scholarly journals CHROMITE CONTENT OF THE PERMIAN-JURASSIC DEPOSITS OF THE VOLGA-URAL BASIN

2021 ◽  
Author(s):  
A.V. Lalomov ◽  
◽  
I.R. Rakhimov ◽  
A.V. Grigorieva ◽  
Sh.R. Zailyamov ◽  
...  
Keyword(s):  
Chromium Content ◽  
The Urals ◽  
High Chromium ◽  
East European ◽  
Economic Significance ◽  
Chromite Concentrate

The chromite content of the Permian and Jurassic deposits of the East European platform’s Eastern part, adjacent to the Urals - the Lukoyanovskoye field and the Sabantuy occurrence, has been established. The economic significance of the Lukoyanovskoe placer chromites is justified by the technology of extracting chromite concentrate, and the Sabantuy paleoplacer has good prospects because of high chromium content in the ore (Cr2O3 15–17 wt%).

scholarly journals Improving the Quality of Ferruginous Chromite Concentrates Via Physical Separation Methods

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 667 ◽  
Author(s):  
Sunil Tripathy ◽  
Y Murthy ◽  
Veerendra Singh ◽  
Saeed Farrokhpay ◽  
Lev Filippov
Keyword(s):  
Magnetic Separation ◽  
Chromium Content ◽  
Detailed Characterization ◽  
Physical Separation ◽  
Chromite Ore ◽  
Chromite Concentrate ◽  
Automated Mineralogy ◽  
Characterization Studies

The low chromium-to-iron ratio of chromite ores is an important issue in some chromite deposits. The value of the chromite ore is indeed dictated in the market by its iron, as well as its chromium content. In the present study, a chromite concentrate was reprocessed by gravity (spiral concentrator) and magnetic separation to enhance the chromium-to-iron ratio. Also, detailed characterization studies including automated mineralogy were carried out to better understand the nature of the samples. Enhancing the chromium-to-iron ratio was achieved by using advanced spiral separators which will be discussed in this paper.

A Devonian >2000-km-long dolerite dyke swarm-belt and associated basalts along the Urals-Novozemelian fold-belt: part of an East-European (Baltica) LIP tracing the Tuzo Superswell

GFF ◽  
2016 ◽  
Vol 138 (1) ◽  
pp. 6-16 ◽  
Author(s):  
Victor Puchkov ◽  
Richard E. Ernst ◽  
Michael A. Hamilton ◽  
Ulf Söderlund ◽  
Nina Sergeeva
Keyword(s):  
Dyke Swarm ◽  
Fold Belt ◽  
The Urals ◽  
Dolerite Dyke ◽  
East European

scholarly journals Reactivity of Low-Grade Chromite Concentrates towards Chlorinating Atmospheres

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4470
Author(s):  
Ndue Kanari ◽  
Eric Allain ◽  
Lev Filippov ◽  
Seit Shallari ◽  
Frédéric Diot ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Thermal Behavior ◽  
Gas Phase ◽  
Low Grade ◽  
Bearing Material ◽  
High Chromium ◽  
Chromyl Chloride ◽  
Chromite Concentrate ◽  
Iron Chromium

The most economically important iron-chromium bearing minerals is chromite. In natural deposits, iron(II) is frequently substituted by magnesium(II) while chromium(III) is replaced by aluminum(III) and/or iron(III) forming a complex chromium bearing material. The majority of mined chromite is intended for the production of ferrochrome which requires a chromite concentrate with high chromium-to-iron ratio. Found mostly in the spinel chromite structure, iron cannot be removed by physical mineral processing methods. In this frame, the present work deals with the reaction of chlorine and chlorine+oxygen with selected samples of chromite concentrates for assessing the reactivity of their components towards chlorinating atmosphere, allowing the preferential removal of iron, hence meeting the chromite metallurgical grade requirements. Isothermal thermogravimetric analysis was used as a reliable approach for the kinetic reactivity investigation. Results indicated a wide difference in the thermal behavior of chromite constituents in a chlorinating atmosphere when considering their respective values of apparent activation energy oscillating from about 60 to 300 kJ/mol as a function of the sample reacted fraction. During the chromite treatment by chlorine in presence of oxygen, chromium was recovered as liquid chromyl chloride by condensation of the reaction gas phase.

