Effect of magnesium reduction on the oxygen content of pickling niobium powder

Considering the problem of high oxygen content in industrial niobium powder, the oxygen reduction of high oxygen niobium powder with the addition of magnesium is studied. Based on the thermodynamic analysis of magnesium thermal reduction of niobium powder, the effects of reduction temperature, magnesium addition, reduction time, and reduction atmosphere on the oxygen content of pickling niobium powder are studied. The results show that with an increase in the magnesium addition, the oxygen content of pickling niobium powder gradually decreases to a certain value, and then remains unchanged. In a certain temperature range (953–1203 K), with an increase in the reduction temperature, the oxygen content of pickling niobium powder first decreases, and then increases; the best oxygen content is 356 ppm at 1133 K. With the extension in reduction time (2–6 h), the oxygen content of pickling niobium powder first decreases, and then remains unchanged. Finally, the oxygen content of pickled niobium powder is reduced to approximately 356 ppm at 400% magnesium addition at 1133 K for 4 h.

A modified graphitic carbon nitride (MCN)/Fe3O4 composite as a super electromagnetic wave absorber

The nitrogen content of g-C3N4 was reduced by magnesium thermal reduction to obtain porous C (MCN), and MCN was combined with Fe3O4 particles by decomposition of ferric acetylacetonate.

High-capacity capacitor tantalum powders from production waste

The possibility of producing high-quality high-capacity tantalum powder from certain types of tantalum wastes by their oxidation and subsequent magnesium thermal reduction is discussed. Capacitor powders with a specific charge of 100000—150000 µC·g–1 and leakage current less than 0.001 μA·μC–1 were obtained.

Fabrication of High-Entropy Disilicide Nanopowders via Molten Salt-Assisted Magnesium Thermal Reduction

In this work, (Nb 0.25 Ta 0.25 Ti 0.25 Hf 0.25 )Si 2 high-entropy disilicide nanopowders were successfully fabricated via molten salt-assisted magnesium thermal reduction for the first time. The results showed that the as-obtained nanopowders possessed a single hexagonal structure (TaSi 2 -type) and consisted of numerous nanopowders with an average particle size of 55 nm . These nanopowders exhibited highly compositional uniformity at microscale , but shown the aggregation of Ti element at nanoscale. In addition, a typical template formation mechanism was proposed and analyzed in detailed. This work would provide a new way to synthesis of high-entropy disilicise powders for potential high-temperature harsh environment applications.

Titanium production by magnesium thermal reduction in the electroslag process

Titanium is widely used in specific applications due to its high strength, low density and good chemical stability. Despite it is one of the most abundant elements in the earth’s crust, it is very expensive, because production of pure metallic titanium is very complex. Kroll process is the way how most of the titanium is produced nowadays. Shortages of this process are that it is batch process and it is very energy exhaustive, because titanium sponge material after reduction reaction needs complex post processing to isolate pure titanium. In this work we describe and experimentally investigate technology for Ti production from titanium tetrachloride using combined Kroll and electroslag process. Such process allows to achieve better reaction product separation by molten slag and process can potentially be continuous, thus technological process to produce metallic titanium can be significantly shortened.

Magnesiothermal synthesis and consolidation of multicomponent powder ceramics in the Zr–Si–Mo–B system

The work aims to obtain composite powder ceramics based on ZrB2–ZrSi2–MoSi2 by the self-propagating high-temperature synthesis (SHS) according to the scheme of magnesium thermal reduction from oxide raw materials, as well as its subsequent consolidation by hot pressing (HP). The combustion of the reaction mixtures is characterized by rather high adiabatic temperatures in the range of 2060 to 2120 K and burning rates in the range of 8,3 to 9,4 g/s. The yield of the end product with magnesiothermal reduction is 34–38 %. The resulting powder contains 13–47 % ZrB2, 21–70 % ZrSi2, 2–32 % ZrSi, and 10–18 % MoSi2 depending on the composition of the initial reaction mixture. It is characterized by high structural homogeneity and consists of composite particles of polyhedral shape with an average about 8 microns in size. The structure of ceramics consolidated by the HP method from SHS powder is homogeneous and includes ZrB2 needle grains distributed in a ZrSi2 matrix, MoSi2 inclusions of various morphology and ZrSiO4 silicate, distributed along the grain boundaries of ZrSi2. The samples obtained by HP are characterized by a high degree of homogeneity of the chemical composition and a residual porosity of 2,5–7,4 %.