143 results about "Coal measures" patented technology

The invention belongs to the field of coal solid waste resource utilization, and relates to a method for preparing a NaP type molecular sieve by utilizing kaolinite rock type coal gangue. The method comprises the following steps: 1) crushing and grinding blocky kaolinite rock type coal gangue into powder; 2) roasting and activating the coal gangue powder to obtain metakaolin; 3) mixing and stirring metakaolin, sodium hydroxide, a silicon source and deionized water to obtain an initial solution; 4) standing and aging the initial solution to obtain a precursor solution; 5) performing dynamic hydrothermal crystallization treatment on the precursor solution to obtain crystals; and 6) washing, neutralizing, centrifuging and drying the crystal to obtain the NaP type molecular sieve. The kaolinite rock type coal gangue is used as a raw material to replace a traditional chemical raw material required by molecular sieve synthesis, and resource utilization of aluminosilicate solid waste is promoted. According to the method, seed crystals or guiding agents are not required to be added in the molecular sieve crystallization process, and special crystallization methods such as microwaves and ultrasound are also not required, so that the process is simple, the cost is low, and the method is environment-friendly.

The invention discloses a coal measure stratum hard coal rock composite structure modifying and cracking system and method. The system comprises a cracking device arranged in a directional drill hole extending into a cracking area, a high-pressure pump and a hydraulic pump, wherein the high-pressure pump and the hydraulic pump are arranged in a coal seam roadway and inject a high-pressure cracking agent into the cracking device. The method comprises the following steps: 1, determining the position of a modified cracking area of the overlying strata of the coal seam; 2, determining drilling parameters; 3, obtaining a directional drill hole; fourthly, a fracturing device is installed, and the hole is sealed; 5, calculating the fracture pressure of the rock stratum and carrying out primary water fracturing; 6, liquid nitrogen reinforced cracking of the rock mass; and 7, judging whether the coal measure stratum hard coal rock composite structure modification cracking effect is achieved or not. On the basis of hydraulic fracturing, liquid nitrogen fracturing and mechanical auxiliary fracturing are introduced and ingeniously combined, meanwhile, the fracturing means can be autonomously adjusted according to different working conditions, the hard roof fracturing modes are enriched, the method has the advantages of being small in engineering amount, low in pollution, high in safety and high in working efficiency, and the cracking effect is enhanced.

The invention discloses a weakly cemented mining stratum roadway roof separation limit value determination method, relates to the technical field of mine roadway damage surrounding rock anchor net cable support and roof stability monitoring, and focuses on roadway surrounding rock roof support and monitoring of a weakly cemented coal mining stratum. The most typical damage form is sudden roadway roof fall and roadway integral convergence, and the life safety of mine engineering technicians is greatly threatened. The roof separation value is the relative displacement between two measuring points in the surrounding rock and between the surrounding rock at the end of the anchor rod and the surface of the roadway roof, belongs to the mine pressure display of the mine roadway, and is an important index for evaluating the anchor net cable supporting effect. The anchor net and anchor cable roof separation value based on the excavation disturbance rock damage degree is accurately calculated and monitored, and the method has important significance for guaranteeing mine safety production.

The invention discloses a biogas logging identification method and device, a medium and electronic equipment. The method comprises the steps that coring observation is conducted on the coal measure strata, seismic data and logging data are combined, geological layering is conducted on the coal measure strata, and the geological layering is used for eliminating the influence of the space structure of the coal measure strata on an acoustic logging curve; an acoustic logging curve of the coal measure stratum is obtained, and borehole environment correction is conducted on the interval transit time corresponding to the acoustic logging curve; establishing a cross plot according to the corrected acoustic logging curve and a neutron gamma curve obtained by analyzing measured data; based on the cross plot, a gas reservoir fitting curve is obtained, and the gas reservoir fitting curve is used for recognizing a gas reservoir in the coal measure strata. The accuracy of identifying the gas reservoir in the coal measure stratum can be improved.

