Method for promoting leaching of ionic rare earth ore

Abstract

The invention provides a method for promoting leaching of ionic rare earth ore, and relates to the technical field of ore dressing. The method comprises the following steps: firstly, uniformly filling the ionic rare earth ore into a column leaching device, and then compounding, dissolving, stirring and mixing a leaching agent and a leaching aid; and finally, leaching the ionic rare earth ore in the column leaching device by using the prepared leaching agent solution through a peristaltic pump in a speed control manner, and collecting the leachate. The leaching agent is at least one of ammonium sulfate, magnesium sulfate and sodium sulfate, and the auxiliary leaching agent is prepared from cocamidopropyl betaine and sodium fatty alcohol-polyoxyethylene ether carboxylate as raw materials. According to the leaching aid, the seepage effect and the mass transfer efficiency in the leaching process are improved; the problems that a leaching agent is poor in surface wettability of clay minerals, the rare earth extraction period is long, the leaching recovery rate is low, the unit consumption of the leaching agent is high, the rare earth residual quantity is large, and environmental pollution is likely to be generated are solved. And ecological restoration and environmental protection of the rare earth mine are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, in particular to a method for promoting leaching of ionic rare earth ores. Background Art

[0002] Rare earth elements are strategic mineral resources that are indispensable to the development of modern industry and science and technology. Almost all heavy rare earth raw materials in the world come from ionic rare earth ores. Since rare earth elements in ionic rare earth ores exist in the form of ion adsorption phase, chemical extraction is carried out by ion exchange, which is essentially an ion exchange reaction between the cations in the leaching agent and the hydrated rare earth ions or hydroxyl hydrated rare earth ions adsorbed on clay minerals. At present, the main way to extract ionic rare earths in industry is to mine them through in-situ leaching processes such as ammonium sulfate and magnesium sulfate, but the leaching effect of a single leaching agent is not good, and more rare earths remain in the soil, resulting in serious waste of resources.

[0003] Ionic rare earth ore bodies are mainly composed of clay minerals, with high fine-grained mineral content, small ore body porosity and dense structure. The bound water on the surface of mineral particles has viscosity and absorption effects on the leaching agent solution and can reduce the pore volume. These characteristics lead to poor penetration of the leaching agent in the ore body during the in-situ leaching process, slow penetration rate, low rare earth leaching recovery efficiency and too long cycle, especially for the ore bodies with relatively complex geological conditions and high degree of weathering that are becoming more and more common.

[0004] During the leaching process, the migration of fine loose particles causes the seepage pores to be blocked, and the leaching agent and rare earth ions in this area cannot seep through and remain in the ore body. As a result, the ion exchange reaction in the in-situ leaching system is insufficient, the seepage and diffusion of the leaching agent on the outer layer of the clay mineral surface is affected by the free water between the layers and the surface bound water, and the slope stability is poor, resulting in low rare earth leaching recovery and great threat to the environment.

[0005] Although the in-situ leaching process commonly used is becoming increasingly mature, with the deepening and continuation of mining, ores that are easy to leach are given priority, and the number of ores with complex deposit structures and greater difficulty in leaching is increasing, resulting in the current problems of difficulty in rare earth extraction and low rare earth utilization becoming increasingly prominent. Summary of the invention

[0006] In order to solve the technical problems existing in the prior art such as the prolonged extraction cycle of ionic rare earth ores, the reduced leaching recovery rate, the increased unit consumption of leaching agents, and the large amount of ore reagents and rare earth residues, the embodiment of the present invention provides a method for promoting the leaching of ionic rare earth ores. The technical solution is as follows:

[0007] A method for promoting leaching of ionic rare earth ores, the method comprising:

[0008] S1. Evenly load the heavy yttrium type ion type rare earth ore into the column leaching device;

[0009] S2, compounding, dissolving, and stirring the sulfate leaching agent and the leaching aid to obtain a mixed agent;

[0010] S3, using the prepared mixed reagent to control the speed of the peristaltic pump to leach the ionic rare earth ore in the column leaching device in step S1 and collecting the leaching liquid.

[0011] In the step S1, -0.15 mm accounts for 20%-30% of the heavy yttrium type ion type rare earth ore.

[0012] In step S2, the leaching agent is at least one of ammonium sulfate, magnesium sulfate and sodium sulfate.

[0013] In the step S2, the soaking aid is prepared by mixing cocamidopropyl betaine and sodium fatty alcohol polyoxyethylene ether carboxylate in a mass ratio of 1.0: (3.4-6.8).

[0014] The cocamidopropyl betaine and sodium polyoxyethylene fatty alcohol ether carboxylate are dissolved and stirred at room temperature for 1 to 2 minutes to prepare a soaking aid.

