27 results about "Sand mining" patented technology

This invention belongs to the field of coal mining technology, specifically relating to a water storage method in aeolian sandy aquifer mining areas. This invention innovatively utilizes directional drilling to connect aeolian sandy aquifers in open-area zones with those in non-open-area zones, improving rapid cross-regional water recharge and significantly increasing the total water storage capacity of the entire mining area. To prevent large amounts of water from being discharged through surface springs, coal pillars are used to alter the original seepage path of the aquifers. The subsidence of the coal pillar area is smaller than that of the mining area, blocking or reducing spring discharge and increasing the migration path of groundwater, thereby increasing infiltration. This invention increases the amount of water resources infiltrated from aeolian sandy ...

The invention relates to a reconstruction method for simulating a local scouring terrain of a bridge pier in a sandpit environment, comprising a bridge pier local scouring experimental model, the bridge pier local scouring experimental model comprises a water tank, gravels are laid at the bottom of the water tank, a vertical support rod for simulating the bridge pier is fixed in the middle of the water tank, and a sunken sandpit area is arranged beside the vertical support rod. An annular track is arranged above the water tank, a mobile camera is arranged on the annular track, a black and white checkerboard is made as a terrain reconstruction control point in the to-be-tested area, and the mobile camera carries out annular shooting in the research area; a PMVS algorithm is adopted, a result of sparse three-dimensional point cloud reconstruction is optimized, then topographic feature analysis of a local scouring bed surface of a pier and quantitative calculation of a pit area are performed when a sand mining pit exists, the method is suitable for a water tank test and a riverbed physical model test, the riverbed three-dimensional topography before and after scouring can be rapidly and efficiently reconstructed, the precision is high, and the method is suitable for popularization and application. And the research of the pier scouring terrain is facilitated.

The invention discloses a remote real-time sand excavation engineering ship operation parameter identification method and system, and belongs to the technical field of sand excavation engineering ship monitoring. Position information of a sand digging engineering ship, engine vibration information, noise information and attitude information of a sand digging pipe and a sand digging rod are collected respectively; the cloud application layer is combined with an engine vibration threshold judgment model to recognize the operation time period of the sand excavation engineering ship, obtains the operation depth of the sand excavation engineering ship through a posture-geometric calculation model and a device position relation, and recognizes the operation area of the sand excavation engineering ship through a space coordinate matching model; the number of operation tools of the sand excavation engineering ship is recognized through the equipment online state statistical model, data verification and early warning triggering are carried out, and operation supervision of the sand excavation engineering ship is achieved. According to the invention, the problems of inaccurate monitoring, weak data fusion capability and difficulty in realizing whole-process refined management and control of the existing river sand excavation supervision means are solved.

The application discloses a kind of tailings pond dry stoping process based on multistage belt conveyor, belong to tailings stoping technical field, mainly include tailings pond exploration, stoping area division and parameter determination, transport laying, stoping sequence planning and drainage facility arrangement;The application is based on the drainage mode of "chute+drainage culvert", including stoping I area, stoping II area, stoping area, block by using sand taking strip, sand taking path, in-pit transport road, belt transport and sand mining pit guide drainage pit, zoning, strip division is carried out in tailings pond in-pit, each area in the pit is layered and taken sand in strip by using excavator+small transport vehicle, and the dam top to dam foot is transported by belt transport, and is transported to large self-unloading truck by unloading buffer bin, effectively solve the stoping condition that tailings pond upper dam road cannot be transported by car, improve the efficiency of tailings pond stoping.

The invention discloses a sand dredger sand excavation behavior real-time monitoring device based on a multi-beam system. The monitoring device comprises a satellite signal receiving module, a multi-beam sounding module, an information processing module, a communication module and a power control module. The satellite signal receiving module is used for receiving Beidou satellite signals; the multi-beam depth sounding module comprises a multi-beam depth sounder used for transmitting and receiving water depth detection sound waves and an attitude sensor used for collecting attitude data of the ship body; the information processing module is used for carrying out position calculation, topograph calculation and sand excavation amount calculation; the communication module communicates with a ground control center and sends the terrain and the sand excavation amount of the measured position in real time; the power controller is used for automatically cutting off a power system of the sand dredger after the sand excavation amount exceeds the limit, and real-time control over the sand excavation behavior is achieved. The behavior of the sand dredger can be monitored in real time, and the over-mining behavior can be controlled in real time; and when a plurality of ships carry out sand excavation operation at the same time, the sand excavation amount of each ship can be distinguished, and accurate control is achieved.

