Method for determining the saturation water capacity of heap leach ores

Abstract

The application provides a kind of heap leaching ore saturation water content determination method, belongs to the technical field of process mineralogy analysis, determination method includes, through exhaust-saturation infiltration-drainage process, accurately calculates the water-holding capacity of ore.The method is first crushed, dried and recorded dry weight, then it is naturally filled in heap leaching column;Through gradient lifting flow rate of deionized water infiltration, exhaust air of ore heap;Then saturated water-holding under negative pressure environment, ensure that micropore is completely filled with water;After constant temperature and humidity, remove free water and lock capillary water, obtain total weight;Introduce the correction coefficient based on the in-situ test, finally substitute into formula to calculate saturation water content.The method avoids the deviation of liquid rapid seepage and structure damage in traditional soaking method, exhausts thoroughly, the original pore is complete, the determination result is close to the actual production of heap leaching, and provides reliable data support for process optimization.

Description

Technical Field

[0001] This application relates to the field of process mineralogical analysis technology, specifically to a method for determining the saturated water content of heap-leached ore. Background Technology

[0002] In the field of mineral resource development, heap leaching is a low-cost, high-efficiency hydrometallurgical process widely used for the extraction of low-grade gold, copper, and uranium ores. Its core principle involves piling up crushed ore and then spraying or dripping a leaching agent to allow it to penetrate the ore pores and react chemically with the target metallic mineral. The metal is ultimately recovered by collecting the leachate.

[0003] In the design, optimization, and operation of heap leaching processes, the ore saturation water content is one of the key fundamental parameters. It directly reflects the liquid-holding capacity of the ore when the pores are filled with leaching agent, determining the uniformity of leaching agent distribution, permeation rate, and reaction contact efficiency within the heap. Failure to accurately control this parameter may result in low metal recovery due to insufficient leaching agent dosage, while excessive leaching agent dosage increases costs, waste, and environmental risks. Furthermore, it is difficult to assess and avoid channeling phenomena and flow dead zones caused by uneven permeation within the heap, where the solution flows rapidly only along a few dominant channels, leaving most of the ore area unwetted, ultimately leading to localized leaching failure. Traditional leaching methods suffer from problems such as fine particle displacement due to rapid liquid permeation during leachate collection, measurement difficulties, impact on ore distribution within the heap, and discrepancies between measured results and actual production.

[0004] Therefore, establishing a scientific and accurate method for determining saturated water content is an important technical prerequisite for the industrial application of heap leaching technology. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a method for determining the saturated water holding capacity of heap leaching ore. The steps of the method include sample preparation, column loading, air removal, saturated permeation, free water removal, and calculation of saturated water holding capacity. The saturated water holding capacity of the ore is calculated by the air removal-saturated permeation-water removal method, providing reliable data support for the heap leaching process.

[0006] To achieve the above objectives, in a first aspect, embodiments of this application provide a method for determining the saturated water content of heap-leached ore, comprising: The ore sample was crushed to the target particle size and then dried to obtain dry ore. The weight m of the dry ore was recorded. 干 ; Dry ore is loaded into the heap leaching column, and the weight m of the heap leaching column without dry ore is recorded. 柱 ; Deionized water is seeped into the ore heap in the heap leaching column through the wetting device. The state of the discharged liquid is observed, the gradient flow rate is controlled, and the air is vented. The heap leaching column is sealed, and the internal pressure of the heap leaching column is regulated by a vacuum control system, while deionized water is permeated. Keep the heap leaching column sealed, balance the air pressure inside and outside the heap leaching column, and place it in a constant temperature and humidity environment to stand. Remove the heap leaching column, adjust the draining device, observe the state of the drained liquid, close the draining device, and record the current total weight (m) of the heap leaching column. 总 ; The saturated water content was measured in both the laboratory environment and the field heap leaching environment, and the ratio of the two was calculated as the correction coefficient K. Based on the total weight m of the collected heap leaching column 总 The weight of the dry ore (m) 干 The weight (m) of the heap leaching column without ore sample. 柱 And the correction factor K, the saturated water content w of the ore is obtained through the water content calculation formula: w = K × (m 总 -m 柱 -m 干 ) / m 干 ×100%.

[0007] Further steps, including crushing the ore sample to the target particle size and then drying it, include: Select ore raw materials, crush them to a particle size of 20-30mm, then grind them with a high-pressure roller mill until the ore particle size is ≤10mm, and dry them in an oven at 105℃ to obtain dry ore.

[0008] Furthermore, the interior of the heap leaching column is divided into an upper column pile area and a lower water collection and drainage area by a partition. The partition has 2-6 drainage holes with a diameter of 3-5mm; The upper surface of the partition is covered from bottom to top with a first nylon filter screen of 80-100 mesh, a layer of coarse gravel with a thickness of 3-5 cm, and a second nylon filter screen of 40-60 mesh, wherein the particle size of the coarse gravel is 5-10 mm.

[0009] Furthermore, the step of packing dry ore into the heap leaching column includes: Mix the dry ore thoroughly and pile it into a ring-shaped pile; Samples were taken from diagonal positions of the annular pile and placed into the heap leaching column; The column wall is struck, causing the ore particles to fill naturally under the influence of gravity, forming the original porous structure.

