China University of Mining and Technology colloquially 矿大 is a national key university under the direct supervision of the Ministry of Education of China as well as a Project 211 and Project 985 university of China. The university consists of two parts, one located in Xuzhou, Jiangsu Province, the other located in Beijing with the name China University of Mining and Technology, Beijing . The latter is formerly the Graduate School of CUMT. CUMT is a leading multi-disciplinary polytechnic university with mining features. Wikipedia.
China University of Mining and Technology | Date: 2015-08-06
A Co_(3)W_(3)C fishbone-like hard phase-reinforced Fe-based wear-resistant coating and the preparation thereof, which belongs to the field of a wear-resistant coating on the surface of a material and a preparation method thereof. The wear-resistant coating comprises: 1.89-3.77% of C, 5.4-11.7% of Cr, 3.3-7.15% of Ni, 28.81-57.83% of W, 4.2-8.4% of Co, 0.03-0.065% of Si and the balance of Fe. The preparation process of the wear-resistant coating comprises: (1) before plasma cladding, pretreating a matrix; (2) pretreating an iron-based alloy powder; and (3) adjusting the process parameters of plasma cladding, preparing a cladding layer with a predetermined width and a predetermined thickness, and naturally cooling same down in air. The wear-resistant coating is simple in process; the prepared cladding layer has a strong metallurgical bonding property with the matrix structure, so that the best performance matching between the ceramic phase of the cladding layer and the matrix can be achieved; a fishbone-like hard phase Co_(3)W_(3)C has a very high hardness value and plays the role of a framework in the frictional process to reduce the wear of the matrix structure, thereby achieving an excellent wear resistance; plasma cladding is convenient to operate, and can be automatized; and the prepared wear-resistant layer is high in size precision and can be widely applied to surface modification of mechanical parts.
China University of Mining and Technology | Date: 2014-11-19
A device and method of using infrared radiation to observe coal rock fracture development processes, for use in experiments to monitor coal rock fracture development using infrared radiation comprises three telescopic box bodies sleeved together. An infrared thermal imager connected to a computer is arranged at the front end of the telescopic box bodies, and a light-blocking plate is installed on a rear end. The distance between a coal rock test block and a lens of the infrared thermal imager can be freely adjusted via the three telescopic box bodies. The telescopic box bodies are installed on a rock press, and a loading test is performed on the coal rock test block.
BEIJING IVY TECHNOLOGY Co., China University of Mining and Technology | Date: 2016-08-25
The present disclosure discloses a fracture AVO inversion method for a fractured medium, wherein, said method includes: acquiring seismic data from the fractured medium; obtaining a reflection coefficient of the fractured medium, by an AVO inversion for the seismic data based on a newly-built equation. The present disclosure also provides a fracture AVO inversion apparatus and device for a fractured medium. The present invention can flexibly and accurately obtain properties of a fractured medium with impedance contrast (rock properties of the host media plus properties of thee fracture).
China University of Mining and Technology | Date: 2015-01-14
In the sorting bed, the material to be sorted enters into the pulsating hot air drying stage, and is dried and upgraded under the effect of air flow and high-temperature hot air, the material enters into the pulsating cold wind sorting stage under the effect of scraper conveyors which are parallely arranged up and down inside. The light products and heavy products sorted and layered are respectively conveyed to fine coal and gangue discharging outlets at both ends of the sorting machine. The float and hypostasis at the corresponding discharging ends are respectively discharged by light product discharging wheel and heavy product discharging wheel. At the discharging ends, the material is removed from the sorted light material and heavy material and the medium is purified and recycled to use through subsequent process. The dry sorted air containing vapor and dust is purified and recycled through a subsequent dust removal process.
China University of Mining and Technology | Date: 2015-02-04
The present disclosure relates to a simulated impact-type rock burst experiment apparatus comprising a bracket, a specimen box assembly, an X-direction, Y-direction and Z-direction loading mechanisms mounted on the bracket, and control systems. Loading mechanism comprises: four supporting posts in a rectangular arrangement, a first and second frames aligned with each other and fixedly connected to both ends of the four supporting posts, a loading hydraulic cylinder and a lead screw mounted on the two frames respectively. The present disclosure is able to load static and dynamic loads to the rock sample in three directions perpendicular with each other, thereby performing experimental method for simulating an impact rockburst. Furthermore, the structures of the three sets of loading mechanisms are substantially the same, which have good symmetry, therefore, it is more easily and accurately to control the operation for loading static or dynamic load to the rock sample.
