Shale gas fracturing flow-back fluid treatment system

Abstract

The invention relates to the technical field of flow-back fluid treatment, and particularly discloses a shale gas fracturing flow-back fluid treatment system which is characterized in that a to-be-treated material is fed into a first-section ball mill for ore grinding, discharged ore of the first-section ball mill is fed into a primary cyclone for grading, primary graded settled sand of the primary cyclone is returned to the first-section ball mill for regrinding, and secondary graded settled sand of the primary cyclone is returned to the second-section ball mill for regrinding. The first treatment mode and the second treatment mode are selected for operation of primary graded overflow of the primary cyclone according to the judgment result of the control equipment, different treatment modes can be implemented on the basis of data generated in the crushing-ball milling process, and the influence of crushed ore argillization on the subsequent crushed ore recycling and machining process is reduced; the purpose of improving the shale layer mineral resource recycling efficiency is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of flowback fluid treatment, and in particular to a shale gas fracturing flowback fluid treatment system. Background Art

[0002] Shale gas is an unconventional natural gas that exists in an adsorbed or free state within shale formations. Its extraction primarily relies on horizontal drilling and hydraulic fracturing. Shale formations have a complex composition, containing minerals such as siliceous minerals (such as quartz and talc), iron oxides (such as magnetite and hematite), clay minerals (such as illite and montmorillonite), and small amounts of detrital minerals (such as feldspar and mica), as well as other chemicals (such as lithium and rare earth elements).

[0003] Generally speaking, shale gas contains little minerals, but there are also cases where the iron mineral content in shale gas in some mining areas is relatively high. In view of the mining in this case, it is economically valuable to recover the iron-containing minerals in the return fluid. However, direct recovery still has some problems. For example, the embedded particle size of the recoverable iron minerals in shale gas is extremely fine, and the crushed ore grade in the return fluid needs to be ground and selected for recycling and processing. However, during the fine grinding process, some siliceous minerals and clastic mineral gangue are severely muddied, which affects the recovery and processing of the iron minerals with extremely fine embedded particle size, resulting in the recovered iron ore grade not meeting market requirements.

[0004] Therefore, the purpose of the present invention is to optimize the management of the return fluid treatment process, and provide a process for efficiently and stably treating shale gas fracturing return fluid. During the treatment process, it can effectively reduce the degree of mudification during the fine grinding process, and reduce the impact of mudification of crushed ore on the subsequent crushed ore recovery processing process, so as to achieve the purpose of improving the recovery and utilization efficiency of shale mineral resources. Summary of the Invention

[0005] The purpose of the present invention is to provide a shale gas fracturing flowback fluid processing system to solve the following technical problems:

[0006] How to efficiently and stably process shale gas fracturing flowback fluid.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A shale gas fracturing flowback fluid processing system, comprising:

[0009] A pre-processing module, wherein the pre-processing module pre-processes the flowback liquid containing crushed ore to obtain material to be processed, and the pre-processing includes pre-magnetic separation;

[0010] The primary processing module includes a first-stage ball mill and a primary cyclone. After the material to be processed is fed into the first-stage ball mill for grinding, the discharge from the first-stage ball mill is fed into the primary cyclone for classification. The first-stage classification sand settling of the primary cyclone is returned to the first-stage ball mill for regrinding. The first-stage classification overflow of the primary ball mill enters the secondary processing module.

[0011] A control module, the control module includes a monitoring unit and a judgment unit, the monitoring unit monitors the pre-magnetic separation of the screening process and obtains first monitoring data, and monitors the working process of the first stage ball mill and the primary cyclone to obtain second monitoring data; the judgment unit obtains the crushing state coefficient according to the change process of the first monitoring data, and obtains the separation state coefficient according to the change process of the second monitoring data; the judgment unit obtains a judgment result based on the crushing state coefficient and the separation state coefficient, and the judgment result includes pass and fail;

[0012] The secondary processing module includes a first processing mode and a second processing mode, and the secondary processing module selects the first processing mode or the second processing mode to operate according to the judgment result.