[0010] Furthermore, the steps of percolating deionized water into the ore pile in the heap leaching column through the wetting device, observing the state of the discharged liquid, controlling the gradient flow rate, and venting include: Inject deionized water into the ore pile at a flow rate of 1-2 mL / min and continue to wet for 8-10 min; When no continuous bubbles are observed in the discharged liquid, inject deionized water at a flow rate of 3-4 mL / min and continue to soak for 5-7 minutes until no bubbles are found in the discharged liquid.

[0011] Furthermore, the immersion device includes a peristaltic pump, an inlet pipe, a deionized water container, and an outlet pipe; The deionized water container is connected to the upper part of the heap leaching column through the inlet pipe, the peristaltic pump is installed on the inlet pipe, and the drain pipe is installed at the bottom of the heap leaching column. Place the outlet of the inlet pipe 0.5-1 cm above the ore pile.

[0012] Furthermore, the steps of sealing the heap leaching column, regulating the internal pressure of the heap leaching column through a vacuum control system, and simultaneously allowing deionized water to permeate include: Turn on the vacuum control system and evacuate the inside of the heap leaching column to -0.06~-0.03MPa; Maintain negative pressure and evacuate air, then soak the ore with deionized water at a fixed flow rate of 2-3 mL / min for 12-18 min.

[0013] Furthermore, the steps of maintaining the heap leaching column in a sealed state, balancing the internal and external air pressures of the heap leaching column, and placing it in a constant temperature and humidity environment include: Close the inlet and vacuum lines of the heap leaching column, open the pressure relief port, and balance the gas pressure inside and outside the heap leaching column; Keep the heap leaching column sealed and place it in a constant temperature and humidity environment with a temperature of 28-32℃ and a relative humidity of 60%-70%. Let it stand for 15-25 minutes in a constant temperature and humidity environment.

[0014] Next, remove the heap leaching column, adjust the draining device, observe the state of the drained liquid, close the draining device, and record the current total weight (m) of the heap leaching column. 总 The steps include: The drainage device includes a regulating valve and a drainage pipe. Keep the heap leaching column vertical and adjust the regulating valve to 1 / 3 opening. Use gravity to naturally drain the unadsorbed free water from the bottom of the ore layer and the pores. Observe the water flow status of the drain pipe. When the water flow changes from continuous flow to intermittent dripping, and the dripping rate is ≤1 drop / 10 seconds, immediately close the regulating valve. The entire heap leaching column was weighed and recorded as the total mass m. 总 .

[0015] Furthermore, the steps of measuring the saturated water content in the laboratory environment and the field heap leaching environment, and calculating the ratio of the two as the correction coefficient K, include: Ore from the same batch and with the same particle size distribution as the ore in the heap leaching column was collected and naturally piled up into a test heap without the constraint of a rigid heap leaching column, according to the on-site production standards. The size of the test heap was ≥1.5m×1.5m×1.0m. The true saturated water volume w1 under industrial conditions was determined by the in-situ saturated seepage test method. The uncorrected indoor saturated water volume obtained by the heap leaching column test is denoted as w0, and the operating condition correction factor K is calculated as K=w1 / w0.

[0016] The beneficial technical effects of this application are as follows: In the technical solution of this application, the saturated water holding capacity of ore is calculated by the degassing-saturated permeation-drainage method. The method is simple and easy to operate, avoiding the influence of factors such as rapid liquid seepage and changes in ore pile structure on the measurement results in the traditional leaching method. By controlling the flow rate and slowly dripping water to remove air and achieve saturated permeation, damage to the ore pile structure is avoided, which is more in line with the actual situation of heap leaching industrial production. With the auxiliary degassing, the air is removed more thoroughly, and the saturated water holding capacity of the ore can be measured more accurately, providing reliable data support for the heap leaching process.

[0017] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0019] Figure 1 This is a schematic diagram of the overall process for determining the saturated water content of heap leaching ore, as provided in an embodiment of this application. Detailed Implementation

[0020] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0024] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0025] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0026] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0027] Unless otherwise specified, the terms "comprising" and "including" as used in this application are open-ended. For example, "comprising" and "including" may mean that other components not listed may also be included or contained.

[0028] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0029] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0030] In the field of mineral resource development, heap leaching is a low-cost, high-efficiency hydrometallurgical process widely used for the extraction of low-grade gold, copper, and uranium ores. Its core principle involves piling up crushed ore and then spraying or dripping a leaching agent to allow it to penetrate the ore pores and react chemically with the target metallic mineral. The metal is ultimately recovered by collecting the leachate.

