Iron ore processing method

Abstract

The invention relates to the field of iron ore processing, in particular to an iron ore processing method which comprises the following steps: performing pretreatment operation on iron ore to obtain to-be-floated minerals, putting the to-be-floated minerals into a flotation tank of which the bottom is provided with a test air pipe, and performing bubble stability test every other preset period to obtain the to-be-floated minerals. The method comprises the following steps: dividing a flotation tank into a plurality of depth areas at preset same intervals, acquiring mineral density values of the plurality of depth areas in a corresponding period to determine a gradient difference quantity, calculating flotation stability characterization parameters based on the gradient difference quantity in combination with bubble stability characteristics, and dividing stability categories of a flotation process based on the flotation stability characterization parameters, therefore, the adjusting mode of the flotation process is adaptively determined, then it is guaranteed that mineral particles are fully collected through bubbles, and the flotation efficiency of iron ore is improved.

Description

Technical Field

[0001] The invention relates to the field of iron ore processing, and in particular to a method for processing iron ore. Background Art

[0002] While the steel industry has a large demand for iron ore, it also has increasingly higher requirements for the quality of iron ore raw materials. Therefore, iron ore flotation technology has developed rapidly. Iron ore flotation is a process of purifying iron ore raw materials, which can produce high-quality iron concentrate to meet the steel industry's demand for raw materials.

[0003] Chinese patent publication number: CN116673121A, discloses a pyrite flotation method, comprising the following steps: magnetic separation of the selected ore pulp to obtain magnetic tailings and pyrrhotite concentrate; concentrating the magnetic tailings to obtain underflow ore pulp and overflow water; roughing the underflow ore pulp to obtain roughing foam and roughing middling; multi-stage concentrating the roughing foam to obtain concentrating middling and pyrite concentrate; combining the roughing middling and the concentrating middling for scavenging, to obtain scavenging foam and tailings; combining the scavenging foam into the underflow ore pulp to enter the roughing again.

[0004] It can be seen that in the process of iron ore flotation, the existence of bubbles and related characteristics affect the flotation effect. The following problems still exist in the prior art:

[0005] 1. Bubbles that are too large or uneven may affect the capture of mineral particles. At the same time, uneven bubble distribution may cause some mineral particles to fail to fully contact with the bubbles, thus affecting flotation efficiency;

[0006] 2. Too fast a bubble rising speed may cause the bubbles to fail to fully contact with the mineral particles, which in turn may cause the bubbles to fail to completely capture the mineral particles, reducing the flotation efficiency. Summary of the invention

[0007] To this end, the present invention provides an iron ore processing method to overcome the problem in the prior art that the size, uniformity and floating speed of bubbles affect the capture of mineral particles, thereby reducing the flotation efficiency.

[0008] To achieve the above object, the present invention provides a method for processing iron ore, comprising:

[0009] Step S1, pre-treating the iron ore, wherein the pre-treating includes preliminarily crushing the iron ore by a jaw crusher, and placing the preliminarily crushed iron ore into a ball mill for further crushing and grinding to obtain the mineral to be floated;

[0010] Step S2, placing the mineral to be floated into a flotation cell with a test air pipe at the bottom, and performing a bubble stability test at predetermined intervals, including introducing an equal amount of gas into the flotation cell at predetermined time intervals, collecting the surface image of the flotation cell by an image acquisition device, and synchronously analyzing the bubble stability characteristics;

[0011] Step S3, dividing the flotation pool into a number of depth zones at predetermined equal intervals, and obtaining the mineral density values ​​of the several depth zones in a corresponding period to determine the gradient difference, calculating the flotation stability characterization parameter based on the gradient difference combined with the bubble stability characteristics, and dividing the stability category of the flotation process based on the flotation stability characterization parameter;

[0012] Step S4, determining the adjustment method of the flotation process according to the stability category of the flotation process, including:

[0013] According to the flotation stability characterization parameter, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted, and according to the mineral density in the middle depth area of ​​the flotation cell after adjustment, whether the flotation process meets the flotation stability standard is determined to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell;

[0014] Alternatively, a predetermined period is maintained to perform bubble stability detection on the flotation process.

