to provide an efficient and low-cost method for removing iron from spodumene smelting slag. Summary of the Invention

[0006] In view of this, the present application provides a method for removing iron from spodumene smelting slag, which can effectively reduce the iron content in spodumene smelting slag, has low cost, and is conducive to improving the economic benefits of the overall process.

[0007] In a first aspect, the present application provides a method for removing iron from spodumene smelting slag, characterized in that it comprises the following steps: Step S1: slurrying spodumene smelting slag with water, and then performing magnetic separation to obtain slurry; Step S2: adding acid to the slurry, stirring, then adding an oxidant, stirring, performing an oxidative acid leaching reaction, then performing solid-liquid separation, and obtaining an aluminum-silicon mixture and a filtrate through separation and washing; the pH of the acid is 1.5-5.5; the mass ratio of the acid to the spodumene smelting slag is 0.01-0.05:1; the oxidant includes at least one of an acidic medium oxidant, an alkaline medium oxidant, and a neutral medium oxidant; Step S3: vacuum drying the aluminum-silicon mixture to obtain aluminum-silicon powder; returning the filtrate to step S1 for recycling.

[0008] By adopting the above technical solution, the method provided in this application for efficiently removing iron from spodumene smelting slag achieves deep removal of iron elements, while reducing processing costs and helping to improve the economic benefits of the overall process.

[0009] In step S1 of the present application, multi-stage magnetic separation is used to generate an extremely high magnetic field gradient, which greatly improves the removal efficiency of magnetic iron minerals in spodumene smelting slag. In step S2, high concentration H + The Fe-O bond in the iron-containing mineral lattice of spodumene smelting slag is destroyed. The oxidant-coupled acid leaching treatment can dissociate the encapsulated fine iron impurities, thereby improving the chemical reactivity of the impurity iron. The fine iron impurities can be converted into dissolved ferrous ions under the joint action of hydrogen ions and oxidants. The oxidant can form a stable water-soluble complex with metallic iron ions in the acid system, thereby effectively reducing the iron content in the spodumene smelting slag. Step S3 returns the filtrate to step S1 for recycling, which not only reduces the consumption of reagents but also avoids wastewater discharge. The entire process of this application is simple to operate, economical and efficient, and environmentally friendly, which significantly improves the feasibility and economy of subsequent resource utilization of spodumene smelting slag.

[0010] Optionally, in step S1, the mass ratio of the spodumene smelting slag to water is 1:(0.5~4).

[0011] By adopting the above technical solution, the mass ratio of spodumene smelting slag to water in the present application can ensure that the spodumene smelting slag is fully dispersed in water to form a uniform slurry, which is helpful for the subsequent magnetic separation process, improves the magnetic separation efficiency, and thus further improves the iron removal efficiency.

[0012] Optionally, in step S1, the mass content of SiO2 in the spodumene smelting slag is 70wt%~75wt%.

[0013] Optionally, in step S1, the slurrying treatment includes stirring and dispersing, and the rotation speed of the stirring and dispersing is 50 rpm to 300 rpm; The temperature of the pulping treatment is 20° C. to 70° C., and the time is 20 min to 600 min.

[0014] By adopting the above technical solution, the present application significantly improves the overall effect of removing iron from spodumene smelting slag by controlling the stirring and dispersion speed, temperature and time parameters of the slurry treatment. The specific stirring and dispersion speed ensures that the spodumene smelting slag is fully dispersed in water, avoids agglomeration between particles, and reduces the risk of material damage caused by excessive shearing. The specific temperature helps to improve the processing efficiency while preventing unnecessary side reactions or volatilization losses of components due to excessively high temperatures. The specific time ensures that all components can reach the optimal mixing state.

[0015] Optionally, in step S1, the magnetic separation process is secondary magnetic separation or tertiary magnetic separation; The feed flow rate of the magnetic separation process is 2m 3 / h~3m 3 / h, the feed pressure is 0.2MPa~2MPa, and the magnetic field strength is 0.8T~1.5T.