Mechanism of High Temperature Embrittlement and Loss of Corrosion Resistance in AISI Type 446 Stainless Steel

CORROSION ◽  
1971 ◽  
Vol 27 (12) ◽  
pp. 531-544 ◽  
Author(s):  
J. J. DEMO
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Material Properties ◽  
Chromium Content ◽  
Raw Material ◽  
Construction Work ◽  
Ferritic Alloys ◽  
High Chromium ◽  
Aisi Type ◽  
Resistance To Stress

Abstract The ferritic alloys, particularly AISI Type 446 steel with its high chromium content, have desirable properties of corrosion resistance, low raw material cost, and resistance to stress corrosion cracking (SCC); yet they are not widely used in construction work because of the damaging effects of high temperature exposures (such as welding) on their corrosion resistance and ductility. This work describes the causes for their loss of corrosion resistance and ductility, and defines changes in composition and heat treatment that would improve their material properties.

Effective Extraction of Vanadium and Chromium from High Chromium Content Vanadium Slag by Sodium Roasting and Water Leaching

2016 ◽  
Vol 863 ◽  
pp. 144-148 ◽  
Author(s):  
Ming Li ◽  
Liang Xiao ◽  
Jing Jing Liu ◽  
Zhi Xin Shi ◽  
Zi Bi Fu ◽  
...  
Keyword(s):  
Chromium Content ◽  
Leaching Rate ◽  
Vanadium Slag ◽  
Water Leaching ◽  
Sodium Salts ◽  
High Chromium ◽  
Effective Factor ◽  
Roasting Process ◽  
Roasting Temperature ◽  
Roasting Time

The extraction of vanadium and chromium from high chromium content vanadium slag by salt roasting and water leaching process has been investigated, which uses mixed sodium salts (Na2CO3 and NaOH) as additive agent in roasting process. The mineralogical morphology was prospected by TG-DSC, XRD, SEM and EDS. The oxidation of slag and transversion of V/Cr-containing phase and sodium salts have been discussed. It has been demonstrated that the presence of NaOH contributes to decompose spinel and olivine phases, which is beneficial to reduce the roasting temperature and elevate V, Cr leaching ratio. The roasting parameters have been studied as a function of roasting temperature, roasting time and ratio of alkali, in which the roasting temperature is the most effective factor on the leaching rate of vanadium and chromium. Under the optimum condition, the leaching rates of V and Cr reached 95.8% and 97.6%, respectively.

scholarly journals Features of earthquake epicenters and mineral deposits spatial relationship in the Urals

2021 ◽  
pp. 31-36
Author(s):  
Aleksandr Guliaev ◽  
Keyword(s):  
Spatial Relationship ◽  
Ore Deposits ◽  
Tectonic Activity ◽  
Mineral Deposits ◽  
The Urals ◽  
Ural Mountain ◽  
Tectonic Structures ◽  
The West ◽  
East European ◽  
Modern Era

Introduction. Recent Ural mountain belt is an N-S Paleozoic orogen rejuvenated in the NeogeneQuaternary period. It separates the East European plate located to the west of it and the West Siberian plate located to the east of it. The Uralian orogeny presumably occurred at the Paleozoic time as a result 36 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 4. 2021 ISSN 0536-1028 of these plates interaction, which affected the geologic structure of the region. In the modern era, low tectonic activity in the bowels of the Urals continues supported by rare tangible earthquakes with a magnitude from 2.0–3.0 to 5.0–5.5, 3.0 – 3.5 on the average, and the intensity in the epicenter from 3.0–4.0 to 5.0–6.0 on MSK-64 scale. Research aim is to analyze the spatial relationship of sensible earthquakes epicenters and mineral deposits in the Urals. Research methodology included estimating the position of Ural earthquakes epicenters and mineral deposits relative to the geologic and tectonic structures of Paleozoic time, recent epoch, and the modern era. Research results. Most earthquake epicenters in the Urals are concentrated within the western part of the Uralian Orogeny to the west of the Main Uralian Fault (MUF), while most mineral deposits, especially ore deposits, are concentrated within the eastern part of the Uralian orogeny to the east of MUF. In the axial zone of MUF, earthquake epicenters are close and sometimes coincide. Consequently, the processes of ore deposits and earthquake foci formation are of a similar nature

scholarly journals Upper Devonian brachiopods from the core of the Kurgan-Uspenskaya-1 key borehole (south-western outlying areas of Western Siberia)

