A method for evaluating flotation processes

Abstract

This invention provides a method for investigating flotation processes, relating to the field of flotation technology. The method includes: a gas phase investigation step: acquiring and comparing data on air dispersion, bubble size distribution characteristics, and gas holdup inside the flotation machine; a solid phase investigation step: sampling from horizontal sections at different depths of the slurry phase to obtain data on the bubble loading level in the slurry phase, and sampling from different depths of the slurry phase to obtain data on the distribution of solid particles in the liquid phase of the slurry phase, comparing the loading level data and the distribution data; and a flotation cell product investigation step: using a sampler to sample the flotation machine and the foam and underflow at each stage of the entire flotation process, screening and analyzing the samples, and comparing them with the loading level data. This method allows for a more systematic and comprehensive analysis of the investigation data, which is of great significance for optimizing the beneficiation plant process and equipment operating parameters.

Description

Technical Field

[0001] This invention relates to the field of flotation technology, and in particular to a method for examining flotation processes. Background Technology

[0002] Conventional flotation utilizes the hydrophobicity of mineral particles, causing them to adhere to air bubbles and float, forming a froth layer which is then recovered, thus completing the mineral enrichment process. In this process, the dispersion state of the gas in the pulp, the adhesion and detachment of solid particles on the bubble surface, the floating of mineralized bubbles in the pulp phase, and the froth discharge all affect the flotation performance. Current technologies mainly focus on the development of instruments and equipment for investigating the kinetics of flotation machines, such as:

[0003] Patent application CN209927538U discloses a deep-tank sampling device for slurry inside a flotation machine. The device is placed at a certain depth inside the flotation machine. A pull rope is then pulled outwards, causing a connected conical cover to move upwards until the top ring of the conical cover is fully inserted into the hollow tube. At this point, a gap of 10-30 mm appears between the conical cover and the sampling cylinder, allowing the slurry to enter the sampling cylinder through this gap. After a pause of 1-3 seconds, the pull rope is quickly released. The conical cover springs back under the restoring force of the elastic rope, re-adhering tightly to the sampling cylinder. Finally, the slurry sampling device is removed. Opening the rubber stopper or ball valve allows the slurry sample collected in the sampling cylinder to be preserved.

[0004] Patent application CN206270114U discloses a flotation bubble load measurement system. The sampling tube can be inserted into the slurry. Bubbles with solid particles adhering to them enter the sampling port and rise to the collection chamber in the sampling tube. The gas is discharged while the solid particles remain in the collection chamber. The solid load per unit gas can be obtained by calculating the gas volume and solid volume.

[0005] Patent application CN202111622108.0 discloses a flotation machine air dispersion detection device, system, and method. Multiple aeration volume measuring devices are connected together via a circuit, and the measurement data is transmitted to a computer. This achieves synchronous measurement of aeration volume at multiple points.

[0006] Patent application CN201811139757.3 discloses a method for measuring bubble diameter in a flotation process. The method employs an automated approach to measure the total volume, total number of bubbles, bubble size, and bubble diameter distribution per unit cross-sectional area at different flotation liquid depths. The slurry containing bubbles is introduced into an observation chamber above through a sampling tube. The bubble distribution in the observation chamber is captured by a high-speed camera. The captured images are then processed and analyzed using software to calculate the bubble diameter distribution characteristics.

[0007] Therefore, existing technologies primarily focus on independent and singular detection of a specific type of data in the flotation process, mainly concentrating on the development of sampling tools for examining the flotation system process. The sampled data is also relatively isolated and cannot provide a comprehensive evaluation and optimization of the flotation system. However, the flotation system itself is a comprehensive process; as a process industry, flotation is difficult to fully analyze its operational status using a single tool or method. Process investigations often only involve examining flotation products such as concentrates and tailings, making it difficult to assess the occurrence of the flotation process within the flotation machine. Existing methods for examining the dynamics of flotation machines, including deep-cell sampling and bubble loading rate measurement, are often limited to sampling and analyzing the pulp phase, resulting in only a one-dimensional evaluation of the flotation system. Summary of the Invention

[0008] The purpose of this invention is to provide a method for evaluating flotation processes, which enables more systematic and comprehensive analysis of evaluation data, and is of great significance for optimizing the process of a flotation plant and optimizing equipment operating parameters.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention provides a method for evaluating a flotation process, comprising:

[0011] Gas phase investigation steps: Obtain and compare data on air dispersion state, bubble size distribution characteristics, and gas holdup inside the flotation machine;

[0012] Solid phase investigation: Samples were taken from horizontal sections at different depths of the slurry phase to obtain data on the loading degree of bubbles in the slurry phase. Samples were also taken from different depths of the slurry phase to obtain data on the distribution state of solid particles in the liquid phase of the slurry phase. The loading degree data and the distribution state data were then compared.

