Iron losses in processing tailings

For ferruginous quartzite of the Mikhailovsk deposit, the features of mineral composition, iron occurrence, granulometric composition, and opening of phases of stage and total tailings of processing are considered. Extraction of hematite from tailings using combined concentration schemes is one of the variants of complex utilization of mineral source in the deposit. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 100–105, November–December, 2005.     

Sleeve piercing on a mill designed by OAO EZTM

In response to the problems arising on introducing a new piercing mill designed by OAO EZTM, the use of continuous-cast billet of a single diameter is proposed for the manufacture of pipe with a diameter of 219–325 mm; the working profile of the mandrel is optimized, with the introduction of alternating curvature; and the conditions of billet heating in the annular furnace prior to piercing are adjusted.     

Friction Stir Welding of an Aluminum Matrix Composite Dispersion-Hardened by SiC Particles

Russian Engineering Research - Friction stir welding may be used to create butt joints of an aluminum matrix composite dispersion-hardened by SiC particles. With increase in content of the...     

Graphene oxide on the surface of basalt fiber

This paper describes possible procedures for immobilizing two-dimensional graphene oxide flakes on the cylindrical surface of basalt fibers. The samples thus obtained have been characterized by analysis for C, H, and N; X-ray diffraction; scanning electron microscopy; Raman spectroscopy; and atomic force microscopy.     

Study of the extraction of zinc(II) ions from ammonia–sulfate solutions

The extraction of zinc(II) ions with DX-510A β-diketone from sulfate and ammonia–sulfate solutions is reported. The effects of the aqueous phase pH and extracting agent concentration on the process have been investigated. The highest zinc(II) ion recovery is observed at pH 8.5–9.0. The time to extraction equilibrium is no longer than 30 s; in back extraction, it does not exceed 70 s. The extraction of zinc(II) ions is accompanied by the formation of an ammonia-containing organic complex. A chemical formula is suggested for this compound.     

Numerical simulation of changes in the composition of detonation products of a free volume of a combustible mixture

Direct numerical simulation of the problem of detonation of a free volume of a gas mixture is performed to study changes in the composition of the detonation products, determine the boundaries of applicability of the model of a mixture in chemical equilibrium, and verify the sufficient condition of the applicability of the model of a chemical-equilibrium mixture proved earlier. The results on the limits of applicability of the model of a chemical-equilibrium mixture obtained earlier using an approximate method are confirmed.     

A synchronization system of very low-frequency interferometers

A solution to the problem of synchronization of spaced autonomous data-acquisition systems and obtaining stable reference-frequency signals for measuring phases of very low-frequency (VLF) radio signals is described. The expediency of using GPS receivers and tunable crystal oscillators in the synchronization system of VLF interferometers is grounded. Measurement results of the phase stability of the reference signal, received from the designed device, are presented. The short-term frequency stability of a 200-kHz pulse signal at the output of the designed unit is no more than 1.5 × 10^?7, allowing one to measure the phase of VLF signals with an accuracy of no worse than ±0.81°.