Ionic rare earth ore in-situ leaching model

Abstract

The invention discloses an ion type rare earth ore in-situ leaching model. According to the model, surface soil and ore soil in a target mining area site are collected firstly, physicochemical characteristic parameters of the surface soil and the ore soil are obtained, then a topless soil storage frame is erected through organic glass, a low-grade ore soil layer, an ore soil layer and a surface soil layer are laid in sequence, liquid injection holes are formed in the surface of the surface soil layer, and a liquid collecting pipe penetrating through the soil storage frame is arranged on the low-grade ore soil layer; then uniformly injecting a leaching agent into liquid injection holes, monitoring dynamic data in the ore leaching seepage process in real time, collecting a rare earth mother solution, calculating the rare earth leaching rate and the ore leaching cost, adjusting parameters of a liquid injection hole net, obtaining multiple groups of rare earth leaching rates and ore leaching costs, optimizing obtained ore leaching parameters, and verifying through a macroscopic experiment. The model effectively solves the problem that the seepage rule and the ore leaching effect of each ore leaching agent in the rare earth ore soil cannot be intuitively obtained during in-situ ore leaching industrial production, so that the cost of the ore leaching agent is greatly reduced on the premise of ensuring the rare earth leaching rate.

Description

Technical Field

[0001] The invention relates to an ore leaching model, in particular to an ion-type rare earth ore in-situ leaching model, and belongs to the technical field of ion adsorption rare earth ore mining. Background Art

[0002] China ranks first in the world in terms of rare earth resource reserves and production, especially ion-adsorbed rare earth resources, which are unique, valuable, and non-renewable strategic resources in my country. Rare earth is an important supporting material in the field of high-tech and is the "industrial monosodium glutamate". my country has listed ion-adsorbed rare earth resources as a special type of mineral for protective mining.

[0003] In-situ leaching is a mining process for ionic rare earth ores. It is a new type of mining method that integrates mining, selection and smelting. In-situ leaching does not require excavation of the mountain, does not damage the surface vegetation, does not discharge industrial solid waste, and industrial water and residual liquid enter a closed-loop cycle, which can improve the process technology level and resource utilization, reduce production costs, and is conducive to organizing large-scale industrial production. The process is simple, reliable and easy to promote. The mining process is divided into ammonium process (i.e. ammonium sulfate or ammonium chloride, etc.) and ammonium-free process (magnesium sulfate, aluminum sulfate or sodium chloride, etc.) according to the leaching agent used. Whether it is an ammonium process or an ammonium-free process, each has its advantages and disadvantages. The starting point is only to consider whether the leakage of some rare earth mother liquor after leaching causes excessive ammonia nitrogen in groundwater and whether there are residual ammonium ions in the mineral soil. Ammonium-free magnesium salts and sodium salts are used as leaching agents. Although there is no problem of excessive ammonia nitrogen after leaching, they will also cause soil compaction. In addition to environmental protection and water conservation issues, the use of ammonium and non-ammonium leaching agents also results in differences in cost and quality of rare earth products obtained after leaching. If the in-situ leaching process is carried out directly on the hilltop of the industrial site, the optimal process parameters cannot be used to serve the leaching of the ore blocks. In order to better protect the environment and improve the comprehensive utilization of resources, the seepage laws and leaching effects of various leaching agents in rare earth ores are intuitively analyzed and studied. The market urgently needs an intuitive leaching parameter acquisition and analysis method to scientifically obtain various leaching parameters and rare earth recovery rates, and scientifically guide the rare earth production of industrial sites. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention aims to provide an ionic rare earth ore in-situ leaching model.

[0005] In order to achieve the above technical objectives, the present invention provides an ionic rare earth ore in-situ leaching model, comprising:

[0006] Step S1, collecting the topsoil and mineral soil at the target mining area, and obtaining the physical and chemical characteristic parameters thereof;

[0007] Step S2, using organic glass to build a roofless soil storage frame, and then laying a low-grade mineral soil layer, a mineral soil layer and a topsoil layer in sequence, the surface of the topsoil layer is provided with a liquid injection hole, and the low-grade mineral soil layer is provided with a liquid collection pipe passing through the soil storage frame;

[0008] Step S3, injecting the leaching agent evenly into the injection hole, monitoring the dynamic data of the leaching seepage process in real time, collecting the leached pre-liquid and the rare earth mother liquor in each time period, and calculating the rare earth leaching rate and leaching cost;

[0009] Step S4, adjusting the injection hole network parameters, obtaining multiple sets of rare earth leaching rates and leaching costs, optimizing the leaching parameters, and verifying through macroscopic experiments.

