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Exploitation and utilization of mineral resources have played a vital role in China’s rapid economic developments. Although the history of mineral processing is quite long, technologies in this field have varied with the changes of market demands. This is particularly the case for minerals whose high-grade deposits are depleting. The aim of this review is to present our recent efforts on developing new routes for the utilization of low-grade minerals, such as iron ores and brine-containing lithium. The emphasis on the two minerals lies in the fact that iron plays a vital role in modern-day civilization and lithium is a key component in electric vehicles for transportation. Furthermore, the utilization of magnesium chloride reserves, one of the largest wastes in western China, as raw materials for fabrication of functional materials is also included in this review.

In this study, a process for preparing battery-grade lithium carbonate with lithium-rich solution obtained from the low lithium leaching solution of fly ash by adsorption method was proposed. A carbonization-decomposition process was carried out to remove impurities such as iron and aluminum. First, primary Li2CO3 was treated by CO2 to get the more soluble bicarbonates. The decomposition of LiHCO3 produced insoluble Li2CO3 at 90 °C And Li2CO3 was smashed by air stream pulverization. The final precipitation yielded a high purity (99.6%) and homogeneous Li2CO3. Some factors affecting production efficiency were investigated. The results showed that a liquid-solid ratio of 25:1, a carbonization temperature of 25 °C, an air velocity of 2 L/min, and a stirring speed of 400 rpm, a decomposition temperature of 90 °C and a stirring speed of 400 rpm, a molar ratio of EDTA to Ca 2:1, an air pressure of 0.3MPa and hot water washing precipitate (L/S mass ratio 2:1) promoted ions removal.

A molecular dynamics simulation was performed to explore the diffusion behavior of counter-ions within polyelectrolyte membranes via Materials Studio software, which could provide a theoretical basis for the screening and performance prediction of selective ion-exchange membranes (IEMs). The mean square displacements of Li+/Mg2+ in sulfonic and phosphatic polyelectrolyte systems were calculated, and the sulfonic group was determined as a higher preference fixed charge group. The conformational variation of the polyelectrolyte chain with the concentration of counter-ion was assessed via the radius of gyration and, in combination with the pair correlations function. The interaction of counter-ions with sulfonic groups in cation exchange membranes (CEMs) was also determined. The results showed that Mg2+ ions were easily adsorbed on sulfonic groups in CEMs, shielding the negative charge of the polyelectrolyte, which resulted in the coiling of the molecular chain; hence, the radius of gyration decreased. By replacing the adsorbed Li+ ions, more Mg2+ ions were preferentially bound on the sulfonic groups with the increase in Mg2+ ions in the aqueous solution, which is consistent with the ion-exchange isotherms of the Selemion CSO membrane. By calculating the interaction energy of the counter-ions toward the polyelectrolyte and via a permeation experiment involving various cations, we found the difference in interaction energy between monovalent and divalent ions was remarkable, indicating that the interaction of counter-ions toward fixed charge groups in polyelectrolyte mainly determined the ionic diffusion performance. Raising the energy barrier on the interface was determined as an efficient method for the modification of selective IEMs.

As the crawler vehicle with the excellent off-road performance, the battlefield survival ability, etc , are widely used in modern weapons systems In order to make teaching model close to the real equipment , designed a tracked vehicle of anti-aircraft gun based on the STM32F103 microcontroller, combined with the H-bridge motor circuit ,photoelectric encoder angle measurement and control principle of single lever operation, experimental results show that the tracked vehicle can complete forward, backward , turning and braking actions in accordance with the control command , with fast dynamic response , high control precision , to meet the design requirements.

In this work, a physical&ndash, chemical activation desilication process was proposed to extract silica from high alumina fly ash (HAFA). The effects of fly ash size, hydrochloric acid concentration, acid activation time, and reaction temperature on the desilication efficiency were investigated comprehensively. The phase and morphology of the original fly ash and desilicated fly ash were analyzed by X-ray diffraction (XRD) and scanning electron microscopy&ndash, energy-dispersive X-ray spectroscopy (SEM-EDS). Compared with the traditional desilication process, the physical&ndash, chemical activation desilication efficiency is further increased from 38.4% to 53.2% under the optimal conditions. Additionally, the kinetic rules and equations were confirmed by the experimental data fitting with shrinking core model of liquid&ndash, solid multiphase reaction. Kinetic studies show that the enhanced desilication process is divided into two processes, and both steps of the two-step reaction is controlled by chemical reaction, and the earlier stage activation energy is 52.05 kJ/mol and the later stage activation energy is 58.45 kJ/mol. The results of mechanism analysis show that physical activation breaks the link between the crystalline phase and the amorphous phase, and then a small amount of alkali-soluble alumina in the amorphous phase is removed by acid activation, thereby suppressing the generation of side reactions of the zeolite phase.