[0015] Furthermore, in step S2, the bubble stability characteristics include bubble rising speed and bubble area mean.

[0016] Furthermore, in step S3, the process of determining the gradient difference includes:

[0017] Acquire the mineral density value of the middle depth area and the mineral density values ​​of the upper and lower depth areas adjacent to the middle depth area acquired by the image acquisition device;

[0018] The absolute value of the difference between the mineral density value of the middle depth area and the mineral density values ​​of the adjacent upper and lower depth areas is calculated respectively;

[0019] The average of the absolute values ​​of the differences is determined as the gradient difference amount.

[0020] Furthermore, in step S3, the flotation stability characterization parameter is calculated according to formula (1):

[0021]

[0022] In formula (1), F represents the flotation stability characterization parameter, T represents the gradient difference, T0 represents the preset gradient difference standard threshold, S represents the bubble floating speed, Se represents the preset bubble floating speed threshold, M represents the bubble area mean, Me represents the preset bubble area mean threshold, α represents the weight coefficient of the gradient difference, and β represents the bubble floating speed and bubble area mean weight coefficient.

[0023] Furthermore, in the step S3, the stability category of the flotation process is divided based on the flotation stability characterization parameter, including:

[0024] If the flotation stability characterization parameter is greater than or equal to the flotation stability characterization parameter threshold, the flotation process is determined to be a strong stability category;

[0025] If the flotation stability characterization parameter is less than the flotation stability characterization parameter threshold, the flotation process is determined to be a weakly stable category.

[0026] Furthermore, in step S4, determining the adjustment method of the flotation process includes:

[0027] If the flotation process is of the weak stability category, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted according to the flotation stability characterization parameter, and the mineral density in the middle depth area of ​​the flotation cell after adjustment is used to determine whether the flotation stability standard is met, so as to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell;

[0028] If the flotation process is of the strong stability category, the bubble stability detection of the flotation process is carried out for a predetermined period.

[0029] Furthermore, in step S4, the bubble particle size and flotation temperature of the bubble nozzle entering the flotation cell are adjusted, including:

[0030] Reducing the bubble size, the amount of bubble size reduction is negatively correlated with the flotation stability characterization parameter;

[0031] The flotation temperature is lowered, and the amount of reduction in the flotation temperature is negatively correlated with the flotation stability characterization parameter.

[0032] Furthermore, in step S4, determining whether the flotation process meets the flotation stability standard includes:

[0033] If the mineral density in the middle depth area of ​​the flotation tank after adjustment is greater than or equal to the mineral density threshold, it is determined that the flotation process meets the flotation stability standard.

[0034] Furthermore, in step S4, the process of adjusting the rotation speed of the impeller includes:

[0035] Obtaining the difference between the mineral density in the middle depth area of ​​the flotation tank and the mineral density before adjustment;

[0036] Determine the difference as a density change;

[0037] If the flotation process does not meet the flotation stability standard, adjust the impeller rotation speed;

[0038] The rotation speed of the impeller is increased, and the increase in the rotation speed is negatively correlated with the density change.

[0039] Furthermore, in step S4, determining whether there is an abnormality in the flotation process includes:

[0040] If the change rate of the profile of the floating objects on the surface of the flotation tank is less than the change rate threshold, it is determined that there is an abnormality in the flotation process.

[0041] Compared with the prior art, the present invention performs a pretreatment operation on iron ore to obtain minerals to be floated, places the minerals to be floated in a flotation tank with a test air pipe at the bottom, performs a bubble stability test at predetermined intervals, divides the flotation tank into a number of depth areas at predetermined equal intervals, and obtains mineral density values ​​of a number of depth areas in a corresponding period to determine a gradient difference, calculates a flotation stability characterization parameter based on the gradient difference combined with bubble stability characteristics, divides the stability category of the flotation process based on the flotation stability characterization parameter, and adaptively determines the adjustment method of the flotation process, thereby ensuring that the bubbles fully capture mineral particles and improving the flotation efficiency of the iron ore.