[0013] Product evaluation of flotation cells: Samples of foam and underflow from the flotation machine and each operation of the entire flotation process are taken using a sampler, and the samples are screened, analyzed and compared with the load data.

[0014] Furthermore, obtaining the air dispersion state data specifically includes:

[0015] Multiple horizontal cross sections at different depths are selected within the flotation machine. Within each horizontal cross section, n measurement points are selected, and the apparent aeration rate at each measurement point is measured to calculate the air dispersion state data.

[0016] Furthermore, the apparent inflation rates at the n measurement points are Jg1, Jg2, Jg3…Jg n The calculation formula for the air dispersion state data adopts the extreme value calculation method;

[0017] The extreme value calculation method is as follows:

[0018]

[0019] in: σ is the average of the apparent inflation rates at each of the n measurement points, and σ is the air dispersion.

[0020] Furthermore, the apparent inflation rates at the n measurement points are Jg1, Jg2, Jg3…Jg n The calculation formula for the air dispersion state data adopts the variance calculation method;

[0021] The variance calculation method is as follows:

[0022]

[0023] Where σ represents air dispersion.

[0024] Furthermore, obtaining the bubble size distribution characteristic data specifically includes:

[0025] The normal distribution curve of the bubble diameter is obtained, and then the average bubble size is calculated based on the normal distribution curve.

[0026] Furthermore, obtaining the gas holdup data specifically includes:

[0027] A graduated cylinder with a volume of V is used for sealed sampling of the slurry. 量 The volume of the slurry in the graduated cylinder is V. 矿 The gas content of the slurry is:

[0028]

[0029] Furthermore, obtaining the gas holdup data also includes:

[0030] The slurry in the flotation cell is divided into n equal depths according to the different longitudinal cross-sectional depths, and the gas holdup of each depth is ε1, ε2, ε2…ε n The volumes of slurry in the graduated cylinders at each depth are V1, V2, V3…V n The calculation method for the overall average gas holdup ε of the entire flotation cell is as follows:

[0031]

[0032] Furthermore, obtaining the load level data specifically includes:

[0033] A measurement point is selected, and the inflation rate at that measurement point is measured as J. bLet t be the sampling time for bubble loading rate, and S be the cross-sectional area of ​​the sampling port of the load measuring instrument. After sampling, the total weight m of the minerals in the sampling cylinder is weighed. Then, the bubble loading rate ε at the measuring point is:

[0034]

[0035] Furthermore, t is 10 min–60 min.

[0036] Furthermore, obtaining the distribution state data specifically includes:

[0037] After the sampled slurry was filtered, dried, sieved, and the useful mineral grade of each particle size was analyzed.

[0038] The flotation process evaluation method provided by this invention can produce the following beneficial effects:

[0039] Compared to existing technologies, the flotation process evaluation method provided by this invention overcomes the shortcomings of traditional single-method evaluation. This method is more systematic and comprehensive, combining multiple evaluation methods to conduct a comprehensive analysis of the evaluation data, and can obtain results that cannot be obtained by a single evaluation method. This is of great significance for guiding production in concentrators and optimizing equipment process operation parameters.