[0013] Through the above technical solution: a method for processing iron-containing crushed ore produced by shale gas mining is provided, which can optimize the ball milling process. The present invention further optimizes and configures the ball milling process of iron-containing crushed ore produced by shale gas mining. First, the ball milling process is refined to reduce the production pressure of the subsequent flotation link, and different processing modes can be implemented based on the data generated by the crushing-ball milling process, thereby solving the problem that the supply properties of iron-containing crushed ore produced by shale gas mining fluctuate greatly, which seriously restricts the stability of downstream process flow, and improves the utilization efficiency of iron ore resources. In addition, based on the three-stage ball milling, the present invention can differentiate and treat crushed ore with extremely fine iron mineral embedding and easy mudification through the judgment unit, thereby reducing the losses caused by gangue mudification and indirectly improving the stability of return water treatment and magnetic levitation operations;

[0014] The process of selecting the first processing mode and the second processing mode for operation according to the judgment result includes:

[0015] As a further technical solution of the present invention: if the judgment result is failure, the process enters the first processing mode, the overflow of the primary cyclone enters the secondary cyclone for classification, the sand settling of the secondary cyclone classification returns to the second-stage ball mill for regrinding, the discharge of the second-stage ball mill is pumped to the secondary cyclone for classification, the overflow product of the secondary classification undergoes a weak magnetic operation and a strong magnetic separation, the weak magnetic concentrate and the strong magnetic concentrate produced enter the third-stage ball mill, the discharge of the third-stage ball mill enters the third cyclone classification, the sand settling of the third classification returns to the third-stage ball mill for regrinding, and the overflow of the third classification enters the second-stage thickener for flocculation and desludging;

[0016] If the judgment result is passed, the process enters the second treatment mode. The overflow of the first cyclone enters the third cyclone classification, the sand settling of the third classification returns to the third ball mill for re-grinding, and the overflow of the third classification enters the second thickener for flocculation and desludging.

[0017] As a further technical solution of the present invention: the ball mill material bin includes a plurality of storage boxes and a rotatable turntable, and the storage boxes are arranged on the turntable and can switch positions as the turntable rotates.

[0018] As a further technical solution of the present invention, the process of obtaining the crushing state coefficient according to the change process of the first monitoring data includes:

[0019] Divide the running time for filling a storage box into a number of first time periods of equal length;

[0020] Obtaining, in a first time period, a first mass of waste discharged during the pre-magnetic separation process and a second mass of waste passed through the pre-magnetic separation in first monitoring data;

[0021] A crushing state coefficient of the material to be processed in a storage box is obtained by calculation based on the first mass and the second mass.

[0022] The crushing state coefficient is obtained through the above technical solution. The first mass and the second mass obtained by pre-magnetic separation are iron-free crushed ore and iron-containing crushed ore, respectively. The current state of the crushed ore is represented by the ratio of the two. That is, the higher the crushing state coefficient is, the more sufficient the iron content of the crushed ore corresponding to the material to be processed in the current storage box will be.

[0023] As a further technical solution of the present invention, the process of obtaining the separation state coefficient according to the change process of the second monitoring data includes:

[0024] During the operation time of a ball mill and a primary cyclone processing the material to be processed in a storage box, a plurality of basic time periods are obtained based on the classified sand settling received by the ball mill;

[0025] Dividing a basic time period into a plurality of second time periods of equal length, and obtaining, within the second time periods, a change state of a third mass of sand deposited in the primary cyclone and a fourth mass of overflow sand based on the second monitoring data;

[0026] The segmented state coefficient is obtained based on the sand settling mass and overflow mass of the primary cyclone, and finally the separation state coefficient is obtained based on multiple segmented state coefficients.

[0027] The above technical solution provides a method for obtaining the separation state coefficient. The separation state coefficient is obtained based on the data generated during the operation of a ball mill and a cyclone. The final separation state coefficient is obtained by comparing with the standard state. The larger the separation state coefficient, the greater the difference between the currently processed crushed ore after two ball millings and the standard state, which means that it is more difficult to process.

[0028] As a further technical solution of the present invention, the process of the judgment unit obtaining the judgment result through the crushing state coefficient and the separation state coefficient includes:

[0029] Setting a first threshold and a second threshold within the value ranges of the crushing state coefficient and the separation state coefficient respectively;

[0030] If the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, a judgment coefficient is obtained based on a weighted sum of the crushing state coefficient and the separation state coefficient;

[0031] Multiple identification intervals are set within the value range of the judgment coefficient. If the judgment coefficient falls within the identification interval, the judgment result is output as passed, otherwise it is output as failed;

[0032] If the crushing state coefficient and the separation state coefficient do not satisfy the conditions that the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, the judgment result is output as passed.

