Method for inhibiting leaching of beryllium in lithium smelting slag

Abstract

The invention discloses a method for inhibiting leaching of beryllium in lithium smelting slag, and the method comprises the following steps: mixing a curing and stabilizing agent and the lithium smelting slag in a ball milling manner, and enabling the leaching concentration of beryllium in the treated lithium smelting slag to meet the national standard; the treatment method can be directly carried out on the basis of the existing lithium smelting process flow; the curing and stabilizing agent comprises a calcium-containing compound; the calcium-containing compound comprises at least one of calcium phosphate, calcium sulfate, calcium carbonate and calcium hydroxide. Based on a compound beryllium fixing principle of lattice substitution and adsorption, after the medicament is used for treating the beryllium-containing lithium smelting slag, beryllium in the treated lithium smelting slag can be stably cured. Besides, the curing and stabilizing agent can be common industrial solid waste, is wide in raw material source, simple to operate, remarkable in effect and easy to realize large-scale application, treats waste with waste and has important significance on harmless treatment and resource utilization of the high-toxicity lithium slag.

Description

Technical Field

[0001] The present application belongs to the technical field of harmless treatment of lithium smelting slag, and specifically relates to a method for inhibiting beryllium leaching in lithium smelting slag. Background Art

[0002] Lithium smelting slag, especially the waste slag produced after lithium mica ore is roasted with sulfate and leached to extract lithium, has become a major problem in environmental governance. With the rapid development of the new energy industry, the demand for lithium carbonate has continued to increase, and the amount of lithium smelting slag produced each year has reached tens of millions of tons. These waste slags contain toxic heavy metals such as thallium, beryllium, rubidium, and cesium, which can be leached and leaked through rainwater and other channels, causing serious pollution to the soil and groundwater. At present, the mainstream treatment idea is to deeply remove these toxic heavy metals through methods such as external field action and mild acid treatment, but the treatment of beryllium is particularly difficult. Beryllium is difficult to completely remove due to its unique properties, and after deep removal treatment, the beryllium that is difficult to leach in lithium smelting slag is activated instead, and its leaching concentration may reach tens or even hundreds of micrograms per liter, far exceeding the national standard. This shows that the existing technology has obvious deficiencies in the treatment of beryllium in lithium smelting slag, and it is urgent to develop new and effective methods to stabilize and solidify beryllium in lithium smelting slag to reduce its leaching toxicity to a level that meets national standards. Summary of the invention

[0003] In view of this, the present application provides a method for inhibiting beryllium leaching from lithium smelting slag, by which the beryllium in the treated lithium smelting slag can be effectively stabilized and solidified, ensuring that the leaching concentration of beryllium is reduced to below the standard specified in the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007), meeting national environmental protection requirements. In addition, the stabilizing and solidifying agent used in the present application belongs to general industrial solid waste, with a wide source of raw materials, low cost, and the advantage of resource recycling, achieving dual benefits of environmental protection and economy.

[0004] In a first aspect, a method for inhibiting beryllium leaching from lithium smelting slag comprises the following steps: S1, mixing a solidifying stabilizing agent with lithium smelting slag to obtain a mixed material; S2, ball milling the mixed material described in step S1; Steps S1 and S2 can be directly carried out in the existing lithium smelting process; The solidification stabilization agent in step S1 includes a calcium-containing compound; The calcium-containing compound includes at least one of calcium phosphate, calcium sulfate, calcium carbonate and calcium hydroxide.

[0005] By adopting the above technical scheme, the present application provides a method for inhibiting the leaching of beryllium in lithium smelting slag, which solves the problem of beryllium leaching in lithium smelting slag. The calcium-containing compound in the present application can effectively fix the beryllium in the lithium smelting slag through lattice substitution and adsorption, reducing its leaching risk; in addition, the entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application. In summary, the present application provides an efficient and easy-to-operate method for inhibiting the leaching of beryllium in lithium smelting slag, which is of great significance for the harmless disposal of highly toxic lithium slag.

[0006] Optionally, the ratio of the amount of the calcium-containing compound to the amount of the lithium smelting slag is 1:(0.2-200).

[0007] Optionally, the source of the solidification and stabilization agent is industrial solid waste; the industrial solid waste includes at least one of waste gypsum, wastewater neutralization slag, carbide slag, desulfurization gypsum slag, and phosphogypsum.