[0010] As a preferred solution, the physical and chemical characteristic parameters include density value and grade.

[0011] As a preferred solution, the soil storage frame is a cube with a side length of 120 to 180 cm.

[0012] As a preferred solution, the density of the low-grade mineral soil layer is the same as that of the original mineral soil, and its thickness is 40 to 70 cm.

[0013] As a preferred solution, the grade of the mineral soil layer is the same as that of the original mineral soil, and its thickness is 30 to 50 cm.

[0014] As a preferred solution, the topsoil layer has the same density as the topsoil in the target mining area, and its thickness is 8 to 12 cm.

[0015] As a preferred solution, the mesh size of the injection holes is 10cm×10cm to 20cm×20cm, and PVC pipes are used for laying.

[0016] As a preferred solution, the height of the PVC pipe exposed from the surface soil layer is 2 to 4 cm, and the insertion depth is 15 to 20 cm.

[0017] As a preferred solution, the diameter of the PVC pipe is 4 to 8 mm, and Φ4 mm small holes are evenly opened at the bottom of the PVC pipe for guiding the extraction agent.

[0018] As a preferred solution, the liquid collection pipe is laid in a single row with equal spacing using PVC pipes with a diameter of 4 to 8 cm. The distance from the bottom of the soil storage frame is 1 to 4 cm, the length inserted into the soil storage frame is 140 to 160 cm, and the length exposed from the soil storage frame is 20 to 30 cm.

[0019] As a preferred solution, the portion of the liquid collecting pipe inserted into the soil storage frame is evenly provided with small holes of Φ4 mm for collecting rare earth mother liquid.

[0020] As a preferred solution, a high liquid pool is also provided above the soil storage frame, and the flow rate of the leaching agent is controlled by a valve.

[0021] As a preferred solution, a liquid collection pool is further provided below the soil storage frame.

[0022] As a preferred solution, the dynamic data of the leaching seepage process includes water pressure, stress, displacement, topsoil stability and leaching blind area.

[0023] As a preferred embodiment, the concentration of the rare earth mother solution is measured by EDTA titration.

[0024] As a preferred solution, the calculation process of the rare earth leaching rate is:

[0025] Formula 1: M = V1ρ1α;

[0026] Formula 2: Q = V2ρ2;

[0027] Formula 3: η = (Q / M) × 100%;

[0028] In formulas 1 to 3: M is the amount of rare earth, with the dimension of g; V is the volume of ore, with the dimension of m 3 , ρ1 is the density of the mineral soil, the unit is g / m 3 , α is the ore grade (%); Q is the amount of leached rare earth, the dimension is g; V1 is the volume of the mother liquor, the dimension is L, ρ2 is the concentration of the mother liquor, the dimension is g / L; η is the rare earth leaching rate.

[0029] As a preferred solution, the calculation process of the leaching cost is:

[0030] Formula 4: t = (T / Q);

[0031] Formula 5: C = (T × P) / Q;

[0032] In Formula 4 and Formula 5: t is unit consumption, T is the total consumption of leaching agent raw materials, Q is the amount of leached rare earth, P is the unit price of leaching agent, and C is the cost of leaching agent required for each ton of rare earth produced.

[0033] Compared with the prior art, the beneficial technical effects of the technical solution of the present invention are:

[0034] 1) The in-situ leaching model provided by the present invention performs injection from the injection holes, simulates the in-situ leaching process with a soil storage frame, and then monitors the seepage field law of the leaching liquid in real time, and then establishes the correlation relationship between the injection hole network parameters and the liquid collection parameters of the leached rare earth mother liquor, and then optimizes the leaching process flow, effectively solving the problems of leaching parameters such as the seepage law of different leaching agents in the ore soil, leaching effect and rare earth recovery rate during in-situ leaching industrial production, thereby greatly reducing the cost of leaching agents while ensuring the rare earth leaching rate.