Fires, floods, gas, roof and coal dust are known as the five major disasters of coal mine, which have always been treated as the focus of prevention and control of coal mine in safety production. Taking the example of Changzhi's experience in Shanxi Province, in order to improve the security basic qualities and skills of mine workers they have reinforced the labor management of the coal industry, built the five systems and two large database, this paper introduces the method of Changzhi city and preliminary effect, it is concluded that improving the safety quality of staffs is the fundamental solution of coal mine safety production, at the same time, it confirms positive significance of the accident of heinrich causal chain theory in the coal mine accident prevention.

A speed control servo system based on STM32 is designed in order to realize the rapid, accurate, smooth speed control of rotary table. the system uses embedded microprocessor STM32F103 as the core, using the absolute encoder as the position sensor.The system achieved control of motor speed by PWM (pulse width modulation).Speed and current double loops control is used,and the expert PID control is used as the control algorithm. Through the analysis of the experimental results can be seen that the system has good stability, and the static and dynamic indicators meet the design accuracy.This design basically has reached the requirement of the servo motor speed control system.

One design method of small digital angle sensor based on microelectronic mechanical system (MEMS) is introduced. The angle sensor is build with the embedded microprocessor STM32F103 as the core. The acceleration value of MEMS accelerometer in X, Y, and Z-axis directions was used to calculate the angle of measured target on the horizontal direction and vertical direction, and the digital and miniaturization of digital angle sensor are realized.

A guide microscope is an important part of a certain photoelectric automatic tracking system, and the angle informations acquisition, processing and transmission are the keys for using the guide microscope. According to the application requirements, a kind of angle information processing system of the guide microscope based on STM32 is designed. This system uses the high-performance STM32F103 as the control core and realizes the angle information acquisition, display and transmission by photoelectric encoders, OLED display and RS-485 bus. Then, the hardware design and software debugging are further explained, that it has the simple circuit and convenient development. The running results show the design has the stable and reliable performance. It can meet the requirements.

In view of the importance of environmental protection and resource recovery, recycling of spent lithium-ion batteries (LIBs) and electrode scraps generated during manufacturing processes is quite necessary. An environmentally sound leaching process for the recovery of Li, Ni, Co, and Mn from spent LiNi

Mesoporous titania nanoribbons were synthesized via an optimized soft hydrothermal process and the derived titania ion-sieves with lithium selective adsorption property were accordingly prepared via a simple solid-phase reaction between Li 2 CO 3 and TiO 2 nanomaterials followed by the acid treatment process to extract lithium from the Li 2 TiO 3 ternary oxide precursors. First, mesoporous titania nanoribbons were prepared and the formation mechanism was discussed; second, the physical chemistry structure and texture were characterized by powder X-ray diffraction (XRD), (high-resolution) transmission electron microscopy (TEM/HRTEM), selected-area electron diffraction (SAED) and N 2 adsorption-desorption analysis (BET); third, the lithium selective adsorption properties were tested by the adsorption isotherm, adsorption kinetics measurement and demonstrated with the distribution coefficient of a series of alkaline and alkaline-earth metal ions.

The cubic phase LiMn 2 O 4 spinel is synthesized via a directly soft chemistry method via hydrothermal reaction of Mn(NO 3 ) 2 , LiOH and H 2 O 2 at 383 K for 5-10h, more favorable to control the nanocrystalline structure with well-defined pore-size distribution and high surface area than traditional solid-phase reaction at high temperature. Further, the 1D MnO 2 nanorod ion-sieves with lithium ion selective adsorption property is prepared by the acid treatment process to completely extract lithium ions from the LiMn 2 O 4 lattice. The effects of hydrothermal conditions on the nanostructure, chemical stability and ion-exchange property of the LiMn 2 O 4 spinel and MnO 2 ion-sieve are examined via powder X-ray diffraction (XRD), N 2 adsorption-desorption at 77 K, high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED) and lithium ion selective adsorption measurements. The results show that the 1D MnO 2 nanorods might be utilized in lithium extraction from aqueous environment including brine, seawater and waste water.

