Nonferrous ore concentration
Rubtsov Yu.I. Substantiation of gold heap leaching acceptability by oxygenized cyanic solutions
The regularities of gold dissolution using oxygenized cyanic solutions were investigated under the “piston” mode of irrigation of palletized ore crushed to –10 mm class. In applying the method proposed, the solution filtration speed was improved. Specific consumption of solutions for irrigation was lowered to 0,03–0,12 m3/(m2 · day). Duration of irrigation cycle was decreased 50 times. Specific charges for oxygen consumption amounted to about 0,5 ruble/t. In this case, 82 %-extraction of gold can be reached 3 times faster than when using the air.
Rubtsov Yu.I. Pilot-field tests of gold leaching by oxygenized cyanic solutions
The tests have confirmed the data of laboratory investigations of the gold extracting speed mode. The following corrections are made: as many as 25 % Au are adsorbed by ore when gold concentration in the production solutions amounts to 24,6 mg/l. The total gold recovery from refractory ore was 75 % for a period of 22 days, solution consumption for irrigation being 22,7 l/(t ∙ day) and oxygen consumption being 1,2 g/(t ∙ day).
Extractive metallurgy of nonferrous metals
Volodin V.N., Khrapunov V.E., Kenzhaliev B.K., Isakova R.A., Bayanzhanova Sh.T. Liquid-vapor phase transfer in the silver–copper–cadmium system
Cadmium vapor pressure over triple liquid alloys with silver and copper with ratio of their concentrations equal to 0,5 and 2 at T = 873÷1273 K was determined by the boiling point method. The partial and integral thermodynamic characteristics of vapor and condensed phases represented as the temperature–concentration dependences are found out. The system is characterized by negative deviation from the law of ideal solutions. Extrapolation of component vapor pressure dependences to the range of high temperatures together with the data of the Ag–Cd and Cu–Cd boundary systems allows us to determine the boundaries of liquid–vapor phase transition in the Ag–Cu–Cd system. The space of coexistence of alloys and vapor restricts from above a relatively small zone of existing liquid silver-copper-cadmium solutions.
Iliev P., Stefanova V. Autoclave dissolution of copper sulfide concentrate produced during processing polymetallic nodules
Copper sulfide concentrate is one of the products produced by two-stage sulfur-sulfur process of selective dissolution of complex alloy obtained by pyrometallurgical processing of polymetallic nodules. Chemical composition of the concentrate is the following (in wt. %): 53,1 Cu, 2,95 Ni, 0,26 Co, 5,12 Fe, 0,48 Mn, 30,9 S, and 7,19 (Si + P + C). From the results of the experiments conducted using laboratory TLA30 type autoclave, optimal technological parameters of the concentrate dissolution process were determined, which affect the degree of copper extraction and hydrolyzed purification of the solution from iron: consumption of sulfuric acid (mole of H2SO4 per Cu gram-ion in the concentrate) H2SO4 /Cu = 1, РО2 = 0,4 MPa, t = 363 K, S : L = 1 : 10, duration of dissolution is 240 min at mixing intensity of 500 min–1.
Extractive metallurgy of less-common and precious metals
Alieva R.A., Alieva F.S., Chyragov F.M. Spectrophotometric determination of gallium (III) complexing with 2,3,4-trihydroxi-4¢ -fluorazobenzide in the presence of urotropin and melaniline
Gallium (III) complexes with 2,3,4-trihydroxi-4¢ -fluorazobenzide were investigated by spectrophotometric method in the presence and absence of urotropin and melaniline. The compositions were studied, analytical and spectrophotometric characteristics of the complexeswere obtained, and the optimal conditions of their formation were found. Photometric procedure was developed to determine gallium (III) with the given reagent and in the presence and absence of third components. It is characterized by high selectivity and it was used for determination of Ga(III) in igneous rock.
Ermilov A.G., Bogatyryova E.V., Medvedev A.S. Estimation of efficiency of multyphase system activation by dint of X-ray crystallography
Taken as an example of activation of multiphase (3 oxide and 3 sulfide phases) copper-containing concentrate, a possibility of determination of the degree of different phase activation was shown. Four processing mode were considered. A qualitative estimation of the degree of mechanical effect upon every phase was carried out for them. A correlation among the data obtained with X-ray crystallography and these given in the literature, which describe the behavior of individual phases of the concentrate in the course of its machining process, was shown.
Ukhov S.A., Bukin V.I., Smirnova A.G. Extraction recovery of indium from sulfate solutions by mixtures of oligomeric alkyl phenol and octanoic acid
The results of the investigations of indium extraction from aqueous zinc sulfate solutions by mixtures of nitrogen-containing resole paratertbutyl-phenol-formaldehyde oligomer “YRB” and caprylic acid (CA) are presented. The extraction parameters (lgDIn, EIn, b In/Zn) are studied as a function of aqueous phase pH, sulfate-ion concentration, and CA concentration in the mixtures with YRB. The synergistic effect by means of isomolaric series method has been found and explored. It has been shown that the effect is caused by the formation and extraction of mixed coordination-saturated hydrophobic complex compounds of indium with YRB and CA. Optimal conditions of extraction and stripping were determined. With the YRB:CA molar ratio equal to 1,5:2,5 … 2,5:1,5 and pH ³ 3,45, the degree of indium recovery is EIn ³ 99 % by separation coefficient b In/Zn > 505. It was obtained that the indium stripping by 0,5 mol/dm3 H2SO4 allow us to extract ~ 99 % of this element from organic phase, by one step, with phase ratio of VO : VA = 1 : 1 and contact time t K = 50 min. A possibility of solvent refining and concentration of indium from processing indium-containing waste or residue processing was discussed. The mixtures of YRB and CA were proposed for indium recovery from zinc sulfate solutions of low Fe(II) concentration.