[0033] The above technical solution provides the working process of the judgment unit and the process of obtaining the judgment coefficient. The judgment unit first roughly classifies the crushed ores by judging the critical values ​​of the crushing state coefficient and the separation state coefficient, thereby identifying the crushed ores with higher iron content and finer iron content. Then, based on the two, a more detailed judgment standard is calculated again. Multiple identification intervals are summarized through historical data. The crushed ores that fall into the identification interval need to enter the second processing mode. In the second processing mode, compared with the three-stage ball milling, one ball milling and desludging operation is reduced. On the one hand, the ball milling efficiency is improved, and on the other hand, the loss caused by the mudification of fine crushed ores can be reduced, thereby improving the utilization rate of crushed ores.

[0034] As a further technical solution of the present invention: the closed-circuit crushing process includes:

[0035] After the ore is crushed in a closed circuit, the particle size of the ore is less than 14mm and is sent to the magnetic pulley for roughing and discarding. The roughing tailings flow by gravity to the strong magnetic drum for scavenging. The scavenged tailings are conveyed by belts to the tailings silo. The tailings are controlled to have a TFe content of less than 10% and an mFe content of less than 1%. The magnetic pulley roughing concentrate and the strong magnetic drum scavenging concentrate are sent to the storage device for temporary storage as materials to be processed by the vehicle;

[0036] The magnetic field strength of the magnetic pulley is 5K-6KGs, and the magnetic field strength of the strong magnetic roller is 8K-9KGs.

[0037] As a further technical solution of the present invention: the grinding concentration during the first stage ball mill grinding is 80% ± 2%; the grinding concentration during the second stage ball mill grinding is 78% ± 2%;

[0038] The magnetic field strength of the primary weak magnetic operation is 3K-4K Gs, the magnetic field strength of the strong magnetic separation is 10K-11KGs, and the grinding concentration during the three-stage grinding is 70%±2%.

[0039] The crushing state coefficient is calculated by the formula:

[0040]

[0041] Obtained, of which Cr j represents the crushing state coefficient of the j-th storage box, is the total first mass in i first time periods, m2 is the total second mass in i first time periods, δ is a preset compensation index, which is a constant, n is the number of first time periods, and i is a natural number greater than 0 and less than n+1.

[0042] By formula:

[0043]

[0044] Get the separation state coefficient Pa of the jth storage box j , where N2 is the number of base time periods, σ k is the weight value preset based on the kth basic time period, Se k is the segmented state coefficient Se of the kth basic time period k , τ is the preset compensation coefficient selection function, τ(m c ) is based on the amount of material remaining in the first cyclone after the previous storage box is judged. c Selected compensation factor.

[0045] By formula:

[0046]

[0047] Obtain a judgment coefficient Ju, where α and β are respectively a preset first weight value and a second weight value, and G is a preset normalization function.

[0048] Beneficial effects of the present invention:

[0049] (1) The present invention provides a method for processing iron-containing crushed ore produced by shale gas mining, which can optimize the ball milling process. The present invention further optimizes and configures the ball milling process of iron-containing crushed ore produced by shale gas mining. First, the ball milling process is refined to reduce the production pressure of the subsequent flotation link, and different processing modes can be implemented based on the data generated by the crushing-ball milling process, thereby solving the problem that the supply properties of iron-containing crushed ore produced by shale gas mining fluctuate greatly, which seriously restricts the stability of the downstream process flow, and improves the utilization efficiency of iron ore resources. In addition, based on the three-stage ball milling, the present invention can differentiate and treat the crushed ore with extremely fine iron mineral embedding and easy to mud, through the judgment unit, thereby reducing the loss caused by gangue mudification and indirectly improving the stability of subsequent backwater treatment and magnetic levitation operations.

[0050] (2) The present invention provides a method for obtaining a separation state coefficient. The separation state coefficient is obtained based on data generated during the operation of a ball mill and a cyclone. The final separation state coefficient is obtained by comparing with the standard state. The larger the separation state coefficient, the greater the difference between the currently processed crushed ore after two ball millings and the standard state, which means that it is more difficult to process.

