Abstract: This study aims to deeply explore the performance, preparation process and application effect of PDC composite sheets for coal field mining. Through experimental analysis and actual working conditions testing, key performance indicators such as hardness, wear resistance, and impact resistance of the composite sheets were evaluated and compared with traditional drilling materials. Research results show that PDC coalfield mining composite sheets have significant advantages and can effectively improve coalfield mining efficiency and drill bit service life. However, there is still room for improvement under certain complex working conditions, which provides the direction and basis for further optimization. .
1. Introduction
In the coalfield mining process, drilling operations are one of the key links, and the performance of drilling tools directly affects mining efficiency and cost. PDC (Polycrystalline Diamond Compact) composite sheet, as a new type of drilling material, has gradually been widely used in coal fields and mining fields due to its unique properties. However, different geological conditions and mining processes have put forward diverse requirements for PDC composite sheets, so it is necessary to conduct in-depth research on them to achieve better application effects and economic benefits.
2. Structure and performance of PDC composite sheets for coal fields and mines
(1) Structural characteristics
PDC composite sheets for coal fields and mines usually consist of a diamond layer and a cemented carbide matrix. The diamond layer is made of tiny diamond particles sintered through high temperature and high pressure, and has extremely high hardness and wear resistance; the carbide matrix provides good toughness and support, allowing it to withstand the impact load during drilling. This structural design enables the composite sheet to combine the high hardness of diamond and the toughness of cemented carbide, which is an important basis for its excellent performance in coalfield mining drilling.
(2) Performance indicators
hardness
The PDC composite sheet was tested using hardness testing equipment. The results showed that its hardness is much higher than that of traditional cemented carbide materials, and it can effectively cut hard formations such as coal and rock and reduce drill bit wear.
Wear resistance
In wear experiments simulating coalfield mine drilling, PDC composite sheets showed excellent wear resistance, and their wear rate was significantly lower than that of traditional drilling materials, which means that under the same drilling conditions, PDC composite sheets have a longer service life. It reduces the number of drill bit replacements and improves mining efficiency.
Impact resistance
The performance of the composite sheet when subjected to impact loads was evaluated through impact experiments, and it was found that it has a certain impact resistance, but there is still a certain risk of damage under high impact energy. This shows that under complex geological conditions, such as coal fields and mines containing hard interlayers or rock fracture zones, the impact resistance of the composite sheets needs to be further optimized to ensure their reliable use.
3. Research on the preparation process of PDC composite sheets for coal fields and mines
(1) Raw material selection
Diamond powder
Diamond powder with high purity and uniform particle size is selected as the key raw material of the composite sheet. Its quality directly affects the hardness and wear resistance of the composite sheet. The effects of diamond micropowders of different particle sizes and quality levels on the performance of the composite sheet were studied. The results showed that moderate particle size distribution and high diamond purity help to improve the overall performance of the composite sheet.
Carbide matrix
The composition and structure of the cemented carbide matrix play an important role in the toughness and bonding strength of the composite sheet. By optimizing the formula of cemented carbide and adding appropriate amounts of alloy elements, such as cobalt, tungsten, etc., the strength and toughness of the matrix are improved, and the bonding force with the diamond layer is enhanced, thereby improving the overall performance of the composite sheet.
(2) Sintering process optimization
PDC composite sheets were prepared using a high-temperature and high-pressure sintering process, and parameters such as sintering temperature, pressure, and time were systematically studied. Experimental results show that appropriately increasing the sintering temperature and pressure can promote the bonding between diamond particles and improve the compactness and hardness of the composite sheet. However, excessive temperature and pressure may lead to graphitization of diamond and reduce its performance. After multiple experimental optimizations, the sintering process parameters suitable for PDC composite sheets for coal fields and mines were determined, which improved production efficiency and product quality stability while ensuring the performance of the composite sheets.
4. Analysis of the effectiveness of PDC composite sheets for coal fields and mines in practical applications
(1) Field application cases
Practical application tests of PDC composite drill bits were carried out in multiple coalfield mines, and mining areas with different geological conditions were selected, including soft coal seams, hard coal seams, and complex strata containing interlayers. During the application process, key indicators such as the drill bit's drilling speed, service life, and drilling quality were recorded and compared with traditional carbide drill bits.
(2) Comparison of application effects
Drilling speed
In soft coal seams and coal rock formations with average hardness, the drilling speed of PDC composite drill bits is increased by more than [X]% than traditional carbide drill bits. This is mainly due to its high hardness and good cutting performance, which can quickly Crushing coal and rock improves mining efficiency.
Service life
According to actual statistics, the average service life of PDC composite drill bits is about [X] times that of traditional carbide drill bits, which reduces the time and cost of frequent drill bit replacements and improves the continuity and stability of operations.
Drilling quality
The hole wall drilled by the PDC composite bit is relatively smooth and the hole diameter deviation is small, which is beneficial to subsequent coal mining operations and gas drainage, and improves the recovery rate and safety of coal resources.
However, under some complex geological conditions containing hard interlayers and rock fracture zones, PDC composite drill bits have experienced chipping, breakage and other problems, resulting in reduced drilling efficiency and shortened drill bit life. This shows that in the face of complex working conditions, Further improvements in composite sheet performance and drill bit design are needed.
5. Improvement directions and suggestions for PDC composite sheets for coal fields and mines
(1) Improve impact resistance
In order to solve the problem of insufficient impact resistance of composite sheets under complex geological conditions, the impact resistance can be improved by optimizing the arrangement of diamond particles, improving the sintering process to increase the bonding strength, and introducing a toughening phase or buffer layer into the composite sheets. , reducing the risk of breakage under high impact loads.
(2) Optimize drill bit design
According to the geological characteristics of different coalfields and mines, a more reasonable drill bit structure is designed, such as optimizing the layout of the cutting teeth, adding a gauge structure, etc., to give full play to the performance advantages of the PDC composite sheet, and improve the adaptability and reliability of the drill bit in complex formations.
(3) Expand application areas
Further study the application potential of PDC composite sheets in other operations in coalfields and mines, such as roadway support, coalbed methane mining and other fields, to develop more targeted products and application technologies to expand its market space and application value.
6. Conclusion
This study conducted a comprehensive and in-depth study on PDC coalfield mining composite sheets, and conducted a systematic analysis from its structural performance, preparation process to practical application effects. The results show that PDC coalfield mining composite sheets have significant advantages under normal geological conditions and can effectively improve the mining efficiency and economic benefits of coalfield mines. However, further improvement and optimization are still needed under complex geological conditions. By taking measures such as improving impact resistance, optimizing drill bit design and expanding application areas, it is expected to further enhance the application level of PDC composite sheets in the coalfield mining industry and provide strong support for efficient and safe mining of coal resources.