The invention discloses a coal series strategic metal collaborative exploration method, which belongs to the technical field of strategic metal mineral products, and comprises the following steps: S1, data collection and preprocessing; s2, multi-source data fusion: performing feature extraction and feature fusion on the obtained data; s3, intelligent analysis and prediction: constructing a coal measure metal ore body identification and prediction model, carrying out training and optimization, and carrying out ore body prediction analysis; and S4, performing three-dimensional visualization and verification: performing three-dimensional modeling on the prediction result obtained in the S3, and verifying the prediction result. According to the method, through multi-source data fusion and intelligent analysis, the exploration period is shortened, the exploration efficiency is improved, the accuracy and reliability of coal series strategic metal mineral resource prediction are improved, and resource evaluation errors are reduced, so that technical support is provided for coal series strategic metal mineral target region optimization and comprehensive exploration demonstration engineering.

The invention discloses a coal-series gas yield increasing and CO2 geological sequestration integrated simulation method and system, and relates to the technical field of gas exploitation of each layer, and the method comprises the following specific steps: building a geological model representing a multi-lithology superposed coal-series reservoir; the coal series reservoir is a heterogeneous reservoir and comprises shale, a coal seam and sandstone, the shale and the coal seam are double-hole double-permeability media, and the sandstone is a single-hole single-permeability medium; based on the geologic model, establishing a multi-physical field coupling model of a coupling temperature field, a seepage field and a stress field; performing discretization solution on the multi-physics field coupling model to obtain a numerical simulation result; constructing a numerical model, and performing inversion correction on model parameters of the numerical model based on experimental data and the numerical simulation result; and utilizing the corrected numerical model to simulate different injection-production working conditions so as to carry out double-target evaluation and scheme optimization of coal-series gas yield increase and CO2 geological sequestration. The method provides a reliable decision basis for engineering scheme design.

The invention provides a coal measure strata weathering zone aquifer water yield evaluation method, and particularly relates to the technical field of well field exploration. The method specifically comprises the following steps: S1, determining main evaluation indexes for evaluating the water yield property, and constructing an index system for evaluating the water yield property of the aquifer of the stratum weathering zone; s2, data quantification, standardization and normalization processing; s3, determining a subjective weight value and an objective weight value of each main evaluation index through an analytic hierarchy process and an entropy weight method; s4, drawing a water yield property single-factor partition map of each main evaluation index; s5, performing weighted combination on the subjective weight value and the objective weight value of each main evaluation index by using a linear method, and determining a comprehensive weight value of each main evaluation index; s6, constructing an evaluation model of the water yield strength of the aquifer of the to-be-studied area; and S7, based on the stratum weathering zone aquifer water yield property comprehensive partition map, carrying out water yield property evaluation. According to the method, the division grade of the water yield property of the weathering zone aquifer of the coal measure strata in the area range to be researched can be more intuitively evaluated.

The invention relates to the technical field of coal gangue resource utilization, in particular to a magnetic coal series kaolin hydrogel adsorbing material as well as a preparation method and application thereof. The preparation method of the material specifically comprises the following steps: carrying out ultrafine grinding, sieving and grading on coal gangue ore to obtain a coal series kaolinite material; further performing magnetic separation to obtain coal series kaolinite iron-rich tailings; further performing magnetizing roasting in a reducing atmosphere to obtain magnetic coal series kaolin; the preparation method comprises the following steps: compounding magnetic coal series kaolin with sodium alginate and chitosan by adopting a gel coating method, dropwise adding a calcium chloride solution for crosslinking, and freeze-drying to obtain the magnetic coal series kaolin hydrogel material. The preparation method is simple, and the obtained adsorption material has the characteristics of low cost, large adsorption capacity, high adsorption rate, high selectivity, excellent cyclic utilization performance and the like.

This application discloses a design method and grouting material for deep coal-bearing strata, comprising the following steps: S1 Data acquisition based on material pre-tests, correlation analysis, and orthogonal experiments; S2 Data expansion based on orthogonal experimental data to establish a dataset; S3 Creating a prediction model based on the RBF algorithm; S4 Optimizing the prediction model based on the PSO-RBF algorithm; S5 Proportion design based on the RBF-PSO-EWM algorithm; S6 Obtaining the proportion of grouting material for deep coal-bearing strata. This application proposes a PSO-RBF-EWM multi-objective optimization grouting material proportion design method and applies this method to design the comprehensive optimal proportion of grouting material for deep coal-bearing strata. The grouting material with the obtained optimal proportion has excellent characteristics such as low water-cement ratio, green environmental protection, and economic efficiency, and is suitable for the reinforcement characteristics of deep coal-bearing strata.