[0051] (3) The present invention provides a working process of a judgment unit and a process for obtaining a judgment coefficient. The judgment unit first numerically classifies the crushed ores by judging the critical values ​​of the crushing state coefficient and the separation state coefficient, thereby identifying the crushed ores with higher iron content and finer iron content. Then, a more detailed judgment standard is calculated again based on the two. Multiple identification intervals are summarized through historical data. The first-stage classification overflow that falls into the identification interval is the first-stage classification overflow that needs to enter the second processing mode. In the second processing mode, compared with the three-stage ball milling, one ball milling and desludging operation is reduced. On the one hand, the ball milling efficiency is improved, and on the other hand, the loss caused by the mudification of fine crushed ores can be reduced, thereby improving the recovery rate of crushed ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present invention will be further described below with reference to the accompanying drawings.

[0053] Figure 1 Schematic diagram of the ball milling process of the present invention; Figure 2 It is a schematic structural diagram of the storage device of the present invention; Figure 3 It is a flow chart of the implementation steps of the processing system of the present invention.

[0054] Description of reference numerals:

[0055] 1. Storage box; 2. Turntable. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0057] See also Figure 1-Figure 3 As shown, in one embodiment, a shale gas fracturing flowback fluid processing system is provided, comprising:

[0058] A pre-treatment module, wherein the pre-treatment module pre-treats the flowback liquid containing crushed ore to obtain the material to be processed. The pre-treatment includes pre-magnetic separation. The pre-treatment process includes filtering the flowback liquid to obtain crushed ore, then performing closed-circuit crushing on the crushed ore, and obtaining the material to be processed by pre-magnetic separation after the closed-circuit crushing. The material to be processed is then sent to the ball mill silo for packaging and storage;

[0059] The primary processing module includes a first-stage ball mill and a primary cyclone. After the material to be processed is fed into the first-stage ball mill for grinding, the discharge from the first-stage ball mill is fed into the primary cyclone for classification. The first-stage classification sand settling of the primary cyclone is returned to the first-stage ball mill for regrinding. The first-stage classification overflow of the primary ball mill enters the secondary processing module.

[0060] A control module, the control module includes a monitoring unit and a judgment unit, the monitoring unit monitors the pre-magnetic separation of the screening process and obtains first monitoring data, and monitors the working process of the first stage ball mill and the primary cyclone to obtain second monitoring data; the judgment unit obtains the crushing state coefficient according to the change process of the first monitoring data, and obtains the separation state coefficient according to the change process of the second monitoring data; the judgment unit obtains a judgment result based on the crushing state coefficient and the separation state coefficient, and the judgment result includes pass and fail;

[0061] The secondary processing module includes a first processing mode and a second processing mode, and the secondary processing module selects the first processing mode and the second processing mode to operate according to the judgment result;

[0062] In one embodiment, the implementation steps are as follows: the crushed ore is subjected to closed-circuit crushing, the product after the closed-circuit crushing is subjected to pre-magnetic separation to obtain the material to be processed, and the material to be processed is sent to the ball mill silo for packaging and storage. The closed-circuit crushing process includes:

[0063] After the ore is crushed in a closed circuit, the particle size reaches below 14mm and is sent to the magnetic pulley for roughing and discarding. The roughing tailings flow by gravity to the strong magnetic drum for scavenging. The scavenging tailings are conveyed by belts to the tailings silo. The tailings are controlled to have a TFe content of less than 10% and a mFe content of less than 1%. The magnetic pulley roughing concentrate and the strong magnetic drum scavenging concentrate are sent to the ball mill silo for temporary storage. TFe represents total iron and mFe represents magnetite. The magnetic field strength of the magnetic pulley is 5K-6KGs, and that of the strong magnetic drum is 8K-9KGs. The storage capacity of the storage box of the ball mill silo is not limited. The storage capacity of the storage box needs to be comprehensively selected based on production factors such as the actual processing volume and the discharge efficiency of the first stage ball mill. In this embodiment, a 10t storage box is selected. After the crushed ore raw materials are discharged from the storage box, they are continuously transported to the subsequent process through a conveying device. In this embodiment, the smaller the reserve, the more times the subsequent judgment unit makes judgments, and the number of mode switches also increases accordingly. In other words, the crushing process is more refined but the processing volume is lower.