Khrennikov A.A., Maltsev G.I., Lebed¢ A.B., Naboichenko S.S. On germanium and zinc recovery from dusts of copper-smelting production
The behavior of germanium and zinc was investigated during sulfuric leaching of dusts from copper-smelting enterprises of Ural Mining-and-Metallurgical Company. The effect of process parameters (duration, temperature, pulp density, residual acidity) as well as chemical and phase compositions of the dusts as to the degree of recovery of germanium, zinc, and a series of other components was established. Allowing to recover 75–85 % Zn and 65–85 % Ge into solution, the optimal leaching mode is recommended.
Krasikov S.A., Chumarev V.M., Sholokhov V.M., Timofeev M.V., Savushkina O.G. The effect of tantalum, niobium, tungsten oxides on surface characteristics and bulk properties of alumina-silicate melts
The effect of rare metal oxides on surface tension (s ) and density (r ) of slag was investigated for the concentration range of Nb2O5, Ta2O5, and WO3 from 0 to 7,4 mol. % or to 25 wt. % at T = 1523÷1873 K. Analysis of the features in s and r changes, temperature coefficients of ds /dT and dr /dT as well as that of adsorption characteristics made it possible to find the complexing character of tantalum, niobium, and tungsten in aluminosilicate melts.
Strizhko L.S., Krivodubsky O.A., Gazimov R.T., Bezrukova Zh.N., Zakharova V.I. Forecasting and control of silver biosorption process
A possibility of forecasting and control of the silver biosorption process was investigated. The results of the works conducted in the Moscow Steel and Alloys Institute and the Institute of microbiology of the Russian Academy of Science have been used. Based on the statistical analysis executed, the regression polynominal was formulated that describes the process correctly enough. The mathematical models developed allowed us to formulate a fundamental diagram for controlling the sorption-desorption cycles. Silver recovery may be controlled by both manually and PC use. The similar processes were verified during pilot tests at one of the refineries.
Materials science and heat treatment
Tikhomirov A.V., Aksyonov A.A., Shelekhov E.V., Kaloshkin S.D. Estimation of mechanical alloying intensity (energy intensity) in planetary mill with quasi-cylindrical grinding body
A mathematical model of mechanical alloying in the planetary mill equipped with a quasi-cylindrical grinding body was developed. Intensity of such processing amounts to 175 W/container and coincides virtually with that determined experimentally (215 W/container). The dependences of the given index on pinion carrier rotating speed, friction coefficient, and collision elasticity have been studied. The motion pattern of a quasi-cylindrical grinding body was considered. It was shown that when it is used, mechanical energy more than tens times is supplied to unit of volume of processed substance as compared with ball load. This results in the high processing efficiency that was verified experimentally by the example of composite material Al–6%Zn–1,6%Mg–1%Cu–20vol.%SiC.
Gishchin A.N., Pachurin G.V. Durability of titanium alloys and welded joints
The article represents the results of the mechanical tests with static and cyclic loading of sheets of OT4-1 and VT-20 titanium alloys in the air and in the presence of 3 % aqueous solution of marine salt as well as cylindrical welded joints of commercial-purity titanium VT1-OS in the Ringer-Lock physiological solution. The effect of preliminary strain on durability of titanium alloys was shown to depend on the initial state of the material, strain rate, level of applied stress, and medium of cyclic stress. As a rule, the effect is stronger for drop forging than for press forging. The regularities connecting the mechanical characteristics in static and cyclic loadings to mechanical irregularity and grain size of softened metal of titanium welded samples were found. Based on the analysis of strength balance condition in loading welded joints, the recommendations for estimation of fatigue characteristics are given by type of mechanical non-uniformity and structural state.
Surface engineering. Multifunctional films. Corrosion and metal protection
Klimov M.Yu., Kozhenkov A.S. Surface tension of solid copper and interfacial tension of copper-bismuth
The surface tension of solid copper (g S) and the interfacial tension of copper–liquid bismuth (g SL) in the hydrogen atmosphere were determined using multiphase equilibrium. Equilibrium angles were measured using optical microscopy. The values of g S = 1,86 · 0,20 N/m and g SL = 1,53 ± 0,30 N/m were calculated for T = 550 ° C. Using the known value of temperature coefficient of surface tension Kg = –5,5 · 10–4 N/(m∙K), the surface tension of solid copper equal to 1,57 ± 0,20 N/m along the boundary with hydrogen at the melting point was obtained by means of extrapolation.
Heat engineering and environment protection in metallurgy
Ibadullaev T.B., Arutyunov V.A., Levitsky I.A., Leshinin S.V. Mathematical model of working process of radiation vortex injector installed in furnace roof
A problem of mathematical description of the processes in the combustion chamber of vortex radiation injector (VRI) and near the working space of the furnace was considered. Modeling of the gas-flowing processes was carried out by numerical solving of averaged Navier-Stokes equations, continuity, energy, and k–e -model of turbulence. The radiation transfer was considered based on differential method with the help of modified P1-approach. For modeling the combustion processes, the finite-thickness flame front model was used. The effect of turbulence was considered with concept of decomposition of vortexes permitting to calculate the speed distribution, pressure, temperature, and mixture component concentrations, find the burning zone configuration, estimate ejecting ability of radiation vortex injector, and solve the outer problem of heat exchange in the VRI fitted furnace. Availability of great speed gradients in the VRI chamber was found to result in generation of turbulence that is characterized by high kinetic pulsation energy.
Chronicle
To 60-year anniversary of Roman L’vovich Shatalov
Information
Exhibitions abroad
Summary of joint meeting of Control-Training Council on Nonferrous Metallurgy and Editorial Staff of “Izvestiya vuzov. Tsvetnaya Metalluria” Journal