[0031] In the design, optimization, and operation of heap leaching processes, the ore saturation water content is one of the key fundamental parameters. It directly reflects the liquid-holding capacity of the ore when the pores are filled with leaching agent, determining the uniformity of leaching agent distribution, penetration rate, and reaction contact efficiency within the heap. Failure to accurately control this parameter may result in low metal recovery due to insufficient leaching agent dosage, while excessive leaching agent dosage increases costs, waste, and environmental risks. Furthermore, it is difficult to assess and avoid channeling phenomena and flow dead zones caused by uneven penetration within the heap, where the solution flows rapidly only along a few dominant channels, leaving most of the ore area unwetted, ultimately leading to localized leaching failure. Traditional leaching methods suffer from problems such as fine particle displacement due to rapid seepage and scouring of the ore heap during leachate collection, difficulties in measurement, impact on ore distribution within the heap, and discrepancies between measured results and actual production.

[0032] To solve the above technical problems, refer to Figure 1 As shown, this application provides a method for determining the saturated water content of heap leaching ore, comprising: The ore sample was crushed to the target particle size and then dried to obtain dry ore. The weight m of the dry ore was recorded. 干 ; Dry ore is loaded into the heap leaching column, and the weight m of the heap leaching column without dry ore is recorded. 柱 ; Deionized water is seeped into the ore heap in the heap leaching column through the wetting device. The state of the discharged liquid is observed, the gradient flow rate is controlled, and the air is vented. The heap leaching column is sealed, and the internal pressure of the heap leaching column is regulated by a vacuum control system, while deionized water is permeated. Keep the heap leaching column sealed, balance the air pressure inside and outside the heap leaching column, and place it in a constant temperature and humidity environment to stand. Remove the heap leaching column, adjust the draining device, observe the state of the drained liquid, close the draining device, and record the current total weight (m) of the heap leaching column. 总 ; The saturated water content was measured in both the laboratory environment and the field heap leaching environment, and the ratio of the two was calculated as the correction coefficient K. Based on the total weight m of the collected heap leaching column 总 The weight of the dry ore (m) 干 The weight (m) of the heap leaching column without ore sample. 柱 And the correction factor K, the saturated water content w of the ore is obtained through the water content calculation formula: w = K × (m 总 -m 柱 -m 干 ) / m 干 ×100%.

[0033] In the technical solution of this application, the ore raw material is crushed to expose the isolated pores inside the ore, increasing the contact area between the ore particles and water, shortening the wetting path, and facilitating saturated water holding. Refining the ore to the target particle size ensures the uniformity of the ore particle size, improving the repeatability of the experiment and the accuracy of the experimental results. The dried ore obtained after drying removes the water absorbed during processing, ensuring the accuracy of the water absorption measurement results during subsequent wetting. After loading the dry ore into the heap leaching column, deionized water is percolated into the ore pile in the heap leaching column through a wetting device, and the state of the effluent from the heap leaching column is observed. When no more bubbles appear in the effluent, the percolation rate is adjusted. Simultaneous wetting of deionized water is achieved while removing bubbles between the ore pores, further ensuring the sufficiency of gas removal and improving wetting efficiency. The method for determining the correction coefficient provided in this application can establish the correspondence between the basic physical properties of the ore and the correction coefficient. For similar ores, since their mineral composition, particle packing characteristics and pore structure are similar, the obtained correction coefficient can be directly used for the rapid determination of the saturated water content of such ores.

[0034] In some embodiments, the step of crushing the ore sample to a target particle size and then drying it includes: Select ore raw materials, crush them to a particle size of 20-30mm, then grind them with a high-pressure roller mill until the ore particle size is ≤10mm, and dry them in an oven at 105℃ to obtain dry ore.

[0035] In this embodiment, a jaw crusher is used to crush the ore, controlling the particle size to 20-30mm. Then, roller milling is continued to further refine the ore particle size to ≤10mm, exposing more intracrystalline cracks, which facilitates the ore saturation process and improves the measurement efficiency.

[0036] In some embodiments, the interior of the heap leaching column is divided by a partition into an upper column pile area and a lower water collection and drainage area; The partition has 2-6 drainage holes with a diameter of 3-5mm; The upper surface of the partition is covered from bottom to top with a first nylon filter screen of 80-100 mesh, a layer of coarse gravel with a thickness of 3-5 cm, and a second nylon filter screen of 40-60 mesh, wherein the particle size of the coarse gravel is 5-10 mm.

[0037] In this embodiment, a partition separates the heap leaching column from the leachate, achieving solid-liquid separation. A first nylon filter, a coarse gravel layer, and a second nylon filter are layered on the partition to achieve staged filtration, preventing mineral particle leakage while ensuring smooth drainage. The partition has only 2-6 small holes with a diameter of 3-5 mm; this small number and moderate pore size control the drainage rate, ensuring uniform leachate release from the heap leaching column and preventing uneven water content in the ore due to excessively rapid local seepage. The 80-100 mesh first nylon filter intercepts fine debris, ensuring unobstructed drainage. The 3-5 cm thick coarse gravel layer forms a highly permeable, highly porosity transverse water-conducting layer, allowing for uniform leachate seepage. The 40-60 mesh second nylon filter prevents mineral particles from entering the coarse gravel layer, reducing sample quality loss due to particle migration and gravel layer pore blockage.

[0038] In some embodiments, the step of filling a heap leaching column with dry ore includes: Mix the dry ore thoroughly and pile it into a ring-shaped pile; Samples were taken from diagonal positions of the annular pile and placed into the heap leaching column; The column wall is struck, causing the ore particles to fill naturally under the influence of gravity, forming the original porous structure.