[0015] In the step S2, at room temperature, the soaking aid is first stirred and dissolved, and then the leaching agent is added and stirred and dissolved, wherein the compounding ratio of the leaching agent to the soaking aid is (60-70):1.

[0016] In step S3, the flow rate of the agent in the peristaltic pump is controlled to be 0.3-0.8 mL / min for leaching.

[0017] In step S3, the leachate is collected at a solid-liquid ratio of 15-25.

[0018] During the leaching process in step S3, in the mixed reagent, the concentration of the leaching agent is 22-42 g / L, and the concentration of the leaching aid is 0.2-0.8 g / L.

[0019] In the above technical scheme, the ionic rare earth ore has high fine-grained mineral content, small ore body porosity and dense structure, and the bound water on the surface of the mineral particles has viscosity and absorption effects on the leaching agent solution, which leads to the poor penetration effect of the leaching agent in the ore body during the in-situ leaching process. In the present invention, a leaching aid is added during the leaching process, and the ether bonds on the sodium fatty alcohol polyoxyethylene ether carboxylate in the leaching aid and the hydrogen atoms and oxygen atoms on the carbon chain have strong hydrogen bond interactions and electrostatic attraction with the hydrogen atoms and oxygen atoms on the surface of the clay mineral, so that the ionized anions of the sodium fatty alcohol polyoxyethylene ether carboxylate are firmly adsorbed on the surface of the clay particles. Both cocamidopropyl betaine and sodium polyoxyethylene fatty alcohol ether carboxylate have good surface wettability, which enhances the wettability of the clay mineral surface, making it easier for the leaching agent solution to spread on the clay mineral surface, resulting in the outer layer seepage diffusion of the leaching agent on the clay mineral surface being unaffected by the interlayer free water and the surface bound water, reducing the viscosity and drag resistance of the liquid phase, reducing the thickness of the water layer on the surface of the rare earth ore particles, weakening the hydration effect, and facilitating the penetration of the leaching solution in the ore body. In addition, this can also enhance the concentration gradient in the leaching mass transfer process, improve the liquid phase fluidity, and thus promote the exchange and desorption of rare earth ions.

[0020] In the traditional ionic rare earth leaching process, only a single ammonium sulfate leaching agent is usually added. Not only is it easy to cause problems such as fine particle migration during leaching, leading to pore blockage, but also because some cations of the leaching agent are adsorbed by anions on the surface of clay minerals, the concentration of cations that react with rare earth ions is reduced, making the seepage effect worse and the exchange reaction insufficient, resulting in a lower leaching rate. To solve this problem, a large amount of leaching agent needs to be added, which increases production costs. When the present invention adopts the leaching agent solution to leach the rare earth in the ionic rare earth ore, the anions dissociated from the fatty alcohol polyoxyethylene ether carboxylate sodium are used to complex with the hydrated rare earth ions or hydroxyl hydrated rare earth ions on the surface of the clay mineral, so as to promote the exchange and dissociation of the cations in the leaching agent with the hydrated rare earth ions or hydroxyl hydrated rare earth ions on the surface of the clay mineral. The exchanged rare earth ions are complexed with organic acid radicals and can also inhibit the re-adsorption of the rare earth ions on the clay mineral, thereby improving the rare earth leaching efficiency and reducing the amount of the leaching agent, avoiding the waste of ionic phase rare earth resources in the traditional rare earth leaching method, and realizing the saving of rare earth resources.

[0021] In view of the environmental protection issues after the rare earths in ionic rare earth ores are leached, the organic active agents remaining in the rare earth mines can achieve rapid ecological recovery of the mines after mining through the decomposition of indigenous microorganisms, avoiding or reducing the ecological damage caused by the leaching of rare earths by chemical leaching agents. In addition, the type of chemical leaching agent in the leaching solution of polymer surfactants can be selected according to the conditions and element content of the ionic rare earth mines at the site of use. For example, water-soluble sodium salts, water-soluble magnesium salts, and water-soluble potassium salts can be used to supplement soil nutrients while leaching ionic rare earth ores. This makes ionic rare earth resources green, efficient, and eco-friendly.