[0064] S2. The material to be processed is fed into a first-stage ball mill for grinding. The discharge port of the first-stage ball mill is connected to the primary cyclone. Specifically, the discharge port feeds the overflow into a storage pool. Then, the discharge pump in the storage pool feeds the overflow of the first-stage ball mill into the primary cyclone for classification. The primary classification sand settling of the primary cyclone returns to the first-stage ball mill for re-grinding. The primary classification overflow of the primary cyclone is operated in the first processing mode and the second processing mode according to the judgment result of the control device. The grinding concentration during the first-stage ball mill grinding is 80%±2%; the grinding concentration during the second-stage ball mill grinding is 78%±2%.

[0065] The control device includes a monitoring unit and a judgment unit. The monitoring unit monitors the pre-magnetic separation of the screening process and obtains first monitoring data, and monitors the working process of the first-stage ball mill and the primary cyclone to obtain second monitoring data. The judgment unit obtains the crushing state coefficient according to the change process of the first monitoring data, and obtains the separation state coefficient according to the change process of the second monitoring data. The judgment unit obtains a judgment result based on the crushing state coefficient and the separation state coefficient, and the judgment result includes pass and fail.

[0066] S3.1. If the judgment result is "fail", the process enters the first treatment mode. The overflow of the primary cyclone enters the secondary cyclone for classification. The particle size of the secondary classification overflow product is controlled at -200 mesh and above at 55%. The secondary cyclone classification sand is returned to the second stage ball mill for regrinding. The discharge of the second stage ball mill is pumped to the secondary cyclone for classification. The particle size of the secondary classification overflow product is controlled at -200 mesh and above at 92%. The overflow product of the secondary classification enters the primary weak magnetic operation. The weak magnetic tailings enter the first stage thickener for concentration and desludging. The bottom flow enters the first coarse and one sweep strong magnetic separation. The weak magnetic concentrate and the strong magnetic concentrate enter the third stage ball mill. The discharge of the third stage ball mill enters the third cyclone classification. The third classification sand is returned to the third stage ball mill for regrinding. The overflow of the third classification enters the second stage thickener for flocculation and desludging. The overflow of the thickener and the strong magnetic tailings are directly discharged into the tailings pond. The tailings grade is controlled to be below TFe 10% and mFe If the concentration is below 1%, the overflow of the thickener will be discharged directly into the tailings pond, and the underflow will enter the secondary one-rougher and two-fine magnetic separation operation. The weak magnetic concentrate will enter the magnetic gravity separation operation, and the magnetic gravity underflow will be used as the final magnetic separation concentrate. The magnetic field intensity of the weak magnetic operation is 3K-4K Gs, and the magnetic field intensity of the strong magnetic separation is 10K-11K Gs. The grinding concentration during the three-stage grinding is 70%±2%;

[0067] If the result of the judgment is "pass", the process enters the second treatment mode. The overflow from the primary cyclone enters the tertiary cyclone for classification. The sand settling from the tertiary cyclone is returned to the third-stage ball mill for regrinding. The overflow from the third cyclone enters the second-stage thickener for flocculation and desludging. In this embodiment, the diameter of the first cyclone is 500 mm, the diameter of the second cyclone is 350 mm, and the diameter of the third cyclone is 150 mm.

[0068] It should be noted that the storage pool in step S2 serves as a necessary transition facility for intermittent operations. The overflow of the materials to be processed from different storage boxes after passing through the first stage of the ball mill will be mixed here. Therefore, in daily operations of this embodiment, three stages of ball milling are required to consume the remaining materials in the storage pool. Then, the input and output of the storage pool are controlled to maintain the same efficiency so as to control the overflow of the first classification that can skip the second stage of ball milling. In addition, considering the different overflow mixing, a delay time needs to be set before entering the second processing mode. The delay time is set taking into account the mixing time of different overflows to avoid the problem that the mixed materials cannot be completely processed after entering the second processing mode.

[0069] S4. The secondary magnetic separation tailings and magnetic gravity overflow enter the third and fourth stages of continuous dense flocculation and desludging operations, and the overflow is directly discharged into the tailings pond. The four-stage bottom flow is pumped to the flotation ore pool, and the medium ore pool enters the flotation operation. One coarse, two fine and three scavenging are carried out to obtain the final qualified concentrate. The flotation feed concentration is 50%±2%, the feed grade is ≥TFe40%, and the pH value is 10-11.