The utility model discloses a riverway sand excavation pit ecological restoration structure which comprises a bottom plate, the top of the bottom plate is fixedly connected with a plurality of vertical rods, the inner walls of the plurality of vertical rods are provided with anti-loss devices, and each anti-loss device comprises a plurality of filter plates which are movably connected to the inner walls of the plurality of vertical rods; the plurality of planting boxes are arranged on the inner wall of the bottom plate; wherein the filter plate can filter silt in water flow in the river channel into the planting box. The utility model relates to the technical field of riverway sand excavation and treatment, in particular to an ecological restoration structure of a riverway sand excavation pit, soil loss is prevented through a loss prevention device, a small amount of soil and aquatic plant seeds are added into a planting box, and a filter plate can filter sludge in river water; the filtered sludge is stored in the planting box to provide nutrients for aquatic plant seeds, soil and seeds do not need to be loaded into a plurality of ecological bags, and the ecological restoration structure is convenient to popularize and use.

The invention discloses a multi-target sand excavation supervision method and system based on the Beidou technology. According to the method, position data of a sand dredger are obtained through a Beidou positioning terminal, and operation data are synchronously obtained through a data acquisition sensor; after compression and encryption, the data are transmitted to a supervision platform through a data transmission module, and the platform stores and analyzes verification data; based on the analysis data, judging whether the sand dredger crosses the border or not by using a ray method, and comparing the operation data with an early warning threshold to judge whether the operation data is excessive or not; early warning information is generated and pushed for abnormity, and a supervisor processes the information and then feeds back a result; and the platform queries and analyzes data to generate a report. According to the invention, the sand excavation supervision precision and efficiency are improved, and support is provided for management decision.

The invention belongs to the technical field of quartz sand screening processes and equipment, and particularly relates to a halter anti-blocking obstacle removing device for a sand dredger. The prior art lacks a special device capable of efficiently, actively and continuously preventing and removing various flexible and winding sundries at a sand suction opening on the premise of not interrupting normal sand excavation operation. The invention provides a halter anti-blocking obstacle removing device for a sand dredger, which is assembled at the end part of a sand suction pipe of an existing sand dredger and is used for removing possible impurities capable of blocking a halter and preventing the halter from being blocked by the impurities to influence the sand dredger to supply mortar raw materials to a silica sand production line. The circumferential rotary rail is adopted to support the cutter sliding along the rail, sundries and grass roots wound on the halter are cut and eliminated, the scheme is simple, convenient and easy to implement, maintenance is fast, and the obstacle removing device is not prone to being wound by weeds and roots for the second time.

This invention discloses a simulation calculation method for the impact of river sand mining on navigation flow conditions, including: collecting and integrating basic geographic information and hydrological data of the sand mining area to construct a digital elevation model and hydrological database covering the entire area; based on the integrated data and Cartesian coordinate system, using an unstructured grid to partition the sand mining area to obtain a grid file of the sand mining area; given the initial conditions, boundary conditions, and dynamic boundary technology of the model, establishing a two-dimensional planar hydrodynamic model based on two-dimensional continuity equations and two-dimensional momentum equations through data collection and preprocessing; conducting model verification and calibration experiments based on existing historical measured data; and designing two sets of working conditions before and after sand mining according to the sand mining scheme and navigation engineering design scheme, obtaining prediction results based on the simulated values ​​of the hydrodynamic model.

The application discloses a kind of based on the real-time monitoring device of sand dredging behavior of sand dredger of multi-beam system.The monitoring device includes satellite signal receiving module, multi-beam sounding module, information processing module, communication module and power control module.Satellite signal receiving module is used to receive Beidou satellite signal;Multi-beam sounding module includes the multi-beam depth finder for emitting and receiving water depth detection acoustic wave, and the attitude sensor for collecting ship body attitude data;Information processing module is used for position solution, topography and sand dredging amount calculation;Communication module communicates with ground control center, and real-time sends the topography and sand dredging amount of measured position;Power controller is used to automatically cut off the power system of sand dredger after sand dredging amount exceeds limit, realizes the real-time control of sand dredging behavior.The application can monitor the behavior of sand dredger in real time, and control over-dredging behavior in real time;And when multiple ships are simultaneously dredging, the sand dredging amount of each ship can be distinguished, and accurate control can be achieved.

