Method for calculating mining scale of ionic rare earth ore based on water environment capacity

Abstract

The invention discloses a method for calculating the mining scale of ionic rare earth ore based on water environment capacity. The method comprises the following steps: calculating the water environment capacity of a drainage basin in a mining area to be mined; calculating the maximum bearable leakage amount of the leaching agent in the drainage basin in the mining area to be mined; calculating the recovery rate of leaching mother liquor; calculating the liquid injection coefficient of the mineral leaching agent; and calculating the maximum mining soil volume in the to-be-mined mining area. According to the technical scheme provided by the invention, the method for calculating the mining scale of the ionic rare earth ore based on the water environment capacity can avoid environmental pollution to a drainage basin in a mining area to be mined.

Description

Technical Field

[0001] The invention relates to the technical field of organic mineral mining, and in particular to a method for calculating the mining scale of ionic rare earth mines based on water environment capacity. Background Art

[0002] Ionic rare earth ore is a special mineral formed by long-term physical, chemical and biological weathering of granite and volcanic rocks containing rare earths under warm and humid climate conditions. Rare earths are mainly present in clay mineral particles in an ionic state and can be leached by exchange reactions with cations in electrolytes. Ionic rare earth ore has undergone three mining processes: pool leaching, heap leaching and in-situ leaching. At present, the in-situ leaching process is the main one.

[0003] In-situ leaching is to inject the leaching agent directly into the ore body through the injection hole. The cations in the leaching agent will exchange and desorb the rare earth ions adsorbed on the surface of the clay mineral to form a rare earth leaching mother liquor, and then the collected rare earth leaching mother liquor is enriched and precipitated to obtain rare earth products. It is different from the ex-situ leaching of mining soil by pool leaching and heap leaching. In-situ leaching does not destroy the surface vegetation of the planned mining area, and does not excavate the topsoil and ore. In the in-situ leaching process, the recovery rate of rare earth leaching mother liquor is greatly affected by factors such as the cracks in the ore body and the layout of the liquid collection project. Since it is difficult to make the ore body bottom plate dense and complete, and its cracks are difficult to completely compensate for by engineering measures, it is inevitable that some leaching agents will seep into the mining process. Leakage to the surrounding watershed of the proposed mining area causes watershed environmental pollution; in the prior art, in order to reduce the impact of the leaching process on the surrounding watershed environment of the mining area, the optimization of the liquid collection project layout and the construction of a tailwater treatment station in the downstream watershed of the mining area are usually adopted for treatment. However, in the method of optimizing the liquid collection project layout, the recovery rate of the leaching agent cannot reach 100%, and the leakage of the leaching agent still exists. The method of building a tailwater treatment station in the mining area can only reduce the scope of influence, and does not solve the pollution problem from the root; on the other hand, the amount of sewage that needs to be treated in the watershed sewage treatment is large, and the slow-release pollution of the leaching agent requires long-term environmental protection investment, which is a heavy burden on the mining company.

[0004] Water environment capacity refers to the ability of a set river section to naturally absorb certain pollutants in order to meet certain water quality requirements, including dilution capacity and self-purification capacity. When the leaching agent leaks into the water body of the proposed mining area, it does not pollute the water environment at the beginning. On the contrary, it can absorb a certain amount of pollutants under the dilution and self-purification of the river water. Only when the leakage of the leaching agent exceeds the water environment capacity will it cause pollution to the basin. Therefore, the impact of ionic rare earth in-situ leaching mining on the basin water environment is not uncontrollable, but needs to be mined within the carrying capacity of the water environment according to the mining process and mining level; therefore, it is necessary to propose a reasonable method for calculating the mining volume of ionic rare earth ore based on water environment capacity. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for calculating the mining scale of ionic rare earth mines based on water environment capacity, which can avoid environmental pollution to the watershed in the planned mining area.

[0006] To achieve the above object, the method for calculating the mining scale of ionic rare earth ore based on water environment capacity proposed in the present invention comprises the following steps:

[0007] Calculate the water environment capacity of the watershed within the proposed mining area;

[0008] Calculate the maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand;

[0009] Calculate the recovery rate of leaching mother liquor;

[0010] Calculate the injection coefficient of the leaching agent;

[0011] Calculate the maximum volume of ore that can be mined within the proposed mining area.