[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0023] First, the invention of a highly efficient leaching aid solved the technical problems of blocked seepage of the leaching agent between clay mineral layers and insufficient ion exchange reaction, significantly improving the mass transfer efficiency and seepage effect of the ionic rare earth ore leaching process;

[0024] Second, the leaching aid and the leaching agent jointly leached the ionic rare earth ore, which solved the technical problems of poor wettability of the leaching agent on the surface of clay minerals, long rare earth extraction cycle, low leaching recovery rate, high leaching agent consumption, large amount of rare earth residue and easy environmental pollution, and significantly improved and strengthened the green chemical extraction of ionic rare earth ores;

[0025] Third, the inventive soaking aid is a polymer surfactant with high-efficiency surface wetting ability and excellent biodegradability. It can provide nutrients for the reproduction of microorganisms and soil remediation, which is beneficial to the ecological restoration and environmental protection of rare earth mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The present invention provides a flow chart of a method for promoting leaching of ionic rare earth ores. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0029] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0030] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0031] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0032] The embodiment of the present invention provides a method for promoting the leaching of ionic rare earth ores. Figure 1 The method for promoting leaching of ionic rare earth ores shown in the figure may include the following steps:

[0033] S1. Evenly load the heavy yttrium type ion type rare earth ore into the column leaching device;

[0034] S2, compounding, dissolving, and stirring the sulfate leaching agent and the leaching aid to obtain a mixed agent;

[0035] S3, using the prepared mixed reagent to control the speed of the peristaltic pump to leach the ionic rare earth ore in the column leaching device in step S1 and collecting the leaching liquid.

[0036] This will be described below with reference to specific embodiments.

[0037] Example 1

[0038] First, 500 ml of a mixed agent was prepared, magnesium sulfate was selected as the leaching agent, and the mass fractions of cocamidopropyl betaine and sodium polyoxyethylene fatty alcohol ether carboxylate in the leaching aid were 0.008% and 0.032%, respectively. The mixed agent was obtained by stirring at room temperature and pressure for 1 to 2 minutes.

[0039] Sample A was taken from an ionic rare earth mine in Yunnan, which was severely weathered and had a high mud content. The total rare earth REO content in the sample was 0.059%. The ore was mainly composed of SiO2 and Al2O3, followed by Fe2O3, K2O, MgO, etc. Rare earth ions were mainly found in clay minerals such as kaolinite, halloysite, and illite, and rare earth elements were produced in the form of ionic phase. The ionic rare earth ore was leached and recovered by traditional leaching process, and the best rare earth leaching rate was 88.49%.

[0040] Reference Figure 1The leaching method provided by the present invention is used to recover rare earth by leaching. A mixed agent is added during the leaching process for leaching. The mixed agent is prepared by compounding the leaching agent MgSO4, the leaching aid cocamidopropyl betaine and the sodium polyoxyethylene fatty alcohol carboxylate. The selection steps are as follows:

[0041] (1) 500 g of ionic rare earth ore A was uniformly loaded into the column leaching device;

[0042] (2) Compounding, dissolving, and stirring the leaching agent MgSO4, the leaching aid cocamidopropyl betaine, and the sodium fatty alcohol polyoxyethylene ether carboxylate;

[0043] (3) The prepared mixed reagent is used to leach the ionic rare earth ore in the column leaching device at a controlled speed by a peristaltic pump and the leachate is collected.

[0044] During the leaching process, the concentration of the leaching agent in the mixed reagent is 22~42g / L, and the concentration of the leaching aid is 0.2~0.8g / L.

[0045] The prepared leachant solution was leached at a flow rate of 0.5 mL / min, and the leachate was collected at a solid-liquid ratio of 30.

[0046] The rare earth leaching rate obtained in this example is 95.48%.

[0047] Example 2

[0048] First, 500 ml of a mixed agent was prepared, magnesium sulfate was selected as the leaching agent, and the mass fractions of cocamidopropyl betaine and sodium fatty alcohol polyoxyethylene ether carboxylate in the leaching aid were 0.01% and 0.028%, respectively. The mixed agent was obtained by stirring at room temperature and pressure for 1 to 2 minutes.

[0049] Sample B was taken from an ionic rare earth mine in Yunnan, which was severely weathered and had a high mud content. The total rare earth REO content in the sample was 0.038%. The ore was mainly composed of SiO2 and Al2O3, followed by Fe2O3, K2O, MgO, etc. Rare earth ions were mainly found in clay minerals such as kaolinite, halloysite, and illite, and rare earth elements were produced in the form of ionic phase. The ionic rare earth ore was leached and recovered by traditional leaching process, and the best rare earth leaching rate was 87.58%.

[0050] Reference Figure 1 The leaching method provided by the present invention is used to recover rare earth by leaching. A mixed agent is added during the leaching process for leaching. The mixed agent is prepared by compounding the leaching agent MgSO4, the leaching aid cocamidopropyl betaine and the sodium polyoxyethylene fatty alcohol carboxylate. The selection steps are as follows:

[0051] (1) 500 g of ionic rare earth ore B was uniformly loaded into the column leaching device;

[0052] (2) Compounding, dissolving, and stirring the leaching agent MgSO4, the leaching aid cocamidopropyl betaine, and the sodium fatty alcohol polyoxyethylene ether carboxylate;

[0053] (3) The prepared mixed reagent is used to leach the ionic rare earth ore in the column leaching device at a controlled speed by a peristaltic pump and the leachate is collected.

