About scientific and practical conference explosives of the Urals

The article reviews the results of the VIII Scientific and Practical Conference with international participation "Technology and Safety of Drilling and Blasting Operations in Surface and Underground Mines of the Urals" which was held at the Ekaterinburg-EXPO Exhibition Center and the Uralasbest Industrial Complex as part of the IX Urals Mining Industry Forum and the URAL MINING' 21 Exhibition dedicated to the Year of Science and Technology in the Russian Federation and the 30th Anniversary of the Urals Mining and Industrial Association. The article also informs about the winners of the Ural Mining Award 2021 and about the research and engineering reports and presentations made during the conference and dedicated to blasting operations. Results are summarized of the visiting seminar at the Uralasbest Industrial Complex, where the Chief Engineer of Promtekhvzvzryv Company N.A. Chistyakov and General Director of the Urals Explosives Association G.P. Bersenev conducted tours to the open-pit mine, the 'Poremit' Plant - the first emulsion explosives production facility in the Urals, a bulk explosives storage, the museum and training center of the Urals Asbestos Mining and Processing Complex. Following the tours of the training center site of the Processing Complex, the second part of the conference was held, during which a number of reports were delivered. Upon completion of the seminar, the Urals Explosives Association awarded honorary certificates and valuable gifts to specialists of the Promtekhvzvzryv Company for their contribution to improvement of drilling and blasting technology and organization of labor on blasting sites. The article is concluded by a summary of the Conference's decisions.

Insight into Saturated Hydraulic Conductivity of Cemented Paste Backfill Containing Polycarboxylate Ether-Based Superplasticizer

Recycling of tailings in the form of cemented paste backfill (CPB) is a widely adopted practice in the mining industry. Environmental performance is an important design criterion of CPB structures. This environmental performance of CPB is strongly influenced by its saturated hydraulic conductivity (permeability). Superplasticizers are usually added to improve flowability, but there is a limited understanding of their influence on the hydraulic properties of the CPB. This paper presents new experimental results on the variations of the hydraulic conductivity of CPB containing polycarboxylate-based superplasticizer with different compositions and curing conditions. It is found that the hydraulic conductivity of the CPB decreases with the addition of superplasticizer, which is beneficial to its environmental performance. The reduction is largely attributable to the influence of the ether-based superplasticizer on particles mobility and cement hydration. Moreover, both curing temperature and time have correlations with the hydraulic conductivity of CPB containing superplasticizer. In addition, the presence of sulfate and partial replacement of PCI with blast furnace slag reduces the hydraulic conductivity. The variations are mainly due to the changes in the pore structure of the CPB. The new results discussed in this manuscript will contribute to the design of more environmental-friendly CPBs, which is essential for sustainable mining.

An Automatic Procedure for Overheated Idler Detection in Belt Conveyors Using Fusion of Infrared and RGB Images Acquired during UGV Robot Inspection

Complex mechanical systems used in the mining industry for efficient raw materials extraction require proper maintenance. Especially in a deep underground mine, the regular inspection of machines operating in extremely harsh conditions is challenging, thus, monitoring systems and autonomous inspection robots are becoming more and more popular. In the paper, it is proposed to use a mobile unmanned ground vehicle (UGV) platform equipped with various data acquisition systems for supporting inspection procedures. Although maintenance staff with appropriate experience are able to identify problems almost immediately, due to mentioned harsh conditions such as temperature, humidity, poisonous gas risk, etc., their presence in dangerous areas is limited. Thus, it is recommended to use inspection robots collecting data and appropriate algorithms for their processing. In this paper, the authors propose red-green-blue (RGB) and infrared (IR) image fusion to detect overheated idlers. An original procedure for image processing is proposed, that exploits some characteristic features of conveyors to pre-process the RGB image to minimize non-informative components in the pictures collected by the robot. Then, the authors use this result for IR image processing to improve SNR and finally detect hot spots in IR image. The experiments have been performed on real conveyors operating in industrial conditions.