[0012] Preferably, in the step of calculating the maximum mineable ore volume in the proposed mining area, the calculation formula is:

[0013]

[0014] Among them, V 渗 The maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand, in m 3 , η 母 is the recovery rate of leaching mother liquor, λ 注 V is the injection coefficient of the leaching agent; 土 The maximum volume of soil that can be mined in the proposed mining area, in m 3 ; T is the mining cycle, unit is d.

[0015] Preferably, the step of calculating the water environment capacity of the watershed in the proposed mining area comprises:

[0016] Calculate the dilution capacity E of the water environment 稀 , the calculation formula is:

[0017] E 稀 =86.4(SC b )Q r ,

[0018] Among them, E 稀 is the dilution capacity of the water environment, in kg / d; S is the water quality parameter, in mg / L; C b is the background concentration of the controlled factor in the basin, in mg / L; Q r is the basin flow, unit: m 3 / s;

[0019] Calculate the water environment self-purification capacity E 自 , the calculation formula is:

[0020]

[0021] Among them, E 自 is the self-purification capacity of the water environment, in kg / d; k is the comprehensive attenuation coefficient, in d -1 ; l is the length of the river section, in meters; u is the river flow velocity, in meters per second,

[0022] The water environment capacity is calculated based on the water environment dilution capacity and the water environment self-purification capacity. The calculation formula is:

[0023] E 水 =E 稀 +E 自 ,

[0024] Among them, E 水 It is the water environment capacity, and the unit is kg / d.

[0025] Preferably, in the step of calculating the maximum tolerable leaching agent leakage amount of the watershed in the planned mining area, the calculation formula for calculating the maximum tolerable leaching agent leakage amount of the watershed in the planned mining area is:

[0026]

[0027] Among them, V 渗 The maximum amount of leaching agent leakage that can be tolerated in the basin, in m3 / d; E 水 is the water environment capacity, in kg / d; S 浸 is the concentration of controlled factors in the leaching agent, in kg / m 3 .

[0028] Preferably, in the step of calculating the recovery rate of the leaching mother liquor, the calculation formula for calculating the recovery rate of the leaching mother liquor is:

[0029]

[0030] Among them, η 母 is the recovery rate of leaching mother liquor, η 综 is the comprehensive recovery rate of ionic rare earth ore mining; η 浸 is the mother liquor leaching rate; η 选 is the mineral processing recovery rate.

[0031] Preferably, in the step of calculating the leaching agent injection coefficient, the leaching agent injection coefficient is the ratio of the leaching agent injection volume to the ore soil volume, and is calculated based on the average natural moisture content of the ore soil, the average particle density of the ore soil and the average porosity of the ore soil. The calculation formula of the leaching agent injection coefficient is:

[0032]

[0033] Among them, λ 注 V is the injection coefficient of the leaching agent; 注 is the injection volume of the leaching agent, in m 3 ; V 土 is the volume of ore soil, in m 3 ρ 水 is the density of the leaching agent, in kg / m 3 θ 天然 is the average natural moisture content of the mineral soil, in %; ρ 颗 is the average particle density of the mineral soil, in kg / m 3 ; e is the average porosity of the mineral soil.

[0034] Preferably, the calculation of the water environment self-purification capacity E 自 The steps include: selecting a river section of a river that is hydraulically connected to the proposed mining area and is near the proposed mining area;

[0035] The first sampling point (point A) was set up in the upstream of the river section, and the second sampling point (point B) was set up in the downstream of the river section;

[0036] The controlled factor concentration values ​​at the first sampling point and the second sampling point are measured respectively, and the average flow velocity of the test river section and the comprehensive attenuation coefficient k are calculated as follows:

[0037]

[0038] Where V is the average flow velocity of the river, in m / s; X is the distance between the first sampling point and the second sampling point, in m; C A is the controlled factor concentration measured at the first sampling point, in mg / L; C B It is the concentration of the controlled factor measured at the second sampling point, in mg / L.