[0008] By adopting the above technical scheme, the source of the solidification and stabilization agent in this application is industrial solid waste. This measure not only effectively solves the problem of beryllium leaching in lithium smelting slag, but also realizes the resource utilization of industrial solid waste, achieving the dual benefits of environmental protection and economy. Using industrial solid waste as a reagent not only has a wide source of raw materials and low cost, but also can reduce secondary pollution and promote the recycling of resources. This makes the entire treatment process more economical and feasible, and it is also in line with the concept of sustainable development. In summary, this technical scheme significantly improves the efficiency and environmental protection performance of lithium smelting slag treatment, and is of great significance to the harmless disposal and resource utilization of highly toxic lithium slag. In addition, the solidification and stabilization agent used is derived from industrial solid waste, with a wide source of raw materials and low cost, which reduces the processing cost; at the same time, using industrial solid waste as a reagent realizes the recycling of resources, reduces secondary pollution, and further enhances the environmental protection effect.

[0009] Further optionally, the weight of the solidification and stabilization agent in step S1 is negatively correlated with the content of calcium-containing compounds in the solid waste; When the calcium content in the industrial solid waste is not less than 60%, the weight of the solidification and stabilization agent is w of the weight of the lithium smelting slag; the w satisfies 0.5%≤w<35%; When the calcium content in the industrial solid waste is lower than 60%, the weight of the solidification and stabilization agent is k of the weight of the lithium smelting slag; and k satisfies 35%≤k<500%.

[0010] By adopting the above technical scheme, the weight of the solidifying and stabilizing agent in this application is negatively correlated with the content of calcium compounds in industrial solid waste. When the calcium content in industrial solid waste is not less than 60%, the dosage of the solidifying and stabilizing agent is 0.5%-35% of the lithium smelting slag; when the calcium content is less than 60%, the dosage of the agent is 35%-500% of the lithium smelting slag. This measure not only significantly improves the solidification effect of beryllium in lithium smelting slag, ensuring that the leaching concentration of beryllium in the treated lithium smelting slag meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007), but also significantly reduces the treatment cost and improves the economic benefits by optimizing the dosage of the agent. At the same time, the use of industrial solid waste as a reagent not only has a wide source of raw materials and low cost, but also can reduce secondary pollution, promote the recycling of resources, and conform to the concept of sustainable development. The entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application, which is of great significance for the harmless disposal and resource utilization of highly toxic lithium slag.

[0011] Preferably, the calcium-containing compound includes calcium sulfate and calcium hydroxide.

[0012] By adopting the above technical scheme, the calcium-containing compounds in the present application include calcium sulfate and calcium hydroxide, which significantly improves the solidification effect of beryllium in lithium smelting slag. Calcium sulfate and calcium hydroxide can efficiently fix beryllium in lithium smelting slag through lattice substitution and adsorption, reduce its leaching risk, and ensure that the leaching concentration of beryllium in the treated lithium smelting slag meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007). These two calcium-containing compounds are widely available and low-cost. Through reasonable selection and proportioning, the processing cost can be significantly reduced and the economic benefit can be improved. At the same time, the scheme has strong adaptability and can achieve good solidification effects under different calcium contents. In addition, the use of calcium sulfate and calcium hydroxide in industrial solid waste as agents not only reduces secondary pollution, but also promotes the recycling of resources, which is in line with the concept of sustainable development. The entire treatment process is simple and easy to implement, which is convenient for large-scale promotion and application, and is of great significance to the harmless disposal and resource utilization of highly toxic lithium slag.

[0013] Optionally, the weight ratio of calcium sulfate to calcium hydroxide is 1:(0.05-1).

[0014] Optionally, the calcium-containing compound includes calcium sulfate, calcium hydroxide and calcium phosphate.