[0040] The following points will be explained in detail: 1. By comparing the data on the distribution of solid particles in the liquid phase of the slurry with the data on the bubble loading rate in the slurry, we can assess whether valuable minerals are gradually enriched as the sampling position increases, and the main reasons for the detachment of valuable minerals during flotation. If valuable minerals are enriched in the slurry but the enrichment effect on the bubbles is poor, it can be inferred that the adhesion between the bubbles and mineral particles is poor, requiring adjustment through reagents and other means. If the enrichment effect of valuable minerals in the slurry is poor, or if the probability of coarse or fine particles detaching from the slurry is high, it may be caused by excessive or insufficient agitation force of the flotation machine. Therefore, optimization needs to be achieved by adjusting the operating parameters or structural parameters of the flotation machine. 2. By comparing the data on the bubble loading rate in the slurry with the data on the froth product, we can analyze that if the bubble loading rate data in the shallow layer is comparable to that of the concentrate product, it indicates that the enrichment of valuable minerals is good and the probability of detachment is low. If the two data differ significantly, it indicates that the useful minerals are severely detached when the mineralized bubbles cross the gas-liquid interface. In this case, the problem can be solved by adjusting the froth layer thickness, the type of frother, or the dosage of the collector. 3. By comparing the data on the air dispersion state inside the flotation machine, the bubble size distribution characteristics, and the bubble size distribution inside the flotation machine, it is possible to assess whether the aeration rate and bubble size of the flotation machine are within the optimal range for the minerals in this process. If the aeration rate and bubble size distribution are mismatched, the parameters can be adjusted to meet the process requirements by adjusting the opening of the flotation machine's air inlet valve, replacing the appropriate air distributor, and adjusting the dosage of the frother. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 A schematic diagram of the data on the maximum and air dispersion provided for embodiments of the present invention;

[0043] Figure 2 A bar chart illustrating the bubble size distribution characteristics in slurry provided in an embodiment of the present invention;

[0044] Figure 3 A bar chart showing the gas holdup at different slurry depths provided in this embodiment of the invention;

[0045] Figure 4 A bar chart showing the bubble loading rate at different depths provided in this embodiment of the invention;

[0046] Figure 5 The graph shows the distribution of mineral particle size in slurry at different depths, as provided in the embodiments of the present invention. Detailed Implementation

[0047] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0051] This invention provides a method for evaluating a flotation process, comprising:

[0052] Gas phase investigation steps: Obtain and compare data on air dispersion state, bubble size distribution characteristics, and gas holdup inside the flotation machine;

[0053] Solid phase investigation: Samples were taken from horizontal sections at different depths of the slurry phase to obtain data on the loading degree of bubbles in the slurry phase. Samples were also taken from different depths of the slurry phase to obtain data on the distribution state of solid particles in the liquid phase of the slurry phase. The loading degree data and the distribution state data were compared.

[0054] Product evaluation of flotation cells: Samplers are used to sample the foam and underflow of the flotation machine and each operation in the entire flotation process, and the samples are screened, analyzed and compared with the load data.

[0055] The flotation process investigation method provided in the above embodiments collects multiple data from the slurry. After collection, the comparative analysis between the various data can determine the factors that cause poor flotation results, which is of great significance for guiding production and optimizing equipment process operation parameters in concentrators.

[0056] First, the composition and particle size of minerals in slurry samples at different depths within the flotation cell can be obtained from the distribution data of solid particles in the liquid phase of the slurry. The composition and particle size of minerals adhering to bubbles in the slurry at different depths can be obtained from the loading data. Comparing the composition and particle size of minerals in slurry samples at different depths with the composition and particle size of minerals adhering to bubbles in the slurry at different depths allows for an assessment of whether valuable minerals are gradually enriched as the sampling position increases, and the main reasons for the detachment of valuable minerals during flotation. If valuable minerals are enriched in the slurry but the enrichment effect on bubbles is poor, it can be inferred that the adhesion between bubbles and mineral particles is poor, requiring adjustment through reagents or other means. If the enrichment effect of valuable minerals in the slurry is poor, or if the probability of coarse or fine particles detaching from the slurry is high, it is caused by excessively strong or weak agitation force in the flotation machine, requiring optimization by adjusting the operating parameters or structural parameters of the flotation machine.

[0057] Secondly, by comparing the data on the loading rate and the data on the foam product, it can be determined that if the shallow bubble loading rate is comparable to the concentrate product data, it indicates that the valuable minerals are well enriched and the probability of detachment is low. If the difference between the two data exceeds a threshold, it indicates that the valuable minerals are severely detached when the mineralized bubbles cross the gas-liquid interface. In this case, the problem can be solved by adjusting the foam layer thickness, the type of frother, or the amount of collector. Furthermore, by examining the foam and the underflow, the operating efficiency of the single-cell flotation machine can be calculated, and the overall operational status of the process can be evaluated.

[0058] Personnel can set the above threshold values ​​based on experience.

