372595898

EXTRACTIVE METALLURGY, MINING

JPRS-UMS-92-003 16 March 1992

The Problem of Creating an Integrated Technology To Reprocess Platinum-Bearing Chromatites—A New Minerał Ore Containing Platinum Metals

927D0090D Ordzhonikidze IZYESTIYA YYSSHIKH UCHEBNYKH ZA YEDENIY: TSYETNA YA METALLURGIYA in Russian No 2, Apr 91 (manuscript received 21 Aug 90) pp 17-24

[Article by L.V. Razin, T.N. Greyver, O.N. Tikhonov, S.A. Gladkov, and T.A. Kozyreva (deceased), Moscow Geological Prospecting Institute and Leningrad Mining Institute]

UDC 669.23

[Abstract] The authors of the study reported herein worked to develop a profitable technology for integrated reprocessing of platinum-bearing chromatites, which are likely to be the main industrial minerał source of platinum metals in the next 10 to 20 years. As an experimental model they selected laboratory and commercial samples of chromatites from rock masses located in the Aldan craton that are similar to the Ural type. Along with platinum-group elements, the samples were also found to contain smali amounts of gold and silver, up to 0.1-0.3% (by mass) Ni and Cu, up to 0.1-0.2% (by mass) Co, up to 1% Ti and Mn, up to 20% Fe, up to 8% Al, up to 12% Mg, and up to 25% Si. After reviewing existing literaturę on the reprocessing of platinum-containing chromatites, the researchers decided to base their new process on gravitation methods. They developed a process entailing disinte-gration by crushing, followed by sieve separation of the disintegration products by grain size. Both the Fine and coarse fractions were subjected to enrichment on a concentration table, and the coarse fraction was also subjected to magnetic separation and special enrichment. The initial experiments revealed that combining magnetic and gravitation enrichment methods does not result in significant extraction of platinum-group elements into the concentrate. Further experiments were conducted to reflne the new process. On the basis of the studies performed, the authors recommended the following regimen for breaking down chromospine-lide concentrates: temperaturę, 160°C; duration, 4 hours; Cr0₃ flow ratę, 30% of the chromium content in the sample; and grist size, 74 pm. The said process parameters resulted in good recovery of chromium and iron, platinum-group elements, and gold and silver. The noble metals were then concentrated in the form of a rich product that was transferred to an insoluble residue that may in tum be reprocessed at a special enterprisc. The chromium in the process Solutions was extracted in accordance with the standard process. Figures 3, tables 2; references 6: 4 Russian, 2 Western.

Operation of the Nonretum Valve in a Separator for Regenerating Magnetic Fluids

927D0090C Ordzhonikidze IZYESTIYA YYSSHIKH UCHEBNYKH ZA YEDENIY: TSYETNA YA METALLURGIYA in Russian No 2, Apr 91 f (manuscript received 20 Aug 90) pp 14-17

[Article by V.N. Gubarevich and S.V. Vidsota, State Scientific Research and Design Institute of Coal Enrichment Equipment]

UDC 622.778.002.5

[Abstract] A new magnetic separator has been developed for use in recovering the magnetic fluid used in processes of enriching materials in magnetic fluid. The new separator consists of an electromagnetic with polar terminals that form a nonuniform magnetic field. A working chamber is located in the gap between the poles. Mounted to the chamber bottom is a nonretum valve intended to automatically drain the magnetic fluid as it accumulates in the working chamber during the regener-ation process. The nonretum valve is simple in design: It consists of a weight madę of a nonmagnetic materiał connected by a rod to a separator that covcrs the drain linę. In the valve’s working modę, the drain linę is covered by the separator under the effect of the weight. As the emulsion moves along the working chamber, droplets of magnetic fluid are extracted from it under the effect of magnetic force as they accumulate up to the top level of the weight. The weight of the materiał floats up, thus opening the drain linę to allow free drainage of the accumulated magnetic fluid. When the fluid level drops under the effect of the weight through the rod, the separator closes the drain linę once again. The valve’s operation is based on two nearly identical competing forces: the upward-directed Archimedian force of the weight pushing outward and the force of the pressure of the column of magnetic fluid on the upper surface of the separator. The authors of the study reported herein calculate these opposing forces and derive an expression for use in optimizing the new nonretum valve’s design and selecting its geometrie parameters. Figures 3.

An Analytic Method of Calculating the Parameters of the Magnetic Field in the Live Zonę of a Magnetic-Gravitation Separator Based on Permanent Magnets

927D0090B Ordzhonikidze IZYESTIYA YYSSHIKH UCHEBNYKH ZA YEDENIY: TSYETNA YA METALLURGIYA in Russian No 2, Apr 91 (manuscript received 5 Jul 90) pp 5-10

[Article by A.B. Solodenko, Useful Minerals Enrichment Department, Northern Caucuses Mining and Metallurgy Institute]

UDC 622.778.002.5

[Abstract] Calculating the design parameters of a mag-netic-gravitation [MG] separator based on permanent