[0039] In this embodiment, when loading dry ore, mixing and piling it into a ring-shaped pile can eliminate particle size segregation. Sampling is performed from diagonal positions of the ring-shaped pile, i.e., multi-point sampling is carried out according to the radially symmetrical sector of the pile to form a stable sampling benchmark. Tapping the column wall provides the particles with a small amount of energy to overcome static friction. During the loading process, the ore settles as a whole, which can effectively prevent the phenomenon of loose tops and tight bottoms or alternating layers of coarse and fine particles, and ensures a uniform flow field inside the column.

[0040] In some embodiments, the steps of permeating deionized water into the ore pile in the heap leaching column through the wetting device, observing the state of the discharged liquid, controlling the gradient flow rate, and venting include: Inject deionized water into the ore pile at a flow rate of 1-2 mL / min and continue to wet for 8-10 min; When no continuous bubbles are observed in the discharged liquid, inject deionized water at a flow rate of 3-4 mL / min and continue to soak for 5-7 minutes until no bubbles are found in the discharged liquid.

[0041] In this embodiment, the aqueous phase is initially infiltrated at a flow rate of 1-2 mL / min for 8-10 min, allowing it to uniformly enter the micropores and propel the air forward as a continuous phase. This prevents the air from being broken into isolated bubbles and trapped inside the pores, thus avoiding false unsaturation. When no more continuous bubbles are observed in the discharged liquid, most of the continuous gas phase in the interconnected pores has been expelled. At this point, the flow rate is increased to 3-4 mL / min and infiltration continues for 5-7 min. A slightly higher pressure gradient is provided to expel any remaining isolated microbubbles from the pores without generating excessive local shear forces that could damage the structure or cause large-scale transport of fine particles.

[0042] In some embodiments, the immersion apparatus includes a peristaltic pump, an inlet pipe, a deionized water container, and an outlet pipe; The deionized water container is connected to the upper part of the heap leaching column through the inlet pipe, the peristaltic pump is installed on the inlet pipe, and the drain pipe is installed at the bottom of the heap leaching column. Place the outlet of the inlet pipe 0.5-1 cm above the ore pile.

[0043] In this embodiment, the peristaltic pump inlet pipe is connected to a deionized water container, and the outlet pipe extends through the column top wetting inlet to 0.5-1 cm above the ore surface filter screen. The drain pipe regulating valve is opened to its minimum opening to maintain a slow seepage state. The peristaltic pump is started, and a gradient flow rate is set: the first gradient flow rate is 1-2 mL / min, and wetting is continued for 8-10 minutes to allow water to slowly wet the ore surface and gradually penetrate downwards, slowly squeezing out the free air in the ore gaps from the bottom drain pipe. It is observed that there are no continuous bubbles in the water coming out of the drain pipe, only a small amount of water droplets seeping out. The flow rate is adjusted to the second gradient flow rate of 3-4 mL / min, and wetting is continued for 5-7 minutes to further deepen the water penetration depth until the water penetrates to the bottom of the ore layer and there are no bubbles in the water coming out of the drain pipe. The drain pipe regulating valve is closed, the peristaltic pump is stopped, and the pre-wetting and air venting are completed. There is no water flow scouring throughout this step, the position of the ore particles does not change, and the pore structure remains in its original state.

[0044] In some embodiments, the steps of sealing the heap leaching column, regulating the internal pressure of the heap leaching column through a vacuum control system, and simultaneously performing deionized water percolation include: Turn on the vacuum control system and evacuate the inside of the heap leaching column to -0.06~-0.03MPa; Maintain negative pressure and evacuate air, then soak the ore with deionized water at a fixed flow rate of 2-3 mL / min for 12-18 min.

[0045] In this embodiment, the heap leaching column is evacuated to -0.06 to -0.03 MPa. This negative pressure environment creates a pressure difference between the entire ore heap and the pores not filled with water. This causes the tiny bubbles remaining in the ore particle pores to expand and escape. While maintaining the negative pressure for evacuation, deionized water is used to wet the ore at a fixed flow rate of 2-3 mL / min for 12-18 minutes. This draws the deionized water into the space left after the gas escapes, forming a "gas exhaust-water absorption" cycle, efficiently achieving volume replacement of gas by water. -0.06 to -0.03 MPa is a medium vacuum level, sufficient to achieve the above-mentioned circulation effect, while being lower than the saturated vapor pressure of water at room temperature. This avoids the deionized water from boiling violently or generating a large amount of water vapor at room temperature, ensuring stable liquid phase flow and maintaining the integrity of the pore structure.

[0046] In some embodiments, the steps of keeping the heap leaching column sealed, balancing the internal and external air pressures of the heap leaching column, and placing it in a constant temperature and humidity environment include: Close the inlet and vacuum lines of the heap leaching column, open the pressure relief port, and balance the gas pressure inside and outside the heap leaching column; Keep the heap leaching column sealed and place it in a constant temperature and humidity environment with a temperature of 28-32℃ and a relative humidity of 60%-70%. Let it stand in a constant temperature and humidity environment for 15-25 minutes.