[0042] In particular, the present invention characterizes the stability of the flotation process by analyzing the stability characteristics of the bubbles. In actual situations, the iron ore is floated by the capture of mineral particles by the bubbles to obtain high-grade minerals, wherein the degree of obstruction and abnormal conditions of the flotation process are characterized by the floating speed of the bubbles, thereby affecting the stability of the foam layer; the uniformity of the bubbles is characterized by the bubble area. If the bubble floating process is greatly obstructed, it is easy to be dispersed, and the bubbles floating to the liquid surface will become smaller. Therefore, the present application determines the bubble floating speed and the average bubble area as the bubble stability characteristics, thereby providing data support for the subsequent calculation of the flotation stability characterization parameters in combination with the mineral density gradient difference, and then divides the stability category of the flotation process to adaptively determine the adjustment method of the flotation process, thereby ensuring that the bubbles fully capture mineral particles and improving the flotation efficiency of the iron ore.

[0043] In particular, the present invention determines the gradient difference through the mineral density values ​​of several depth areas. In the flotation process of iron ore, the rotation of the impeller makes the bubbles collect mineral particles in a dynamic state of motion, and the flotation pool is divided into depth areas at the same distance intervals. Due to the rotation and stirring of the impeller and the bubbles constantly capturing the mineral particles and floating dynamically, the mineral density in the middle depth area of ​​the flotation pool is relatively large and uniform. The gradient difference of the mineral density is determined based on the mineral density of the depth area adjacent to the middle depth areas, so as to characterize the uniformity of the distribution of bubbles in each depth area in the longitudinal direction, and provide data support for the subsequent calculation of the flotation stability characterization parameters in combination with the bubble stability characteristics, and then divide the stability category of the flotation process to adaptively determine the adjustment method of the flotation process, and then ensure that the bubbles fully capture the mineral particles and improve the flotation efficiency of the iron ore.

[0044] In particular, the present invention characterizes the stability of the flotation process by calculating the flotation stability characterization parameter, comprehensively determines the stability of the flotation process according to the floating speed, uniformity and bubble distribution of the flotation process, provides data support for the subsequent classification of the stability category of the flotation process, and adaptively determines the adjustment method of the flotation process, thereby ensuring that the bubbles fully capture the mineral particles and improving the flotation efficiency of the iron ore.

[0045] In particular, under the weak stability category of the flotation process, the present invention improves the stability of the flotation process by adjusting the bubble particle size and the flotation temperature of the bubble nozzle entering the flotation tank. For example, reducing the bubble particle size can increase the contact probability between the bubble and the mineral particles, which is helpful for the bubble to capture and float the mineral particles; too high a temperature may cause the average area of ​​the bubbles to increase, resulting in a weakened capture ability of the bubbles, reduced stability, and affected flotation efficiency. Furthermore, the mineral density in the middle depth area of ​​the flotation tank after adjustment is compared with the mineral density threshold to characterize the stability of the flotation process after adjustment, thereby ensuring that the bubbles fully capture the mineral particles and improving the flotation efficiency of the iron ore.

[0046] In particular, in the weak stability category of the flotation process, whether to adjust the rotation speed of the impeller is determined based on the result of the preliminary overall adjustment, and the rate of change of the profile of the floating object on the surface of the flotation tank is monitored in real time. When the flotation process after the preliminary overall adjustment still does not meet the flotation stability standard, the present invention increases the rotation speed of the impeller, increases the collision between mineral particles and bubbles, promotes the capture of mineral particles by bubbles, and improves the flotation efficiency. The rate of change of the profile of the floating object on the surface of the flotation tank monitored in real time characterizes the abnormal tendency of the flotation process. When the rate of change of the profile of the floating object on the surface of the flotation tank is less than the change rate threshold, it may be that the flotation process is abnormal, resulting in a decrease in the flotation minerals floating to the liquid surface. This is used to determine whether there is an abnormality in the flotation process, thereby ensuring that the bubbles fully capture the mineral particles and improving the flotation efficiency of the iron ore. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the steps of the iron ore processing method according to an embodiment of the invention;