According to the roof coal measure aquifer post-mining partition grouting water-resisting layer reconstruction method and the related equipment provided by the invention, for the post-mining coal seam roof water disaster treatment problem, accurate analysis of coal seam roof rock stratum hydrogeological characteristics is realized by comprehensively considering the geological parameters and the stratum distribution parameters of the target mining area. Then, the development height of the water-flowing fractured zone is accurately determined by using a distribution characteristic algorithm and a numerical simulation algorithm, and then the correlation between the water-flowing fractured zone and hydrogeological characteristics is deeply analyzed through a distribution relation algorithm, so that the difference of different geological conditions can be fully considered; therefore, grouting treatment is carried out according to the target grouting treatment strategy of the mined coal seam roof determined based on the distribution relation, the pertinence of water disaster treatment can be remarkably improved, the problem that the grouting treatment effect is poor due to complex geological conditions is solved, and the water disaster risk of the coal seam roof is effectively reduced.

The invention relates to the technical field of ore recognition, in particular to a method and a system for quickly and preliminarily recognizing field ore quality of coal-series trilean metal mineral products, which comprises the following steps of: acquiring ore samples and acquiring main peaks, structures and infrared images, extracting image features to generate mutation numbers, analyzing sampling coordinates to reconstruct a connection structure, and calculating the quality of the coal-series trilean metal mineral products. Drawing a closed boundary to judge coordinate attribution, and outputting an ore quality identification scheme. According to the method, main peak reflection, microscopic image layers and infrared spectrum acquisition results are numbered in a unified manner and are subjected to time sequence binding, a synchronous corresponding relation among multi-source images is established, continuous change nodes and sudden change areas are identified in combination with offset tracks and structural features, spatial concentration blocks are generated by using number and coordinate mapping, and a connected structure is reconstructed; and drawing a closed boundary according to the track to form a region classification basis, verifying a mass change direction through image sequence coherence, and outputting a tagging identification result, thereby realizing rapid positioning and accurate classification of the field ore sample.

The invention provides an intelligent recognition and separation system, method and device for coal series kaolinite in coal gangue, and belongs to the field of coal gangue separation. The problems that in an existing coal gangue separation technology, coal series kaolinite recognition and separation efficiency is low, and precision is poor are solved. The system comprises a multi-modal data acquisition and processing module which is used for acquiring and processing a ray image, a texture image and the thickness of the coal gangue to obtain a comprehensive feature vector containing the gray scale, the texture and the thickness data of the coal gangue; the coal series kaolinite evaluation label establishing module is used for establishing an evaluation label; the image input classification algorithm module is used for taking the comprehensive feature vector as input, taking the evaluation label as a classification label, training a classification identification model and outputting a classification result; the control and separation execution module is used for generating a separation instruction according to the classification result and separating coal series kaolinite from the common coal gangue; the method is applied to separation of coal series kaolinite in coal gangue.

The invention discloses a coal mining full-life-cycle coal, gas and heat combined development method which comprises the following steps: before coal mining, carrying out combined development on coal series gas and terrestrial heat in a coal series reservoir through a ground combined development well; in the coal mining process, coal seam gas is extracted through bottom drainage roadway gas extraction holes, circulating water pipes are arranged in an underground bottom drainage roadway or a coal face air return roadway and a transportation roadway, cold water is injected from the ground for cyclic heating while coal mining is conducted, and combined development of coal, gas and terrestrial heat is achieved; after coal mining, a goaf is filled and blocked to form a relatively closed mining influence body, coal gas and hot water in the mining influence body are extracted through the ground coal gas extraction hole and the geothermal energy extraction hole, and combined development of the coal gas and geothermal energy in the mining influence body is achieved. According to the application, transformation and upgrading of coal resource development from single energy acquisition to multi-energy collaborative, efficient and clean utilization are promoted.