[0047] In this embodiment, the ambient temperature of a typical industrial heap leaching site is 28-32℃ and the relative humidity is 60%-70%. The ore is left to stand at a constant temperature for 15-25 minutes to allow the moisture in the ore pores to stabilize fully, balance the distribution of adsorbed water and free water, and eliminate the problem of uneven moisture distribution during the synchronous infiltration process. At the same time, the actual temperature and humidity environment of industrial heap leaching is simulated to ensure that the measurement conditions are completely matched with the on-site production, avoid the deviation in water holding rate caused by environmental temperature and humidity differences, and solve the core drawback of existing methods that are detached from actual working conditions.

[0048] In some embodiments, the heap leaching column is removed, the draining device is adjusted, the state of the drained liquid is observed, the draining device is turned off, and the current total weight m of the heap leaching column is recorded. 总 The steps include: The drainage device includes a regulating valve and a drainage pipe. Keep the heap leaching column vertical and adjust the regulating valve to 1 / 3 opening. Use gravity to naturally drain the unadsorbed free water from the bottom of the ore layer and the pores. Observe the water flow status of the drain pipe. When the water flow changes from continuous flow to intermittent dripping, and the dripping rate is ≤1 drop / 10 seconds, immediately close the regulating valve. The entire heap leaching column was weighed and recorded as the total mass m. 总 .

[0049] In this embodiment, the regulating valve is only opened to 1 / 3, limiting the bottom drainage and allowing free water at the bottom of the ore layer and within the pores to be released slowly at an extremely low flow rate. By controlling the shear force of the water flow, the original pore structure of the column is protected. Slow drainage ensures that the gravity water throughout the column can collect downwards evenly and smoothly, reducing concentrated leakage. Continuous water flow indicates that the water discharged from the pores is still interconnected free gravity water, with sufficient drainage momentum. When the water flow becomes intermittent dripping with a drip rate ≤ 1 drop / 10 seconds, it indicates that the main body of interconnected gravity water in the pores has been drained, and the remaining water mainly exists in isolation around the contact points of the ore particles. Quantitative standards ensure that each experiment can be stopped at the same drainage stage, resulting in high data reproducibility.

[0050] In some embodiments, the step of measuring the saturated water content in a laboratory environment and an on-site heap leaching environment, and calculating the ratio of the two as a correction factor K, includes: Ore from the same batch and with the same particle size distribution as the ore in the heap leaching column was collected and naturally piled up into a test heap without the constraint of a rigid heap leaching column, according to the on-site production standards. The size of the test heap was ≥1.5m×1.5m×1.0m. The true saturated water volume w1 under industrial conditions was determined by the in-situ saturated seepage test method. The uncorrected indoor saturated water volume obtained by the heap leaching column test is denoted as w0, and the operating condition correction factor K is calculated as K=w1 / w0.

[0051] In this embodiment, the actual pore structure and stress state are reproduced through on-site natural stacking. In the laboratory, the loose particle accumulation near the smooth column wall of the heap leaching column creates preferential flow and additional pores, often resulting in an overestimation of w0 measured by the heap leaching column test method. The on-site in-situ saturated seepage test method involves on-site stacking of the column, grouting, and cyclic spraying until saturated, then weighing the outflow. The measurement steps include: on-site stacking of the same batch of dry ore, recording the total mass M of the dry ore. 干 Spray water into the unconstrained ore pile to achieve saturated seepage; collect and measure the discharged free water M through a seepage-proof bottom blind ditch. 排水 Simultaneously record the total injected water volume M 注水 Subtracting the discharged water from the total injected water volume yields the actual water retention in the ore. Dividing this by the dry ore mass gives the actual industrial saturated water content w1 = (M... 注水 -M 排水 ) / M 干×100%. On-site testing of the ore pile requires no rigid confinement and a size on the meter scale. w1 reflects the true porosity of the naturally accumulated ore. The on-site in-situ saturated seepage test method is used to determine w1. Its advantages are: during on-site seepage, ore particles may locally clog, altering the water-holding capacity. w1 incorporates this dynamic change, more closely approximating the water-holding capacity under actual operating conditions; simultaneously, the stress field inside the large pile compresses the pores, potentially altering the relationship between capillary force and water-holding capacity. It is more instructive than w0 from a pure laboratory system. When the corrected saturated water-holding capacity is used to calculate the ore's saturated water-holding capacity, it can more accurately predict the on-site solution retention, peak leachate concentration, and total recovery cycle, avoiding design errors in the heap leaching column or leaching time estimation due to deviations in water-holding capacity prediction.

[0052] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0053] Example 1 1. Sample Preparation: Gold ore raw material numbered #1 was selected and crushed to a particle size of 20mm using a jaw crusher. Subsequently, it was ground to a particle size of 10mm using a high-pressure roller mill and dried in an oven at 105℃ for later use. The mass of the dried ore is recorded as m. 干 =64.78kg.