[0015] By adopting the above technical scheme, the calcium-containing compounds in this application include calcium sulfate, calcium hydroxide and calcium phosphate, which significantly improves the solidification effect of beryllium in lithium smelting slag. Calcium sulfate, calcium hydroxide and calcium phosphate can effectively fix beryllium in lithium smelting slag through lattice substitution and adsorption, reduce its leaching risk, and ensure that the leaching concentration of beryllium in the treated lithium smelting slag meets the requirements of "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007). These three calcium-containing compounds are widely available and low in cost. Through reasonable selection and proportioning, the processing cost can be significantly reduced and the economic benefit can be improved. At the same time, the scheme has strong adaptability and can achieve good solidification effect under different calcium contents. When the calcium content in industrial solid waste is not less than 60%, the dosage of the solidification stabilization agent is 0.5%-35% of the lithium smelting slag; when the calcium content is less than 60%, the dosage of the agent is 35%-500% of the lithium smelting slag. In addition, the use of calcium sulfate, calcium hydroxide and calcium phosphate in industrial solid waste as reagents not only reduces secondary pollution, but also promotes the recycling of resources, which is in line with the concept of sustainable development. The entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application, which is of great significance for the harmless disposal and resource utilization of highly toxic lithium slag.

[0016] Optionally, the weight ratio of calcium sulfate, calcium hydroxide and calcium phosphate is 1: (0.05-1): (0.01-0.3) Optionally, the calcium-containing compound includes calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate.

[0017] By adopting the above technical scheme, the calcium-containing compounds in this application include calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate, which significantly improves the solidification effect of beryllium in lithium smelting slag. These calcium-containing compounds work together through multiple mechanisms to more comprehensively and effectively fix beryllium in lithium smelting slag, reduce its leaching risk, and ensure that the leaching concentration of beryllium in the treated lithium smelting slag meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007). These four calcium-containing compounds are widely available and low-cost. Through reasonable selection and proportioning, the treatment cost can be significantly reduced and the economic benefit can be improved. The scheme has strong adaptability and can achieve good solidification effect under different calcium contents. When the calcium content in industrial solid waste is not less than 60%, the dosage of the solidification stabilization agent is 0.5%-35% of the lithium smelting slag; when the calcium content is less than 60%, the dosage of the agent is 35%-500% of the lithium smelting slag. In addition, using these calcium compounds in industrial solid waste as reagents not only reduces secondary pollution, but also promotes the recycling of resources, which is in line with the concept of sustainable development. The entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application, which is of great significance for the harmless disposal and resource utilization of highly toxic lithium slag.

[0018] Optionally, the weight ratio of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate is 1:(0.05-1):(0.01-0.3):(0.005-0.2).

[0019] Optionally, the ball milling speed in step S2 is 100-2000 rpm; and the ball milling time is 05-4h.

[0020] In summary, the present invention includes at least one of the following beneficial technical effects.

[0021] 1. The present application provides a method for inhibiting the leaching of beryllium in lithium smelting slag, which solves the problem of beryllium leaching in lithium smelting slag. The calcium-containing compound in the present application can effectively fix the beryllium in the lithium smelting slag through lattice substitution and adsorption, reducing its leaching risk; in addition, the entire treatment process is simple and easy to implement, which is convenient for large-scale promotion and application. In summary, the present application provides an efficient and easy-to-operate method for inhibiting the leaching of beryllium in lithium smelting slag, which is of great significance for the harmless disposal of highly toxic lithium slag.

[0022] 2. The source of the solidification and stabilization agent in this application is industrial solid waste. This measure not only effectively solves the problem of beryllium leaching in lithium smelting slag, but also realizes the resource utilization of industrial solid waste, achieving the dual benefits of environmental protection and economy. The use of industrial solid waste as a reagent not only has a wide source of raw materials and low cost, but also can reduce secondary pollution and promote the recycling of resources. This makes the entire treatment process more economical and feasible, and it is also in line with the concept of sustainable development. In summary, this technical solution significantly improves the efficiency and environmental protection performance of lithium smelting slag treatment, and is of great significance to the harmless disposal and resource utilization of highly toxic lithium slag.

[0023] 3. The calcium-containing compounds in this application include calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate, which significantly improves the solidification effect of beryllium in lithium smelting slag. These calcium-containing compounds work together through multiple mechanisms to more comprehensively and effectively fix beryllium in lithium smelting slag, reduce its leaching risk, and ensure that the leaching concentration of beryllium in the treated lithium smelting slag meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007). These four calcium-containing compounds are widely available and low-cost. Through reasonable selection and proportioning, the treatment cost can be significantly reduced and the economic benefit can be improved. The scheme has strong adaptability and can achieve good solidification effect under different calcium contents. When the calcium content in industrial solid waste is not less than 60%, the dosage of the solidification and stabilization agent is 0.5%-35% of the lithium smelting slag; when the calcium content is less than 60%, the dosage of the agent is 35%-500% of the lithium smelting slag. In addition, using these calcium compounds in industrial solid waste as reagents not only reduces secondary pollution, but also promotes the recycling of resources, which is in line with the concept of sustainable development. The entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application, which is of great significance for the harmless disposal and resource utilization of highly toxic lithium slag. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0025] The scheme of the present application is described below in conjunction with 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.