Spinoffs’ alliance network growth beyond parental ties: performance diminishing, then performance enhancing

Spinoff firms are a common phenomenon in entrepreneurship where employees leave incumbent parent firms to found their own. Like other types of new firms, such new spinoffs face liabilities of newness and smallness. Previous research has emphasised the role of the initial endowments from their parent firm to overcome such liabilities. In this study, we argue and are the first to show, that, in addition to such endowments, growing an alliance network with firms other than their parents’ is also critical for spinoff performance. Specifically, we investigate the performance effect of alliance network growth in newly founded spinoffs using a longitudinal sample of 248 spinoffs and 3370 strategic alliances in the mining industry. Drawing on theory based on the resource adjustment costs of forming alliances, we posit and find a U-shaped relationship between the alliance network growth and spinoff performance, above and beyond the parent firm’s influence. We further hypothesise and find that performance effects become stronger with increased time lags between alliance network growth and spinoff performance, and when spinoffs delay growing their alliance networks. Implications for theory and practice are discussed.

The Recent Progress China Has Made in the Backfill Mining Method, Part III: Practical Engineering Problems in Stope and Goaf Backfill

With the continuous innovation and development of science and technology, the mining industry has also benefited greatly and improved over time, especially in the field of backfill mining. Mining researchers are increasingly working on cutting-edge technologies, such as applying artificial intelligence to mining production. However, in addition, some problems in the actual engineering are worth people’s attention, and especially in China, such a big mining country, the actual engineering faces many problems. In recent years, Chinese mining researchers have conducted a lot of studies on practical engineering problems in the stope and goaf of backfill mining method in China, among which the three most important points are (1) Calculation problems of backfill slurry transportation; (2) Reliability analysis of backfill pipeline system; (3) Stope backfill process and technology. Therefore, this final part (Part III) will launch the research progress of China’s practical engineering problems from the above two points. Finally, we claim that Part III serves just as a guide to starting a conversation, and hope that many more experts and scholars will be interested and engage in the research of this field.

Mining Industry of the Republic of Sakha (Yakutia) and Problems of Environmental and Social Security of Indigenous Peoples

The Republic of Sakha (Yakutia; RS(Y)) is located in the northeast of Siberia (Russia) in the basins of the Lena, Yana, and Indigirka rivers, in the lower reaches of the Kolyma River. Yakutia is an industrial–agrarian republic with a developed mining, fuel, and energy industry. Indigenous peoples live mainly in the Arctic regions, where the large-scale development of mineral resources is planned, and South Yakutia, where the mining industry is well developed. The aim of this study is the development of methodological approaches to assessing the impact of the mining industry on the natural environment and the social sphere in the places of residence and traditional economic activities of the indigenous peoples of the North. We used the results of research work (R&D), materials of expeditionary work, and regulatory documents of the Republic of Sakha (Yakutia) and the Russian Federation (RF). The state of the environment (ES) was assessed on the basis of the analysis of indicators for three areas: (a) anthropogenic load, (b) environmental and social consequences, and (c) resistance of natural complexes to technogenic impacts. In total, 22 indicators were used for the 3 areas, for example, population density, person/km2; the volume of extraction of rock mass, million m3; and emissions, t/year. To bring dissimilar indicators into comparable ones, we used a methodological approach with the use of the social risk index (SRI). In Arctic regions (mainly agricultural), the ES is in a favorable and relatively favorable state: SRI 0.61–0.70; in the central regions (mainly agricultural), it is satisfactory and relatively satisfactory: SRI 0.71–1.0; in the southern and western regions with a developed mining industry, it is relatively tense and tense: SRI 1.01–3.0. An extremely tense state of environmental conditions has developed in the city of Yakutsk: SRI ≥ 3. Generally, the deterioration of the environmental situation and vital activity of the indigenous peoples in investigated Arctic region correlated with the impact of the mining industry.