[0059] Finally, the aeration rate and bubble size of the flotation machine can be evaluated by comparing data on air dispersion state, bubble size distribution characteristics, and gas holdup to determine if they are within the optimal range for the minerals being processed. If the aeration rate and bubble size distribution are mismatched, the parameters can be adjusted to meet the process requirements by changing the opening of the flotation machine's air inlet valve, replacing the appropriate air distributor, and adjusting the amount of frothing agent.

[0060] In some embodiments, obtaining air dispersion state data specifically includes: selecting multiple horizontal cross sections at different depths within the flotation machine, selecting n measurement points within each horizontal cross section, measuring the apparent aeration rate at each measurement point, and calculating the air dispersion state data.

[0061] The aforementioned aeration rate can be measured using existing aeration volume measurement devices to calculate the dispersion of air fed into the flotation machine throughout the entire tank.

[0062] In some embodiments, the apparent inflation rates of n measurement points are set as Jg1, Jg2, Jg3…Jg n The calculation formula for air dispersion state data adopts the extreme value calculation method; the extreme value calculation method is as follows:

[0063]

[0064] in: Let σ be the average of the apparent inflation rates at each of the n measurement points, and σ be the air dispersion.

[0065] In some other embodiments, the apparent inflation rates at the n measurement points are Jg1, Jg2, Jg3…Jg n The formula for calculating air dispersion state data uses the variance calculation method; the variance calculation method is as follows:

[0066]

[0067] Where σ represents air dispersion.

[0068] In some embodiments, obtaining bubble size distribution characteristic data specifically includes: statistically analyzing the normal distribution curve of bubble diameter, and then calculating the average bubble size based on the normal distribution curve.

[0069] The above data can be obtained using an existing bubble diameter measuring instrument. That is, the calculation process is already programmed into the computer program that comes with the bubble diameter measuring instrument. After the camera takes pictures and samples, the computer can output the above curves and average values.

[0070] In some embodiments, obtaining gas holdup data specifically includes: using a graduated cylinder to take a sealed sample of the slurry, the graduated cylinder having a volume of V. 量 The volume of the slurry in the graduated cylinder is V. 矿 The gas content of the slurry is:

[0071]

[0072] The gas holdup data mentioned above can be obtained using a dual-sphere sampler.

[0073] Specifically, the dual-ball sampler includes a sampling barrel, a pin, and sealing balls located on both sides of the measuring cylinder. The two sealing balls are connected by an elastic rope running through the sampling barrel, and the pin is connected to the two sealing balls via the rope. When lowering the sampling barrel, the two sealing balls are pulled outward by the rope, allowing the slurry to flow through the sampling barrel. The slurry inside the sampling barrel is completely connected to the slurry in the flotation cell, and the gas holdup remains consistent. The rope is then released, and under the action of the elastic rope, the two sealing balls seal both ends of the sampling barrel, isolating the slurry inside the sampling barrel from the external slurry. The sampling barrel is then removed and placed vertically. The volume V of the slurry inside is read. 矿 The gas content of the slurry was calculated.

[0074] In some embodiments, obtaining gas holdup data further includes:

[0075] The slurry in the flotation cell is divided into n equal depths according to the different longitudinal cross-sectional depths, and the gas holdup of each depth is ε1, ε2, ε2…ε n The slurry volumes in each depth graduated cylinder are V1, V2, V3…V n The calculation method for the overall average gas holdup ε of the entire flotation cell is as follows:

[0076]

[0077] In normal operation, gas holdup at four depths is selected.

[0078] In some embodiments, obtaining load level data specifically includes: selecting a measurement point and measuring the inflation rate at the measurement point as J. b (L / m 2 / min), the sampling time for bubble loading rate is t (min), and the cross-sectional area of ​​the sampling port of the load measuring instrument is S (m²). 2 After sampling, the total weight m (g) of the minerals in the sampling tube is weighed. Then, the bubble loading rate ε (g / L) at the measuring point is:

[0079]

[0080] Among them, t is usually 10min-60min.

[0081] The above inflation rate J b The measurement can be achieved using existing bubble loading rate measuring devices. After calculating the bubble loading rate, the obtained slurry is filtered, dried, sieved, and the grade of useful minerals in each particle size is analyzed. Finally, the size distribution characteristics, solid particle content, and grade of the solid particles carried on the bubbles at the sampling point are obtained.

[0082] In some embodiments, obtaining distribution status data specifically includes: filtering and drying the sampled slurry, screening it, and analyzing the grade of useful minerals in each particle size. The final results show the size distribution characteristics, solid particle content, and grade of the solid particles in the slurry.