[0039] Preferably, the calculation of the leaching agent injection coefficient λ 注 After the step, the following step further includes: according to the maximum tolerable leaching agent leakage amount V of the watershed in the proposed mining area 渗 , calculate the required leaching agent injection volume during the mining process of the proposed mining area, the calculation formula is as follows:

[0040]

[0041] Among them, V 注 The volume of leaching agent injection required during the mining process of the proposed mining area, in m 3 ; T is the mining cycle, in days; η 母is the recovery rate of leaching mother liquor, in %.

[0042] Preferably, the step of calculating the water environment capacity of the watershed in the proposed mining area also includes:

[0043] Sampling points are selected in the watershed within the proposed mining area, and samples are taken at the sampling points to test the water quality parameters of the watershed within the proposed mining area.

[0044] Preferably, in the step of calculating the leaching agent injection coefficient, the calculation formula of the leaching agent injection coefficient is determined by the following steps:

[0045] The calculation formula for calculating the average natural moisture content of mineral soil is:

[0046]

[0047] Among them, V 颗 is the average particle volume of the mineral soil, in m 3 , V 水 is the pore volume occupied by water under natural moisture content conditions;

[0048] The formula for calculating the pore volume occupied by water under the average natural moisture content condition is:

[0049]

[0050] The relationship between the average particle volume of mineral soil and the volume of mineral soil is:

[0051]

[0052] The calculation formula of the pore volume occupied by water under the average natural moisture content condition and the relationship between the average particle volume of mineral soil and the volume of mineral soil are obtained:

[0053]

[0054] The calculation formula for calculating the pore volume of mineral soil is:

[0055]

[0056] Among them, V 孔 is the pore volume of the mineral soil, in m 3 ,

[0057] The volume of leaching agent injection required during the mining process in the proposed mining area can also be calculated according to the following formula:

[0058]

[0059] From this we can infer that

[0060] In the technical solution of the present invention, the maximum tolerable leakage amount of the leaching agent in the watershed of the planned mining area is calculated according to the water environment capacity of the watershed in the planned mining area, and the maximum mineable ore volume in the planned mining area is calculated according to the leaching mother liquor recovery rate and the leaching agent injection coefficient. The minerals in the planned mining area are mined according to the maximum mineable ore volume in the planned mining area. The leakage amount of the leaching agent used in the mining process will not exceed the water environment capacity of the watershed in the planned mining area, and the leaching agent that leaks into the watershed in the planned mining area will be dissolved due to the dilution and self-purification effect of the water area in the planned mining area, and will not cause environmental pollution to the watershed in the planned mining area. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 the structures shown in these drawings without paying any creative work.

[0062] Figure 1 The present invention is a flow chart of a method for calculating the scale of ionic rare earth ore mining based on water environment capacity.

[0063] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0064] The following will be combined with the drawings in 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0066] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0069] See also Figure 1 To achieve the above purpose, the method for calculating the mining scale of ionic rare earth ore based on water environment capacity proposed in the present invention comprises the following steps:

[0070] Step S1, calculating the water environment capacity of the watershed in the proposed mining area;

[0071] Step S2, calculating the maximum tolerable seepage amount of the leaching agent in the watershed within the planned mining area;

[0072] Step S3, calculating the recovery rate of the leaching mother liquor;

[0073] Step S4, calculating the injection coefficient of the leaching agent;

[0074] Step S5, calculating the maximum mineable ore volume in the planned mining area.

[0075] Specifically, during the in-situ leaching of ionic rare earths, except for the leaked leaching agent, the remaining collected leaching agent is used to prepare the leaching agent again for circulating leaching after the rare earth enrichment and precipitation. At the same time, some water is also added from the watershed of the proposed mining area to make up for the leakage loss of the leaching agent. Therefore, the water flow rate in the watershed of the proposed mining area during the in-situ leaching process can be considered to be approximately unchanged.