[0035] 2) The in-situ leaching model provided by the present invention is aimed at ion adsorption type rare earth ores. The indoor leaching model is made of the surface soil and mineral soil of the target mining area, so as to directly monitor the saturation state of the mineral soil under leaching with different leaching agents, obtain data such as the size of the injection blind area, deformation of the surface soil layer, recovery rate of rare earth mother liquor, leaching rate and unit consumption of raw materials, and obtain the original data of the original ore leaching while avoiding the amplification effect, thereby achieving a guiding role in the on-site process production. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic diagram of the in-situ leaching model provided by the present invention;

[0037] Figure 1 In the middle, 1-high-level pool, 2-high-level pool injection pipeline and gate valve, 3-glass frame, 4-injection hole, 5-surface soil, 6-ore soil, 7-low-grade ore soil, 8-liquid collection pipe, 9-liquid collection pool;

[0038] Figure 2 The experimental process flow chart of the in-situ leaching model provided by the present invention;

[0039] Figure 3 This is a flow chart of the on-site production process of in-situ leaching provided by the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative ideas are within the scope of protection of the present invention.

[0041] Example 1

[0042] This specific implementation provides an ionic rare earth ore in-situ leaching model, and the specific process is as follows:

[0043] 1. Obtain the density of the surface soil and mineral soil at the target mining area. The mineral soil density is 1.54T / m 3 , topsoil density 1.47T / m 3 Then the topsoil and mineral soil were transported back to the room, the mineral soil was mixed, and samples were taken for testing, and the ion adsorption type mineral soil grade α=0.081% was obtained.

[0044] 2. Use 20mm thick organic glass to make a cubic soil storage frame, with four sides and a bottom plate, and the size of the frame is 160cm×160cm×160cm. Use drilling equipment to drill 10 holes on one side of the frame wall at a height of 3cm from the bottom of the frame, with a hole diameter of Φ25mm and a spacing of 15cm. Use a 6-point PVC pipe to insert into the hole as a liquid collection pipe with a length of 185cm, 155cm inside the frame, and 30cm outside the frame. Before insertion, use a small electric drill to drill a Φ4mm hole in the frame to form a twisted shape. After insertion, wrap the twisted pipe with linen to prevent the mineral soil from blocking the small holes and play a role in infiltration. Then, put the low-grade mineral soil into the bottom layer. The ion adsorption grade is tested to be 0.012%. Compact layer by layer to reach the density of the original mineral soil of 1.54T / m 3 , with a thickness of about 70cm, and then a layer of mineral soil with the same average grade as the production ore block is laid on top, compacted to the same density as the original mineral soil, with a thickness of about 50cm, and finally a 10cm thick topsoil layer with original density is laid. The shape of the mineral soil and the topsoil surface is similar to the topography of the hill on site. Furthermore, a 6-point diameter PVC plastic pipe with a length of 20cm is inserted into the topsoil layer according to a mesh size of 15cm×15cm. One end is required to be 3cm exposed from the topsoil layer. After pulling it out, remove the filling in the pipe and then insert it into the hole for use as an injection pipe. The 5cm part at the bottom of the injection pipe is drilled into a Φ4mm small hole with a small electric drill to facilitate injection.

[0045] 3. Above the soil storage frame is a high-level injection tank made of glass with a size of 80cm×80cm×40cm (length, width, height). The outlet pipe at the bottom of the tank uses a small ball valve to control the flow rate of the leaching agent solution during injection. The pipe after the ball valve is made of a 2-point diameter hose, and one end of the hose is placed in the injection hole; below the soil storage frame is a rare earth mother liquor collection tank made of glass with a size of 160cm×40cm×40cm. The mother liquor flowing out of the collection pipe flows into the lower collection tank. Its structure is as follows: Figure 1 shown.