[0016] By adopting the above technical solution, the present application adopts secondary or tertiary magnetic separation, which can achieve efficient step-by-step separation of magnetic iron minerals. Multi-stage magnetic separation can more fully capture the weakly magnetic or fine-grained iron minerals remaining in the slurry, significantly improving the overall iron removal rate. The control of the feed flow rate ensures that the material has sufficient residence time in the magnetic separation equipment, so that the magnetic particles are fully exposed to the magnetic field, thereby improving the magnetic separation efficiency, while avoiding the loss of iron minerals caused by excessive flow rate. The control of the feed pressure helps to maintain a stable flow of slurry in pipes and equipment, prevent the occurrence of blockages, and enhance the migration ability of solid particles under the action of the magnetic field, which is conducive to improving the capture efficiency of magnetic substances. The specific magnetic field strength can achieve selective iron removal, effectively attracting a variety of iron-containing impurities including weakly magnetic iron minerals, without interfering with non-magnetic components.

[0017] Optionally, in step S2, the acid includes at least one of hydrochloric acid, hydrofluoric acid, nitric acid, oxalic acid, and sulfuric acid.

[0018] By adopting the above technical solution, the selection of acid in the present application can cope with the complex mineral composition of spodumene smelting slag, is suitable for destroying Fe-O bonds in iron-containing minerals, and further improves the removal efficiency of iron elements.

[0019] Optionally, in step S2, the moisture content of the aluminum-silicon mixture is 10% to 50%.

[0020] By adopting the above technical solution, the moisture content of the aluminum-silicon mixture of the present application helps to ensure the smooth progress of subsequent processing steps, maintaining the good dispersion of the aluminum-silicon mixture and preventing particle agglomeration, while also preventing the material from being too dry and increasing the difficulty of operation.

[0021] Optionally, the acidic medium oxidant includes at least one of concentrated sulfuric acid, concentrated hydrochloric acid, concentrated nitric acid, and peroxide acid; The alkaline medium oxidant includes at least one of persulfate, sodium hypochlorite, ozone, and chlorine dioxide; The neutral medium oxidant includes at least one of carbon monoxide, nitric oxide, and nitrogen dioxide.

[0022] By adopting the above technical solution, the oxidant of the present application is divided into acidic medium oxidant, alkaline medium oxidant and neutral medium oxidant according to its applicable medium environment, achieving flexible adaptation to different process conditions and meeting the needs of efficient iron removal.

[0023] The acidic medium oxidant of the present application is suitable for use under acidic conditions, and can work together with acid to enhance the ability to destroy Fe-O bonds in the lattice of iron-containing minerals, thereby improving the leaching rate and removal efficiency of iron elements, and is suitable for treating fine iron impurities wrapped in silicates, thereby achieving deep de-ironification. The alkaline medium oxidant of the present application can function in an alkaline or moderately alkaline environment, usually has strong oxidizing ability and good stability, and effectively promotes the conversion and dissolution of iron ions. The neutral medium oxidant of the present application can work in a pH environment close to neutral, and its mild operating conditions help maintain the structural stability of the aluminum-silicon mixture and the integrity of other useful components, which is beneficial to the performance control of subsequent resource products.

[0024] Optionally, in step S2, the mass ratio of the oxidant to the spodumene smelting slag is 0.01-0.05:1.

[0025] By adopting the above technical solution, the present application controls the mass ratio of the oxidant to the spodumene smelting slag, ensuring sufficient oxidant participation in the reaction, increasing the iron leaching rate and achieving deep iron removal, while avoiding excessive oxidant use and the initiation of unnecessary side reactions. This achieves both efficient iron removal and cost-effectiveness, maximizing economic efficiency.

[0026] Optionally, in step S2, the reaction temperature of the oxidative acid leaching reaction is 20° C. to 80° C., and the reaction time is 20 min to 600 min.