[0070] This embodiment provides a method for processing iron-containing crushed ore produced by shale gas extraction, which can optimize the ball milling process. The present invention further optimizes and configures the ball milling process of iron-containing crushed ore produced by shale gas extraction. First, the ball milling process is refined to reduce the production pressure of the subsequent flotation stage. Different processing modes can be implemented based on the data generated by the crushing-ball milling process, thereby solving the problem of large fluctuations in the supply properties of iron-containing crushed ore produced by shale gas extraction, which seriously restricts the stability of downstream process flows, and improves the efficiency of iron ore resource utilization. In addition, based on the three-stage ball milling, the present invention can use a judgment unit to differentiate and process crushed ore with extremely fine iron mineral embedding and easy mudification, thereby reducing losses caused by gangue mudification and indirectly improving the stability of subsequent return water treatment and magnetic levitation operations.

[0071] refer to Figure 2 The ball mill material bin includes a plurality of storage boxes 1 and a rotatable turntable 2. The storage boxes are arranged on the turntable and can switch positions as the turntable rotates. The storage capacity of each storage box is the same and the error between the actual storage mass and the standard mass is required to be within ±3%;

[0072] The process of obtaining the crushing state coefficient according to the change process of the first monitoring data includes:

[0073] Divide the running time of filling a storage box into a number of first time periods of equal length, where equal length means the same duration;

[0074] Obtaining, in a first time period, a first mass of waste discharged during the pre-magnetic separation process and a second mass of waste passed through the pre-magnetic separation in first monitoring data;

[0075] The crushing state coefficient of the crushed ore in a storage box is obtained by calculating based on the first mass and the second mass.

[0076] The crushing state coefficient is calculated by the formula:

[0077]

[0078] Among them Cr j represents the crushing state coefficient of the j-th storage box, is the total first mass in i first time periods, m2 is the total second mass in i first time periods, δ is a preset compensation index, which is a constant, n is the number of first time periods, and i is a natural number greater than 0 and less than n+1.

[0079] In this embodiment, the crushing state coefficient is obtained. The first mass and the second mass obtained by pre-magnetic separation are the iron-free crushed ore and the iron-containing crushed ore, respectively. The current crushing state is represented by the ratio of the two. That is, the higher the crushing state coefficient, the more sufficient the iron content of the crushed ore corresponding to the material to be processed in the current storage box.

[0080] The process of obtaining the separation state coefficient according to the change process of the second monitoring data includes:

[0081] During the operation time of a first-stage ball mill and a primary cyclone processing the material to be processed in a storage box, multiple basic time periods are obtained based on the graded sand received by the first-stage ball mill. Specifically, the first-stage ball mill adopts a reflux mechanism. After the initial processing of the material to be processed is completed, the sand of the cyclone will be refluxed to continue the ball milling process. Based on this process, multiple basic time periods are divided. That is, before the first sand reflux is the first basic time period, before the second sand reflux is the second basic time period, and so on.

[0082] Dividing a basic time period into a plurality of second time periods of equal length, and obtaining, within the second time periods, a change state of a third mass of sand deposited in the primary cyclone and a fourth mass of overflow sand based on the second monitoring data;

[0083] The segmented state coefficient is obtained based on the sand settling mass and overflow mass of the primary cyclone, and finally the separation state coefficient is obtained based on multiple segmented state coefficients.

[0084] Among them, through the formula:

[0085]

[0086] Get the segment state coefficient Se representing the kth basic time period k , M con is the mass change reference coefficient, represents the third mass of the lth second time period of the kth basic time period, represents the fourth mass of the lth second time period of the kth basic time period, g1 and g2 are preset reference table functions, represents the difference between the third mass of the lth time period and the third mass of the l+1th time period in the current basic time period, N1 is the number of the second time period, l is a natural number greater than 0 and less than N1+1, γ l It is a preset benchmark coefficient based on the current storage box crushing state coefficient. It is a constant value obtained by summarizing multiple crushing experiments with the same crushing state coefficient under standard conditions.

[0087] And through the formula:

[0088]

[0089] Get the separation state coefficient Pa of the jth storage box j , where N2 is the number of base time periods, σ k is the weight value preset based on the kth basic time period, Se kis the segmented state coefficient Se of the kth basic time period k , τ is the preset compensation coefficient selection function, τ(m c ) is based on the amount of material remaining in the first cyclone after the previous storage box is judged. c The selected compensation coefficient is selected based on empirical data.