[0054] 2. Column Loading: ① The heap leaching column is designed with a diameter of 16cm. The interior of the column is divided into an upper column loading area and a lower water collection and drainage area by a partition. A PVC pipe is installed on the side of the water collection and drainage area as a conduit, with a beaker connected to the end for collecting the drained water. A partition separates the column loading area from the water collection and drainage area, with four 5mm diameter drainage holes in the partition. From bottom to top, the partition is layered with an 80-mesh nylon filter, a 4.2cm thick layer of coarse gravel with a particle size of 50-10mm, and a 60-mesh nylon filter. The total mass of the empty column at this point is denoted as m. 柱 =3.58kg. ② Packing the column: Mix the ore of each particle size, form a ring, take ore diagonally and place it into the heap leaching column, gently tap the column wall to allow the particles to fill naturally.

[0055] 3. Gradient Pre-wetting and Degassing: Connect the peristaltic pump inlet line to the deionized water storage tank, and extend the outlet pipe 0.8 cm above the ore surface filter screen; open the bottom drain pipe regulating valve to the minimum opening. Start the peristaltic pump to perform gradient wetting and degassing: the first gradient flow rate is 1.5 mL / min, and the wetting continues for 9 minutes. Observe that only a small amount of water droplets seep out of the drain outlet, and there are no continuous bubbles; switch to the second gradient flow rate of 3.5 mL / min, and the wetting continues for 6 minutes. The water has completely penetrated to the bottom of the ore layer, and there are no bubbles overflowing from the drain outlet; close the drain pipe regulating valve and stop the peristaltic pump to complete the surface gentle pre-degassing. The ore layer structure remains undisturbed throughout the process.

[0056] 4. Vacuum Synchronous Saturated Osmosis: Seal the top of the column with a sealed cap, and connect the vacuum interface of the cap to the vacuum control system with a pressure-stabilizing valve via a pressure-resistant rubber tube; seal the outlet pipe of the peristaltic pump to the inlet of the cap. Start the vacuum system and slowly adjust the negative pressure to stabilize at -0.03MPa; after the negative pressure stabilizes, restart the peristaltic pump, fix the inlet flow rate at 2.5mL / min, and run the vacuum negative pressure and micro-inlet water synchronously for 15 minutes.

[0057] 5. Constant temperature and static water holding: Turn off the vacuum control system and peristaltic pump, open the pressure relief port at the top of the column to balance the atmospheric pressure inside and outside the column; keep the heap leaching column completely sealed and place it in a constant temperature and humidity incubator; set the incubator parameters: temperature 30℃, relative humidity 65%, and seal and let it stand for 20 minutes.

[0058] 6. Controlled Gravity Discharge of Free Water: Remove the heap leaching column and place it on a horizontal operating table, ensuring the column is vertical and tilt-free. Adjust the bottom drain pipe regulating valve to 1 / 3 of the standard opening, allowing the interstitial free water to drain under the weight of the ore. Observe the drainage status; when the water flow changes from continuous to intermittent dripping with a stable drip rate ≤1 drop / 10s, immediately close the drain regulating valve, retaining only the saturated adsorbed water from the ore. Accurately weigh the entire heap leaching column (column body + saturated ore + internal saturated adsorbed water) and record the data (m). 总 =74.74kg.

[0059] 7. Calibration of correction factor K: (1) On-site sampling: Collect crushed ore of the same batch and particle size from the gold mine and naturally pile it up in an unfenced test pile of 1.5m×1.5m×1.0m at the industrial heap leaching site to restore the density of the natural pile on site; (2) Control test: Simultaneous indoor heap leaching column tests were conducted using ore from the same source, and the uncorrected indoor saturated water content w0 was calculated. Uncorrected indoor saturated water content w0 = (m... 总 -m 柱 -m 干 ) / m 干 ×100%=(74.74-3.58-64.78)÷64.78×100%=9.85%.

[0060] In-situ saturated seepage tests were conducted on the unconstrained ore pile at the site. The measurement steps are as follows: Ore stockpiling and weighing: For on-site stockpiling of the same batch of dry ore, record the total mass M of the dry ore. 干 =12650kg; In-situ spray saturation: Spraying water into an unconstrained ore pile to achieve a saturated seepage state; Water collection and metering: Collecting and metering the discharged free water M through a seepage-proof bottom blind ditch. 排水 =563.22kg, and the total injected water volume M was recorded simultaneously. 注水 =1685.28kg; Calculate the saturated water capacity: Subtract the discharged water volume from the total injected water volume to obtain the actual water retention in the ore, then divide by the dry ore mass. The actual industrial saturated water capacity w1 = (M... 注水- M 排水 ) / M 干 ×100%=(1685.28-563.22)÷12650=8.87%.

[0061] (3) Coefficient calculation: K=w1 / w0=8.87÷9.85=0.90.

[0062] 8. Calculation of saturated water capacity: according to w=K×(m 总 -m 柱 -m 干 ) / m 干 The saturated water content of the ore in Example 1 is calculated as w = 0.90 × (74.74 - 3.58 - 64.78) ÷ 64.78 × 100% = 8.865%.