[0026] Lithium smelting slag, especially the waste slag produced after lithium mica ore is roasted with sulfate and leached to extract lithium, has become a major problem in environmental governance. With the rapid development of the new energy industry, the demand for lithium carbonate has continued to increase, and the amount of lithium smelting slag produced each year has reached tens of millions of tons. These waste slags contain toxic heavy metals such as thallium, beryllium, rubidium, and cesium, which can be leached and leaked through rainwater and other channels, causing serious pollution to the soil and groundwater. At present, the mainstream treatment idea is to deeply remove these toxic heavy metals through methods such as external field action and mild acid treatment, but the treatment of beryllium is particularly difficult. Beryllium is difficult to completely remove due to its unique properties, and after deep removal treatment, the beryllium that is difficult to leach in lithium smelting slag is activated instead, and its leaching concentration may reach tens or even hundreds of micrograms per liter, far exceeding the national standard. This shows that the existing technology has obvious deficiencies in the treatment of beryllium in lithium smelting slag, and it is urgent to develop new and effective methods to stabilize and solidify beryllium in lithium smelting slag to reduce its leaching toxicity to a level that meets national standards.

[0027] In view of this, the present application provides a method for inhibiting beryllium leaching in lithium smelting slag, comprising the following steps: S1, mixing a solidifying stabilizing agent with lithium smelting slag to obtain a mixed material; S2, ball milling the mixed material in step S1; Steps S1 and S2 can be directly carried out in the existing lithium smelting process; The solidification stabilization agent in step S1 includes a calcium-containing compound; The calcium-containing compound includes at least one of calcium phosphate, calcium sulfate, calcium carbonate, calcium hydroxide, etc. The present invention provides a method for inhibiting the leaching of beryllium in lithium smelting slag, which solves the problem of beryllium leaching in lithium smelting slag. The calcium-containing compound in the present application can effectively fix the beryllium in the lithium smelting slag through lattice substitution and adsorption, reducing its leaching risk; in addition, the entire treatment process is simple and easy to implement, and is convenient for large-scale promotion and application. In summary, the present application provides an efficient and easy-to-operate method for inhibiting the leaching of beryllium in lithium smelting slag, which is of great significance for the harmless disposal of highly toxic lithium slag.

[0028] In some embodiments, the source of the solidification and stabilization agent is industrial solid waste. Industrial solid waste includes at least one of waste gypsum, wastewater neutralization slag, carbide slag, desulfurized gypsum slag, and phosphogypsum. The source of the solidification and stabilization agent in the present application is industrial solid waste. This measure not only effectively solves the problem of beryllium leaching in lithium smelting slag, but also realizes the resource utilization of industrial solid waste, achieving the dual benefits of environmental protection and economy. The use of industrial solid waste as an agent not only has a wide source of raw materials and low cost, but also can reduce secondary pollution and promote the recycling of resources. This makes the entire treatment process more economical and feasible, and it also conforms to the concept of sustainable development. In summary, this technical solution significantly improves the efficiency and environmental protection performance of lithium smelting slag treatment, and is of great significance to the harmless disposal and resource utilization of highly toxic lithium slag.

[0029] If the calcium-containing compound used in step S1 is a commercially available calcium-containing compound, the weight ratio of the calcium-containing compound to the lithium smelting slag in step S1 is 1:(0.2-200). In some embodiments, the weight ratio of the calcium-containing compound to the lithium smelting slag is 1:0.2, 1:2, 1:20, 1:40, 1:120, 1:150, 1:180, 1:200. The weight ratio of the calcium-containing compound to the lithium smelting slag in step S1 is related to the type and purity of the calcium-containing compound. If the purity and content of the calcium-containing compound are high, the solidification effect of beryllium in the lithium smelting slag is better, and the dosage is also lower.