[0076] In the technical solution of the present invention, the maximum tolerable leakage amount of the leaching agent in the watershed of the planned mining area is calculated according to the water environment capacity of the watershed in the planned mining area, and the maximum mineable ore volume in the planned mining area is calculated according to the leaching mother liquor recovery rate and the leaching agent injection coefficient. The minerals in the planned mining area are mined according to the maximum mineable ore volume in the planned mining area. The leakage amount of the leaching agent used in the mining process will not exceed the water environment capacity of the watershed in the planned mining area, and the leaching agent that leaks into the watershed in the planned mining area will be dissolved due to the dilution and self-purification effect of the water area in the planned mining area, and will not cause environmental pollution to the watershed in the planned mining area.

[0077] Preferably, in the step S5, in the step of calculating the maximum mineable ore volume in the proposed mining area, the calculation formula is:

[0078]

[0079] Among them, V 渗 The maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand, in m 3 , η 母 is the recovery rate of leaching mother liquor, λ 注 V is the injection coefficient of the leaching agent; 土 The maximum volume of soil that can be mined in the proposed mining area, in m 3 ; T is the mining cycle, unit is d.

[0080] Preferably, the step S1 comprises:

[0081] Step S11: Calculate the water environment dilution capacity E 稀 , the calculation formula is:

[0082] E 稀 =86.4(SC b )Q r ,

[0083] Among them, E 稀 is the dilution capacity of the water environment, in kg / d; S is the water quality parameter, in mg / L; C b is the background concentration of the controlled factor in the basin, in mg / L; Q r is the basin flow, unit: m 3 / s

[0084] Step S12: Calculate the water environment self-purification capacity E 自 , the calculation formula is:

[0085]

[0086] Among them, E 水is the water environment capacity, in kg / d; k is the comprehensive attenuation coefficient, in d -1 ; l is the length of the river section, in meters; u is the river flow velocity, in meters per second,

[0087] Step S13: Calculate the water environment capacity according to the water environment dilution capacity and the water environment self-purification capacity, and the calculation formula is:

[0088] E 水 =E 稀 +E 自 ,

[0089] Among them, E 自 It is the self-purification capacity of water environment, and the unit is kg / d.

[0090] Specifically, the controlled factors include pollutants generated by leaching with leaching agents. Different leaching agents generate different pollutants. For example, when ionic rare earths are leached with ammonium sulfate, the pollutants are ammonia nitrogen, and the controlled factors are ammonia nitrogen and sulfate. When ionic rare earths are leached with magnesium sulfate, the pollutants are magnesium, and the controlled factors are magnesium and sulfate. In this embodiment, the controlled factors are ammonia nitrogen and sulfate. The length of the river section l is determined as follows: the starting position of the river section is the proposed mining area, and the end position of the river section is the sampling position specified in the "Ionic Rare Earth Mine Mining Water Pollutant Emission Standard" (DB1016-2018) of Jiangxi Province; the water quality parameter S refers to the "Ionic Rare Earth Mine Mining Water Pollutant Emission Standard" (DB 361016-2018) of Jiangxi Province; the comprehensive attenuation coefficient k is measured by the actual measurement method; the water quality parameter S is determined according to the "Ionic Rare Earth Mine Mining Water Pollutant Emission Standard" (DB 36 The ammonia nitrogen limit specified in 1016-2018) is 25 mg / L.

[0091] Preferably, in step S2, the formula for calculating the maximum tolerable seepage amount of the leaching agent in the watershed within the planned mining area is:

[0092]

[0093] Among them, V 渗 The maximum amount of leaching agent leakage that can be tolerated in the basin, in m3 / d; E 水 is the water environment capacity, in kg / d; S 浸 is the concentration of controlled factors in the leaching agent, in kg / m 3 .

[0094] Preferably, in step S3, the formula for calculating the recovery rate of the leaching mother liquor is:

[0095]

[0096] Among them, η母 is the recovery rate of leaching mother liquor, η 综 is the comprehensive recovery rate of ionic rare earth ore mining; η 浸 is the mother liquor leaching rate; η 选 is the mineral processing recovery rate.