[0048] Figure 2 A logical decision diagram for classifying the stability categories of the flotation process for the embodiments of the invention;

[0049] Figure 3 A logic decision diagram for determining whether a flotation process meets the flotation stability standard for an embodiment of the invention;

[0050] Figure 4 This is a logical decision diagram for determining whether there is an abnormality in the flotation process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0053] See also Figures 1 to 4 As shown, Figure 1 Schematic diagram of the steps of the iron ore processing method according to an embodiment of the present invention, Figure 2 A logical decision diagram for classifying the stability categories of the flotation process for an embodiment of the invention, Figure 3 A logical decision diagram for determining whether the flotation process meets the flotation stability standard for the embodiment of the invention, Figure 4 The invention embodiment is a logic determination diagram for determining whether there is an abnormality in the flotation process. The iron ore processing method of the embodiment of the invention includes:

[0054] Step S1, pre-treating the iron ore, wherein the pre-treating includes preliminarily crushing the iron ore by a jaw crusher, and placing the preliminarily crushed iron ore into a ball mill for further crushing and grinding to obtain the mineral to be floated;

[0055] Step S2, placing the mineral to be floated into a flotation cell with a test air pipe at the bottom, and performing a bubble stability test at predetermined intervals, including introducing an equal amount of gas into the flotation cell at predetermined time intervals, collecting the surface image of the flotation cell by an image acquisition device, and synchronously analyzing the bubble stability characteristics;

[0056] Step S3, dividing the flotation pool into a number of depth zones at predetermined equal intervals, and obtaining the mineral density values ​​of the several depth zones in a corresponding period to determine the gradient difference, calculating the flotation stability characterization parameter based on the gradient difference combined with the bubble stability characteristics, and dividing the stability category of the flotation process based on the flotation stability characterization parameter;

[0057] Step S4, determining the adjustment method of the flotation process according to the stability category of the flotation process, including:

[0058] According to the flotation stability characterization parameter, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted, and according to the mineral density in the middle depth area of ​​the flotation cell after adjustment, whether the flotation process meets the flotation stability standard is determined to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell;

[0059] Alternatively, a predetermined period is maintained to perform bubble stability detection on the flotation process.

[0060] Specifically, the structure of the test air pipe is not specifically limited, and it is only necessary to ensure that the gas can flow smoothly into the flotation tank, for example, an air pipe, which will not be described in detail.

[0061] Specifically, the structure of the image acquisition device is not limited, and it only needs to be able to acquire the surface image of the flotation tank. For example, an industrial CCD camera is set on one side of the flotation tank to photograph the surface of the flotation tank to obtain a high-precision surface image of the flotation tank. This will not be repeated here.

[0062] Specifically, there is no limitation on the specific structure of the bubble nozzle in the flotation tank, and it is only necessary to be able to adjust the particle size of the ejected bubbles. It can be understood that the bubble nozzle is used to eject microbubbles to improve the flotation efficiency, which will not be elaborated here.

[0063] Specifically, ultrasonic sensors are set at several depth regions to determine the mineral density value of each depth region, which will not be described in detail here.

[0064] In this embodiment, when the bubble stability test is performed, gas is introduced into the flotation cell through the test air pipe to form bubbles with larger particle sizes for easy observation, thereby making a preliminary determination of the stability of the flotation process.

[0065] Specifically, the structure of the impeller is not limited, and it only needs to have the function of stirring the slurry. It can be composed of blades and a hub, or it can be other forms, which will not be described in detail.

[0066] Specifically, after flotation, the remaining slurry can be concentrated, dried, filtered, and processed to obtain iron ore, which will not be described in detail.

[0067] Specifically, in step S2, the bubble stability characteristics include the bubble floating speed and the bubble area mean.

[0068] The bubble rising speed is determined by the time from the start of ventilation of the corresponding test air tube to the time of floating to the liquid surface of the flotation tank and the distance from the surface of the flotation tank to the test air tube.