[0083] The above distribution data can be obtained by deep cell sampling, using existing flotation cell deep cell sampling devices.

[0084] In addition, during the product evaluation process in the flotation cell, the sampler can be either an automatic sampler or a manual sampler.

[0085] The following is an example of a specific embodiment:

[0086] The KYF-680 ultra-large flotation machine system was tested using the flotation process evaluation method disclosed in the above embodiments. The tests included aeration volume and air dispersion, bubble size distribution characteristics in the pulp, air holdup and bubble loading rate at different pulp depths, and particle size distribution of minerals in pulp at different depths. The results are as follows: Figure 1 As shown in Figure 5.

[0087] Under optimal aeration conditions, the air dispersion degree can reach above 7, indicating good dispersion effect; the average air content of the flotation machine under ore conditions is about 7%; and the average aeration rate is 1.30 m³ / min. 3 ·m －2 ·min －1 Under the given conditions, the bubble diameter D 32 The value is approximately 3.34 mm, corresponding to a bubble surface area flux of 39.20 S. －1 The bubble load increases as the bubbles rise, reaching a maximum of 3.37 g·L⁻¹. －1 The pulp concentration distribution is uniform in flotation cells at different depths, and the particle size distribution is also relatively consistent across depths.

[0088] The above test cases demonstrate that by employing the flotation process depth assessment method provided in this invention, the overall operating status of the flotation system can be comprehensively evaluated.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for investigating a flotation process, characterized in that The method comprises the following steps: The gas phase investigation step: obtaining and comparing the air dispersion state data, the bubble size distribution characteristic data and the gas holdup data in the flotation machine; The solid phase investigation: sampling from the horizontal sections at different depths of the pulp phase to obtain the bubble load degree data in the pulp phase, sampling from different depths of the pulp phase to obtain the solid particle distribution state data in the liquid phase of the pulp phase, and comparing the load degree data and the distribution state data; The flotation tank product investigation: using a sampler to sample the froth and the underflow of the flotation machine and each operation of the entire flotation process, screening, analyzing and comparing the samples with the load degree data; The air dispersion state data specifically comprises: Selecting multiple horizontal sections at different depths in the flotation machine, selecting n measurement points in each horizontal section, measuring the apparent aeration rate of each measurement point, and calculating the air dispersion state data; The apparent aeration rates of the n measuring points are Jg1, Jg2, Jg3…Jg respectively n The calculation formula of the air dispersion state data adopts an extreme value calculation method. The extreme value calculation method is: ； wherein: is the average value of the apparent aeration rate for each of the n measurement points, for the air dispersivity; Or the calculation formula of the air dispersion state data adopts a variance calculation method; The variance calculation method is: ； wherein, for air dispersibility.

2. The flotation circuit investigation method according to claim 1, characterized in that, The bubble size distribution characteristic data specifically comprises: Statistically obtaining the normal distribution curve of the bubble diameter, and then calculating the average bubble size according to the normal distribution curve.

3. The flotation circuit investigation method according to claim 1, characterized in that, The gas holdup data specifically comprises: The pulp is closed sampled using a graduated cylinder, the volume of which is V 量 , the volume of the pulp in the graduated cylinder is V 矿 , the gas holdup of the pulp is: 。 4. The flotation circuit investigation method according to claim 3, characterized in that, The gas holdup data further comprises: The pulp in the flotation tank is evenly divided into n depths according to the longitudinal section depth, and the gas holdup of each depth is ε1, ε2, ε2…ε n The volume of the pulp in each depth of the measuring cylinder is V1, V2, V3…V n The calculation method of the comprehensive average gas holdup ε of the entire flotation tank is: 。 5. The flotation circuit investigation method according to claim 1, characterized in that, The load degree data specifically comprises: A measuring point is selected, and the aeration rate of the measuring point is measured as J b The sampling time of the bubble loading rate is t, the sampling port cross-sectional area of the loading measurer is S; after sampling, the total weight m of the mineral in the sampling cylinder is weighed, and the bubble loading rate ε of the measuring point is: 。 6. The flotation circuit investigation method according to claim 5, characterized in that, t is 10 min-60 min.

7. The flotation circuit investigation method according to claim 1, characterized in that, The distribution state data specifically comprises: After filtering and drying the sampled pulp, screening and assaying the useful mineral grade of each particle size.

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