The invention belongs to the technical field of quartz sand screening processes and equipment, and particularly relates to a conical roller screen with a multi-layer screen structure. The front end of a production line is not provided with an efficient and special impurity screening device, and a simple grating or manual sorting is mostly adopted, so that the problems of incomplete screening, high labor intensity, easiness in blockage and the like exist. Therefore, the special screening equipment capable of efficiently and continuously removing the impurities in the raw ore is urgently needed and is arranged behind a sand dredger and in front of a hydraulic classifier so as to guarantee stable operation and product quality of a whole production line. The invention provides a conical roller screen with a multi-layer screen structure, which is arranged at the front end of a silica sand mining and dressing production line, is positioned between a raw ore outlet provided by a sand dredger and a hydraulic classifier, and is mainly used for screening out non-silica sand raw materials such as branches, garbage and sundries in raw ores. The device has the characteristics of high screening efficiency, high treatment capacity, difficulty in blockage, compact structure and the like.

The utility model discloses a dust isolation device with centrifugal fan for open-air quartz sand mining, which comprises: a centrifugal fan body, a mounting motor arranged outside the centrifugal fan body, and an impeller back disc mounted at the output end of the mounting motor, wherein the outside of the impeller back disc is connected with a blade, and the lower end of the centrifugal fan body is provided with a mounting bracket, and the outside of the mounting bracket is welded with an outer support plate; the outside of the blade is connected with an impeller front disc; the outside of the centrifugal fan body is fixed with an external interface plate, and the inside of the external interface plate is provided with an exhaust port; and the air inlet of the centrifugal fan body is provided with a dustproof assembly. The dust isolation device with centrifugal fan for open-air quartz sand mining can filter the air before entering the device through the setting of the dust screen, thereby playing a dust isolation role, and the dust screen can be disassembled and replaced under the setting of the dustproof assembly.

The utility model discloses a spray dryer for ceramic colored sand, which relates to the technical field of ceramic colored sand processing, and comprises a mixing tank, a heating box body and a motor, the bottom end of the mixing tank is connected with a discharge pipe in a penetrating manner, a feeding through hole is formed right above the mixing tank in a penetrating manner, a drying mechanism is arranged on the outer side of the heating box body, and the motor is connected with the heating box body. The drying mechanism heats the surface of ceramic and meanwhile heats and dries the sprayed dyeing material, the time of colored sand in the processing process is shortened, a processing mechanism is arranged in the mixing tank, the processing mechanism continuously mixes ceramic sand and stone, and meanwhile the dyeing material is sprayed to the surface of the sand and stone, so that the color sand processing time is shortened. And then ceramic sand excavation processing is completed. In the using process, the motor drives the fan blades to rotate at the same time, meanwhile, the motor is used for driving the spiral blades to rotate, and therefore materials and ceramic particles are evenly heated while the materials are lifted and sprayed.

The utility model relates to quartz sand mining and mineral processing technical field especially, relates to a kind of quartz sand mining recovery device of adaptation different granularity, including support frame, hopper, mounting frame, mineral processing filter frame and filter screen etc., support frame top fixedly connected mounting frame, mounting frame top is equipped with the hopper of front high rear low inclination arrangement, mounting frame left and right sides slidingly connected three vertical arrangement mineral processing filter frame, each is located directly below hopper, each mineral processing filter frame is equipped with filter screen, aperture increases gradually from top to bottom, the filter screen of first mineral processing filter frame is rear high front low inclination arrangement, filter screen higher end lower side is equipped with discharge port.The utility model is arranged three vertical arrangement and filter screen aperture increases gradually from top to bottom mineral processing filter frame, and in combination with each layer filter screen inclination arrangement and vibrating screen design, reached to quartz sand material according to granularity high-efficiency classification, continuous screening effect, significantly improved the separation precision and recovery efficiency of different particle size particles.