[0069] The present invention characterizes the stability of the flotation process by analyzing the stability characteristics of bubbles. In actual situations, iron ore is floated by the capture of mineral particles by bubbles to obtain high-grade minerals, wherein the degree of obstruction and abnormal conditions of the flotation process are characterized by the floating speed of the bubbles, thereby affecting the stability of the foam layer; the uniformity of the bubbles is characterized by the bubble area. If the bubble floating process is greatly obstructed, it is easy to be dispersed, and the bubbles floating to the liquid surface will become smaller. Therefore, the present application determines the bubble floating speed and the average bubble area as bubble stability characteristics, thereby providing data support for the subsequent calculation of flotation stability characterization parameters in combination with the mineral density gradient difference, thereby dividing the stability category of the flotation process, and adaptively determining the adjustment method of the flotation process, thereby ensuring that the bubbles fully capture mineral particles and improving the flotation efficiency of the iron ore.

[0070] Specifically, in step S3, the process of determining the gradient difference includes:

[0071] Acquire the mineral density value of the middle depth area and the mineral density values ​​of the upper and lower depth areas adjacent to the middle depth area acquired by the image acquisition device;

[0072] The absolute value of the difference between the mineral density value of the middle depth area and the mineral density values ​​of the adjacent upper and lower depth areas is calculated respectively;

[0073] The average of the absolute values ​​of the differences is determined as the gradient difference amount.

[0074] In this embodiment, the flotation tank is divided into three depth areas with the same longitudinal distance, and the mineral density of each area is detected. Taking a flotation tank with a depth of 1m as an example, when dividing the depth areas, the same longitudinal distance is selected in the interval [0.28m, 0.33m].

[0075] The present invention determines the gradient difference through the mineral density values ​​of several depth areas. In the flotation process of iron ore, the rotation of the impeller makes the bubbles collect mineral particles in a dynamic state of motion, and the flotation pool is divided into depth areas at the same distance intervals. Due to the rotation and stirring of the impeller and the bubbles continuously capturing the mineral particles for dynamic floating, the mineral density in the middle depth area of ​​the flotation pool is relatively large and uniform. The gradient difference of the mineral density is determined according to the mineral density of the depth area adjacent to each depth area in the middle, so as to characterize the uniformity of the distribution of bubbles in each depth area in the longitudinal direction, provide data support for the subsequent calculation of the flotation stability characterization parameter in combination with the stability characteristics of the bubbles, and then divide the stability category of the flotation process to adaptively determine the adjustment method of the flotation process, and then ensure that the bubbles fully capture the mineral particles and improve the flotation efficiency of the iron ore.

[0076] Specifically, in step S3, the flotation stability characterization parameter is calculated according to formula (1):

[0077]

[0078] In formula (1), F represents the flotation stability characterization parameter, T represents the gradient difference, T0 represents the preset gradient difference standard threshold, S represents the bubble floating speed, Se represents the preset bubble floating speed threshold, M represents the bubble area mean, Me represents the preset bubble area mean threshold, α represents the weight coefficient of the gradient difference, and β represents the bubble floating speed and bubble area mean weight coefficient.

[0079] Specifically, in this embodiment, the standard threshold value T0 of the gradient difference, the threshold value Se of the bubble floating speed and the mean value Me of the bubble area are obtained by pre-selection measurement, and relevant data of several completed iron ore flotation are obtained to solve the mean value ΔT of the gradient difference, the mean value ΔSe of the bubble floating speed and the average value ΔMe of the bubble area, and set, T0 = c1 × ΔT, Se = c2 × ΔSe, Me = c2 × ΔMe, wherein c1 is the first precision coefficient, c2 is the second precision coefficient, 0.75 < c1 < 0.9, 1.25 < c2 < 1.35.

[0080] α is 0.37 and β is 0.63.

[0081] The flotation stability characterization parameter threshold F0 is selected in the interval [1.07, 1.16].