[0030] Optionally, the weight of the solidification and stabilization agent in step S1 is negatively correlated with the content of calcium-containing compounds in the solid waste; When the calcium content in industrial solid waste is not less than 60%, the weight of the solidification and stabilization agent is w of the weight of lithium smelting slag; w satisfies 0.5%≤w<35%; When the calcium content in industrial solid waste is less than 60%, the weight of the solidification and stabilization agent is k of the weight of the lithium smelting slag; k satisfies 35%≤k<500%.

[0031] In some embodiments, the calcium content in the industrial solid waste is 60%, 65%, 70%, 80%, 85%, 90%, 95%, 98% or a value within the range consisting of any two thereof.

[0032] In some embodiments, the weight of the solidification stabilization agent is 0.5%, 5%, 10%, 15%, 20%, less than 35% of the weight of the lithium smelting slag, or a value within a range consisting of any two thereof.

[0033] In some embodiments, the calcium content in the industrial solid waste is less than 60%, 45%, 30%, 25%, 20%, 10%, 5%, 3% or a value within a range consisting of any two thereof.

[0034] In some embodiments, the weight of the solidification stabilization agent is 35%, 50%, 65%, 75%, 90%, 100%, 200%, 300%, 400%, 500% of the weight of the lithium smelting slag, or a value within a range consisting of any two of them.

[0035] Optionally, the calcium-containing compound includes calcium sulfate and calcium hydroxide.

[0036] Optionally, the weight ratio of calcium sulfate to calcium hydroxide is 1:(0.05-1).

[0037] In some embodiments, the weight ratio of calcium sulfate to calcium hydroxide is 1:0.05, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, or a value within the range consisting of any two thereof.

[0038] In some embodiments, the calcium-containing compound includes calcium sulfate, calcium hydroxide, and calcium phosphate.

[0039] Optionally, the weight ratio of calcium sulfate, calcium hydroxide and calcium phosphate is 1:(0.05-1):(0.01-0.3).

[0040] Optionally, the weight ratio of calcium sulfate, calcium hydroxide and calcium phosphate is 1:0.05:0.01, 1:1:0.2, 1:1:0.3 or a value within the range of any two thereof.

[0041] In some embodiments, the calcium-containing compound includes calcium sulfate, calcium hydroxide, calcium phosphate, and calcium carbonate.

[0042] Optionally, the weight ratio of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate is 1:(0.05-1):(0.01-0.3):(0.005-0.2).

[0043] In some embodiments, the weight ratio of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate is A value in the range of 1:0.05:0.01:0.005, 1:0.8:0.2:0.1, 1:1:0.3:0.2, or any two of them.

[0044] Optionally, the ball milling speed in step S2 is 100-2000 rpm; and the ball milling time is 0.5-4 h.

[0045] In some embodiments, the ball milling speed in step S2 is 100 rpm, 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm or a value within the range formed by any two of them; the ball milling time is 0.5 h, 2 h, 3 h, 4 h or a value within the range formed by any two of them.

[0046] Example 1 This embodiment provides a method for inhibiting beryllium leaching in lithium smelting slag, comprising the following steps: S1. Weigh two portions of deeply detoxified lithium smelting slag samples A and C, 10 g each, and put them into a 250 ml conical flask, and record them as lithium smelting slag samples A1, A2 and C1, C2; S2, take the lithium smelting slag samples A2 and C2 weighed in step S1 and put them into 50 ml centrifuge tubes respectively, and then add 2 g of solidification stabilization agent respectively to mix; S3. Add zirconium oxide ball milling beads (three types of ball milling beads: 9 4 mm, 6 6 mm, and 3 8 mm) in equal portions to the centrifuge tube containing the mixed material in step S2. S4. Finally, place the centrifuge tube loaded with ball milling beads in S3 in a ball mill at a speed of 1400 rpm for 1 hour; S5, weighing 10 g of the mixed materials A2 and C2 after ball milling in step S4, and then adding them into 250 ml conical flasks respectively; S6. Perform leaching experiments on the lithium smelting slag samples A1 and C1 obtained in step S1 and the mixed materials A2 and C2 after ball milling in step S5 according to "Solid Waste Leaching Toxicity Leaching Method Sulfuric Acid and Nitric Acid Method" (HJT299-2007); (4) The concentration of beryllium in the leachate sample was determined by ICP-MS combined with external standard analysis.