β-MnO 2 , spinel-type Li 4 Mn 5 O 12 and pure cubic phase MnO 2 nanorod, with the size about 20–140 nm in diameter and 0.8–4 μm in length, were synthesized via a combination of hydrothermal synthesis and low temperature solid-phase reaction, more favorable to control the nanocrystalline structure with well-defined pore size distribution and high surface area than the traditional high temperature calcination process. Further, the MnO 2 ion-sieves with lithium selective adsorption property were prepared by the acid treatment process to completely extract lithium from the spinel Li 4 Mn 5 O 12 precursor with little change to the Mn–O lattice structure and the 1-D nanorod morphology. The effects of hydrothermal and solid-phase reaction process on the nanostructure, chemical stability and ion-exchange property of the ion-sieve material were examined with powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), N 2 adsorption–desorption at 77 K, and Li + selective adsorption measurements. The lithium selective adsorption capacity was improved remarkably to 6.62 mmol g −1 at equilibrium and about 5 mmol g −1 at the initial lithium concentration of only 5.0 mmol l −1 , which is significant for lithium extraction from aqueous solutions with very low lithium content.

In order to analyze the influencing factors of near-miss initiative report in coal mine, a random questionnaire survey was designed based on nine factors that affect the miners un-initiative report near-miss that were identified by interviews and literature review. Then using AMOS 7.0 the influencing factors of near-miss initiative report in coal mine were analyzed by confirmatory factor analysis (CFA). The results show that near-miss initiative report has three influencing dimensions: near-miss cognition, near-miss management and reported have harmful effects on oneself. Coal mine managers should improve the miner's positivity of near-miss initiative report from paying great attention to near-miss management, strengthen miners' education and training, advocating "initiative report, non-punitive" and establishing scientific and concise reporting process.

Spinel-type ternary LiMn 2 O 4 oxide precursor was synthesized by direct hydrothermal synthesis of Mn(N0 3 ) 2 , LiOH, and H 2 O 2 at 383 K for 8 h, a better technique for controlling the nanocrystalline structure with well-defined pore size distribution and high surface area than the traditional solid state reaction method. The final low-dimensional MnO 2 nanorod ion-sieve with a lithium ion selective adsorption property was further prepared by an acid treatment process to completely extract lithium ions from the Li-Mn-O lattice. The effects of hydrothermal reaction conditions on the nanostructure, chemical stability, and ion-exchange property of the LiMn 2 O 4 precursor and MnO 2 ion-sieve were systematically examined via powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), and lithium ion selective adsorption measurements. The results show that this new kind of low-dimensional MnO 2 nanorod can be used for lithium extraction from aqueous environments, including brine, seawater, and waste water.

This paper highlights our recent work on preparation and characterization of nanostructure transition metal (Me) oxide (Me = Mn, Ti and Zr) ion-sieves. The controlled hydrothermal and Sol-Gel method have been developed in the synthesis of ion-sieves by the acid treatment of Li-Me-O tri-oxide precursors. The structure characteristic and ion-exchange property are studied by XRD, TEM, nitrogen adsorption-desorption analysis, lithium ion adsorptive isotherm and kinetics measurement. The result shows that these transition metal oxide ion-sieves, promising in the lithium extraction from brine or seawater, have good selectivity and remarkable adsorption capacity for lithium ions. The maximum adsorption capacity of manganese dioxide and titania by now is 3.47 and 4.02 mmol/g, respectively. The adsorption capacity of zirconia ion-sieve is only 0.675 mmol/g. To the best of our knowledge there is no other report on zirconia with the lithium adsorption property up-to-date.

To study the possibility of hyaluronic acid as densifier of Shuanguangliao eye-drops.The factors related with hyaluronic acid s viscosity, such as pH-value and storing temperature, are tested in this experiment. At the same time, we checked the stimulation, stability of the densifier.There was not effect on viscosity of pH-value and storing temperature. No stimulation on the eye was found after densified with hyaluronic acid. The viscosity properties of hyaluronic acid are stablile.The hyaliuronic acid added to Shuanghuanglian eye-drops are stabiliable and it can be applied in eye-drops. The increased viscosity is benefit to extend the residence time of drug in eye.