[0090] This embodiment provides a method for obtaining a separation state coefficient. The separation state coefficient is obtained based on data generated during the operation of a first-stage ball mill and a first-stage cyclone. The final separation state coefficient is obtained by comparing it with the standard state. The larger the separation state coefficient, the greater the difference between the currently processed crushed ore after two ball millings and the standard state, which means that it is more difficult to quickly separate the ore through the first-stage ball mill.

[0091] The process of the judgment unit obtaining the judgment result through the crushing state coefficient and the separation state coefficient includes:

[0092] Setting a first threshold and a second threshold within the value ranges of the crushing state coefficient and the separation state coefficient respectively;

[0093] If the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, a judgment coefficient is obtained based on a weighted sum of the crushing state coefficient and the separation state coefficient;

[0094] Multiple identification intervals are set within the value range of the judgment coefficient. If the judgment coefficient falls within the identification interval, the judgment result is output as passed, otherwise it is output as failed;

[0095] If the crushing state coefficient and the separation state coefficient do not satisfy the conditions that the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, the judgment result is output as passed.

[0096] The judgment coefficient is calculated by the formula:

[0097]

[0098] Obtain a judgment coefficient Ju, where α and β are respectively a preset first weight value and a second weight value, are constants, and G is a preset normalization function.

[0099] In this embodiment, the working process of the judgment unit and the process of obtaining the judgment coefficient are provided. The judgment unit first roughly classifies the crushed ores by judging the critical values ​​of the crushing state coefficient and the separation state coefficient, thereby identifying the crushed ores with higher iron content and finer iron content, that is, the parts with poor performance in the weak magnetic operation and the strong magnetic separation process. Then, based on the two, a more linear judgment standard is calculated again. Multiple identification intervals are summarized through historical data. The crushed ores that fall into the identification interval are the crushed ores that need to enter the second processing mode. In the second processing mode, compared with the three-stage ball milling, one ball milling and desludging operation is reduced. On the one hand, the ball milling efficiency is improved, and on the other hand, the loss caused by the mudification of fine crushed ores can be reduced, thereby improving the utilization rate of crushed ores. In particular, the crushed ores that skip the second stage of ball milling can improve the efficiency of magnetite beneficiation, thereby reducing the requirements of the magnetic separation process, such as reducing the number of magnetic separation links or reducing the magnetic separation intensity, which is of great significance to saving production costs and increasing production efficiency.

[0100] In this embodiment, the judgment coefficient is a description of the processing status of the crushed ore in the current equipment. The judgment coefficient numerically describes the difficulty of the processing, which facilitates the refined control of the production process.

[0101] It should be noted that the figure also includes other specific steps of this embodiment, which belong to the existing technology and are not described in detail.

[0102] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A shale gas fracturing flowback fluid processing system, characterized in that: include: A pre-processing module, wherein the pre-processing module pre-processes the flowback liquid containing crushed ore to obtain material to be processed, and the pre-processing includes pre-magnetic separation; The primary processing module includes a first-stage ball mill and a primary cyclone. After the material to be processed is fed into the first-stage ball mill for grinding, the discharge from the first-stage ball mill is fed into the primary cyclone for classification. The first-stage classification sand settling of the primary cyclone is returned to the first-stage ball mill for regrinding. The first-stage classification overflow of the primary ball mill enters the secondary processing module. A control module, the control module includes a monitoring unit and a judgment unit, the monitoring unit monitors the pre-magnetic separation of the screening process and obtains first monitoring data, and monitors the working process of the first stage ball mill and the primary cyclone to obtain second monitoring data; the judgment unit obtains the crushing state coefficient according to the change process of the first monitoring data, and obtains the separation state coefficient according to the change process of the second monitoring data; the judgment unit obtains a judgment result based on the crushing state coefficient and the separation state coefficient, and the judgment result includes pass and fail; The secondary processing module includes a first processing mode and a second processing mode, and the secondary processing module selects the first processing mode or the second processing mode to operate according to the judgment result.

