Vol 43, No 4 (2020)
Exploration and Development of Mineral Deposits
Current methods of technogenic gold placer deposit mining with small size gold extraction technology
Abstract
The purpose of this article is to conduct industrial tests of spiral separation technology on technogenic refractory raw materials. The object of the study is the Yurskoye gold placer deposit in the Republic of Sakha (Yakutia). An OKV-100 benefication complex with the productive capacity of 100 m3 /h by initial sands was set up in order to conduct pilot mining of the fine-grained tailings dumps of the Yurskoye deposit with the maximum extraction of small size gold. Sands supplied from the different sections of the technogenic deposit had different gold content, granulometric characteristics, and mineralogical composition. The study included experiments carried out at different initial feed; equipment was adjusted for specific raw material depending on productive capacity, liquid/solid ratio, product yield of the small size gold recovery module. The complex productivity was from 90 to 150 m3 /h. The yield and extraction of gold-bearing concentrate, as well as its gold content were determined. The pilot washing with the use of small size gold recovery technology resulted in the average additional gold recovery from sluice tailings of 19.07 %, which is a high indicator, given the low content of gold in technogenic placers. The technology under consideration can be used for the development of both technogenic and operated gold placer deposits.
Earth sciences and subsoil use. 2020;43(4):458-466
458-466
Benefication and Processing of Minerals
Studying the effect of carbon dioxide oil solubility on asphaltene aggregation under conditions of the Bashkortostan Republic fields
Abstract
The purpose of this work is to study the effect of carbon dioxide oil solubility on the aggregation of asphaltene associates and decrease of oil permeability of sandstones. Consideration is given to the interaction variants of oil and carbon dioxide in a free volume before being injected into a porous medium and immediately in the porous medium. The influence of oil composition on the aggregation of asphaltene associates is studied. The effect of the dissolved carbon dioxide on associate dispersion in oil is examined through oil filtering in sandstones. If asphaltene aggregation occurs in a porous medium it causes pore plugging leading to reduced permeability, complicates the development of carbon dioxide injection wells and, as a result, prevents from achieving the planned indicators of oil production and oil recovery. It is found that in the case when oil interacts with carbon dioxide in the free volume before being injected into a porous medium, the increase in the volume of filtered oil and the concentration of carbon dioxide dissolved in oil, and decrease in sandstone permeability reduce the relative mobility of oil with the dissolved carbon dioxide. The significant influence of sandstone permeability on the experimental results indicates that the sizes of asphaltene aggregates are comparable to the sizes of small pores. We have not observed complete attenuation of filtration after passing of oil with dissolved carbon dioxide through sandstones. Based on the analysis of changes in oil composition and properties carried out in the laboratory experiments on oil displacement by carbon dioxide rims, it has been determined that aggregation of asphaltene associates takes place under immediate contact of oil and carbon dioxide in a porous medium. The higher the asphaltene content in oil, the lower the formation permeability, whereas tight formations feature a more significant decrease in permeability.
Earth sciences and subsoil use. 2020;43(4):467-475
467-475
Geoecology
Occupational hazards at the Irkutsk region oil and gas production facilities
Abstract
The oil and gas industry belongs to the high risk activity. Today, the enterprises engaged in this field including oil and gas production facilities implement a risk-based approach, which involves the identification of risk criteria and risk categories, timely reassessment of risks based on updated and formed normative legal documents. In this regard, the purpose of this research is the analysis of the management system of occupational hazards and measures to minimize them using innovations and innovative solutions at the oil and gas production facilities in the Irkutsk region of the Russian Federation. The object of the study is working conditions and occupational hazards at the oil and gas production facilities of two leading oil companies of the Irkutsk region: they are the Irkutsk branch of Gazprom Bureniye LLC and the Irkutsk branch of RN-Bureniye LLC. As a result possible reasons for the discrepancy between the physical factors of the working environment of oil industry workers when pеrforming works on oil rigs are analyzed. Professional risks having been assessed, a register of high-risk professions and hazardous areas of technological processes under the operation of oil and gas drilling rigs has been compiled. The professions studied in this paper are classified as high-risk and medium-risk ones. It is found out that the negative effects of moving machines and mechanisms, general vibration, local vibration, noise, low air temperatures in winter are unacceptable. To minimize unacceptable risks, it is proposed to introduce a low-cost technology for visualizing hazardous areas on a drilling rig with the installation of proven innovative safety barriers in addition to the related training of employees.
Earth sciences and subsoil use. 2020;43(4):476-485
476-485
Results of Field Studies
Clockwise rotation of the Tarim basin driven by the Indian plate impact. Part II*
Abstract
In the previous article**, data were given on the clockwise rotation of the Tarim Basin at a speed of 0.461° per million years around a virtual axis within the structure. Additional fieldwork and new evidence confirm earlier findings about the asymmetry of the Indo-Asian collision zone. These data are additional arguments in favor of the rotation of the Tarim Basin and lithospheric interactions along the Tarim boundaries. Conclusions are based on detailed geological and geophysical data.
Earth sciences and subsoil use. 2020;43(4):486-498
486-498
Hypotheses, Reports, Discussion
Features of distance learning by the disciplines in the Earth Sciences direction at a technical university
Abstract
: Distance education has become widely used both in Russia and abroad in recent decades. A particularly powerful impetus to distance education technology development and spread was given by the coronavirus pandemic in 2019. To improve learning efficiency in the system of distance education, it was required to refine various and accessible forms of education. It was also necessary to make a wider use of new educational technologies. The purpose of this study is to analyze the use of the latest educational technologies in the distance learning of students in the disciplines of the Earth Sciences direction at a technical university, as well as to form a modern educational space in online learning and stimulate students' independent work based on the assignments supervised by teachers. The study described in this paper deals with the following application features of distance learning at Irkutsk National Research Technical University: the presentation specifics of the theory and the introduction forms of material for laboratory works, choice of the most effective teaching aids, methodology for the current and final control of students' knowledge. Irkutsk National Research Technical University has chosen Moodle from a wide variety of distance learning systems. The advantage of this system is the ability to perform laboratory, practical and course works, which is important for a technical university, also to conduct tests, the results of which can be monitored by both teachers and students in an electronic gradebook. The distance learning system turned out to be more multisided, but more laborious than in-person training. Moreover, it is also complicated by a number of technical problems. The distance learning process requires the establishment of a certain parity of interests, abilities and opportunities between the teaching (professor/lecturer) and the learning (student) parties. The distance learning system has a number of features that should be taken into account when introducing theoretical and lecture material, which requires a more rigorous selection of files or their conversion into less heavy ones, as well as conciseness and clarity of material presentation. The use of virtual laboratories for carrying out laboratory works, availability of distance technologies for training disabled students and corresponding students is gaining great importance. The research results imply that today distance learning is a necessary part of the educational system along with in-person (full-time) or correspondent (part-time) training and one of the main goals of modern distance learning is the ability to work with information and selfimprovement.
Earth sciences and subsoil use. 2020;43(4):499-509
499-509
Articles
Information for the Authors
Earth sciences and subsoil use. 2020;43(4):510-514
510-514