[0054] During the leaching process, the concentration of the leaching agent in the mixed reagent is 22~42g / L, and the concentration of the leaching aid is 0.2~0.8g / L.

[0055] The prepared leachant solution was leached at a flow rate of 0.5 mL / min, and the leachate was collected at a solid-liquid ratio of 30.

[0056] The rare earth leaching rate obtained in this example is 94.12%.

[0057] Example 3

[0058] First, 500 ml of a mixed agent was prepared, magnesium sulfate was selected as the leaching agent, and the mass fractions of cocamidopropyl betaine and sodium polyoxyethylene fatty alcohol ether carboxylate in the leaching aid were 0.006% and 0.042%, respectively. The mixed agent was obtained by stirring at room temperature and pressure for 1 to 2 minutes.

[0059] The selected sample C was taken from an ionic rare earth mine in Yunnan, which was severely weathered and had a high mud content. The sample contained 0.072% of the total rare earth REO. The ore was mainly composed of SiO2 and Al2O3, followed by Fe2O3, K2O, MgO, etc. Rare earth ions were mainly found in clay minerals such as kaolinite, halloysite, and illite, and rare earth elements were produced in the form of ionic phase. The ionic rare earth ore was leached and recovered by traditional leaching process, and the best rare earth leaching rate was 88.92%.

[0060] Reference Figure 1 The leaching method provided by the present invention is used to recover rare earth by leaching. A mixed agent is added during the leaching process for leaching. The mixed agent is prepared by compounding the leaching agent MgSO4, the leaching aid cocamidopropyl betaine and the sodium polyoxyethylene fatty alcohol carboxylate. The selection steps are as follows:

[0061] (1) 500 g of ionic rare earth ore C was uniformly loaded into the column leaching device;

[0062] (2) Compounding, dissolving, and stirring the leaching agent MgSO4, the leaching aid cocamidopropyl betaine, and the sodium fatty alcohol polyoxyethylene ether carboxylate;

[0063] (3) The prepared mixed reagent is used to leach the ionic rare earth ore in the column leaching device at a controlled speed by a peristaltic pump and the leachate is collected.

[0064] During the leaching process, the concentration of the leaching agent in the mixed solution is 22~42g / L, and the concentration of the leaching aid is 0.2~0.8g / L.

[0065] The prepared leachant solution was leached at a flow rate of 0.5 mL / min, and the leachate was collected at a solid-liquid ratio of 30.

[0066] The rare earth leaching rate obtained in this example is 96.62%.

[0067] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for promoting leaching of ionic rare earth ores, characterized in that: The method comprises: S1. Evenly load the heavy yttrium type ion type rare earth ore into the column leaching device; S2, compounding, dissolving, and stirring the sulfate leaching agent and the leaching aid to obtain a mixed agent; S3, using the prepared mixed reagent to control the speed of the peristaltic pump to leach the ionic rare earth ore in the column leaching device in step S1 and collecting the leaching liquid.

2. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In the step S1, -0.15 mm accounts for 20%-30% of the heavy yttrium type ion type rare earth ore.

3. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In step S2, the leaching agent is at least one of ammonium sulfate, magnesium sulfate and sodium sulfate.

4. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In the step S2, the soaking aid is prepared by mixing cocamidopropyl betaine and sodium fatty alcohol polyoxyethylene ether carboxylate in a mass ratio of 1.0: (3.4-6.8).

5. The method for promoting leaching of ionic rare earth ores according to claim 4, characterized in that: The cocamidopropyl betaine and sodium fatty alcohol polyoxyethylene ether carboxylate are dissolved and stirred at room temperature for 1 to 2 minutes to prepare a soaking aid.

6. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In the step S2, at room temperature, the soaking aid is first stirred and dissolved, and then the leaching agent is added and stirred and dissolved, wherein the compounding ratio of the leaching agent to the soaking aid is (60-70):

1.

7. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In step S3, the flow rate of the agent in the peristaltic pump is controlled to be 0.3-0.8 mL / min for leaching.

8. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: In step S3, the leachate is collected at a solid-liquid ratio of 15-25.

9. The method for promoting leaching of ionic rare earth ores according to claim 1, characterized in that: The rare earth leaching rate in the leaching solution in step S3 is not less than 94%.

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