[0027] By adopting the above technical solution, the present application controls the reaction temperature of the oxidative acid leaching reaction, which helps enhance the efficiency of the acid and oxidant on the iron mineral, thereby improving the reaction activity and destroying the Fe-O bonds in the iron-containing mineral lattice, thereby increasing the iron leaching rate. The specific reaction time ensures that the acid and oxidant have sufficient time to fully contact the iron mineral and complete the reaction, completely dissociating the lattice iron and the fine iron impurities in the inclusions, effectively improving the solubility and removal rate of the iron element.

[0028] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The method provided in this application achieves deep removal of iron elements, while reducing processing costs and helping to improve the economic benefits of the overall process.

[0029] 2. The present invention uses magnetic separation and oxidant-coupled acid leaching to deeply remove iron from spodumene smelting slag. Multi-stage magnetic separation is used to generate extremely high magnetic field gradients, which greatly improves the removal efficiency of magnetic iron minerals in spodumene smelting slag. High concentration of H + Destroy the Fe-O bonds in the iron-containing mineral lattices of spodumene smelting slag; fine iron impurities are converted into dissolved ferrous ions under the synergistic action of hydrogen ions and oxidants. The oxidants can form stable water-soluble complexes with metallic iron ions in the acid system, and are removed after filtration and washing.

[0030] 3. The entire process of this application is simple to operate, economical and efficient, and environmentally friendly, which significantly improves the feasibility and economy of subsequent resource utilization of spodumene smelting slag. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a method for removing iron from spodumene smelting slag provided in Example 1 of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0033] The inventors of this application discovered, during their research on iron removal from spodumene smelting slag, that CN112551535A discloses a process for iron removal and whitening spodumene. By combining appropriate hydrochloric acid ratios, heating temperatures, and holding times, the Fe₂O₃ impurity content in spodumene smelting slag is reduced, thereby increasing whiteness. However, this process involves significant issues, such as the high hydrochloric acid dosage, high heating temperatures, and long processing times. CN115353128A discloses a method for iron removal during lithium carbonate production. The slurry prepared when producing lithium carbonate is passed into a demagnetizer and filtered to obtain filtered slurry, limestone slurry is added to the filtered slurry, and the pH value is adjusted to 6~7, leachate and filter cake are obtained, and the leachate purification adopts alkalization decalcification method, alkalizes the leachate with lime milk, and the pH value is increased to 11~12, so that iron is hydrolyzed into hydroxide precipitation, and purified liquid is obtained; CN114789087A discloses a kind of efficient iron removal equipment and iron removal method of lithium battery material, by arranging servo drive assembly to drive rotating rod to rotate, and then under the effect of centrifugal force, drive recovery column motion to knock lithium battery material, make the lithium battery material of agglomeration pulverize and fully contact with recovery column, then by passing electromagnet energization to produce magnetism iron is recovered, thus reach the effect of lithium battery material efficient iron removal. But there is invention cost height in the above-mentioned prior art scheme, is unfavorable for the further high-value harmless utilization of spodumene smelting slag, and there are the problems such as the use of a large amount of reagents simultaneously, bring certain pressure to post-processing process.

[0034] In order to solve the above problems, the present application proposes a method for removing iron from spodumene smelting slag, comprising the following steps: Step S1: slurrying spodumene smelting slag with water, and then performing magnetic separation to obtain slurry; Step S2: adding acid to the slurry, stirring, then adding an oxidant, stirring, performing an oxidative acid leaching reaction, and then performing solid-liquid separation, and obtaining an aluminum-silicon mixture and a filtrate through separation and washing; the pH of the acid is 1.5-5.5; the mass ratio of the acid to the spodumene smelting slag is 0.01-0.05:1; and the oxidant includes at least one of an acidic medium oxidant, an alkaline medium oxidant, and a neutral medium oxidant; Step S3: vacuum drying the aluminum-silicon mixture to obtain aluminum-silicon powder. The inventors found that the present invention uses a method for deep removal of iron from spodumene smelting slag by magnetic separation and oxidant-coupled acid leaching. Multi-stage magnetic separation is used to generate an extremely high magnetic field gradient, which greatly improves the removal efficiency of magnetic iron minerals in spodumene smelting slag. High concentration H +The Fe-O bonds in the iron-containing mineral lattice of spodumene slag are destroyed. Fine iron impurities are converted into dissolved ferrous ions under the synergistic action of hydrogen ions and oxidants. The oxidants, in an acidic system, form stable water-soluble complexes with metallic iron ions, which are then removed through filtration and washing. This method facilitates the deep removal of iron from spodumene slag and improves the economic benefits of its back-end utilization.