The invention relates to the field of coal-based graphite purification monitoring management, and particularly discloses an operation data acquisition optimization analysis system based on a coal-based graphite purification system.The operation data acquisition optimization analysis system is characterized in that technological parameters of raw material pretreatment are preliminarily set, and the technological parameters are optimized according to particle size distribution after raw material pretreatment; preliminarily setting technological parameters of acid leaching, and optimizing the technological parameters according to the acid consumption rate and the reaction heat release temperature in the acid leaching process; preliminarily setting process parameters of alkali neutralization, and optimizing the process parameters according to the neutralization rate of the alkali neutralization process; preliminarily setting process parameters of washing and dewatering, and optimizing the process parameters according to the conductivity of a washing solution for washing and dewatering and the water content of a filter cake; preliminarily setting drying process parameters, and optimizing the process parameters according to the residual moisture content after drying; the self-adaptive optimization of key process parameters of each process link of coal-based graphite purification is realized, and the production efficiency and the product quality of coal-based graphite purification are better guaranteed.

The invention belongs to the field of rare earth extraction processes, and particularly relates to a closed-loop dressing and smelting process for coal-series associated rare earth mineral resources based on a DESs solvent. Comprising the following steps: taking a sample, carrying out ball milling, adding a leaching agent into the sample after ball milling, leaching the ion adsorption type rare earth elements in the sample, and stirring to obtain a turbid solution; adding a precipitant into the leachate, and then carrying out solid-liquid separation to obtain supernate and precipitates; taking supernate and analyzing the extraction efficiency of the rare earth elements through inductively coupled plasma mass spectrometry (ICP-MS); and adding deionized water into the obtained supernate to recover the leaching agent for next use. The invention aims to obtain a series of deep eutectic solvent (DESs) systems capable of efficiently leaching coal series associated rare earth mineral resources, so that the efficient separation and leaching of ion adsorption type rare earth elements in coal ores are realized; and by utilizing the reversibility of DESs, the recycling of the DESs solvent and the closed-loop dressing and smelting process of coal-series associated rare earth mineral resources are realized.

The present invention relates to a method for predicting sandstone reservoirs in coal-bearing strata, belonging to the technical field of predicting sandstone reservoirs in coal-bearing strata. The present invention utilizes the difference in frequency attenuation of seismic waves propagating in sandstone and mudstone in coal-bearing strata. First, forward modeling is performed on the well logging data of the wells with measured sandstone reservoirs obtained to obtain the corresponding pre-stack gathers; then, the well logging data of the sandstone section in the well is replaced with mudstone well logging data, and forward modeling is performed again using the replaced data to obtain the corresponding pre-stack gathers; frequency analysis is performed on the pre-stack gathers obtained before and after replacement to determine the attenuation of the reflected waves in the sandstone section; the pre-stack gathers of the target area to be predicted are obtained, and sandstone prediction is performed on the target area according to the attenuation of the reflected waves in the sandstone section. The present invention does not require complex post-stack data processing, reduces the errors caused by data processing, and improves the prediction accuracy.

The invention discloses a tectonic coal reservoir stress release modifiability evaluation method, and belongs to the technical field of coal bed gas development. The method comprises the four steps of sample testing, evaluation index selection, evaluation index weight calculation and tectonic coal reservoir stress release modifiability evaluation. The method comprises the following steps: quantitatively evaluating the reformability of a tectonic coal reservoir in a stress release manner, designing a coal measure strata structure reconstruction and similar material simulation device to test a tectonic coal sample to obtain sample parameters, and comparing the sample under different strata environment occurrence conditions. According to the change conditions of the gas permeability and the gas desorption amount after the stress release of the tectonic coal reservoir, proper evaluation indexes are selected, and the influence weight of each evaluation index on the gas permeability and the gas desorption amount of a sample is calculated, so that the method for evaluating the stress release modifiability of the tectonic coal reservoir is established and is highly consistent with the actual engineering condition; the method is high in operability, can be quantified, and can truly and effectively evaluate the potential of exploiting the coal bed gas of the tectonic coal reservoir.