[0082] The present invention characterizes the stability of the flotation process by calculating the flotation stability characterization parameter, comprehensively determines the stability of the flotation process according to the floating speed, uniformity and bubble distribution of the flotation process, provides data support for the subsequent classification of the stability category of the flotation process, and adaptively determines the adjustment method of the flotation process, thereby ensuring that the bubbles fully capture the mineral particles and improving the flotation efficiency of the iron ore.

[0083] Specifically, in step S3, the stability category of the flotation process is divided based on the flotation stability characterization parameter, including:

[0084] If the flotation stability characterization parameter is greater than or equal to the flotation stability characterization parameter threshold, the flotation process is determined to be a strong stability category;

[0085] If the flotation stability characterization parameter is less than the flotation stability characterization parameter threshold, the flotation process is determined to be a weakly stable category.

[0086] Specifically, in step S4, determining the adjustment method of the flotation process includes:

[0087] If the flotation process is of the weak stability category, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted according to the flotation stability characterization parameter, and the mineral density in the middle depth area of ​​the flotation cell after adjustment is used to determine whether the flotation stability standard is met, so as to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell;

[0088] If the flotation process is of the strong stability category, the bubble stability detection of the flotation process is carried out for a predetermined period.

[0089] Specifically, in step S4, the bubble particle size and flotation temperature of the bubble nozzle entering the flotation cell are adjusted, including:

[0090] Reducing the bubble size, the amount of bubble size reduction is negatively correlated with the flotation stability characterization parameter;

[0091] The flotation temperature is lowered, and the amount of reduction in the flotation temperature is negatively correlated with the flotation stability characterization parameter.

[0092] In this embodiment, optionally,

[0093] The flotation stability characterization parameter F is compared with the first flotation stability characterization parameter comparison threshold F1 and the second flotation stability characterization parameter comparison threshold F2.

[0094] If F>F2, the bubble size reduction amount is determined to be the first bubble size reduction amount p1, and p1=0.25p0 is set;

[0095] If F1≤F≤F2, the bubble size reduction amount is determined to be the second bubble size reduction amount p2, and p2=0.35p0 is set;

[0096] If F<F1, the bubble particle size reduction amount is determined to be the third bubble particle size reduction amount p3, and p3=0.45p0 is set;

[0097] Wherein, p0 represents the initial bubble particle size, 200 μm<p0<300 μm, F1=0.76F0, F2=0.85F0.

[0098] The flotation stability characterization parameter F is compared with the first flotation stability characterization parameter comparison threshold F1 and the second flotation stability characterization parameter comparison threshold F2.

[0099] If F>F2, the flotation temperature reduction amount is determined to be the first flotation temperature reduction amount h1, and h1=0.21h0;

[0100] If F1≤F≤F2, the flotation temperature reduction amount is determined to be the second flotation temperature reduction amount h2, and h2=0.37h0 is set;

[0101] If F<F1, the flotation temperature reduction amount is determined to be the third flotation temperature reduction amount h3, and h3=0.46h0;

[0102] Wherein, h0 represents the initial flotation temperature, 30℃<h0<50℃, F1=0.76F0, F2=0.85F0.

[0103] Under the weak stability category of the flotation process, the present invention improves the stability of the flotation process by adjusting the bubble particle size and the flotation temperature of the bubble nozzle entering the flotation tank. For example, reducing the bubble particle size can increase the contact probability between the bubble and the mineral particles, which is helpful for the bubble to capture and float the mineral particles; too high a temperature may cause the average area of ​​the bubbles to increase, resulting in a weakened capture ability of the bubbles, reduced stability, and affected flotation efficiency. Furthermore, the mineral density in the middle depth area of ​​the flotation tank after adjustment is compared with the mineral density threshold to characterize the stability of the flotation process after adjustment, thereby ensuring that the bubbles fully capture the mineral particles and improving the flotation efficiency of the iron ore.

[0104] Specifically, in step S4, determining whether the flotation process meets the flotation stability standard includes:

[0105] If the mineral density in the middle depth area of ​​the flotation tank after adjustment is greater than or equal to the mineral density threshold, it is determined that the flotation process meets the flotation stability standard.

