scholarly journals Investigation of the influence of electrochemical action on the recovery of hematite in the composition of oxidized ferrous quartzites

2019 ◽  
Vol 1 (1) ◽  
pp. 71-76
Author(s):  
Myanovska Ya ◽  
Kamkina L ◽  
Ivaschenko V ◽  
Ankudinov R ◽  
Dvorkovyy O

The purpose of the work is to develop methods for the treatment of oxidized quartzite, using methods of electochemical effects on hematite grains, converting it into magnetite for further magnetic separation. In laboratory conditions, the basic parameters of the process of recovery of hematite component of oxidized quartzite in aqueous suspension to magnetite with its magnetic properties have been established. When conducting the process of recovery of hematite to magnetite, the possibility of replacement of high-alkaline electrolytes with neutral salts formed by solutions has been established.The influence of structural features of experimental reactors on the recovery of hematite to magnetite has been developed and analyzed; the ability of membrane materials to effectively separate the anolytic and catholic spaces; the influence of electrode materials - anode and cathode, on the magnetization process; electrical parameters of electrical influence on the course of the process; composition of the electrolyte in the process of magnetization. The fiberglass membrane was shown to have a better ability to separate the anolytic and katholyte; maximum degrees of magnetization obtained when using electrodes from low carbon steels; optimal values of the degree of recovery of hematite in laboratory conditions were obtained at 15-25 V and 2.0-4.0 A. The thermodynamic possibility and realization of the processes of reduction of oxidized ores in aqueous solutions of electrolytes at low temperatures with obtaining the magnetic phase are shown. For electrolysis, high alkaline electrolytes can be replaced by electrolytes based on chloride and sulfate salts. The best results are obtained using NH4Cl ammonium chloride.

Author(s):  
J. Y. Koo ◽  
G. Thomas

High resolution electron microscopy has been shown to give new information on defects(1) and phase transformations in solids (2,3). In a continuing program of lattice fringe imaging of alloys, we have applied this technique to the martensitic transformation in steels in order to characterize the atomic environments near twin, lath and αmartensite boundaries. This paper describes current progress in this program.Figures A and B show lattice image and conventional bright field image of the same area of a duplex Fe/2Si/0.1C steel described elsewhere(4). The microstructure consists of internally twinned martensite (M) embedded in a ferrite matrix (F). Use of the 2-beam tilted illumination technique incorporating a twin reflection produced {110} fringes across the microtwins.


Author(s):  
F. A. Khalid ◽  
D. V. Edmonds

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.


Alloy Digest ◽  
1977 ◽  
Vol 26 (3) ◽  

Abstract FROSTLINE is a fine-grain, columbium-treated carbon steel designed to be an economical solution to structural design requirements at cold temperatures. Available in plate thicknesses up to 6 inches, it offers high levels of toughness at temperatures to 80 F and higher strength levels than conventional carbon steels. Frostline also offers excellent welding characteristics, because of its low carbon equivalent. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: CS-67. Producer or source: Lukens Steel Company.


Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  

Abstract MITTAL DI-FORM T700 and HF80Y100T are low-carbon steels with a manganese and silicon composition. Dual-phase (DP) steels are one of the important advanced high-strength steel (AHSS) products developed for the automotive industry. Their microstructure typically consists of a soft ferrite phase with dispersed islands of a hard martensite phase. The martensite phase is substantially stronger than the ferrite phase. The DI-FORM grades exhibit low yield-to-tensile strengths, and the numeric designation in the name corresponds to the tensile strength. This datasheet provides information on microstructure and tensile properties as well as deformation and fatigue. It also includes information on forming. Filing Code: SA-561. Producer or source: Mittal Steel USA Flat Products.


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