The invention provides a cross-cycle dynamic monitoring processing method and device for a coal measure strata. The method comprises the following steps: determining array combinations corresponding to each measuring point taking a main micro-motion detector in a micro-motion detector array as a center; based on the array combination corresponding to each measuring point, background noise data of the detection area before recovery, during recovery and after recovery are obtained respectively; frequency dispersion curves of surface waves are extracted based on the background noise data of the detection area before recovery, during recovery and after recovery; performing inversion analysis on the frequency dispersion curve of the surface wave to obtain inversion results of all the measuring points; fitting the inversion results of all the measuring points into a three-dimensional stratigraphic structure diagram; and based on the three-dimensional stratigraphic structure diagram, geological anomalous body discrimination and monitoring are carried out, and a coal measure stratigraphic monitoring result is obtained. According to the method provided by the invention, cross-cycle dynamic monitoring of overlying strata movement information in the whole mining process can be realized, and the detection cost is greatly reduced.

The invention discloses a non-coal measure stratum natural gas displacement mathematical model construction method. The method comprises the following steps that gas migration equations are established, wherein the gas migration equations comprise the step of establishing a rock mass pore gas diffusion motion control equation and the step of establishing a stratum fracture gas seepage equation; establishing a stratum rock mass deformation control equation; establishing a dynamic porosity and permeability change control equation: establishing a rock mass porosity dynamic change equation, establishing a stratum fracture rate dynamic change equation and establishing a permeability dynamic change equation; and establishing a non-coal measure stratum natural gas displacement mathematical model based on the above steps. The non-coal measure stratum natural gas displacement mathematical model is established by combining the non-coal measure stratum natural gas displacement characteristics, and a scheme which is good in treatment effect, low in cost and high in efficiency is provided for non-coal measure stratum natural gas emission.

The invention discloses a method and device for identifying a coal reservoir, and the method comprises the steps: obtaining a coal rock sample of a target interval, and carrying out a thermogravimetric experiment on the coal rock sample; performing image analysis on data obtained by the thermogravimetric experiment to determine a first coal series reservoir; performing thermogravimetric mass spectrometry data analysis on the coal rock sample corresponding to the first coal series reservoir; and determining a final coal reservoir according to a thermogravimetric mass spectrometry data analysis result.

The invention relates to the technical field of unconventional resource development, in particular to a method and a device for determining lithology space-time distribution characteristics of coal measure gas, and the corresponding method comprises the following steps: building a sequence stratigraphic framework of a target work area according to rock debris logging data and logging data of the target work area; determining dominant storage lithology corresponding to each coal series gas; according to the sequence stratigraphic framework and the advantage storage lithology corresponding to each type of coal measure gas, establishing a well connection section and a lithology plane graph; and according to the well connection profile and the lithologic plan, determining the lithologic spatial-temporal distribution characteristics of the coal-series gas. The effective determination method of the lithology space-time distribution rule is formed on the basis of combination of the sequence strata, the rock core and the logging, rock core constraint, logging lithology correction and high-precision sequence strata isochronous framework constraint, and then the lithology space-time distribution rule of coal bed gas, coal series shale gas and coal series tight sandstone gas evaluation is determined.

The application provides a roof coal series aquifer post-mining partition grouting aquifuge reconstruction method and related equipment, aiming at the problem of coal seam roof water disaster control after mining, by comprehensively considering the geological parameters and stratum distribution parameters of the target mining area, the accurate analysis of the hydrogeological characteristics of the coal seam roof rock stratum is realized. Then, the development height of the water flowing fractured zone is accurately determined by using the distribution characteristic algorithm and the numerical simulation algorithm, and then the correlation between the water flowing fractured zone and the hydrogeological characteristics is analyzed in depth by using the distribution relationship algorithm, so that the difference of different geological conditions can be fully considered, therefore, the grouting treatment according to the target grouting treatment strategy of the post-mining coal seam roof determined based on the distribution relationship can significantly improve the pertinence of water disaster control, avoid the problem of poor grouting treatment effect caused by complex geological conditions, and effectively reduce the risk of coal seam roof water disaster.