[0063] Example 2 Gold ore raw material numbered #2 was selected, and the remaining determination methods and procedures were the same as in Example 1. Its dry ore mass m was recorded. 干 =65.32kg, the total mass of the empty column is still m 柱 =3.58kg, accurately weigh the entire heap leaching column (column + saturated ore + internal saturated adsorbed water), and record the data. 总 =75.21kg.

[0064] Calculate the saturated water capacity w in Example 2: w = K × (m 总 -m 柱 -m 干 ) / m 干 ×100%=0.90×(75.21-3.58-65.32)÷65.32×100%=8.69%.

[0065] Example 3 Gold ore raw material numbered #3 was selected, and the remaining determination methods and procedures were the same as in Example 1. Its dry ore mass m was recorded. 干 =64.95kg, the total mass of the empty column is still m 柱 =3.58kg, accurately weigh the entire heap leaching column (column + saturated ore + internal saturated adsorbed water), and record the data. 总 =74.98kg.

[0066] Calculate the saturated water capacity w of Example 3: w = K × (m 总 -m 柱 -m 干 ) / m 干 ×100%=0.90×(74.98-3.58-64.95)÷64.95×100%=8.94%.

[0067] Comparative Example 1 The same gold ore raw material as in Example 1 was selected, and the saturated water content of the ore was determined using the traditional leaching method. The specific implementation process is as follows: 1. Sample preparation: Gold ore raw material from the same source as in Example 1 was selected and dried to constant weight in an oven at 105℃, recorded as dry weight m1 = 64.78 kg. The dried ore was gently compacted and placed into a heap leaching column, with a filter screen at the bottom of the container.

[0068] 2. Initial soaking saturation: Quickly inject deionized water from the top of the heap leaching column until the water surface completely submerges the top of the ore by several centimeters, and record the total injected water volume as m2 = 10 kg. Maintain the submerged state and let it soak for 24 hours.

[0069] 3. Gravity-based water release: Open the valve at the bottom of the metal cylinder to allow water to flow freely under gravity. Continue draining until the water flow changes from a continuous stream to intermittent droplets. Visually observe to confirm that no more droplets are being discharged, indicating that the gravity-based water release is complete. The remaining water is then capillary-held.

[0070] 4. Weighing and Calculation: Wipe the outer wall of the container dry and immediately weigh the discharged free water m3 = 5.52 kg. Calculate the saturated water content w2 of Comparative Example 1 using the formula w2 = (m2 - m3) / m1 × 100% = 6.92%.

[0071] Comparative Example 2 The same gold ore raw material as in Example 2 was selected, and the remaining measurement methods and steps were the same as in Comparative Example 1. The dry weight of the dried ore was recorded as m1 = 65.32 kg, the total amount of water injected after the top of the ore was completely submerged was m2 = 10.21 kg, and the free water discharged after the heap leaching was completed was m3 = 5.73 kg.

[0072] Calculate the saturated water capacity of Comparative Example 2: w2 = (m2 - m3) / m1 × 100% = (10.21 - 5.73) ÷ 65.32 × 100% = 6.86%.

[0073] Comparative Example 3 The same gold ore raw material as in Example 3 was selected, and the remaining measurement methods and steps were the same as in Comparative Example 1. The dry weight of the dried ore was recorded as m1 = 64.95 kg, the total amount of water injected after the top of the ore was completely submerged was m2 = 9.94 kg, and the free water discharged after the heap leaching was completed was m3 = 5.49 kg.

[0074] Calculate the saturated water capacity of Comparative Example 3: w2 = (m2 - m3) / m1 × 100% = (9.94 - 5.49) ÷ 64.95 × 100% = 6.85%.

[0075] Results Analysis: The calculation results of Example 1 differed from those of Comparative Example 1 by 1.945%, Example 2 by 1.83%, and Example 3 by 2.09%. These differences are not random errors, but rather due to improvements in the uniformity and sufficiency of saturated water holding capacity in the method of this application. Firstly, the measurement method of this application achieves uniform and stable wetting of the ore by deionized water through adjusting the gradient seepage rate, protecting the integrity of the ore's pore structure; it controls the simultaneous venting and seepage, ensuring sufficient water holding capacity in the ore's interstices to a greater extent; and it balances the distribution of adsorbed and free water during static water holding, eliminating the problem of uneven water distribution during synchronous infiltration. Secondly, this application measures the saturated water holding capacity in both laboratory and field heap leaching environments, introducing the ratio of the two as a correction coefficient K. This allows for more accurate prediction of the on-site solution retention, peak leachate concentration, and total recovery cycle, avoiding errors in heap leaching column design or leaching time estimation due to deviations in water holding capacity prediction.

[0076] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing embodiments by combining some of the constituent elements, are also included in the scope of this application without departing from the spirit of this application.