[0047] After analysis and comparison, the beryllium concentrations in the leachate of lithium smelting slag samples A1 and C1 were 342ug / L and 269ug / L, respectively, while the beryllium concentrations in the leachate of the mixed materials A2 and C2 after chemical treatment and ball milling were 0.52ug / L and 2.78ug / L, respectively.

[0048] It is shown that the above-mentioned reagents and methods can effectively inhibit the leaching of beryllium in lithium smelting slag, reducing the leaching concentration of beryllium to below 10ug / L, which meets the requirements of "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007).

[0049] The solidification stabilization agent in step S2 of this embodiment is calcium sulfate, which is purchased from Shanghai MacLean Biochemical Technology Co., Ltd. or CAS No. 7778-18-9.

[0050] Embodiment 2-4 The difference between Example 2-4 and Example 1 is that Example 2-4 uses calcium phosphate, calcium carbonate and calcium hydroxide as solidification stabilizing agents (all commercially available), and the steps are consistent with Example 1. The sample used in Example 2-4 is Sample A.

[0051] The CAS number of calcium phosphate is 10103-46-5; the CAS number of calcium carbonate is 471-34-1; the CAS number of calcium hydroxide is 1305-62-0.

[0052] The experimental test results of Examples 2-4 are shown in Table 1.

[0053] Table 1 - Experimental test results of Examples 2-4

[0054] Analysis of results: Combining the experimental test results of Examples 1 to 4 and the control test, it can be seen that when calcium sulfate, calcium phosphate, calcium carbonate and calcium hydroxide are used as curing and stabilizing agents, they can achieve better curing effects on beryllium in lithium smelting slag, indicating that these calcium-containing compounds can effectively fix beryllium in lithium smelting slag through various mechanisms, reduce its leaching risk, and ensure that the treated lithium smelting slag meets environmental protection standards. In the control test, the leaching concentration of beryllium in lithium smelting slag without using a curing and stabilizing agent was as high as 342 μg / L, which further verified the effectiveness of the agent. In summary, the use of calcium sulfate, calcium phosphate, calcium carbonate and calcium hydroxide as curing and stabilizing agents can significantly improve the curing effect of beryllium in lithium smelting slag, which is of great significance for the harmless disposal of highly toxic lithium slag.

[0055] Example 5-8. The sample used in Example 5-8 is sample A; Example 5 The difference between this embodiment and embodiment 1 is that the solidification stabilization agent in step S1 of this embodiment is prepared by mixing calcium sulfate and calcium hydroxide in a weight ratio of 1:0.05, and the rest is consistent with embodiment 1.

[0056] Example 6 The difference between this embodiment and embodiment 1 is that the solidification stabilization agent in step S1 of this embodiment is prepared by mixing calcium sulfate and calcium hydroxide in a weight ratio of 1:0.8, and the rest is consistent with embodiment 1.

[0057] Example 7 The difference between this embodiment and embodiment 1 is that the solidification stabilization agent in step S1 of this embodiment is prepared by mixing calcium sulfate and calcium hydroxide in a weight ratio of 1:1, and the rest is consistent with embodiment 1.

[0058] Example 8 The difference between this embodiment and embodiment 1 is that the solidification stabilization agent in step S1 of this embodiment is prepared by mixing calcium phosphate and calcium carbonate in a weight ratio of 1:1, and the rest is consistent with embodiment 1.

[0059] Examples 9-11. The sample used in Examples 9-11 is sample A; Example 9 The difference between this embodiment and embodiment 7 is that the solidification stabilization agent in step S2 of this embodiment is prepared by mixing calcium sulfate, calcium hydroxide and calcium phosphate in a weight ratio of 1:0.05:0.01, and the rest is consistent with embodiment 1.

[0060] Example 10 The difference between this embodiment and embodiment 9 is that the solidification stabilization agent in step S2 of this embodiment is prepared by mixing calcium sulfate, calcium hydroxide and calcium phosphate in a weight ratio of 1:0.8:0.2, and the rest is consistent with embodiment 1.

[0061] Embodiment 11 The difference between this embodiment and embodiment 9 is that the solidification stabilization agent in step S2 of this embodiment is prepared by mixing calcium sulfate, calcium hydroxide and calcium phosphate in a weight ratio of 1:1:0.3, and the rest is consistent with embodiment 1.