[0106] The mineral density threshold D0 is preset, wherein the mineral density data of several iron ore flotation processes are obtained in advance, and the mean value ΔD of the obtained mineral density data is solved, and it is set that D0=k×ΔD, k represents the deviation coefficient, 0.89<k<0.94.

[0107] Specifically, in step S4, the process of adjusting the rotation speed of the impeller includes:

[0108] Obtaining the difference between the mineral density in the middle depth area of ​​the flotation tank and the mineral density before adjustment;

[0109] Determine the difference as a density change;

[0110] If the flotation process does not meet the flotation stability standard, adjust the impeller rotation speed;

[0111] The rotation speed of the impeller is increased, and the increase in the rotation speed is negatively correlated with the density change.

[0112] In this embodiment, optionally,

[0113] The density change De is compared with the first density change comparison threshold value De1 and the second density change comparison threshold value De2.

[0114] If De>De2, the rotation speed increase value is determined to be the first rotation speed increase value z1, and z1=0.3z0;

[0115] If De1≤De≤De2, the rotation speed increase value is determined to be the second rotation speed increase value z2, and z2=0.37z0 is set;

[0116] If De<De1, the rotation speed increase value is determined to be the third rotation speed increase value z3, and z3=0.43z0;

[0117] Wherein, z0 represents the initial rotation speed, 500r / min<z0<1000r / min, De1=0.85De0, De2=0.97De0.

[0118] In the weak stability category of the flotation process, whether to adjust the rotation speed of the impeller is determined according to the result of the preliminary overall adjustment, and the change rate of the profile of the floating object on the surface of the flotation tank is monitored in real time. When the flotation process after the preliminary overall adjustment still does not meet the flotation stability standard, the present invention increases the rotation speed of the impeller, increases the collision between mineral particles and bubbles, promotes the capture of mineral particles by bubbles, and improves the flotation efficiency. The abnormal tendency of the flotation process is characterized by the change rate of the profile of the floating object on the surface of the flotation tank monitored in real time. When the change rate of the profile of the floating object on the surface of the flotation tank is less than the change rate threshold, the flotation process may be abnormal, resulting in a decrease in the flotation minerals floating to the liquid surface, so as to determine whether there is an abnormality in the flotation process, and further ensure that the bubbles fully capture the mineral particles, thereby improving the flotation efficiency of the iron ore.

[0119] Specifically, in step S4, determining whether there is an abnormality in the flotation process includes:

[0120] If the change rate of the profile of the floating objects on the surface of the flotation tank is less than the change rate threshold, it is determined that there is an abnormality in the flotation process.

[0121] The change rate threshold R0 is preset, wherein the rate data of several completed iron ore flotation are obtained in advance, and the rate change value is calculated based on the rate of the contour of the floating object on the surface of the flotation tank at each moment within a predetermined time, and the change rate mean ΔR is calculated based on the rate change value, and it is set that R0=z×ΔR, z represents the deviation coefficient, 0.85<z<0.95.

[0122] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for processing iron ore, It is characterized in that include: Step S1, pre-treating the iron ore, wherein the pre-treating includes preliminarily crushing the iron ore by a jaw crusher, and placing the preliminarily crushed iron ore into a ball mill for further crushing and grinding to obtain the mineral to be floated; Step S2, placing the mineral to be floated into a flotation cell with a test air pipe at the bottom, and performing a bubble stability test at predetermined intervals, including introducing an equal amount of gas into the flotation cell at predetermined time intervals, collecting the surface image of the flotation cell by an image acquisition device, and synchronously analyzing the bubble stability characteristics; Step S3, dividing the flotation pool into a number of depth zones at predetermined equal intervals, and obtaining the mineral density values ​​of the several depth zones in a corresponding period to determine the gradient difference, calculating the flotation stability characterization parameter based on the gradient difference combined with the bubble stability characteristics, and dividing the stability category of the flotation process based on the flotation stability characterization parameter; Step S4, determining the adjustment method of the flotation process according to the stability category of the flotation process, including: According to the flotation stability characterization parameter, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted, and according to the mineral density in the middle depth area of ​​the flotation cell after adjustment, whether the flotation process meets the flotation stability standard is determined to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell; Alternatively, a predetermined period is maintained to perform bubble stability detection on the flotation process.