2. A shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The process of selecting the first processing mode and the second processing mode for operation according to the judgment result includes: If the judgment result is "fail", the process enters the first processing mode. The overflow from the primary cyclone enters the secondary cyclone for classification. The sand settling from the secondary cyclone is returned to the second-stage ball mill for regrinding. The discharge from the second-stage ball mill is pumped to the secondary cyclone for classification. The overflow from the secondary classification undergoes a weak magnetic operation and a strong magnetic separation. The resulting weak magnetic concentrate and strong magnetic concentrate enter the third-stage ball mill. The discharge from the third-stage ball mill enters the third cyclone for classification. The sand settling from the third classification is returned to the third-stage ball mill for regrinding. The overflow from the third classification enters the second-stage thickener for flocculation and desludging. If the judgment result is passed, the process enters the second treatment mode. The overflow of the first cyclone enters the third cyclone classification, the sand settling of the third classification returns to the third ball mill for re-grinding, and the overflow of the third classification enters the second thickener for flocculation and desludging.

3. A shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The ball mill material bin comprises a plurality of storage boxes (1) and a rotatable turntable (2); the storage boxes are arranged on the turntable and can switch positions as the turntable rotates.

4. A shale gas fracturing flowback fluid processing system according to claim 3, characterized in that: The process of obtaining the crushing state coefficient according to the change process of the first monitoring data includes: Divide the running time for filling a storage box into a number of first time periods of equal length; Obtaining, in a first time period, a first mass of waste discharged during the pre-magnetic separation process and a second mass of waste passed through the pre-magnetic separation in first monitoring data; A crushing state coefficient of the material to be processed in a storage box is obtained by calculation based on the first mass and the second mass.

5. The shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The process of obtaining the separation state coefficient according to the change process of the second monitoring data includes: During the operation time of a ball mill and a primary cyclone processing the material to be processed in a storage box, a plurality of basic time periods are obtained based on the classified sand settling received by the ball mill; Dividing a basic time period into a plurality of second time periods of equal length, and obtaining, within the second time periods, a change state of a third mass of sand deposited in the primary cyclone and a fourth mass of overflow sand based on the second monitoring data; The segmented state coefficient is obtained based on the sand settling mass and overflow mass of the primary cyclone, and finally the separation state coefficient is obtained based on multiple segmented state coefficients.

6. A shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The process of the judgment unit obtaining the judgment result through the crushing state coefficient and the separation state coefficient includes: Setting a first threshold and a second threshold within the value ranges of the crushing state coefficient and the separation state coefficient respectively; If the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, a judgment coefficient is obtained based on a weighted sum of the crushing state coefficient and the separation state coefficient; Multiple identification intervals are set within the value range of the judgment coefficient. If the judgment coefficient falls within the identification interval, the judgment result is output as passed, otherwise it is output as failed; If the crushing state coefficient and the separation state coefficient do not satisfy the conditions that the crushing state coefficient is greater than the first threshold and the separation state coefficient is less than the second threshold, the judgment result is output as passed.

7. A shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The grinding concentration of the first-stage ball mill is 80% ± 2%; the grinding concentration of the second-stage ball mill is 78% ± 2%; The magnetic field strength of the primary weak magnetic operation is 3K-4K Gs, the magnetic field strength of the strong magnetic separation is 10K-11KGs, and the grinding concentration during the three-stage grinding is 70%±2%.

8. The shale gas fracturing flowback fluid processing system according to claim 1, characterized in that: The crushing state coefficient is calculated by the formula: Obtained, of which Cr j represents the crushing state coefficient of the j-th storage box, is the total first mass in i first time periods, m2 is the total second mass in i first time periods, δ is a preset compensation index, which is a constant, n is the number of first time periods, and i is a natural number greater than 0 and less than n+1.

9. A shale gas fracturing flowback fluid processing system according to claim 8, characterized in that: By formula: Get the separation state coefficient Pa of the jth storage box j , where N2 is the number of base time periods, σ k is the weight value preset based on the kth basic time period, Se k is the segmented state coefficient Se of the kth basic time period k , τ is the preset compensation coefficient selection function, τ(m c ) is based on the amount of material remaining in the first cyclone after the previous storage box is judged. c Selected compensation factor.

10. A shale gas fracturing flowback fluid processing system according to claim 9, characterized in that: The judgment coefficient is calculated by the formula: Obtain a judgment coefficient Ju, where α and β are respectively a preset first weight value and a second weight value, and G is a preset normalization function.

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