[0035] In some embodiments, in step S1, the filtrate is returned to step S1 for recycling. In the present application, the filtrate is returned to step S1 for recycling, which further reduces costs and improves economic benefits.

[0036] In some embodiments, in step S1, the mass ratio of spodumene smelting slag to water is 1:(0.5-4). The present application controls the mass ratio of spodumene smelting slag to water to further improve the iron removal efficiency.

[0037] In some embodiments, in step S1, the mass content of SiO2 in the spodumene smelting slag is 70wt%~75wt%.

[0038] In some embodiments, in step S1, the pulping process includes stirring and dispersing, and the stirring and dispersing speed is 50 rpm to 300 rpm. The pulping process of the present application further improves the iron removal efficiency.

[0039] In some embodiments, the temperature of the pulping treatment is 20° C. to 70° C., and the time is 20 min to 600 min. The present application controls the temperature and time of the pulping treatment to further improve the iron removal efficiency.

[0040] In some embodiments, in step S1, the magnetic separation process is a secondary magnetic separation or a tertiary magnetic separation. The multi-stage magnetic separation of the present application further improves the iron removal efficiency.

[0041] In some embodiments, the feed flow rate of the magnetic separation process is 2m 3 / h~3m 3 / h, the feed pressure is 0.2MPa~2MPa, and the magnetic field strength is 0.8T~1.5T. The present application controls the magnetic separation parameters to further improve the iron removal efficiency.

[0042] In some embodiments, in step S2, the acid comprises at least one of hydrochloric acid, hydrofluoric acid, nitric acid, oxalic acid, and sulfuric acid. The present application controls the selection of acid to further improve the iron removal efficiency.

[0043] In some embodiments, in step S2, the moisture content of the aluminum-silicon mixture is 10% to 50%. The present application controls the moisture content of the aluminum-silicon mixture to further improve the iron removal efficiency.

[0044] In some embodiments, the acidic medium oxidant includes at least one of concentrated sulfuric acid, concentrated hydrochloric acid, concentrated nitric acid, and peroxide acid. The selection of the oxidant in the present application further improves the iron removal efficiency.

[0045] In some embodiments, the alkaline medium oxidant includes at least one of persulfate, sodium hypochlorite, ozone, and chlorine dioxide. The selection of the oxidant in the present application further improves the iron removal efficiency.

[0046] In some embodiments, the neutral medium oxidant includes at least one of carbon monoxide, nitrogen monoxide, and nitrogen dioxide. The selection of the oxidant in the present application further improves the iron removal efficiency.

[0047] In some embodiments, in step S2, the mass ratio of the oxidant to the spodumene smelting slag is 0.01 to 0.05: 1. The present application controls the mass ratio of the oxidant to the spodumene smelting slag to further improve the iron removal efficiency.

[0048] In some embodiments, in step S2, the reaction temperature of the oxidative acid leaching reaction is 20° C. to 80° C., and the reaction time is 20 min to 600 min. The present application controls the reaction conditions of the oxidative acid leaching reaction to further improve the iron removal efficiency.

