Home – Home – Jornals – Advanced Search

Exploitation of Mutnovskoe Geothermal Field, which is a key asset of geothermal power engineering in Russia, is faced with the problem connected with reduction in pressure in the producing reservoir, which results in decommissioning of production wells. Production capacity of planned wells 3 and 4 km deep for treating deeper horizons in Mutnovskoe Field is predicted. The prediction results are compared with the data of a standard production well 2 km deep in this field and prove the promising nature of the deeper horizons of this reservoir. In particular, essentially greater steam flow rate out is expected in the deeper production well as compared with the standard well. Furthermore, it is expected to produce much more geothermal energy owing to the increased allowable reduction in the reservoir pressure and thanks to additional heat elimination from larger volume of enclosing rock mass of the produced fluid.

Based on the mathematical model of hydro vortex orthokinetic inertia hetero coagulation, the hydro-vortex nozzle parameters air identified for a dust suppression facility for prevention of blasts and induced accidents in mines. Using the similarity theory and dimensionality analysis, the similarity criteria are obtained for the process of dispergating in the conditions of rotational motion of liquid drops. It is shown that the main pulverization efficiency criteria for liquid drop in the hydro vortex nozzle are the Weber number, Laplace criterion and three indicators of inertia and viscosity of liquid, and kinematic similarity. The calculations and tests reveal the possibility of enhancing dispergating efficiency by 15%, reducing the average diameter of liquid drops by 2.5 times, and reducing the liquid flow rate by 10%.

The test data on confined air throw ranges in dead ends are reviewed. It is found that the research findings differ greatly and disable the single-value determination of the allowable lag between the air duct and heading fact at the acceptable accuracy. It is supposed that the discrepancy of the testing data is ensues from the empirical concept of independency of the confined dead-end air throw range from the initial air flow velocity, which is strictly unproved. The supposition is backed with the numerical modeling data on blind roadway ventilation with visualization of air flow shortage at air velocities not less than 0.25 m/s. At the increased capacity of air fan and with the enhanced initial air flow velocity from 5 to 80 m/s, the air throw grows to 56 m. The authors come to a conclusion that the efficient and resource-saving approach to blind roadway ventilation is the increased air supply in air ducts, which makes it possible to extend the distance between the air duct and the face toward safe blasting.

Flotation of pyrite is examined as function of pH and ferrous ion concentration. To explain depression of pyrite flotation in the neutral pH range and at high concentration of ferrous ions, the mechanism of physisorption of a collecting agent is used. It is experimentally determined that interaction products of xanthate and ferrous ions possess different velocities of spreading over the gas-water interface dep0ending on their concentrations and on the solution pH. Furthermore, they have different influence on the velocity of liquid removal from the interlayer between mineral particle and gas bubble. The mechanism of physisorption of a collecting agent discloses the causes of suppressed flotation of pyrite in the neutral pH zone and increased pyrite flotation in the alkaline medium.

The authors propose the technological algorithm to obtain the required quality characteristics of beneficiation feed based on the estimate of useful mineral distribution and amount of gangue in a preset volume. The target useful component content is implemented by combining separation and blending of crushed ore less than 100 mm in size. It is shown that this approach to the feed quality ensures the standard content of Р₂О₅ in the feed at the level of 12.1-12.3% with dumping not less than 29% of gangue - 100_{+ 20 mm in size with the content of Р2О5 under 1.9%. It is proved that the proposed technology for the control of quality characteristics of low-grade apatite-bearing ore has a beneficial effect on the environment in mining and processing areas.}

The article describes the non-frothing flotation data of monomineral fractions of tennantite, chalcopyrite and pyrite, measurements of electrokinetic potential of the phases, and the concentration control of butyl xanthate, sulfhydryl collector M-TF and hydrogen peroxide. The measurements of the electrokinetic potential and intensity of the characteristic UV bands reveal the influence of H₂O₂ concentration on the ion-molecular condition of the solutions of sulfhydryl collectors. It is found that butyl xanthate in the presence of hydrogen oxide fails to prove selective separation of tennantite and chalcopyrite from pyrite. M-TF ensures the contrast flotoactivity between copper and pyrite sulfides in softer treatment with H₂O₂. Hydrogen peroxide is recommended for scavenging of copper concentrate. Efficiency of H₂O₂ in recleaning of copper concentrate at a commercial scale is lower because of variable mineral composition of flotation feed.

The experimental data on modification of magnetic properties of gold-bearing sulfide ore using magnetic colloids are reported. The magnetic product of the high-gradient separator has the increased gold content by 2.52% at the higher recovery by 1.67%.

The objective of this study is the recuperation of metal nickel by adsorption with activated carbon prepared from natural waste (the peel of the apricot kernel), where adsorption is controlled by a chemical phenomenon driven by a series of factors. The adsorption efficiency was evaluated after carbonization of the raw material at 600 ° C and after its activation with citric acid at 500 ° C. The characterization of the material after physicochemical treatment has shown the possibility of its improvement. The IR spectroscopy technique has shown the material becomes very rich in carbon and oxygen, and is well functionalized. The activated carbon can adsorb nickel efficiently, and then inverted conditions ensure efficient elution. Kinetic adsorption is dependent on the activated carbon, while equilibrium loading is not but is dependent on plant conditions. The kinetic study of the optimal adsorption of nickel ions follows the models of Langmuir and Freundlich, and exhibits a high affinity between the metal nickel examined and the carbon active, which enables the highest adsorption.

Mine reclamation has to be considered from the very beginning stages of mining. In the reclamation plan of the Sungun copper mine in Iran, tree planting is the most appropriate option. In this regard, the main parameters as well as criteria should be taken into account. Since plant type choosing is a Multi-Criteria Decision-Making (MCDM) problem, two outstanding MCDM methods-PROMETHEE and ELECTRE-are considered through the analyses as well as verification of the results. Decision matrix was first provided based on questionnaires filled by experts and the next stages, rankings were then carried out using aforementioned approaches. The findings demonstrated that the most suitable plant type with the highest score of 5 in ELECTRE and 4.34 in PROMETHEE method is Acer monspesulanum tree.

Estimation of iron ore grade distribution has been done using geostatistics and Artificial Neural Network (ANN) models for an iron ore body in Central Iran. The methods implemented include Ordinary Kriging (OK), Sequential Gaussian Simulation (SGS), and ANN. A comparison of the estimates from these techniques was done to investigate which method gives more accurate estimates.