Based on the analysis of ore dilution in Barun mine, the dilution rate at the junction of ore and rock in Barun open-pit mine was controlled. With the actual production into consideration, some controlling measures are put forward for the mine, including accurately identifying ore-rock boundary by drilling and sampling, separating ore and rock by blasting, accurately identifying the ore-rock boundary in muck-pile by blasting, and optimizing shovel loading operation among others. As a result, less waste rock has been mixed with ore, leading to the ore dilution down to below 2%. It is shown that the rate of extraction can be obviously improved.

The lifting of polymetallic nodules was simulated by using a CFD-DEM coupling approach, and the influence of different swirling flow on hydraulic lifting of polymetallic nodules in vertical pipelines was explored. The results show that as swirl ratio increases, the intensity of swirl will be enhanced significantly, and both the maximum fluid velocity and the average axial velocity of particle group will increase. It is found that intensity of swirl can bring obvious impact to the distribution of particles with different velocity in the pipe, showing that particles with high velocity are gradually distributed around the pipe wall, while the particles with low velocity in the center of the pipe. Swirling flow can reduce the local concentration of particles, which is beneficial to reducing the risk of pipeline blockage due to higher concentration of particles caused by retention effect.

In order to avoid formation of material ring in a rotary kiln caused by kiln phosphoric acid process, a technique of high-temperature consolidation of pellets was proposed, and the effects of types of binder, temperature and time of consolidation on the strength and reducibility of phosphate ore pellets were investigated. The results show that consolidation at a temperature over 800 ℃ with bentonite as binder can lead to the pellets with compressive strength and drop numbers obviously higher than those with sodium humate as the binder. With an addition of carbon at 1.4 times of the theoretical amount, CaO and SiO₂ at a molar ratio of 0.35, an addition of bentonite at an amount of 1.5% of the total material weight, consolidation at 1 000 ℃ for 30 min results in the produced pellets with compressive strength of 345.36 N and drop numbers of 33.50.

To examine the industrial feasibility of pre-discarding by using screening classification combined with gravity separation in processing of a scheelite ore from Hunan Province, industrial distributary and flotation trial tests were carried out. The results show that a process consisting of screening and spiral chute discarding under optimized conditions can discard tailings grading 0.034% WO₃ with a yield of 25.50% in mass, leading to tungsten loss of only 2.99%. With this pre-discarding before flotation process, both the grade and recovery of the final flotation concentrate are improved, compared to the concentrate obtained from direct flotation of overflow product.

To study the effects of welding parameters on the tolerance of friction stir welding (FSW) of dissimilar aluminum alloys, the mechanical properties and structure of joint of dissimilar aluminum alloys (A356 and AA6061) by FSW under different welding parameters were studied by means of micro-hardness testing, tensile mechanical properties testing, scanning electron microscopy among other analytical testing means. The results show that as for the workpieces with the gap from 0 mm to 1 mm, the welded joint has tensile strength decreased significantly and presents visible welding defects. With tool pin of the same specification, the material flow can be promoted by decreasing the welding speed from 120 mm/min to 80 mm/min, thus the tolerance of workpiece gap will be greatly improved. The tool pin with diameter increased from 4 mm to 6 mm can lead to higher tolerance for welding, but also the material with a higher fusion degree and without delamination.

To solve the problem of structural instability of cathode material (LiNi_0.8Co_0.1Mn_0.1O₂)(NCM)) during cycling, a strategy of co-doping of Rb⁺ and Cl^- was proposed for NCM materials. The synergistic effect of co-doping of Rb⁺ and Cl^- in the NCM lattice can increase the diffusion rate of Li⁺ and relieve the internal strain, thus hindering the mixing of Li⁺/Ni²⁺ during high cut-off voltage cycling. Electrochemical test results show that Li_0.99Rb_0.01(Ni_0.8Co_0.1Mn_0.1) O_1.99Cl_0.01 (RbCl-NCM) has a discharge capacity up to 176.9 mAh/g at a current density of 10C. The initial discharge capacity at 1C is 203.5 mAh/g. After 200 cycles, its capacity retention ratio is as high as 87.8%, showing an excellent cycling performance, while the capacity retention ratio of NCM material is only 57.3%.

Based on the process mineralogy study, an experiment was performed on flotation of a phosphogypsum from Hubei Province for its purification. The experiment was run in stronger acid solution with T-609 as the collector, by adopting a process consisting of one roughing, one scavenging, and two cleaning, resulting in the final cleaning concentrate with the content of calcium sulfate dihydrate over 99%, with a whiteness of 75% at 200 ℃. It is shown that this processing flow is characterized by simplicity, high separation rate of phosphogypsum, less addition of agent. The obtained product, with low content of impurities, is up to the special grade in the national standard for gypsum, and can be used for preparation of high-end building materials and gypsum whiskers.

The ground surface displacement caused by open-pit mining of a large iron mine in Hainan was analyzed by using fuzzy measurement theory. Base on the comparison with the calculated results by using the theory of random media, it has verified that the fuzzy measurement theory is superior and practicable in the analysis of influence of open-pit mining on the surrounding environment.

Alkali leaching of indium from zinc indium ferrite (ZnFe_2-xIn_xO₄) was strengthened by applying a combination of ultrasound and microwave. The results show that there are not a great amount of solid solution of indium in the octahedral lattice of ZnFe_2-xIn_xO₄, and the maximum solid solution approaches 4.0% in a mass fraction (x=0.088). The leaching rate of indium can be enhanced by the external fields in the following descending order: a combined application of ultrasound and microwave, single application of microwave, application of ultrasound followed by microwave or microwave followed by ultrasound, and single application of ultrasound. It is shown that the leaching rate of indium can be up to 56.6% with a combined application of ultrasound and microwave, but only reach 30.2% by singly applying ultrasound. During the alkaline leaching under the external fields, In³⁺ can be released from the lattice, while the octahedral lattice of zinc ferrite will not collapse. With a combined application of ultrasound and microwave, more In³⁺ can be released, leading to lattice constant becoming much smaller. The XRD spectrum shows obvious reduced intensity and rightward movement of diffraction peaks.

Aiming at low intelligence in nickel plate surface defect detection, a detection method based on improved YOLOv5 was proposed. Firstly, the image-enhanced dataset of nickel plate was re-clustered by K-means++ to improve the adaptability of the anchor frame to the dataset. Secondly, the convolutional block attention module (CBAM) was added into the Backbone network to strengthen the feature recognition of interest areas and unclear targets by integration of spatial and channel information. Finally, an efficient IoU (EIoU) loss was introduced to replace the original CIoU loss during bounding box regression to effectively improve the convergence speed of regression, thereby increasing the model detection speed. The experimental results show that with the self-established dataset of nickel plate defect, the improved model, compared to Faster R-CNN, SSD, YOLOv3 and YOLOv5, has higher detection accuracy up to 81.4% on average, with detection speed reaching 61 frames per second. It is concluded that this model can not only improve detection accuracy, but also satisfy the requirements for detection speed.