The invention discloses a crushing, slurry-making and slag-isolating machine for upstream type tailing pond wet mining. The crushing, slurry-making and slag-isolating machine is formed by combining a crushing, slurry-making system and a screening and slag-removing system. The crushing and slurry making system comprises a shearing and crushing device, the shearing and crushing device is composed of a double-shaft central pipe (4) and rolling blades (3) installed on the double-shaft central pipe (4), and the slag separating and removing system comprises a rolling screen (9). And detachable buoys (18) and rolling wheels (19) are arranged at the bottom of the crushing and pulping system and the bottom of the screening and deslagging system. The tailings are separated and purified by using the crushing and slurry making system and the screening and deslagging system. Tailings are crushed by the rolling blades (3) to form primary tailing slag slurry, and impurities in the slag slurry are filtered out by the rolling screen (9). The crushing, slurry-making and slag-isolating machine is convenient to assemble and disassemble, low in construction cost, high in operability, capable of effectively solving the problems that wet mining and slurry-making of tailings are difficult and a conveying pump pipe is blocked, capable of improving the efficiency of stoping and slurry-making, high in sand mining quality, free of impurities and convenient for subsequent comprehensive utilization.

The present invention discloses a marine sand mining monitoring system and method, which are used to solve the problems of insufficient monitoring accuracy and insufficient environmental change early warning faced by existing marine sand mining monitoring systems; the system comprises a monitoring and acquisition module, an environmental monitoring and analysis module, a precision monitoring and analysis module and an execution module; the system effectively evaluates the impact of sand mining activities on the environment by real-time monitoring and analysis of environmental factors and the accuracy of sand mining equipment, calculates the environmental quality impact coefficient and the environmental state impact coefficient, and makes adjustments in combination with dynamic environmental data to timely discover environmental changes and reduce the negative impact of sand mining on the ecological environment; the system also automatically analyzes the accuracy deviation of the equipment through the precision monitoring and correction module, and makes dynamic corrections based on the correlation analysis results, so that the equipment always operates within a high-precision range; the precise control method optimizes the sand mining process, improves sand mining efficiency and resource utilization, and reduces operation errors and environmental disturbances.

The invention relates to the technical field of electric digital processing, in particular to a sand excavation behavior recognition method and system based on a ship list and time-space characteristics, and the method comprises the following steps: screening a ship track coordinate set located in a sea sand exploitation supervision area, dividing coordinate points into a plurality of equal-length time sections according to a time sequence, relative position deviation values of the coordinate points in the section are calculated, and a space-time deviation matrix is generated. According to the method, the stability and the accuracy of the identification process of the illegal sand excavation behavior can be improved in a complex environment based on spatial-temporal characteristic optimization calculation of the track coordinates. Through the time sequence division and equal-length section processing mode of the track coordinates, the coordinate point deviation calculation is more accurate, and the analytic property of the data is improved through matrix storage. In the data compression process, run counting is combined with Huffman coding and dictionary mapping, redundant information storage is reduced, and the real-time performance of data transmission and calculation is improved.

This invention discloses a big data-driven optimization method and system for tailings dam recovery schemes, relating to the field of mineral resource recovery and intelligent optimization technology. The system's operation includes: constructing a detailed three-dimensional digital model of the dam area; conducting value zoning evaluation to delineate high-value recovery zones and low-value replacement zones; implementing surface mining and pipeline transportation of high-value zones using a floating sand mining platform; simultaneously filling low-value materials into the goaf to maintain stress balance; and dynamically regulating the hydraulic system based on intelligent monitoring data of the entire dam area to ensure the safety of the dry beach length and phreatic line. The system comprises six modules: multi-source data acquisition, digital modeling, intelligent zoning evaluation, recovery operation execution, synchronous filling and reinforcement, and dynamic monitoring and balance control. This application achieves synergistic optimization of efficient high-value tailings recovery and dam structural safety through spatial replacement and dynamic balance mechanisms.

The application discloses a sand mining ship identification method, a sand mining activity dynamic monitoring method and a system for large rivers, and the sand mining ship identification method comprises the following steps: S100, processing low-resolution remote sensing images of a target river basin at multiple time sequences into low-resolution slice images; S200, performing super-resolution image reconstruction on the low-resolution slice images by using a super network to obtain high-resolution reconstructed slice images at multiple time sequences; and S300, performing sand mining ship identification on the high-resolution reconstructed slice images by using a sand mining ship instance segmentation model, and outputting multiple time sequence images containing sand mining ship identification results; the sand mining ship identification results comprise a boundary box, a target category, a confidence degree and a sand mining ship instance mask. The application can accurately identify sand mining ships with various sizes and dynamic multi-directional characteristics in large rivers, and can meet the complex scene requirements of sand mining ship monitoring in large rivers.

