A Review of Intelligent Unmanned Mining Current Situation and Development Trend

Intelligent unmanned mining is a key process in coal mine production, which has direct impact on the production safety, coal output, economic benefits and social benefits of coal mine enterprises. With the rapid development and popularization of 5G+ intelligent mines and coal mine intelligent equipment in China, the intelligentization of intelligent unmanned mining has become an important research topic. Especially with the promulgation of some Chinese policies and regulations, intelligent unmanned mining technology has become one of the key technologies of coal mine production. To understand the connotation, status quo and development trends of intelligent unmanned mining, this paper takes the relationship between key technologies and engineering application of intelligent unmanned mining in China as the perspective. It is proposed that the intelligent unmanned mining technology is in the whole process of working face mining. A research structure of unmanned follow-up operation and safe patrol is changing to the mode of intelligent adaptive mining, followed by the basic concepts and characteristics of intelligent unmanned mining. Relevant researches that maybe beneficial to the proposed research content are reviewed in four layers, which include basic theory, key technology, mining mode, and overall design system theory and technology. Finally, the current intelligent unmanned mining mode and future trends in this field in China are summarized.

Dispatch Optimization Model for Haulage Equipment between Stopes Based on Mine Short-Term Resource Planning

The working environment of underground mines is complicated, making it difficult to construct an underground mine production plan. In response to the requirements for the preparation of a short-term production plan for underground mines, an optimization model for short-term resource planning was constructed, with the goal of maximizing the total revenue during the planning period. The artificial bee colony optimization algorithm is used to solve the model using MATLAB. According to the basic requirements of underground mine ore haulage and ore hoisting, a haulage equipment inter-stopes dispatch plan model was constructed, with the primary goal of minimizing the haulage equipment wait time. A non-dominated sorting genetic algorithm is used to solve the optimization model. An underground mine is examined using the two models, and the optimization results are compared and verified with the scheme obtained by using traditional optimization algorithms. Results show that based on the improved optimization algorithm, the use of short-term production planning schemes to guide mine production operations can increase the haulage equipment utilization rate, thereby increasing mine production revenue.

Assessing the Availability of Global Metals and Minerals for the Sustainable Century: From Aluminium to Zirconium

Mining supplies metals and minerals to meet the material and energy needs of the modern world. Typically, mineral resources are widely considered to be ‘finite’ in nature, yet, paradoxically, global production and reported reserves and resources continue to grow. This paper synthesizes an extensive array of data on the long-term trends in cumulative mine production, reserves and resources at a global level as well detailed case studies of Australia, a global leader in many sectors of mining, and lithium, a new metal with rapidly growing demand. Overall, the paper shows that growing mine production has been clearly matched by growing reserves and resources, although there are numerous complex social, environmental and governance factors which are already affecting mines and are expected to increasingly affect mining into the future. Thus it is not possible at present to determine the ‘ultimately recoverable resource’, especially as this is a dynamic quantity dependent on a variety of inter-related factors (e.g., exploration, social issues, technology, market dynamics, environmental risks, governance aspects, etc.). This finding reinforces the need for continuing detailed studies of all metals and minerals to understand their individual supply and use dynamics to help modern society meet its needs and sustainable development goals.

The effect of methane emission on air distribution in potash mine production units

Introduction. It has been found that due to light gas (including methane) emission in rooms under development, there develops an additional natural draught between the mine workings. The calculation has shown that methane emission from the rock mass conditions the low value of the additional natural draught. However, even minor additional natural draught interacting with a thermal drop of pressure caused by temperature rise in the conveyor shaft changes the direction of the delivery air stream. While in up the dip blocks and panels the resultant natural draught promotes ventilation, in the down the dip production units it prevents air circulation in the required direction. Research methods. The methods and results of calculating the value and direction of the natural draught for real panels of potash mines at the Upper Kama potash deposit under various conditions have been presented together with the simulation observations of methane distribution in the room with a point source of emission. Results. Model analysis has shown that even under the low amount of gas emission out of the point source in the blind room (of a hole drilled in the roof), the concentration of gas in the gas-air mixture entering the belt heading reaches 2%. Conclusions. To ensure the safety of mining and reduce the risk of emergency when calculating the volume of air required to ventilate the production units, the dynamics of methane emission out of the rock mass should be taken into account as well as its further distribution across the mine workings.

Study on Bidirectional Blasting Technology for Composite Sandstone Roof in Gob-Side Entry-Retaining Mining Method

The traditional gob-side entry-retaining mining method has problems such as difficulty in roof collapse and large deformation of the entry, which may affect the safety of mine production. In this study, we introduced a bidirectional blasting technology (BBT) to make the roof collapse smoothly and to improve the traditional gob-side entry-retaining mining method. A theoretical model of the BBT was established and the stress propagation of the BBT was analyzed by numerical simulation. The gob-side entry-retaining mining method was then applied in a composite sandstone roof condition. Compared with ordinary blasting, the concentrated stress and directional cracks can be generated in the set direction after using the BBT technology. Field monitoring data suggested that the deformation of the retained entry met the requirements of mining, verifying the effectiveness of the proposed technology for composite sandstone roof. The results of the study have an important significance in solving the high pressure and large deformation problems in the coal mine roadway and saving coal resources, which also provided a reference for similar geotechnical mines.

A Review of Tungsten Resources and Potential Extraction from Mine Waste

Tungsten is recognized as a critical metal due to its unique properties, economic importance, and limited sources of supply. It has wide applications where hardness, high density, high wear, and high-temperature resistance are required, such as in mining, construction, energy generation, electronics, aerospace, and defense sectors. The two primary tungsten minerals, and the only minerals of economic importance, are wolframite and scheelite. Secondary tungsten minerals are rare and generated by hydrothermal or supergene alteration rather than by atmospheric weathering. There are no reported concerns for tungsten toxicity. However, tungsten tailings and other residues may represent severe risks to human health and the environment. Tungsten metal scrap is the only secondary source for this metal but reprocessing of tungsten tailings may also become important in the future. Enhanced gravity separation, wet high-intensity magnetic separation, and flotation have been reported to be successful in reprocessing tungsten tailings, while bioleaching can assist with removing some toxic elements. In 2020, the world’s tungsten mine production was estimated at 84 kt of tungsten (106 kt WO3), with known tungsten reserves of 3400 kt. In addition, old tungsten tailings deposits may have great potential for exploration. The incomplete statistics indicate about 96 kt of tungsten content in those deposits, with an average grade of 0.1% WO3 (versus typical grades of 0.3–1% in primary deposits). This paper aims to provide an overview of tungsten minerals, tungsten primary and secondary resources, and tungsten mine waste, including its environmental risks and potential for reprocessing.