[0049] The scheme of the present application is described below with reference to the following specific examples. Unless otherwise specified, the raw materials used in the following examples are all from common commercial products, and the devices or equipment used are all purchased from conventional market sales channels. Specific embodiments Example 1 This embodiment provides a method for removing iron from spodumene smelting slag, characterized in that it includes the following steps: Step S1: Spodumene smelting slag with a SiO2 content of 74wt% and water are pulped in a pulping tank at a mass ratio of 1:4, and then transported to a magnetic separation device with a magnetic field strength of 0.8T for a preliminary iron removal reaction, and magnetic iron impurities are collected at the bottom of the magnetic separation device. The slurry after magnetic separation is transported from the top to the acid hydrolysis device; wherein, the pulping treatment is stirring and dispersing, the rotation speed is 50rpm; the pulping treatment temperature is 40℃, the time is 20min; the magnetic separation treatment is secondary magnetic separation, and the feed flow rate of the magnetic separation treatment is 2m 3 / h, feed pressure is 1MPa; Step S2: adding acid to the slurry at a mass ratio of acid to spodumene smelting slag of 0.01:1, stirring, then adding an oxidant at a mass ratio of oxidant to spodumene smelting slag of 0.01:1, stirring, and performing an oxidative acid leaching reaction, the reaction temperature is 20°C, the reaction time is 300 minutes, and then performing solid-liquid separation, and obtaining an aluminum-silicon mixture with a water content of 30% and a filtrate through separation and washing; the pH of the acid is 2; the acid is hydrochloric acid and sulfuric acid in a mass ratio of 1:1; the oxidant is concentrated nitric acid and sodium persulfate in a mass ratio of 1:1; Step S3: vacuum-dry the aluminum-silicon mixture to obtain aluminum-silicon powder; and return the filtrate to the slurrying step of step S1 for recycling.

[0051] Example 2 This embodiment provides a method for removing iron from spodumene smelting slag, characterized in that it includes the following steps: Step S1: Spodumene smelting slag with a SiO2 content of 74wt% is treated with water in a mass ratio of 1:3, and then transported to a magnetic separation device with a magnetic field strength of 1T for a preliminary iron removal reaction, and magnetic iron impurities are collected at the bottom of the magnetic separation device. The slurry after magnetic separation is transported from the top to the acid hydrolysis device; wherein, the slurry treatment is stirring and dispersing, the speed is 150rpm; the slurry treatment temperature is 20℃, the time is 200min; the magnetic separation treatment is secondary magnetic separation, and the feed flow rate of the magnetic separation treatment is 2m 3 / h, feed pressure is 0.2MPa; Step S2: adding acid to the slurry at a mass ratio of acid to spodumene smelting slag of 0.02:1, stirring, then adding an oxidant at a mass ratio of oxidant to spodumene smelting slag of 0.02:1, stirring, and performing an oxidative acid leaching reaction at a reaction temperature of 40°C and a reaction time of 200 minutes, then performing solid-liquid separation, and obtaining an aluminum-silicon mixture with a water content of 30% and a filtrate through separation and washing; the pH of the acid is 2; the acid is hydrochloric acid and sulfuric acid in a mass ratio of 1:1; and the oxidant is concentrated nitric acid and sodium persulfate in a mass ratio of 1:1; Step S3: vacuum-dry the aluminum-silicon mixture to obtain aluminum-silicon powder; and return the filtrate to the slurrying step of step S1 for recycling.