The present application relates to an ecological restoration method for in-situ resource utilization of contaminated pond sediment of sandy coast, and belongs to the technical field of ecological restoration and solid waste resource utilization. The method comprises the following steps: evaluating the pollution condition of the sandy sediment at the bottom of the eutrophic pond of the sandy coast; under the condition that the water pollutants exceed the standard but the greening planting soil does not exceed the standard, using the dry dredging and temporary storage method, transporting the sandy sediment to the greening planting area in the project area after excavation, and using the pretreated sandy sediment as the greening planting soil of the local sand vegetation. The present application avoids the secondary pollution caused by the external transportation of the sandy sediment, the restriction of the sand mining policy and the pollution disposal problem, reduces the cost, fully utilizes the nutrient elements in the sandy sediment to provide nutrition for the vegetation, plants the local sand vegetation, maximizes the survival rate of the vegetation, avoids the introduction of alien species to cause damage to the local ecology, and realizes the resource utilization and harmless utilization of the sandy contaminated sediment.

The application discloses a kind of cross-sea immersed tunnel siltation and sudden silt load calculation method, comprising: sufficient investigation, collect tunnel area marine environment monitoring data basis, theoretical analysis, according to field test results, establish siltation thickness theoretical model and calculation method under two conditions of sand mining open period and closed period.According to the characteristics of the project area, the siltation load calculation model is established, and the siltation thickness is layered and stacked based on the siltation thickness model.The total load and the incremental load of the tunnel siltation under the siltation state are established.According to the collapse and formation characteristics of the sudden silt material in seawater, a marine sudden silt geometric model is established.The probability density function is used to establish the sudden silt spatial distribution function and the corresponding sudden silt load distribution function.According to the application, the theoretical model and calculation method of the marine environment siltation load and the disaster load formed by the rare sudden siltation in the project area are established, which provides a practical method for calculating the dynamic load on the immersed tunnel during operation.

The invention relates to the technical field of intelligent monitoring, and provides an illegal sand excavation behavior identification method and system, and the method comprises the steps: collecting image data of a sand excavation region; sand excavation equipment is selected from the image data, and position information of the sand excavation equipment is extracted; for the sand excavation equipment in the sand excavation state, generating a movement track; calculating the speed and the acceleration of the sand excavation equipment based on the motion trail, and constructing a space-time diagram based on the motion trail, the speed and the acceleration of the sand excavation equipment; extracting spatiotemporal features of the sand excavation equipment based on the spatiotemporal diagram; time sequence action features of the sand excavation equipment are extracted from the image data of the sand excavation areas at the multiple different visual angles, and the time sequence action features are fused to obtain fused action features; and on the basis of the fused action features and the spatial-temporal features, illegal sand excavation behaviors of the sand excavation equipment are judged. According to the method, comprehensive real-time monitoring of the sand excavation area can be realized, and illegal sand excavation behaviors can be accurately identified.

The invention relates to a river sand excavation management and control method based on digital twinning, which belongs to the technical field of sand excavation, and comprises the following steps: respectively establishing digital twinning models of a river sand plant, sand excavation equipment and a sand transport vehicle; dividing a sand excavation area in the river sand plant model into a plurality of sand excavation unit areas; the initial sand storage amount of each sand excavation unit area is obtained, and the initial state of each sand excavation equipment model and the initial state of each sand transport vehicle model are recorded as idle states; the sand excavation unit area with the maximum sand storage amount currently is selected as the current sand excavation unit area, sand excavation equipment and sand transporting vehicles in the idle state are dispatched nearby to enter the current sand excavation unit area according to the bidirectional mapping relation, and the states of the sand excavation equipment and the sand transporting vehicles are adjusted to be in the working state; after each sand excavation operation is completed, the sand storage amount of the corresponding sand excavation unit area is updated, and the states of the corresponding sand excavation equipment model and the sand transporting vehicle model are adjusted to be idle states; and repeatedly and alternately carrying out the steps of dispatching the sand excavation equipment and the sand transporting vehicle and updating the sand storage amount and the equipment state so as to control the sand excavation process. According to the river sand excavation control method, the sand excavation amount and the river sand storage amount can be mastered in real time, a sand excavation plan can be reasonably arranged, meanwhile, sand excavation vehicles can be reasonably arranged, and the sand excavation efficiency is improved.