[0097] Specifically, according to the relevant provisions of the "Access Conditions for the Rare Earth Industry" (Ministry of Industry and Information Technology

[2012] No. 33) and the "Notice of the Ministry of Land and Resources on the Minimum Indicator Requirements for the "Three Rates" of Rational Development and Utilization of Mineral Resources Such as Iron, Copper, Lead, Zinc, Rare Earth, Potash and Fluorite (Trial)" (No. 21 of 2013), the comprehensive recovery rate of ionic rare earth mining and dressing should be ≥ 75%. The comprehensive recovery rate of ionic rare earth mining and dressing can be calculated by the following formula:

[0098] η 综 =η 浸 ·η 母 ·η 选 ,

[0099] From this we can deduce:

[0100]

[0101] Furthermore, according to the provisions of Jiangxi Province's "Ionic Rare Earth Mine Water Pollutant Emission Standards" (DB 361016-2018), the mother liquor recovery rate must reach more than 80%, and the leaching mother liquor recovery rate is 80%.

[0102] Preferably, in step S4, the leaching agent injection coefficient is the ratio of the leaching agent injection volume to the ore volume, which is calculated based on the average natural moisture content of the ore, the average particle density of the ore and the average porosity of the ore, and the calculation formula is:

[0103]

[0104] Among them, λ 注 V is the injection coefficient of the leaching agent; 注 is the injection volume of the leaching agent, in m 3 ; V 土 is the volume of ore soil, in m 3 ρ 水 is the density of the leaching agent, in kg / m 3 θ 天然 is the average natural moisture content of the mineral soil, in %; ρ 颗 is the average particle density of the mineral soil, in kg / m 3 ; e is the average porosity of the mineral soil.

[0105] Specifically, the volume of leaching agent required for leaching is related to the volume of the ore soil, the average porosity of the ore soil, the average natural water content, the average particle density of the ore soil, etc. After the leaching agent is injected into the ore soil, the closer the ore soil is to a saturated state, the more complete the ion exchange will be, that is, the injected leaching agent should fill the pore volume of the ore soil as much as possible.

[0106] Furthermore, before step S1, the method further includes: sampling the ionic rare earth ore to be mined, and determining the average natural moisture content, average density, average particle density and average porosity of the ore soil in the mining area to be mined.

[0107] Preferably, the calculation of the water environment self-purification capacity E 自 The steps include: selecting a river section of a river that is hydraulically connected to the proposed mining area and is near the proposed mining area;

[0108] The first sampling point (point A) was set up in the upstream of the river section, and the second sampling point (point B) was set up in the downstream of the river section;

[0109] The controlled factor concentration values ​​at the first sampling point and the second sampling point are measured respectively, and the average flow velocity of the test river section and the comprehensive attenuation coefficient k are calculated as follows:

[0110]

[0111] Where V is the average flow velocity of the river, in m / s; X is the distance between the first sampling point and the second sampling point, in m; C A is the controlled factor concentration measured at the first sampling point, in mg / L; C B It is the concentration of the controlled factor measured at the second sampling point, in mg / L.

[0112] Preferably, in the step of selecting a river section near the proposed mining area that is hydraulically connected to the proposed mining area, the selected river section is straight, the water flow is stable, there are no tributaries merging into the middle of the river section, and there is no sewage outlet.

[0113] Preferably, after step S4, the method further includes calculating the required volume of leaching agent injection during the mining process of the proposed mining area according to the maximum leaching agent leakage that can be tolerated by the watershed in the proposed mining area, and the calculation formula is as follows:

[0114]

[0115] Among them, V 注 The volume of leaching agent injection required during the mining process of the proposed mining area, in m 3 ; T is the mining cycle, in days; is the leaching mother liquor recovery rate, in %.

[0116] Preferably, before step S1, the step further includes:

[0117] Sampling points are selected in the watershed within the proposed mining area, and samples are taken at the sampling points to test the water quality parameters of the watershed within the proposed mining area.

[0118] Specifically, the sampling point is selected from the surface water catchment section or sewage treatment plant outlet that is closest to the legal boundary downstream of the mining enterprise and has hydraulic connection in the planned mining area.

[0119] Specifically, the sampling point is selected from the surface water catchment section or sewage treatment plant outlet that is closest to the legal boundary downstream of the mining enterprise and has hydraulic connection in the planned mining area.

