The improper disposal of retired lithium batteries will cause environmental pollution and a waste of resources. In this study, a waste lithium iron phosphate battery was used as a raw material, and cathode and metal materials in the battery were separated and recovered by mechanical crushing and electrostatic separation technology. The effects on material electrostatic separation of separation parameters such as the crushing particle size, the voltage of the static electrode, and the rotating speed of the grounding rotor were all studied combined with trajectory simulation and separation experiments. The results show that the crushing particle size of the material has the most significant impact on the separation effect, and the material separation effect primarily occurs in the range of 0.2–2.0 mm particle sizes. When the voltage of the static electrode is 30 kV, the rotating speed of the grounded rotor is 60 r/min, and the particle size is 0.4–0.8 mm, and the recovery rates for aluminum, copper, and lithium iron phosphate reach 93.2%, 91.1%, and 97.1%, respectively. In the recovery process for waste lithium batteries, using electrostatic separation technology instead of high-temperature roasting or chemical leaching can effectively improve the separation efficiency and reduce secondary pollution.

Sandy clay loam has the characteristics of both sand and clay. Because of these characteristics, both frictional resistance and adhesive resistance occur between the soil and tillage tool. The combined effect of the two frictional forces increases the external friction angle between the soil and tillage tool, thus increasing the working resistance. To address this issue, this study investigated the coupling effect of high pressure and hot air on the external friction angle by using a self-developed device to measure the external friction angle. Test results showed that high-pressure air between the soil and tillage tool formed a high-pressure air curtain layer which acted as a lubricant, thereby reducing the external friction angle. The external friction angle decreased as the airflow pressure increased. The reduction in the moisture content of the subsoil to less than 30% by the high-pressure hot air reduced the resistance between the soil and tillage tool. The approach with the high-pressure hot air curtain was verified in tests on a subsoiling shovel; the working resistance of the shovel under high-pressure hot air was reduced by 14.8%, demonstrating that this approach was effective in reducing the working resistance of the shovel.

The problems of the uneven strip shape and low efficiency of tea de-enzyming and carding machines in the working process were addressed by analyzing the trajectory of tea particles and establishing a force model diagram of tea particles in the pot slot. The three-dimensional geometric model of the tea de-enzyming and carding machine was drawn using UG software, and the simulation model of tea particles was established using EDEM software. The work efficiency of the tea de-enzyming and carding machine was improved, and the rate of broken tea was reduced using the EDEM software to simulate the movement of tea particles in the pot slot under different heights of the convex bar, pot slot angle of inclination, and number of slots. The average velocity and interaction force curve of tea particles were obtained. The influence of the number of slots, the inclination angle of the slot, and the height of the convex bar on the effect of tea into strips were verified using a scheme design based on the quadratic regression orthogonal combination rotation test, and experimental research based on three factors and three levels was carried out. Design-Expert 11 software (Stat-Ease, Minneapolis, MN, USA) was used to optimize the response surface and analyze the regression model of the relevant test data. The 6CSL-800 tea de-enzyming (Anji Yuanfeng Tea Machinery Co., Ltd., Huzhou, China) and carding machine (Anji Yuanfeng Tea Machinery Co., Ltd., Huzhou, China) was used as the verification test prototype, six sets of verification tests were carried out, and the test results showed that the maximum value of the strip rate index and the minimum value of the broken tea rate index were obtained. The order of the indicators affecting the bar-type rate and broken tea rate of the de-enzyming and carding machine from high to low is as follows: the height of the convex bar, the inclination angle of the slot body, and the number of slots bodies. When the height of the convex bar was 10 mm, the inclination angle of the slot was 90°, the number of slots was 12, the bar-type rate was 89.45%, and the broken tea rate was 1.63%. The prediction results of the regression model of the bar-type rate and broken tea rate of the tea de-enzyming and carding machine were verified by employing six sets of control tests with the 6CSL-800 tea de-enzyming and carding machine as the validation test prototype. The actual values of the bar-type rate obtained from the six sets of control tests were 88.19%, 90.37%, and 87.33% (1,2,3 group), and the actual values of the broken tea rate were 1.66%, 1.69%, and 1.61% (4,5,6 group), with average values of 88.63% and 1.65%. The control test was basically consistent with the results of parameter optimization. The processed finished tea has good quality, which can provide theoretical reference for the optimization and design of tea de-enzyming and carding machines and similar tea machines in the future.

Introduction: The uneven heating of the U-shaped multi-groove pot in gas-fired tea fixation and shaping machines results in inconsistent quality of tea leaves.Methods: A three-dimensional model of the gas-fired tea fixation and shaping machine was established by using SOLIDWORKS software. With the use of ANSYS finite element software, the orthogonal experiment method was applied to analyze and optimize the design of the spacing arrangement, the shape of the heating parts, and the heat conduction temperature field.Results: Results show that the optimized heating parts significantly reduce the temperature difference on the surface of the U-shaped multi-groove pot, and the surface temperature field of the multi-groove pot is more uniform, which greatly improves the efficiency and quality of fresh tea leaf fixation and shaping. Prototype temperature and tea sample fixation ratio tests verified that the optimized heating components significantly improved the temperature uniformity of the U-shaped multi-groove pot and the quality of the finished tea.Discussion: The research findings provide insights for further improving the uniformity of the U-shaped multi-groove pot’s temperature in the tea fixation and shaping machine.