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Date submitted2023-06-21
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Date accepted2023-10-25
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Date published2024-08-26
Specific action of collector from phosphoric acid alkyl esters class in flotation of apatite-nepheline ores
Increasing amount of apatite-nepheline ores with complex mineral composition involved in processing, growing content of the associated minerals in ore which are similar in their floatability to apatite lead to the necessity of using highly selective collectors. Non-frothing flotation method gave a comparative assessment of floatability of pure minerals and demonstrated a high selectivity of the action of phosphoric acid esters in relation to apatite. The effect of four reagent modes differing in the number of selective synthetic collectors was studied using the example of flotation of an apatite-nepheline ore sample containing 17.27 % apatite and 40.18 % nepheline. Mineralogical analysis of crushed ore showed that it contained two apatite varieties – coarse-grained free and finer poikilitic as inclusions in rock-forming minerals. Free apatite opens and occurs as open grains even in coarse-grained (+0.16 mm) grades. Poikilitic apatite occurs as intergrowths with different minerals, mainly with nepheline and its alteration products (natrolite, spreustein, sodalite, etc.), and pyroxene. Optical microscopy demonstrated that a growing share of reagent from the phosphoric acid oxyethylated esters class in the composition of the collector mixture allows improving the quality of the produced apatite concentrates by reducing the number of apatite intergrowths with nepheline and pyroxenes in the concentrates. In the concentrate obtained in the most selective reagent mode, the intergrowths are characterized by a 50/50 and higher ratio in favour of apatite. Concentrates of lower quality comprised intergrowths with lower apatite content, to 20/80 or less.
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Date submitted2014-11-15
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Date accepted2015-01-11
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Date published2015-10-26
On the necessity of taking into consideration the increment of the growing stock in cadastral valuation of lands of forest fund
- Authors:
- V. F. Kovyazin
Currently there are no methods of cadastral valuation of forest land although the area covers 2/3 of the territory of the Russian Federation. In 2002, the Federal Land Inventory Service of Russia proposed a method but it failed to find practical use due to the complicated calculation of the cadastral value according to the Faustmann formula and lack of open access to some information about the forest fund and was totally abolished seven years later. There were several reasons for abolishing the method and the main reason was lack of methods to predict a supply of wood to the age of maturity when the cadastral assessment was carried out in the plantations under the age of main felling. The author proposes to take into account the current growth rate of the growing stock per year on one hectare of land in the cadastral evaluation of forest fund lands. Based on the increment of the growing stock it is possible to construct a mathematical model of changes in the forest reserve to the age of maturity. The author suggests using the existing forest inventory materials to build the model. By updating existing data you can obtain any inventory indices including the growing stock in different age plantations. The resulting inventory of plantations at the age of maturity is recommended for cadastral valuation of the forest fund lands. The calculation of the cadastral value of forest land for one taxation quarter with and without current increment of the growing stock is given and the difference is 37 %.
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Date submitted2014-11-27
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Date accepted2015-01-15
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Date published2015-10-26
Socio-economic potential of large-scale projects to develop offshore oil and gas: risks and stakeholder expectations
- Authors:
- A. E. Cherepovitsyn
The development of the Arctic shelf is a strategic long-term objective of the energy development of the Russian Federation. At the present time, resource and economic potential of offshore oil and gas development projects is huge. However, it is constrained by the complexity of developing offshore oil and gas resources due to climatic, geological and technological conditions. In addition, the current unstable situation with world oil prices is also a constraint on largescale involvement in the industrial development of offshore oil and gas resources. The aim of the research is to determine socioeconomic potential of large-scale projects to develop oil fields in the Arctic shelf of Russia. The article presents the peculiarities of developing offshore fields, which are characterized by severe climatic conditions, high environmental risks, unique technological solutions, lack of infrastructure in coastal areas. A comparative analysis of projects to develop land and shelf is performed. The regional authorities’ and businesses capability of implementing large-scale projects to develop offshore fields on economic, social and environmental criteria is identified. The positive and negative effects of socio-economic development of the territory implementing projects of hydrocarbon field development are evaluated. A schematic diagram of the socio-economic potential of hydrocarbon resources development projects reflecting the opportunities and risks of such projects from the perspective of key stakeholders is developed. A set of strategic objectives to successfully implement projects in the Arctic shelf of Russia are proposed. The findings of the research can be used by the departments of energy, industry and mineral resources in the preparation of long-term strategic development programs for the oil and gas industry.
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Date submitted2014-06-23
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Date accepted2014-08-27
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Date published2014-12-22
Theoretical aspects of the kinetics of gas hydrates
- Authors:
- E. P. Zaporozhets
- N. A. Shostak
In the systems of collection, preparation, transportation and processing of hydrocarbons in conditions of a certain temperature and pressure, gas hydrates, which adversely affect the operation of the processing equipment, are formed. To prevent hydrate formation, it is necessary to determine the time and rate of growth. For this purpose, physical and mathematical models describing the growth of crystalline hydrates are being designed and developed. The developed models differ from one other. The reason for the difference is that each model is designed for specific temperature and pressure conditions and individual gas hydrates (or mixtures). The main theoretical models describing the process of growth of hydrates under different conditions are presented.
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Date submitted2009-10-20
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Date accepted2009-12-26
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Date published2010-09-22
Change in presentations on mechanism of rock and tectonic bursts at ore mines at present time
- Authors:
- A. V. Lovchikov
It was shown that presentations on mechanism of rock and tectonic bursts developed for coal deposits, are not suitable for the conditions of ore deposits. Forms of manifestations of rock and tectonic bursts at ore deposits have been determined by experimental data including the artificial initiation of rock bursts in pillars.
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Date submitted2009-10-14
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Date accepted2009-12-11
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Date published2010-09-22
Investigation of present-day stress-strain state of rock mass by the results of observations at geodynamic polygons
- Authors:
- S. N. Savchenko
- E. V. Kasparyan
- Yu. G. Smagina
The methods are suggested for treatment of the results of optical distance and levelling measurements at the underground geodynamic polygons involving in their calculation the tensors of additional stresses and deformations, component of rotation and specific energy of deformability. As an example, consideration is given to changes in time of movements, deformations and specific energy of deformability at one of geodynamic polygons of the Kola peninsular.
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Date submitted2008-11-01
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Date accepted2009-01-27
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Date published2009-12-11
The influence of the technological and organizational factors on the steady growth of the mining industry
- Authors:
- E. M. Pronin
- V. E. Vasiliev
The steady growth of the mining industry calls forth the character of its activities connected with the dependence of the work on the natural conditions which are practically unpredictable and constantly changeable. The two basic factors are chosen – the technology of the mining work and the organization of the industry, which have the decisive importance in the increasing of the basic indices of the activity of the enterprise. The possible technological and organizational solutions are offered as they permit to find possible directions in the lowering of the negative influence of the appearing problems.