[0120] Preferably, in step S4, the calculation formula of the leaching agent injection coefficient is determined by the following steps:

[0121] The calculation formula for calculating the average natural moisture content of mineral soil is:

[0122]

[0123] Among them, V 颗 is the average particle volume of the mineral soil, in m 3 , V 水 is the pore volume occupied by water under natural moisture content conditions;

[0124] The formula for calculating the pore volume occupied by water under the average natural moisture content condition is:

[0125]

[0126] The relationship between the average particle volume of mineral soil and the volume of mineral soil is:

[0127]

[0128] The calculation formula of the pore volume occupied by water under the average natural moisture content condition and the relationship between the average particle volume of mineral soil and the volume of mineral soil are obtained:

[0129]

[0130] The calculation formula for calculating the pore volume of mineral soil is:

[0131]

[0132] Among them, V 孔 is the pore volume of the mineral soil, in m 3 ,

[0133] The volume of leaching agent injection required during the mining process in the proposed mining area can also be calculated according to the following formula:

[0134]

[0135] From this we can infer that

[0136] The following is a specific embodiment:

[0137] The ionic rare earth ore in the planned mining area was sampled to determine the average grade of ionic rare earth in the mining area, the average natural moisture content, average density, average particle density and average porosity of the ore soil. The results are shown in Table 1.

[0138] Table 1 Basic physical and chemical parameters of mineral soil

[0139]

[0140] Prepare the leaching agent, which is a 2% ammonium sulfate solution. The density measurement result is 1.03kg / L. Calculate the leaching agent injection coefficient λ according to the following formula 注 The result is 0.33.

[0141]

[0142] λ 注 V is the injection coefficient of the leaching agent; 注 is the injection volume of the leaching agent, in m 3 ; V 土 is the volume of ore soil, in m 3 ρ 水 is the density of the leaching agent, in kg / m 3 θ 天然 is the average natural moisture content of the mineral soil, in %; ρ 颗 is the average particle density of the mineral soil, in kg / m 3 ; e is the average porosity of the mineral soil.

[0143] The background concentration of the controlled factor (ammonia nitrogen) Cb and the river flow Qr were 8.9 mg / L and 5 m 3 / s, the water quality standard S is calculated according to the ammonia nitrogen limit of 25 mg / L specified in the "Ionic Rare Earth Mining Water Pollutant Discharge Standard" (DB 36 1016-2018) of Jiangxi Province, and the water environment dilution capacity E is calculated according to the following formula 稀 Get 6955.2kg / d.

[0144] E 稀 =86.4(SC b )Q r ,

[0145] Among them, E 稀 is the dilution capacity of the water environment, in kg / d; S is the water quality parameter, in mg / L; Cb is the background concentration of the controlled factor in the basin, in mg / L; Q r is the basin flow, unit: m 3 / s.

[0146] A river section with a straight river channel, stable water flow, no tributaries and no sewage outlets near the mining area and hydraulic connection with the mining area was selected. The first sampling point (point A) was arranged upstream of the river section, and the second sampling point (point B) was arranged downstream of the river section. The concentration values ​​of the controlled factors at the first sampling point and the second sampling point were monitored, and the hydrological parameters were tested at the same time to determine the average flow velocity of the river section. The comprehensive attenuation coefficient k was calculated as follows:

[0147]

[0148] Where V is the average flow velocity of the river, in m / s; X is the distance between the first sampling point and the second sampling point, in m; C A is the controlled factor concentration measured at the first sampling point, in mg / L; C B is the controlled factor concentration measured at the second sampling point, in mg / L;

[0149] The calculated k is 0.11d -1 .

[0150] The length of the river section l closest to the surface water catchment section with hydraulic connection downstream of the legal boundary of the mining area is measured to be 5000m, and the average flow velocity u of the river is 1.5m / s. The self-purification capacity of the water environment E is calculated according to the following formula: 自 -45.93kg / d,

[0151]

[0152] Among them, E 自 is the self-purification capacity of the water environment, in kg / d; k is the comprehensive attenuation coefficient, in d -1 ; l is the length of the river section, in meters; u is the river flow velocity, in meters per second;

[0153] The water environment capacity is calculated according to the following formula: water environment capacity E 水 is 6909.27kg / d,

[0154] E 水 =E 稀 +E 自 ,

[0155] Among them, E 水 is the water environment capacity, in kg / d,

[0156] The maximum amount of leaching agent leakage that can be tolerated in the watershed within the proposed mining area is calculated according to the following formula V渗 , where the controlled factor concentration S in the leaching agent is 浸 20kg / m 3 , the maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand V is calculated 渗 345.46m 3 / d.