LITOSFERA ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 560-573
Author(s):  
A. G. Mizens ◽  
L. I. Mizens
Keyword(s):  
East European Platform ◽  
Western Siberia ◽  
Upper Devonian ◽  
Tectonic Block ◽  
Research Subject ◽  
The South ◽  
The Urals ◽  
East European ◽  
The Core ◽  
Host Rocks

Research subject. Brachiopods from the core of the Kurgan-Uspenskaya-1 parametric borehole. The borehole was drilled in the south of Western Siberia 80 km southeast of the Kurgan town. Brachiopods were collected at a depth of 1,525.4 m in the IV tectonic block (core interval 1,450–1,794 m) in the greenish-gray marls of the Famennian stage of the Upper Devonian.Materials and methods. The paleontological material is presented in the form of complete undamaged shells and individual valves of small- and medium-sized brachiopods. The safety of brachiopods makes it possible to determine their species and genera, sometimes in open nomenclature. The article provides a brief description of the available material.Results. 11 species of brachiopods of the subtype Rhynchonelliformea belonging to six orders and nine genera were identified. The following ten species were described: Orbinaria fallax (Pand.), Semiproductus amplus Bubl., Schuchertella sp., Dalejina? sp., Camarotoechia panderi (Sem.et Moell.), C. volucera Nal., Athyris tobolica Nal., Cleiothyridina tenuilineata (Row.), Cl. ex gr. pectinata (Sem. et Moell.), Retzia? sp. The presented information allows conclusions about the age of the sediments enclosing the brachiopods under study and expands the existing knowledge of both the composition of the Upper Famennian brachiopods of the basement of the south of Western Siberia and their geographical and stratigraphic distribution.Conclusion. An analysis of the stratigraphic distribution of the described brachiopods taking into account data on foraminifera allowed us to determine the age of the host rocks as the very top of the Famennian stage. The composition of the brachiopods allows these rocks to be correlated with coeval deposits of the East European Platform, Timan, the Urals, Kuzbass, the Gorny Altai, Kazakhstan and North America.

scholarly journals A Step by Step Investigation of Cr(III) Recovery from Tannery Waste

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 1
Author(s):  
Evgenios Kokkinos ◽  
Anastasios Zouboulis
Keyword(s):  
Hazardous Waste ◽  
Circular Economy ◽  
Chromium Content ◽  
Chemical Characterization ◽  
High Chromium ◽  
Tannery Waste ◽  
Physical Chemical

The effluent of tanneries is a hazardous waste and a combination of physical-chemical and biological techniques is required for its treatment. As a result of the previous processes, a sludge with high chromium content is produced. So, the aim of this study is the hydrometallurgical recovery of chromium in the context of a circular economy. According to chemical characterization, the only form of metal that existed in the sludge was the trivalent, while its content was up to 14.8% w/w. Among the examined acids, the highest efficiency in Cr(III) leaching was achieved by the H2SO4 (93%), due to the formation of the soluble CrSO4+. Regarding the step of precipitation, no significant varions were observed between the two alkaline medias that were tested, namely NaOH and Ca(OH)2.

NICROFER 6030

Alloy Digest ◽  
1996 ◽  
Vol 45 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Chromium Content ◽  
Iron Alloy ◽  
Heat Treating ◽  
High Chromium ◽  
Nickel Chromium ◽  
Alloy 690 ◽  
Nuclear Systems

Abstract Nicrofer 6030 (alloy 690) is a nickel-chromium-iron-alloy with high chromium content (30%) to resist both oxidizing environments and primary and secondary water in PWR nuclear systems. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-513. Producer or source: VDM Technologies Corporation.

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