Synthesis of a Composite Alloy Based on Ore Concentrate and Oxide Compounds

The conditions for the synthesis of Al-Cr-W alloys during the aluminothermic reduction of a mineral tungsten concentrate - scheelite were considered. The alloys were identified as an aluminum matrix by the methods of elemental and X-ray phase analyzes. It is shown that the alloy synthesized from scheelite concentrate contains small amounts of iron and oxygen impurities (1.2 wt. %). It has been established that the alloys have a composite structure: inclusions of continuously solid solutions based on chromium and tungsten, as well as chromium aluminides Al3(Cr, W, Fe)2, which have increased microhardness values (12.9 GPa) are distributed in the aluminum matrix.

Flotation of Vostok-2 skarn scheelite sulphide ore with modifiers

This paper describes the results of a study that looked at different reagent regimes of flotation of scheelite skarn ores with soda, sodium bicarbonate and sodium sulphide. According to published research data, these regimes of selective recovery scheelite from Skarn ores of Portuguese and Chinese deposits as an alternative to Petrov method. The results of studying the changes of the optical density of water glass in mixing with soda, sodium bicarbonate and sodium hydroxide at different temperatures are presented. Gelation of water glass is observed in a mixture of soda or sodium bicarbonate. The authors were studied the floatability of calcium minerals of scheelite sulphide ore by combined depressants (water glass and sodium sulphide), their dose (0–11.4 kg/t) and proportions (0.7 to 8), as well as the duration of conditioning at the Laboratory of Primorsky Concentrating Plant (PCP). In the course of research, it was established that a high dose of soda and sodium bicarbonate in the scheelite rougher flotation cycle determines a 2- to 6-times higher yield of rough scheelite concentrate with a 1.8-times lower WO3 enrichment ratio. A rise in the water dose to 1.4 kg/t in the rougher flotation cycle led to the recovery of scheelite falling to 30.4–41%, with the WO3 concentrate quality being 22.78–50.5%, corres pondingly. No commercial quality was reached when scheelite concentrate was subjected to heat treatment in a sodium sulphide (43–62 kg/t) and alkaline environment (рН 13) without water glass. Addition of 3.3 kg/t of water glass to sodium sulphide helped raise the quality of scheelite concentrate after three cleaner flotation to 54% WO3 and the recovery of scheelite was 68.4% only. A recovery of more than 82% of commercial grade scheelite concentrate (WO3 > 50%) was reached when running in standard mode using Petrov method of heat treatment. Application of the above processes, which demonstrated high performance in relation to scheelite ores taken from Skarn deposits of Portuguese and Chinese, to samples of Skarn scheelite sulphide ores from Far Eastern deposits, did not prove successful. The authors would like to thank the Research Laboratory of PCP for support with lab studies.

Alloying working surface during electroslag surfacing

Parts subject to intense abrasive wear have a short service life. In the manufacture or restoration of such parts by electroslag surfacing, strengthening of the deposited metal is required. The use of ready-made alloying powders in surfacing increases the cost of the finished part, which necessitates the search for cheaper materials for alloying the parts being welded. The study of the efficiency of alloying the deposited metal through the melted insert, as well as by direct introduction of alloying powders into the slag bath has been carried out. Mixtures based on enriched mineral scheelite concentrate and graphite are used as alloying powders

Laboratory Testing of Scheelite Flotation from Raw Ore in Sangdong Mine for Process Development

Tungsten is an essential metal for the manufacture of special alloys, which is in constant demand due to the development of the industry. The recovery of scheelite from undeveloped tungsten ore in South Korea was investigated to improve the flotation performance for high grade and recovery of concentrate. To investigate the interaction between the flotation reagents and the minerals, the adsorption experiments of oleic acid as a collector on Ca-bearing minerals, such as scheelite, calcite, and fluorite were carried out. This reaction was confirmed chemical adsorption by analysis of zeta potential and FTIR analysis. The batch test was performed using a raw ore to enhance the grade and recovery of the scheelite concentrate. It was obtained at the optimal conditions for high WO3 grade and recovery of scheelite concentrate by using a simple process. In particular, the sodium carbonate used as a pH modifier was investigated to increase scheelite flotation performance by supporting the selective depression of Ca-bearing gangue minerals. Furthermore, a locked cycle test (LCT) was carried out based on batch test results for the design of a continuous pilot plant.

Research on modeling the technology of processing anthropogenic old tailings of Primorsky Concentrating Factory

The possibility of processing old tailings of the Primorsky Concentrating Factory (PCF) has been assessed. The average mass fraction of WO3 is 0.08%, Cu is 0.052%, the average content of Au is 0.38 ppm, Ag is 1.1 ppm. The grain size of scheelite and chalcopyrite is from 0.03 mm and below. Basically, intergrowths of scheelite are in quartz, less often is in pyroxene, chalcopyrite is in pyrrhotite, less often is in quartz. The results of experimental studies of the washability of secondary mineral material using flotation and gravity beneficiation methods are presented. The possibility of intensifying the flotation process of concentration using a Pneuflot® flotation machine was investigated. The recovery of scheelite at the same degree of concentration using a Pneuflot® flotation machine is 16.5% higher compared to the standard mechanical flotation machine, mainly due to the more efficient flotation (1.5 times) of sludge (-15+0 μm). Flotation of the sand fraction of old tailings (SFOT) in a Pneuflot® flotation machine showed an opportunity of scheelite recovery into enriched concentrate of rough flotation from -44+15 microns material by 82%, and -15+0 microns (from sludge) by 75% of those classes, the case being for the mechanical machine (volume 3 l) – 77% and 49% of those classes, respectively. The content of the obtained flotation concentrate corresponds to the quality of the feed of rough scheelite flotation at PCF (at a concentration degree of 8.5 in the enriched product, the scheelite recovery was 69%), enabling to integrate it to the technological scheme of PFC. According to the combined gravity-flotation concentration scheme, a conditioned scheelite concentrate with a mass fraction of 70.9% WO3 was obtained, throughout recovery being 57.3%.