[0052] Example 3 This embodiment provides a method for removing iron from spodumene smelting slag, characterized in that it includes the following steps: Step S1: Spodumene smelting slag with a SiO2 content of 74wt% is slurried with water in a mass ratio of 1:2, and then transported to a magnetic separation device with a magnetic field strength of 1.5T for preliminary iron removal reaction, and magnetic iron impurities are collected at the bottom of the magnetic separation device. The slurry after magnetic separation is transported from the top to the acid hydrolysis device; wherein, the slurry treatment is stirring and dispersing, the rotation speed is 300rpm; the slurry treatment temperature is 60℃, the time is 600min; the magnetic separation treatment is secondary magnetic separation, and the feed flow rate of the magnetic separation treatment is 3m 3 / h, feed pressure is 1.5MPa; Step S2: adding acid to the slurry at a mass ratio of acid to spodumene smelting slag of 0.03:1, stirring, then adding an oxidant at a mass ratio of oxidant to spodumene smelting slag of 0.03:1, stirring, and performing an oxidative acid leaching reaction at a reaction temperature of 80°C and a reaction time of 400 minutes, then performing solid-liquid separation, and obtaining an aluminum-silicon mixture with a water content of 30% and a filtrate through separation and washing; the pH of the acid is 1.5; the acid is hydrochloric acid and sulfuric acid in a mass ratio of 1:1; and the oxidant is concentrated nitric acid and sodium persulfate in a mass ratio of 1:1; Step S3: vacuum-dry the aluminum-silicon mixture to obtain aluminum-silicon powder; and return the filtrate to the slurrying step of step S1 for recycling.

[0053] Example 4 This embodiment provides a method for removing iron from spodumene smelting slag, characterized in that it includes the following steps: Step S1: Spodumene smelting slag with a SiO2 content of 74wt% is slurried with water in a mass ratio of 1:1.5, and then transported to a magnetic separation device with a magnetic field strength of 1.8T for a preliminary iron removal reaction, and magnetic iron impurities are collected at the bottom of the magnetic separation device. The slurry after magnetic separation is transported from the top to an acid hydrolysis device; wherein, the slurry treatment is stirring and dispersing, and the rotation speed is 200rpm; the slurry treatment temperature is 70℃, and the time is 400min; the magnetic separation treatment is secondary magnetic separation, and the feed flow rate of the magnetic separation treatment is 2.5m 3 / h, feed pressure is 2MPa; Step S2: adding acid to the slurry at a mass ratio of acid to spodumene smelting slag of 0.04:1, stirring, then adding an oxidant at a mass ratio of oxidant to spodumene smelting slag of 0.04:1, stirring, and performing an oxidative acid leaching reaction, the reaction temperature is 60°C, the reaction time is 600 minutes, and then solid-liquid separation is performed, and separation and washing are performed to obtain an aluminum-silicon mixture with a water content of 30% and a filtrate; the pH of the acid is 1.5; the acid is hydrochloric acid and sulfuric acid in a mass ratio of 1:1; the oxidant is concentrated nitric acid and sodium persulfate in a mass ratio of 1:1; Step S3: vacuum-dry the aluminum-silicon mixture to obtain aluminum-silicon powder; and return the filtrate to the slurrying step of step S1 for recycling.

[0054] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no oxidant is added in Comparative Example 1, and the other conditions are the same as those in Example 1.

[0055] Experimental testing Test items SiO2 content in aluminum silicon powder: detected by X-ray fluorescence spectrometer; Al2O3 content in aluminum silicon powder: detected by X-ray fluorescence spectrometer; Fe2O3 content in aluminum silicon powder: detected by inductively coupled plasma mass spectrometry.

[0056] The aluminum silicon powder obtained by the method for removing iron from spodumene smelting slag provided in Examples 1 to 4 and Comparative Example 1 was tested for SiO2 content, Al2O3 content, and Fe2O3 content. The test results are shown in Table 1.

[0057] Table 1

[0058] From the test results in Table 1, it can be seen that the aluminum silicon powder obtained by treating spodumene smelting slag using the method of the present application has higher SiO2 content and Al2O3 content and lower Fe2O3 content, which fully proves that the method provided by the present application can achieve deep removal of iron.

[0059] In the aluminum silicon powder obtained in Comparative Example 1, the SiO2 content and the Al2O3 content are significantly reduced, while the Fe2O3 content is significantly increased, and its deironing efficiency is lower than that of Example 1.

[0060] Examples 5 to 8 Example 5 The difference between Example 5 and Example 2 is that in step S2 of Example 5, the moisture content of the aluminum-silicon mixture is 10%.