China University of Mining and Technology | Date: 2015-02-11
An experiment method for a simulated impact-type rock burst, comprising the following steps: manufacturing a rock sample piece having a through hole or a half-formed hole; loading a three-way initial static load stress onto the rock sample piece; loading a disturbance load onto the rock sample piece for 0.5 to 10 minutes, observing whether or not a spalling phenomenon is found on the inner surface of the through hole or of the half-formed hole of the rock sample piece; if further destruction is found by observing whether or not the spalling phenomenon is found on the inner surface of the hole, then observing and recording the destruction process; if not, then increasing the value of the static load stress loaded onto the rock sample piece, or increasing the strength of the disturbance load and proceeding to repeat the experiment process until the rock sample piece enters the destruction process, observing and recording the destruction process, thus ending the impact rock burst experiment. Under the effect of the disturbance load, the experiment method successfully induces the occurrence of a rock burst phenomenon of the rock sample piece, and, by researching the mechanisms of the rock burst phenomenon of the rock sample piece, lays a foundation for gradual understanding and comprehension of the nature of actual rock burst phenomenon.
China University of Mining and Technology | Date: 2015-04-20
This invention relates to the coal mining field, specifically, to an integrated experimental system of hydrofracturing, water jet slotting, seepage and gas displacement under true triaxial stress. This invention consists of true triaxial stress loading experimental framework, a loading system and a monitoring system. Under true triaxial stress, experiments can be conducted with sample size as large as of 500 mm500 mm500 mm. The hydrofracturing experiment can be controlled by as many as 5 independent boreholes at the same time. The borehole water pressure in hydraulic fracturing can reach 63 MPa. Experiments of seepage and fluid-structure interaction with high seepage pressure can be achieved with sample dimension as large as 400 mm400 mm400 mm. Mine-used experimental bench of high pressure pump with rated flow of 70 L/min and maximum water pressure of 70 MPa can be used to drill borehole and the like.
China University of Mining and Technology | Date: 2015-06-16
A tensioning device and a tensioning method for a steel wire rope of a cage guide of an ultra-deep vertical shaft. The tensioning device comprises an upper rope clamping device, a rope adjustment guide frame, a lower hydraulic rope locking device, and a lower hydraulic rope adjustment device. The upper rope clamping device is provided with a rope clamp and a pressure sensor. The rope adjustment guide frame comprises a steel frame body, double fixed clamp-plates, a balance weight, and a balance weight steel wire rope. Double moving clamp-plates are disposed in a guide groove of the steel frame body. The double moving clamp-plates are provided with a rope clamp and a lower guide pulley. The double fixed clamp-plates are provided with an upper guide pulley. The balance weight is provided with a fastening joint. Each of the upper rope clamping device, the lower hydraulic rope locking device and the lower hydraulic rope adjustment device comprises a wedged iron block and a shim. Each of the lower hydraulic rope locking device and the lower hydraulic rope adjustment device further comprises a lever wedge adjustment mechanism and a wedge adjustment hydraulic cylinder. A wedge adjustment hydraulic pressing rod is connected to the wedged iron block. The bodies of the wedge adjustment hydraulic cylinders are connected to the shims. The tensioning device and the tensioning method can be used for implementing automatic adjustment and control of the tensile force of the steel wire rope of the cage guide of the ultra-deep vertical shaft.
China University of Mining and Technology | Date: 2015-07-17
A geomechanical fluid-solid coupling testing device for water inrush from coal mine collapse column is disclosed, which comprises a testing bed and a collapse column simulating device, wherein the testing bed has a box type structure with an opening at its top and is provided therein with multiple layers of similar materials in which a tunnel or a mining face can be dug out; and the collapse column simulating device comprises a plexiglass barrel with openings at both its top and bottom, the plexiglass barrel is provided at its top opening with a plexiglass lifting device and a hard plastic baffle, and the plexiglass lifting device is provided with a lifting level which is connected with a lifting rope. It can be used for simulating a construction process in a situation of tunnel digging or coal seam mining, for example, for collecting water inrush omen information, and for studying on surrounding rock mechanics, deformation and collapse column seepage rules during construction, thus facilitating safe construction and early warning in practical engineering.
China University of Mining and Technology | Date: 2015-08-19
A four-phase switched reluctance motor torque ripple three-level suppression method. A first set of torque thresholds is set in rotor position interval [0, _(r)/4]. A second set of torque thresholds is set in rotor position interval [_(r)/4, _(r)/2]. Power is supplied to adjacent phase A and phase B for excitation. The power supplied for excitation to phase A leads the power supplied for excitation to phase B by _(r)/4. An entire commutation process from phase A to phase B is divided into two intervals. In rotor position interval [0, _(1)], phase A uses the second set of torque thresholds while phase B uses the first set of torque thresholds. Critical position _(1 )automatically appears in the commutation process, thus obviating the need for additional calculations. Total torque is controlled between [T_(e)+th2_(low )and T_(e)+th2_(up)]. In rotor position interval [_(1), _(r)/4], phase A continues to use the second set of torque thresholds, phase B continues to use the first set of torque thresholds, and the total torque is controlled between [T_(e)+th1_(how )and T_(e)+th1_(up)]. This suppresses torque ripples of a four-phase switched reluctance motor and provides great engineering application values.