[0046] 4. Calculate the amount of ionic rare earth in the frame and the water content of the ore soil according to the volume, density and grade of the ore soil, and calculate the total amount of ion adsorption rare earth. The calculation formula is:

[0047] Formula 1: M = V1ρ1α;

[0048] In formula 1, M is the amount of rare earth, with the dimension of g; V is the volume of ore, with the dimension of m 3 , ρ1 is the density of the mineral soil, the unit is g / m 3 , α is the ore grade (%), after calculation, the total amount of ion adsorption type rare earth is 1906.7g;

[0049] The magnesium sulfate leaching agent solution is prepared at a concentration of 5% by weight, and the solution volume is prepared at a solid-liquid ratio of 1:0.50. It is sent to the high-level pool, and the injection speed of each hole is controlled by a ball valve to ensure that the solution does not overflow. As the leaching solution gradually infiltrates into the homogeneous mineral soil, the seepage field changes from an unsaturated state to a saturated state, and its seepage conforms to Darcy's Law: Q 渗 =KFI; Among them, Q 渗 is the seepage rate per unit time, K is the permeability coefficient, F is the water-passing section, I is the hydraulic slope, h is the head height, and L is the length of the seepage path. The stability of the topsoil, the blind area of ​​leaching and other data are observed and monitored through surface monitoring methods. The results show that the topsoil is in a stable state during the leaching process, and the blind area of ​​leaching is 2.1%.

[0050] 5. The liquid collection pool collects the leached pre-liquid and rare earth mother liquors of different concentrations at different times, titrates the mother liquor concentration with EDTA, obtains the mother liquor volume and its residual magnesium sulfate concentration, and calculates the leached rare earth amount. The calculation formula is:

[0051] Formula 2: Q = V2ρ2;

[0052] In formula 2, Q is the amount of leached rare earth, with the dimension of g; V1 is the volume of the mother liquor, with the dimension of L, and ρ2 is the concentration of the mother liquor, with the dimension of g / L; after testing, the volume of the leached mother liquor is 4415L, the average rare earth concentration is 0.42 (g / L), and the amount of leached rare earth is calculated to be 1854.3g;

[0053] The rare earth leaching rate is calculated based on the total amount of ion adsorption rare earth and the amount of leached rare earth. The calculation process is as follows:

[0054] Formula 3: η = (Q / M) × 100%;

[0055] According to calculation, the rare earth leaching rate obtained by this model is 97.25%.

[0056] 6. Further calculate the leaching cost, the calculation process is:

[0057] Formula 4: t = (T / Q);

[0058] Formula 5: C = (T × P) / Q;

[0059] In Formula 4 and Formula 5: t is unit consumption, T is the total consumption of leaching agent raw materials, Q is the amount of leached rare earth, P is the unit price of leaching agent, and C is the cost of leaching agent required for each ton of rare earth produced. After calculation, under the condition that the unit price of leaching agent is 500 yuan / ton, the total consumption of leaching agent raw materials is 51922.6g, the unit consumption is 28 tons / ton.REO (rare earth oxide), and the required leaching agent cost is 14,000 yuan / ton.REO.

[0060] Example 2

[0061] This embodiment is exactly the same as the embodiment 1, except that: a PVC plastic pipe with a diameter of 6 cm is inserted into the topsoil layer according to a mesh size of 20 cm×20 cm;

[0062] Through observation and monitoring of surface soil stability, leaching blind area and other data by means of appearance and other monitoring methods, the results showed that the surface soil was stable during the leaching process, and the leaching blind area was 3.2%;

[0063] After testing, the volume of the leaching mother liquor in this embodiment is 4681L, the average rare earth concentration is 0.38 (g / L), the amount of leached rare earth is calculated to be 1778.78g, the total consumption of raw materials of the leaching agent is 52301g, the unit consumption is calculated to be 29.4 tons / ton.REO (rare earth oxide), and the cost of the leaching agent is 14,700 yuan / ton.REO.

[0064] Further, in order to verify the comprehensiveness and excellence of the model provided by the present invention for the optimization of the in-situ leaching process, the present invention takes a rare earth mining area in Dingnan County, Jiangxi Province as an example, and uses model 1 for process optimization. The hilltop shape of the mining area is circular, the terrain height difference is 30 to 50m, the average thickness of the topsoil layer is 2.0m, the rare earth ore body is approximately layered, with an average thickness of 7m, and the lower part of the ore layer is a low-grade granite weathering layer to a semi-weathering layer. The bedrock is buried deep and belongs to a full-complex type. The model obtained in Example 1 is used for on-site production in the mining area. Under the premise of no additional raw materials, equipment and labor costs, the rare earth leaching rate of in-situ leaching is increased from 80% of the original process to 95%, and the leaching rate is increased by as much as 18.75%, which greatly improves the utilization rate of rare earth resources and reduces the environmental pressure caused by the recycling of tailings resources.