2. The method for processing iron ore according to claim 1, It is characterized in that In step S2, the bubble stability characteristics include the bubble floating speed and the bubble area average.

3. The method for processing iron ore according to claim 1, It is characterized in that In step S3, the process of determining the gradient difference includes: Acquire the mineral density value of the middle depth area and the mineral density values ​​of the upper and lower depth areas adjacent to the middle depth area acquired by the image acquisition device; The absolute value of the difference between the mineral density value of the middle depth area and the mineral density values ​​of the adjacent upper and lower depth areas is calculated respectively; The average of the absolute values ​​of the differences is determined as the gradient difference amount.

4. The method for processing iron ore according to claim 1, It is characterized in that In step S3, the flotation stability characterization parameter is calculated according to formula (1): In formula (1), F represents the flotation stability characterization parameter, T represents the gradient difference, T0 represents the preset gradient difference standard threshold, S represents the bubble floating speed, Se represents the preset bubble floating speed threshold, M represents the bubble area mean, Me represents the preset bubble area mean threshold, α represents the weight coefficient of the gradient difference, and β represents the bubble floating speed and bubble area mean weight coefficient.

5. The method for processing iron ore according to claim 1, It is characterized in that In the step S3, the stability category of the flotation process is divided based on the flotation stability characterization parameter, including: If the flotation stability characterization parameter is greater than or equal to the flotation stability characterization parameter threshold, the flotation process is determined to be a strong stability category; If the flotation stability characterization parameter is less than the flotation stability characterization parameter threshold, the flotation process is determined to be a weakly stable category.

6. The method for processing iron ore according to claim 1, It is characterized in that In step S4, the adjustment method of the flotation process is determined, including: If the flotation process is of the weak stability category, the bubble particle size and the flotation temperature of the bubble nozzle in the flotation cell are adjusted according to the flotation stability characterization parameter, and the mineral density in the middle depth area of ​​the flotation cell after adjustment is used to determine whether the flotation stability standard is met, so as to adjust the rotation speed of the impeller, and the change rate of the profile of the floating objects on the surface of the flotation cell is monitored in real time, and whether there is an abnormality in the flotation process is determined according to the change rate of the profile of the floating objects on the surface of the flotation cell; If the flotation process is of the strong stability category, the bubble stability detection of the flotation process is carried out for a predetermined period.

7. The method for processing iron ore according to claim 1, It is characterized in that In the step S4, the bubble particle size and flotation temperature of the bubble nozzle entering the flotation cell are adjusted, including: Reducing the bubble size, the amount of bubble size reduction is negatively correlated with the flotation stability characterization parameter; The flotation temperature is lowered, and the amount of reduction in the flotation temperature is negatively correlated with the flotation stability characterization parameter.

8. The method for processing iron ore according to claim 1, It is characterized in that In step S4, it is determined whether the flotation process meets the flotation stability standard. include, If the mineral density in the middle depth area of ​​the flotation tank after adjustment is greater than or equal to the mineral density threshold, it is determined that the flotation process meets the flotation stability standard.

9. The method for processing iron ore according to claim 1, It is characterized in that In step S4, the process of adjusting the rotation speed of the impeller includes: Obtaining the difference between the mineral density in the middle depth area of ​​the flotation tank and the mineral density before adjustment; Determine the difference as a density change; If the flotation process does not meet the flotation stability standard, adjust the impeller rotation speed; The rotation speed of the impeller is increased, and the increase in the rotation speed is negatively correlated with the density change.

10. The method for processing iron ore according to claim 1, It is characterized in that In step S4, determining whether there is an abnormality in the flotation process includes: If the change rate of the profile of the floating objects on the surface of the flotation tank is less than the change rate threshold, it is determined that there is an abnormality in the flotation process.

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