The present invention discloses a method for generating initial stress of coal-bearing strata and tunnels in PFC3D, including: obtaining the ground stress parameters of the research block location and the macroscopic basic physical and mechanical parameters corresponding to the coal body and the rock mass, and calibrating the parameters through the PFC3D triaxial compression numerical simulation technology; preliminarily establishing the PFC3D coal-bearing strata numerical model according to the microscopic mechanical parameters and stratum size corresponding to the coal body and the rock mass, and preloading through the wall servo; establishing the FLAC3D model area boundary of the PFC3D coal-bearing stratum numerical model, and generating the coupling surface of the PFC‑FLAC calculation, setting the constitutive model and material parameters corresponding to the coal body and the rock mass at the FLAC3D model area boundary; assigning ground stress to the coal body and the rock mass at the FLAC3D model area boundary and setting the boundary conditions of the model, performing equilibrium calculation on the entire numerical model to generate the initial stress of the coal-bearing strata, and generating a three-dimensional model of the coal tunnel according to the tunnel size excavation calculation. The present invention realizes the accurate generation of the initial stress of the coal-bearing strata and the tunnel.

The present invention discloses a method for underground sand and coal dust prevention in a combined-layer coalbed methane well. Two upper and lower drainage devices are provided in the combined-layer coalbed methane well. First, a combined-layer development coalbed methane well with a two-wellbore structure is constructed on the ground, and the lower structural coal and the upper native structural coal are subjected to fracturing transformation in sequence. A packer is used to suspend a lower drainage pipe string at the top plate of the structural coal producing layer, so that the return fluid, formation water, and coalbed methane produced by the structural coal producing layer can enter the interior of the lower drainage pipe string through the wire-wound screen pipe. At the same time, the proppant and coal dust produced in large quantities by the structural coal producing layer are blocked from entering the drainage pipe string, and the proppant and coal dust are caused to sink to the bottom of the artificial well under the action of gravity. The lower drainage pipe string is used to prevent sand and coal dust, reduce the risk of pump sticking, and ensure the continuity of the drainage process of the combined-layer development coalbed methane well. It is particularly suitable for coalbed methane drainage under conditions where the coal body structure of the main coalbed methane producing layer in the middle and lower coal measures is broken and a large amount of sand and dust is expelled during combined-layer drainage.

The embodiment of the invention provides a simulation experiment device and method for coal-series gas enrichment, and relates to the technical field of natural gas exploration and development. The simulation experiment device for coal series gas enrichment comprises a first reaction cabin, a second reaction cabin and a third reaction cabin which are sequentially communicated and stacked, the first reaction cabin is used for containing a bottom rock sample, the second reaction cabin is used for containing a coal seam sample, and the third reaction cabin is used for containing a top rock sample; the injection system is communicated with the first reaction cabin; the first reaction cabin, the second reaction cabin and the third reaction cabin are respectively provided with at least one stress loader and at least one heater. Through collaborative design of multi-cabin layered sample bearing and independent stress and temperature regulation, confining pressure constraint and interlayer stress transfer of a top plate rock sample and a bottom layer rock sample to a coal seam sample are accurately simulated, the real occurrence environment of coal series gas in a stratum is reduced, the influence of interlayer stress on coal series gas enrichment is prevented from being ignored, and obtained experimental data are more reliable.

The invention belongs to the technical field of coal mine water quality formation and evolution. A coal mine water quality formation and evolution simulation device comprises a constant temperature control box used for controlling the temperature in the constant temperature control box to be in a constant temperature state; the spraying end of the spraying device is arranged in the constant-temperature control box, and the spraying device is used for spraying water into the constant-temperature control box; the hydrological structure layer is arranged below the spraying end of the spraying device, so that the spraying end sprays liquid, and the liquid is absorbed by the hydrological structure layer; the coal measure stratum is arranged on the lower end face of the hydrological structure layer and used for simulating an actual coal mine; the first water-resisting layer is arranged on the lower end face of the coal measure strata and used for isolating the coal measure strata; the rock stratum is arranged on the lower end face of the first water-resisting layer and used for simulating a rock caving area in the coal mining process; the water flowing fractured zone extends to the first water-resisting layer from the hydrological structure layer and is used for simulating fractures in the stratum; and a monitoring section of the multi-index monitoring system is arranged at a water outlet of the caving rock zone and is used for monitoring water quality.