The invention discloses an efficient and environment-friendly sand pumping device, and belongs to the technical field of sand excavation. An efficient and environment-friendly sand pumping device comprises a mounting support and a sand hopper which are arranged on a ship, and further comprises a bridge supporting piece, a discharging pipe and a supporting frame, and the bridge supporting piece is fixedly arranged in the sand hopper and used for dividing falling sand; the discharging pipe is fixedly arranged on the lower side of the sand hopper; a driving motor is fixedly arranged on the supporting frame, an output shaft of the driving motor is connected with a rotating shaft rotationally connected with the supporting frame, and the end, away from the driving motor, of the rotating shaft extends into the discharging pipe and is connected with a spiral conveying blade; wherein the rotating shaft is provided with a sand homogenizing mechanism for uniformly discharging; by improving the sand unloading point, the superficial area of the sand unloading point is increased, the scattering area of sand is increased, sand accumulation during sand unloading is prevented, the air carrying amount when the sand enters a dredge pump is reduced, the cavitation amount of the dredge pump is reduced, and the phenomena of plugging and blocking the dredge pump are avoided, so that the sand excavation construction efficiency is improved.

The application discloses a kind of river and lake water area dynamic monitoring method based on remote sensing image, for suspected sand mining and other activities concealment, difficult to take evidence, method with difference detection identifies change patch, generates constraint boundary and labels space-time information with concurrent water level line and main flow direction;Patch is semantically classified, extracts shoreline cut-in angle, channel center line normal distance, contour slope and spatial relationship with channel, shoal, management range, dynamic electronic fence;Multi-agent model of electronic fence, unmanned aerial vehicle, suspected sand mining ship and transfer point is constructed, according to contour passage zone and time window, evasive path is deduced, narrow corridor is set in intersection section and trigger threshold, and unmanned aerial vehicle standby point and flight path are arranged and operated in linkage;After triggering, evidence is pushed to law enforcement terminal for comparison and disposal;The method realizes closed loop from monitoring to evidence.

The application discloses a kind of sand suction head monitoring systems, belongs to sand mining technical field.A kind of sand suction head monitoring system, including sand mining ship deck, swing arm is provided on sand mining ship deck, swing arm is provided with a plurality of angle sensors for monitoring swing arm swing amplitude, suction pipe is provided along swing arm on sand mining ship deck, one end of suction pipe is connected with the pump body being set on sand mining ship deck, sand mining conical suction head is provided at the end of suction pipe away from sand mining ship deck, the end of swing arm is fixedly provided with mounting plate, sand mining conical suction head is fixedly connected with mounting plate, camera and sand loosening crushing mechanism are provided on mounting plate;The application can monitor the posture of sand mining conical suction head by angle sensor, and then analyze the stress condition and suction effect of suction pipe, and loosen and crush the sand and gravel at the bottom of riverbed using sand loosening crushing mechanism, so that the sand and gravel at the bottom of riverbed meet the sand mining requirements, without shifting position to sand mine, ensure sand mining efficiency.

The invention discloses a novel upstream type tailing pond wet mining pulping method. A tailing pond wet mining crushing pulping filter composed of a crushing pulping system and a screening deslagging system is adopted. The crushing and slurry making system comprises a shearing and crushing device, the shearing and crushing device is composed of a double-shaft central pipe (4) and rolling blades (3) installed on the double-shaft central pipe (4), and the slag separating and removing system comprises a rolling screen (9). And detachable buoys (18) and rolling wheels (19) are arranged at the bottom of the crushing and pulping system and the bottom of the screening and deslagging system. The tailings are separated and purified by using the crushing and slurry making system and the screening and deslagging system. Tailings are crushed by the rolling blades (3) to form primary tailing slag slurry, and impurities in the slag slurry are filtered out by the rolling screen (9). The method can effectively solve the problems of difficulty in wet mining and slurry making of tailings and blockage of a conveying pump pipe, is simple and convenient to operate, can improve the efficiency of stoping and slurry making, is high in stoping efficiency and high in sand mining quality, does not contain impurities, and is convenient for subsequent comprehensive utilization.