A method for controlling pellet quality in iron ore production includes the steps of mixing water, binder and iron ore particles in at least one mixer to form a mixture (step (i)) and pelletizing the mixture into green pellets (step (ii)). Between step (i) and step (ii), a part of the mixture is taken in a sampling operation, formed into a test specimen and subjected to a test.

A system and a method evaluate the effect of proactive utilization of a spatial stress field in laboratory. The system includes a rock sample placement device for placing a rock sample, a confining pressure control device for applying a set confining pressure to the rock sample, a fracture imaging device, a fracturing fluid injection device for injecting fracturing fluid into the perforation in the wellbore of the rock sample to form fractures within the rock sample, a stress measurement device, and a processing device for calculating a stress field proactive utilization coefficient of the rock sample.

The invention discloses an experimental apparatus and an experimental method for the negative bending moment zone of a continuous beam to bear load under chloride environment, relating to the technical field of engineering experiment, comprising a high-rigidity main frame, a loading system, an erosion system and a test beam; the test beam is detachably arranged on the high-rigidity main frame; the loading system is installed on the high-rigidity main frame and under the test beam, and is used to apply load to the test beam; the erosion system is arranged on the test beam with built-in chloride solution; the test beam is a continuous beam that meets the design requirements. The experimental apparatus provided by the invention is stable and reliable, easy to use, and can provide the experimental conditions for the wet-dry cycle and the load-bearing coupling reaction in chloride environment.

A test apparatus comprises a probe movably mounted relative to a carrier. The probe comprises an end portion with a surface area of about 5 mm.sup.2 or less. The test apparatus can be used in methods of determining a crush strength of an edge of a substrate. Methods can comprise aligning the probe with a test location of the substrate at a predetermined angle relative to a probe axis. Methods can further comprise applying a mechanical force to the test location with the probe in the direction of the probe axis. Also, methods can comprise increasing the mechanical force applied by the probe until the substrate cracks or a predefined force applied by the probe is reached. Based on the mechanical force applied by the probe, a crush strength of an edge can be determined.

The present disclosure discloses a reciprocating rock fracture friction-seepage characteristic test device and method. The test device includes an X-axis shear system, a Y-axis stress loading system, a Z-axis stress loading system, a servo oil source system, 5 a pore pressure loading system, and a host. The X-axis shear system includes an X-axis EDC controller, an upper shear box, a lower shear box, an X-axis left hydraulic cylinder, an X-axis right hydraulic cylinder, an X-axis left pressure head, an X-axis right pressure head, an X-axis left pressure sensor, an X-axis right pressure sensor, an X-axis displacement sensor, and an X-axis 10 displacement sensor. The pore pressure loading system includes an air cylinder, a pressure gauge, a pressure reducing valve, a fluid inlet pipeline, a fluid outlet pipeline, and a flowmeter.

Disclosed are a hydro-mechanical coupling experimental device with CT real-time scanning and a use method thereof. The hydro-mechanical coupling experimental device with the CT real-time scanning includes a CT scanning room and further includes a support frame, a hydro-mechanical coupling mechanism and a jack that are arranged in the CT scanning room. The support frame includes a base, a top plate, a plurality of columns for arranging the top plate and the base at intervals, and a movable plate that is arranged between the top plate and the base and can slide on the plurality of columns. The hydro-mechanical coupling mechanism includes an experimental box, a pressure box arranged inside the experimental box and a compression leg slidingly worn on a top of the experimental box; and the experimental box is arranged on the movable plate, and the jack is arranged on the base.

A pressure-preserving conventional triaxial compression loading apparatus of the present invention includes a pressure vessel, an upper piston rod, a lower piston rod, and an annular oil bag assembly. Hollow chambers of the pressure vessel in vertical communication sequentially include an upper chamber, an upper sealed chamber, a confining pressure chamber, a lower sealed chamber, and a lower chamber from top to bottom. The annular oil bag assembly is placed in the confining pressure chamber. When an annular inner chamber of an annular oil bag is filled with medium, an outer wall of the annular oil bag and an inner wall of the confining pressure chamber are attached together. A fidelity specimen is placed in a specimen chamber defined by a lower end surface of the upper piston rod, an upper end surface of the lower piston rod, and an inner wall of the annular oil bag. A variety of measuring sensors are disposed in the annular inner chamber of the annular oil bag. The pressure-preserving conventional triaxial compression loading apparatus of the present invention may accommodate a fidelity specimen, and use the annular oil bag assembly and the upper and lower piston rods to perform a pressure-preserving conventional triaxial loading test on the fidelity specimen, so that test data is more accurate and reliable, to help to study the mechanical behavior of in-situ rock and measure their properties more faithfully.

Provided is a test system for hard rock breaking by a microwave intelligent loading based on true triaxial stress, including: a true triaxial stress loading device consisting of a loading frame and a rock sample moving structure; a microwave-induced hard rock breaking device consisting of an excitation cavity, a rectangular waveguide, a magnetron, a thermocouple, a circulator, a cold water circulation device, a flowmeter, a power meter, an automatic impedance tuner, a coupler, a microwave heater and a shielding cavity; and a dynamic rock response monitoring and intelligent microwave parameter control system consisting of a CCD industrial camera, a temperature acquisition device and an anti-electromagnetic high-temperature resistant acoustic wave-acoustic emission integrated sensor. According to the test system, the microwave-induced hard rock breaking test, dynamic monitoring temperature and rock breaking in microwave-induced breaking process and intelligent control over microwave power and heating time are achieved.

A hardness tester includes an image acquirer (controller) acquiring an image of a surface (surface image) of a sample captured by an image capturer, an identifier (controller) identifying, based on the surface image of the sample, a non-conformity region inside the image that is unsuitable for the hardness test using predetermined conditions, and a test position definer (controller) defining a test position in an area outside the non-conformity region identified by the identifier.

A fracture toughness testing machine of the invention makes it possible to evaluate fracture toughness of a specimen in pure mode such that the effect of thermal residual stresses is removed, when the stresses are present in the specimen obtained by bonding dissimilar materials. The testing machine includes: testing-load applying means for applying a predetermined testing load to the specimen, in which the stresses are present; and cancelling-load applying means for applying a cancelling load to the specimen to cancel the stresses therein. The cancelling-load applying means includes: a pressing-force applying portion that applies a pressing force to the specimen as the canceling load; and a pressing-force determining portion that determines magnitude of the force. The pressing-force determining portion calculates the magnitude of the force using pre-stored equations so that an energy release rate related to in-plane shear mode crack deformation becomes zero.