Claims

1. An ionic rare earth ore in-situ leaching model, characterized in that: include: Step S1, collecting the topsoil and mineral soil at the target mining area, and obtaining the physical and chemical characteristic parameters thereof; Step S2, using organic glass to build a roofless soil storage frame, and then laying a low-grade mineral soil layer, a mineral soil layer and a topsoil layer in sequence, the surface of the topsoil layer is provided with a liquid injection hole, and the low-grade mineral soil layer is provided with a liquid collection pipe passing through the soil storage frame; Step S3, injecting the leaching agent evenly into the injection hole, monitoring the dynamic data of the leaching seepage process in real time, collecting the leached pre-liquid and the rare earth mother liquor in each time period, and calculating the rare earth leaching rate and leaching cost; Step S4, adjusting the injection hole network parameters, obtaining multiple sets of rare earth leaching rates and leaching costs, optimizing the leaching parameters, and verifying through macroscopic experiments.

2. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The physical and chemical characteristic parameters include density value and grade; the soil storage frame is a cube with a side length of 120 to 180 cm.

3. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The density of the low-grade mineral soil layer is the same as that of the original mineral soil, and its thickness is 40 to 70 cm; the grade of the mineral soil layer is the same as that of the original mineral soil, and its thickness is 30 to 50 cm; the density of the topsoil layer is the same as that of the target mining area, and its thickness is 8 to 12 cm.

4. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The mesh size of the injection holes is 10cm×10cm~20cm×20cm, and PVC pipes are used for laying; the height of the PVC pipes exposed from the surface soil layer is 2~4cm, and the insertion depth is 15~20cm.

5. The in-situ leaching model of an ionic rare earth ore according to claim 4, characterized in that: The diameter of the PVC pipe is 4 to 8 mm, and Φ4 mm small holes are evenly opened at the bottom of the PVC pipe for guiding the extraction agent.

6. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The liquid collecting pipe is made of PVC pipes with a diameter of 4 to 8 cm and is laid in a single row at equal intervals. The distance from the bottom of the soil storage frame is 1 to 4 cm, the length inserted into the soil storage frame is 140 to 160 cm, and the length exposed from the soil storage frame is 20 to 30 cm; the part of the liquid collecting pipe inserted into the soil storage frame is also evenly provided with Φ4 mm small holes for collecting rare earth mother liquor.

7. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: A high pool is also provided above the soil storage frame, and the flow rate of the leaching agent is controlled by a valve; and a liquid collecting pool is also provided below the soil storage frame.

8. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The dynamic data of the leaching seepage process include water pressure, stress, displacement, surface soil stability and leaching blind area; the concentration of the rare earth mother solution is measured by EDTA titration.

9. The in-situ leaching model of an ionic rare earth ore according to claim 8, characterized in that: The calculation process of the rare earth leaching rate is: Formula 1: M = V1ρ1α; Formula 2: Q = V2ρ2; Formula 3: η = (Q / M) × 100%; In formulas 1 to 3: M is the amount of rare earth, with the dimension of g; V is the volume of ore, with the dimension of m 3 , ρ1 is the density of the mineral soil, the unit is g / m 3 , α is the ore grade (%); Q is the amount of leached rare earth, the dimension is g; V1 is the volume of the mother liquor, the dimension is L, ρ2 is the concentration of the mother liquor, the dimension is g / L; η is the rare earth leaching rate.

10. The in-situ leaching model of an ionic rare earth ore according to claim 1, characterized in that: The calculation process of the leaching cost is: Formula 4: t = (T / Q); Formula 5: C = (T × P) / Q; In Formula 4 and Formula 5: t is unit consumption, T is the total consumption of leaching agent raw materials, Q is the amount of leached rare earth, P is the unit price of leaching agent, and C is the cost of leaching agent required for each ton of rare earth produced.

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