[0062] Examples 12-14. The sample used in Examples 12-14 is sample A; Example 12 The difference between this embodiment and embodiment 10 is that the solidification stabilization agent in step S2 of this embodiment is a mixture of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate in a weight ratio of 1:0.05:0.01:0.005, and the rest is consistent with embodiment 1.

[0063] Embodiment 13 The difference between this embodiment and embodiment 12 is that the solidification stabilization agent in step S2 of this embodiment is a mixture of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate in a weight ratio of 1:0.8:0.2:0.1, and the rest is consistent with embodiment 1.

[0064] Embodiment 14 The difference between this embodiment and embodiment 12 is that the solidification stabilization agent in step S2 of this embodiment is a mixture of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate in a weight ratio of 1:1:0.3:0.2, and the rest is consistent with embodiment 1.

[0065] The experimental test results of Examples 5-14 and Example 1 are shown in Table 2.

[0066] Table 2 - Experimental test results of Examples 5-14 and Example 1

[0067] Result analysis: Combined with the experimental test results in Table 2, compared with Example 1, in Example 5-14, after using different types and ratios of solidification and stabilization agents, the leaching concentration of beryllium in lithium smelting slag was significantly reduced, especially when used in combination. Specifically, in Example 5-8, only calcium sulfate and calcium hydroxide were used as solidification and stabilization agents, showing a certain solidification effect. However, when a variety of calcium-containing compounds were used in combination, the effect was more prominent. In Examples 9-11, a compound agent of calcium sulfate, calcium hydroxide and calcium phosphate was used, and the leaching concentration was further reduced to 0.20 μg / L, which was significantly better than a single-component agent. In Examples 12-14, calcium carbonate was further added to form a four-component compound agent of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate, and the leaching concentration was reduced to 0.10 μg / L, which was far lower than the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB5085.3-2007) (20 μg / L). These results indicate that the solidification effect of beryllium in lithium smelting slag can be significantly improved and its leaching can be effectively prevented through the rational compound use of calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate, which is of great significance for the harmless disposal of highly toxic lithium slag.

[0068] Examples 15-16,The samples used in Examples 15-16 are industrial solid waste; Embodiment 15 The difference between this embodiment and embodiment 1 is that the source of the solidification stabilization agent in step S2 of this embodiment is industrial solid waste, and the type of industrial solid waste is waste gypsum. In this embodiment, the content of calcium compounds in the waste gypsum is 85%, and the rest is impurities. The calcium compound in this embodiment is calcium sulfate (the content of calcium sulfate accounts for 99% of the total weight of the calcium compound).

[0069] In this embodiment, the single amount of industrial solid waste is 3g, and the single amount of lithium smelting slag is 10g.

[0070] This example is used for a lithium smelting slag sample after deep removal in Yichun City (consistent with Example 1). This example uses a 250ml conical flask as a reaction container and specifically includes the following steps: S1. Weigh two portions of deeply detoxified lithium smelting slag samples A and C, 10 g each, and put them into a 250 ml conical flask, and record them as lithium smelting slag samples A1, A2 and C1, C2; S2, take the lithium smelting slag samples A2 and C2 weighed in step S1 and put them into 50 ml centrifuge tubes respectively, and then add 3 g of solidification stabilization agent respectively to mix; S3. Add zirconium oxide ball milling beads (three types of ball milling beads: 9 4 mm, 6 6 mm, and 3 8 mm) in equal portions to the centrifuge tube containing the mixed material in step S2. S4, placing the centrifuge tube loaded with ball milling beads in step S3 in a ball mill at a speed of 2000 rpm for 0.8 h; S5, weighing 10 g of the mixed materials A2 and C2 after ball milling in step S4, and then adding them into 250 ml conical flasks respectively; S6. Perform leaching experiments on the lithium smelting slag samples A1 and C1 obtained in step S5 and the ball-milled mixed materials A2 and C2 according to the "Solid Waste Leaching Toxicity Leaching Method Sulfuric Acid and Nitric Acid Method" (HJT299-2007); S7. The concentration of beryllium in the leachate sample was determined by ICP-MS combined with external standard analysis.

[0071] After analysis and comparison, the concentrations of beryllium in the leaching solutions of lithium smelting slag samples A1 and C1 were 342ug / L and 269ug / L, respectively, while the concentrations of beryllium in the leaching solutions of mixed materials A2 and C2 after reagent treatment and ball milling were 0.46ug / L and 2.33ug / L, respectively. This indicates that the above reagents and methods can effectively inhibit the leaching of beryllium in lithium smelting slag, reducing the leaching concentration of beryllium to below 10ug / L, which meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007).