[0077] Furthermore, although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for determining the saturated water content of heap-leached ore, characterized in that, include: The ore sample was crushed to the target particle size and then dried to obtain dry ore. The weight m of the dry ore was recorded. 干 ; The dry ore is loaded into a heap leaching column, and the weight m of the heap leaching column without the dry ore is recorded. 柱 ; Deionized water is permeated into the ore pile in the heap leaching column through the wetting device, the state of the discharged liquid is observed, the gradient flow rate is controlled, and the air is vented. The heap leaching column is sealed, and the internal pressure of the heap leaching column is regulated by a vacuum control system, while deionized water is permeated. Maintain the heap leaching column in a sealed state, balance the air pressure inside and outside the heap leaching column, and place it in a constant temperature and humidity environment to stand. Remove the heap leaching column, adjust the draining device, observe the state of the drained liquid, close the draining device, and record the current total weight (m) of the heap leaching column. 总 ; The saturated water content was measured in both the laboratory environment and the field heap leaching environment, and the ratio of the two was calculated as the correction coefficient K. Based on the total weight m of the collected heap leaching column 总 The weight of the dry ore (m) 干 The weight (m) of the heap leaching column without ore sample. 柱 And the correction factor K, the saturated water content w of the ore is obtained through the water content calculation formula: w = K × (m 总 -m 柱 -m 干 ) / m 干 ×100%.

2. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The step of crushing the ore sample to the target particle size and then drying it includes: Select ore raw materials, crush them to a particle size of 20-30mm, then grind them with a high-pressure roller mill to a particle size of ≤10mm, and dry them in an oven at 105℃ to obtain the dry ore.

3. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The interior of the heap leaching column is divided into an upper column pile area and a lower water collection and drainage area by a partition. The partition plate has 2-6 drainage holes with a diameter of 3-5mm; The upper surface of the partition is sequentially covered from bottom to top with an 80-100 mesh first nylon filter, a 3-5 cm thick layer of coarse gravel, and a 40-60 mesh second nylon filter, wherein the coarse gravel has a particle size of 5-10 mm.

4. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The step of filling the dry ore into the heap leaching column includes: The dry ore is mixed evenly and piled into a ring-shaped pile; Samples are taken from diagonal positions of the annular pile and placed into the heap leaching column; The column wall is struck, causing the ore particles to fill naturally under the influence of gravity, forming the original porous structure.

5. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The steps of permeating deionized water into the ore pile in the heap leaching column through the wetting device, observing the state of the discharged liquid, controlling the gradient flow rate, and venting include: Inject deionized water into the ore pile at a flow rate of 1-2 mL / min and continue to wet for 8-10 min; When no continuous bubbles are observed in the discharged liquid, inject deionized water at a flow rate of 3-4 mL / min and continue to soak for 5-7 minutes until no bubbles are found in the discharged liquid.

6. The method for determining the saturated water content of heap leached ore according to claim 5, characterized in that, The immersion device includes a peristaltic pump, an inlet pipe, a deionized water container, and an outlet pipe; The deionized water container is connected to the upper part of the heap leaching column through the inlet pipe, the peristaltic pump is installed on the inlet pipe, and the drain pipe is installed at the bottom of the heap leaching column; The outlet of the inlet pipe is placed 0.5-1 cm above the ore pile.

7. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The steps of sealing the heap leaching column, regulating the internal pressure of the heap leaching column through a vacuum control system, and simultaneously allowing deionized water to permeate include: The vacuum control system is activated to evacuate the inside of the heap leaching column to -0.06 to -0.03 MPa; Maintain negative pressure and evacuate air, then soak the ore with deionized water at a fixed flow rate of 2-3 mL / min for 12-18 min.

8. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The steps of maintaining the heap leaching column in a sealed state, balancing the internal and external air pressure of the heap leaching column, and placing it in a constant temperature and humidity environment include: Close the inlet and vacuum lines of the heap leaching column, open the pressure relief port, and balance the gas pressure inside and outside the heap leaching column; Keep the heap leaching column sealed and place it in a constant temperature and humidity environment with a temperature of 28-32℃ and a relative humidity of 60%-70%. Let it stand for 15-25 minutes in the constant temperature and humidity environment.

9. The method for determining the saturated water content of heap leached ore according to claim 1, characterized in that, The process involves removing the heap leaching column, adjusting the drainage device, observing the state of the drained liquid, closing the drainage device, and recording the current total weight (m) of the heap leaching column. 总 The steps include: The drainage device includes a regulating valve and a drainage pipe. The heap leaching column is kept vertical. The regulating valve is adjusted to 1 / 3 opening, and the unadsorbed free water in the bottom of the ore layer and the pores is discharged naturally by gravity. Observe the water outlet status of the drain pipe. When the water outlet changes from continuous flow to intermittent dripping, and the dripping rate is ≤1 drop / 10 seconds, immediately close the regulating valve. The entire heap leaching column was weighed and recorded as the total mass m. 总 .

10. The method for determining the saturated water content of heap leaching ore according to claim 1, characterized in that, The steps of separately measuring the saturated water content in laboratory and field heap leaching environments, and calculating the ratio of the two as a correction coefficient K, include: Ore of the same batch and particle size distribution as the ore in the heap leaching column is collected and naturally piled into a test heap without the constraint of a rigid heap leaching column. The size of the test heap is ≥1.5m×1.5m×1.0m. The true saturated water volume w1 under industrial conditions was determined by the in-situ saturated seepage test method. The uncorrected indoor saturated water volume obtained by the heap leaching column test is denoted as w0, and the operating condition correction factor K is calculated as K=w1 / w0.

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