The invention relates to the technical field of beneficiation and purification of cryptocrystalline graphite, in particular to a beneficiation method of coal-series cryptocrystalline graphite. The beneficiation method specifically comprises the following steps that raw ore is crushed to be smaller than 15 mm, products with the particle size smaller than 0.5 mm are screened out, and tailings of the products with the particle size of 0.5-15 mm are discarded in advance in a heavy liquid floating and sinking mode; the obtained gravity concentrate is combined with a product with the particle size smaller than 0.5 mm and crushed to be smaller than 0.5 mm for ore grinding and flotation; and stage grinding and stage grading are adopted, namely two times of grinding, one time of roughing, one time of scavenging and six times of concentration. According to the beneficiation method, tailings are discarded in advance, the content of gangue entering flotation is reduced, the influence of gangue argillization mixed in foam on flotation indexes is relieved, the beneficiation cost and reagent consumption are reduced, the graphite concentrate with the fixed carbon grade being 90% or above is obtained, and efficient utilization of coal-series cryptocrystalline graphite is achieved.

This invention belongs to the field of quartz sandstone purification technology, specifically relating to a simple purification method for coal-based graphite, comprising the following steps: crushing low-grade coal-based graphite as raw material to obtain crushed coal-based graphite; mixing the crushed coal-based graphite with solid alkali and flux, followed by calcination and alkali fusion treatment to obtain calcined and alkali-fused coal-based graphite; acid leaching the calcined and alkali-fused coal-based graphite, followed by water washing, filtration, and drying to obtain high-grade coal-based graphite. Compared with existing graphite purification technologies, this invention does not require costly and hazardous reaction reagents or harsh conditions of high temperature and high pressure, and has advantages such as high graphite product purity, simple processing, convenient operation, mild conditions, environmental friendliness, and low cost. Using low-grade coal-based graphite with a fixed carbon content of 65%–85% as raw material, the process of this invention can obtain high-purity graphite with a fixed carbon content greater than 99.5%.

The invention belongs to the field of drilling sampling, and relates to an embedded hollow spray pipe type single-wall coring device and a working method thereof.The device comprises a coring pipe, an embedded coring barrel and a connector, the coring pipe and the embedded coring barrel are in clearance fit, a groove in the inner wall of the coring pipe forms the hollow spray pipe, a drill bit nozzle on the front portion of the coring pipe is connected with the hollow spray pipe, and the hollow spray pipe is connected with the embedded coring barrel. The coring pipe is connected with the drill rod through the connector. When the device is adopted for sampling, compressed air enters the hollow spray pipe through the inner cavity of the drill rod and flows out at a high speed through the coring drill bit nozzle, heat generated by cutting friction of the drill bit is rapidly taken away, disturbance to drilling cuttings particles is reduced, a core sample embedded in the coring barrel does not make direct contact with the wall of the coring pipe, and air in a gap forms a heat insulation layer; the taken core sample is complete, keeps the original property, and is suitable for coal seam gas content measurement coring and broken coal measure strata down hole drilling coring.

The application discloses a kind of complex coal measures strata double horizontal well cyclic injection CO2 vertical displacement coalbed gas mining method, belong to coalbed gas development technical field.Deep coal measures strata is selected as purpose layer, and two single branch horizontal wells are drilled in the same well group.One horizontal section is located at the top of purpose layer for coalbed gas extraction and fracturing;Another horizontal section is located at the bottom of purpose layer for injecting liquid CO2.Before extraction, by continuously injecting liquid CO2 into the bottom of purpose layer, the displacement and displacement effect of CO2 on CH4 are used to improve the recovery of deep coalbed gas;During extraction, part of CO2 is extracted with CH4, and the extracted CO2 is liquefied and recycled into the bottom of purpose layer through CO2 separation device;At the end of extraction, most of CH4 has been extracted, and the horizontal well is sealed to prevent CO2 from leaking, achieving the purpose of CO2 storage.The method is simple and easy to implement, and can be used for complex structure of purpose layer.