[0072] Example 16 The difference between this embodiment and embodiment 15 is that the source of the solidification stabilization agent in step S2 of this embodiment is industrial solid waste, and the type of industrial solid waste is desulfurized gypsum slag. The content of calcium compounds in the desulfurized gypsum slag is about 90%, and the rest is impurities. The ball milling speed in this embodiment is 1800rpm, and the ball milling is 1.5h; The calcium-containing compound in this embodiment includes calcium sulfate and calcium carbonate in a weight ratio of 1:0.2. The total amount of calcium sulfate and calcium carbonate accounts for about 99% of the total weight of the calcium-containing compound. In this embodiment, the single amount of industrial solid waste is 2.5g, and the single amount of lithium smelting slag is 10g.

[0073] The experimental test results of Examples 15-16 are shown in Table 3.

[0074] Table 3 - Experimental test results of Examples 15-16

[0075] Result analysis: The difference between Example 15-16 and Example 1 is that industrial solid waste is used in Example 15-16 instead of calcium sulfate (commercially available) used in Example 1. Combined with the experimental data provided in Table 3, it can be seen that the use of industrial solid waste reduces the leaching concentration of beryllium to below 10ug / L, which meets the requirements of the "Hazardous Waste Identification Standard Leaching Toxicity Identification" (GB 5085.3-2007). It can be seen that industrial solid waste not only effectively solves the leaching problem of beryllium in lithium smelting slag, but also realizes the resource utilization of industrial solid waste, achieving the dual benefits of environmental protection and economy. Using industrial solid waste as a reagent not only has a wide source of raw materials and low cost, but also can reduce secondary pollution and promote the recycling of resources. This makes the entire treatment process more economical and feasible, and also conforms to the concept of sustainable development. In summary, the technical solution provided by the present application significantly improves the efficiency and environmental protection performance of lithium smelting slag treatment, and is of great significance to the harmless disposal and resource utilization of highly toxic lithium slag.

[0076] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for inhibiting beryllium leaching from lithium smelting slag, characterized in that: The method comprises the following steps: S1, mixing a solidifying stabilizing agent with lithium smelting slag to obtain a mixed material; S2, ball milling the mixed material described in step S1; The solidification stabilization agent in step S1 includes a calcium-containing compound; The calcium-containing compound includes at least one of calcium phosphate, calcium sulfate, calcium carbonate and calcium hydroxide.

2. The method according to claim 1, characterized in that The solidification and stabilization agent is sourced from industrial solid waste; the industrial solid waste includes at least one of waste gypsum, wastewater neutralization slag, carbide slag, desulfurization gypsum slag, and phosphogypsum.

3. The method according to claim 2, characterized in that The weight of the solidification and stabilization agent in step S1 is negatively correlated with the content of calcium compounds in the solid waste; When the content of calcium compounds in the industrial solid waste is not less than 60%, the weight of the solidification and stabilization agent is w of the weight of the lithium smelting slag; the w satisfies 0.5%≤w<35%; When the content of calcium compounds in the industrial solid waste is less than 60%, the weight of the solidification and stabilization agent is k of the weight of the lithium smelting slag; and k satisfies 35%≤k<500%.

4. The method according to claim 1, characterized in that: The calcium-containing compounds include calcium sulfate and calcium hydroxide.

5. The method according to claim 4, characterized in that The weight ratio of calcium sulfate to calcium hydroxide is 1:(0.05-1).

6. The method according to claim 1, characterized in that The calcium-containing compounds include calcium sulfate, calcium hydroxide and calcium phosphate.

7. The method according to claim 6, characterized in that The weight ratio of the calcium sulfate, calcium hydroxide and calcium phosphate is 1:(0.05-1):(0.01-0.3).

8. The method according to claim 1, characterized in that The calcium-containing compounds include calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate.

9. The method according to claim 8, characterized in that The weight ratio of the calcium sulfate, calcium hydroxide, calcium phosphate and calcium carbonate is 1: (0.05-1): (0.01-0.3): (0.005-0.2).

10. The method according to claim 1, characterized in that In step S2, the ball milling speed is 100-2000 rpm; and the ball milling time is 0.5-4 h.

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