[0061] Example 6 The difference between Example 6 and Example 2 is that in step S2 of Example 6, the moisture content of the aluminum-silicon mixture is 50%.

[0062] Example 7 The difference between Example 7 and Example 2 is that in step S2 of Example 7, the mass ratio of the oxidant to the spodumene smelting slag is 0.01:1. Example 8 The difference between Example 8 and Example 2 is that in step S2 of Example 8, the mass ratio of the oxidant to the spodumene smelting slag is 0.05:1. The aluminum silicon powder obtained by the method for removing iron from spodumene smelting slag provided in Examples 5 to 8 was tested for SiO2 content, Al2O3 content, and Fe2O3 content. The test results are shown in Table 2.

[0063] Table 2

[0064] From the test results in Table 2, it can be seen that the difference between Example 5, Example 6 and Example 2 is that the moisture content of the aluminum-silicon mixture is different. Among them, the aluminum-silicon powder obtained in Example 2 has the lowest Fe2O3 content and the best deironing efficiency.

[0065] The difference between Example 7 and Example 8 and Example 2 is that the mass ratio of the oxidant to the spodumene smelting slag is different. Among them, the aluminum silicon powder obtained in Example 8 has the lowest Fe2O3 content and the best deironing efficiency.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for removing iron from spodumene smelting slag, characterized in that, The steps include: Step S1: slurrying spodumene smelting slag with water, and then performing magnetic separation to obtain slurry; Step S2: adding acid to the slurry, stirring, then adding an oxidant, stirring, performing an oxidative acid leaching reaction, then performing solid-liquid separation, and obtaining an aluminum-silicon mixture and a filtrate through separation and washing; the pH of the acid is 1.5-5.5; the mass ratio of the acid to the spodumene smelting slag is 0.01-0.05:1; the oxidant includes at least one of an acidic medium oxidant, an alkaline medium oxidant, and a neutral medium oxidant; Step S3: vacuum drying the aluminum-silicon mixture to obtain aluminum-silicon powder; returning the filtrate to step S1 for recycling.

2. The method according to claim 1, characterized in that In the step S1, the mass ratio of the spodumene smelting slag to water is 1:(0.5-4).

3. The method according to claim 1, characterized in that In the step S1, the mass content of SiO2 in the spodumene smelting slag is 70wt%~75wt%.

4. The method according to claim 1, wherein In the step S1, the slurrying treatment includes stirring and dispersing, and the rotation speed of the stirring and dispersing is 50 rpm to 300 rpm; The temperature of the pulping treatment is 20° C. to 70° C., and the time is 20 min to 600 min.

5. The method according to claim 1, wherein In the step S1, the magnetic separation process is a secondary magnetic separation or a tertiary magnetic separation; The feed flow rate of the magnetic separation process is 2m 3 / h~3m 3 / h, the feed pressure is 0.2MPa~2MPa, and the magnetic field strength is 0.8T~1.5T.

6. The method according to claim 1, characterized in that In step S2, the acid includes at least one of hydrochloric acid, hydrofluoric acid, nitric acid, oxalic acid, and sulfuric acid.

7. The method according to claim 1, characterized in that In step S2, the moisture content of the aluminum-silicon mixture is 10% to 50%.

8. The method according to claim 1, characterized in that The acidic medium oxidant includes at least one of concentrated sulfuric acid, concentrated hydrochloric acid, concentrated nitric acid, and peroxide acid; The alkaline medium oxidant includes at least one of persulfate, sodium hypochlorite, ozone, and chlorine dioxide; The neutral medium oxidant includes at least one of carbon monoxide, nitric oxide, and nitrogen dioxide.

9. The method according to claim 1, characterized in that In step S2, the mass ratio of the oxidant to the spodumene smelting slag is 0.01-0.05:

1.

10. The method according to claim 1, characterized in that In step S2, the reaction temperature of the oxidative acid leaching reaction is 20° C. to 80° C., and the reaction time is 20 min to 600 min.

Images