[0157]

[0158] Among them, V 渗 The maximum amount of leaching agent leakage that can be tolerated in the basin, in m3 / d; E 水 is the water environment capacity, in kg / d; S 浸 is the concentration of controlled factors in the leaching agent, in kg / m 3 .

[0159] According to the following formula, the maximum tolerable leaching agent leakage in the basin within one year is 630470.82m3, where the mother liquor recovery rate comprehensively considers the relevant provisions of the "Access Conditions for the Rare Earth Industry" (Ministry of Industry and Information Technology

[2012] No. 33) and the "Ministry of Land and Resources on the Minimum Requirements for the "Three Rates" of Rational Development and Utilization of Mineral Resources such as Iron, Copper, Lead, Zinc, Rare Earth, Potash and Fluorite (Trial)" (No. 21, 2013). The comprehensive recovery rate of ionic rare earth mining should be ≥ 75%, and the provisions of the "Ionic Rare Earth Mine Mining Water Pollutant Emission Standards" (DB 36 1016-2018) of Jiangxi Province require that the mother liquor recovery rate must reach more than 80%, and the leaching mother liquor recovery rate η 母 Take 80%;

[0160]

[0161] Among them, V 注 The volume of leaching agent injection required during the mining process of the proposed mining area, in m 3 ; T is the mining cycle, in days; η 母 is the recovery rate of leaching mother liquor, in %,

[0162] The maximum mineable soil V in the proposed mining area is calculated according to the following formula 土 Volume is 1910517.64m 3 ,

[0163]

[0164] Among them, V 渗 The maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand, in m 3 , η 母 is the recovery rate of leaching mother liquor, λ 注 V is the injection coefficient of the leaching agent;土 The maximum volume of soil that can be mined in the proposed mining area, in m 3 ; T is the mining cycle, unit is d;

[0165] According to the average grade of ionic rare earth in the proposed mining area of ​​0.45‰ and the average density of ore soil of 1.57kg / L, the maximum scale of ionic rare earth that can be mined in the proposed mining area is calculated to be 1349.78t;

[0166] Specifically, the maximum scale of ionic rare earths that can be mined in the proposed mining area shall be calculated based on the controlled factor with a smaller water environment capacity limit.

[0167] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for calculating the scale of ionic rare earth mining based on water environment capacity, characterized in that: The steps include: Calculate the water environment capacity of the watershed within the proposed mining area; Calculate the maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand; Calculate the recovery rate of leaching mother liquor; Calculate the injection coefficient of the leaching agent; Calculate the maximum volume of ore that can be mined within the proposed mining area.

2. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: In the step of calculating the maximum mineable ore volume in the proposed mining area, the calculation formula is: Among them, V 渗 The maximum amount of leaching agent leakage that the watershed in the proposed mining area can withstand, in m 3 , η 母 is the recovery rate of leaching mother liquor, λ 注 V is the injection coefficient of the leaching agent; 土 The maximum volume of soil that can be mined in the proposed mining area, in m 3 ; T is the mining cycle, unit is d.

3. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: The steps of calculating the water environment capacity of the watershed in the proposed mining area include: Calculate the dilution capacity E of the water environment 稀 , the calculation formula is: E 稀 =86.4(S-C b )Q r , Among them, E 稀 is the dilution capacity of the water environment, in kg / d; S is the water quality parameter, in mg / L; C b is the background concentration of the controlled factor in the basin, in mg / L; Q r is the basin flow, unit: m 3 / s; Calculate the water environment self-purification capacity E 自 , the calculation formula is: Among them, E 自 is the self-purification capacity of the water environment, in kg / d; k is the comprehensive attenuation coefficient, in d -1 ; l is the length of the river section, in meters; u is the river flow velocity, in meters per second, The water environment capacity is calculated based on the water environment dilution capacity and the water environment self-purification capacity. The calculation formula is: AND 水 =And 稀 +E 自 , Among them, E 水 It is the water environment capacity, and the unit is kg / d.

4. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: In the step of calculating the maximum amount of leaching agent leakage that the watershed in the planned mining area can bear, the calculation formula for calculating the maximum amount of leaching agent leakage that the watershed in the planned mining area can bear is: Among them, V 渗 The maximum amount of leaching agent leakage that can be tolerated in the basin, in m3 / d; E 水 is the water environment capacity, in kg / d; S 浸 is the concentration of controlled factors in the leaching agent, in kg / m 3 .

5. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: In the step of calculating the recovery rate of the leaching mother liquor, the calculation formula is: Among them, η 母 is the recovery rate of leaching mother liquor, η 综 is the comprehensive recovery rate of ionic rare earth ore mining; η 浸 is the mother liquor leaching rate; η 选 is the mineral processing recovery rate.

6. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: In the step of calculating the leaching agent injection coefficient, the leaching agent injection coefficient is the ratio of the leaching agent injection volume to the ore soil volume, and is calculated based on the average natural moisture content of the ore soil, the average particle density of the ore soil, and the average porosity of the ore soil. The calculation formula of the leaching agent injection coefficient is: Among them, λ 注 V is the injection coefficient of the leaching agent; 注 is the injection volume of the leaching agent, in m 3 ; V 土 is the volume of ore soil, in m 3 ρ 水 is the density of the leaching agent, in kg / m 3 θ 天然 is the average natural moisture content of the mineral soil, in %; ρ 颗 is the average particle density of the mineral soil, in kg / m 3 ; e is the average porosity of the mineral soil.

7. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 3, characterized in that: The step of calculating the water environment self-purification capacity comprises: selecting a river section of a river that is hydraulically connected to the proposed mining area and is near the proposed mining area; The first sampling point was set up in the upstream of the river section, and the second sampling point was set up in the downstream of the river section; The controlled factor concentration values ​​at the first sampling point and the second sampling point are measured respectively, and the average flow velocity of the test river section and the comprehensive attenuation coefficient k are calculated as follows: Where V is the average flow velocity of the river, in m / s; X is the distance between the first sampling point and the second sampling point, in m; C A is the controlled factor concentration measured at the first sampling point, in mg / L; C B It is the concentration of the controlled factor measured at the second sampling point, in mg / L.

8. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 1, characterized in that: The step of calculating the leaching agent injection coefficient also includes: calculating the leaching agent injection volume required during the mining process of the proposed mining area according to the maximum leaching agent leakage that the watershed in the proposed mining area can bear, and the calculation formula is as follows: Among them, V 注 The volume of leaching agent injection required during the mining process of the proposed mining area, in m 3 ; T is the mining cycle, in days; η 母 is the recovery rate of leaching mother liquor, in %.

9. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 3, characterized in that: The step of calculating the water environment capacity of the watershed in the proposed mining area also includes: Sampling points are selected in the watershed within the proposed mining area, and samples are taken at the sampling points to test the water quality parameters of the watershed within the proposed mining area.

10. The method for calculating the mining scale of ionic rare earth ore based on water environment capacity according to claim 6, characterized in that: In the step of calculating the leaching agent injection coefficient, the calculation formula of the leaching agent injection coefficient is determined by the following steps: The calculation formula for calculating the average natural moisture content of mineral soil is: Among them, V 颗 is the average particle volume of the mineral soil, in m 3 , V 水 is the pore volume occupied by water under natural moisture content conditions; The formula for calculating the pore volume occupied by water under the average natural moisture content condition is: The relationship between the average particle volume of mineral soil and the volume of mineral soil is: The calculation formula of the pore volume occupied by water under the average natural moisture content condition and the relationship between the average particle volume of mineral soil and the volume of mineral soil are obtained: The calculation formula for calculating the pore volume of mineral soil is: Among them, V 孔 is the pore volume of the mineral soil, in m 3 , The volume of leaching agent injection required during the mining process in the proposed mining area can also be calculated according to the following formula: From this we can infer that

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