Interaction of tricalcium phosphate with products of carbothermic reduction of silicon oxide

The article presents the research results on the interaction of tricalcium phosphate with the products of carbothermic reduction of silicon oxide (SiOg, SiC, iron silicides). The research was carried out by computer thermodynamic modeling using the HSC-6.0 software package. It was established that SiOg, Si, and SiC are highly reactive towards tricalcium phosphate at relatively low temperatures. It was found that, according to the formation degree of gaseous phosphorus from Ca3 (PO4)2, silicon-containing reducing agents form a decreasing series: (SiOg, Si)>SiC>FeSi2>FeSi

Electrothermal co-production of ferrosilicon, calcium carbide and gaseous phosphorus from the chilisay phosphorite

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated

Electrothermal co-production of ferrosilicon, calcium carbide and gaseous phosphorus from the chilisay phosphorite

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated

Interaction of tricalcium phosphate with products of carbothermic reduction of silicon oxide

The article presents the research results on the interaction of tricalcium phosphate with the products of carbothermic reduction of silicon oxide (SiOg, SiC, iron silicides). The research was carried out by computer thermodynamic modeling using the HSC-6.0 software package. It was established that SiOg, Si, and SiC are highly reactive towards tricalcium phosphate at relatively low temperatures. It was found that, according to the formation degree of gaseous phosphorus from Ca3 (PO4)2, silicon-containing reducing agents form a decreasing series: (SiOg, Si)>SiC>FeSi2>FeSi

Complete thermodynamic analysis of the interaction of iron phosphate (FePO4) with hydrogen (H2) and carbon monoxide (CO)

Iron phosphate in the composition of concentrate is a fairly strong chemical compound. However, with the help of gaseous substances, such complex compounds decompose when heated to the required temperature, which contributes to the reduction of not only iron, but also phosphorus. Hydrogen and carbon monoxide were used as gaseous reducing agents. This article describes in detail the thermodynamic analysis of the reduction of phosphorus from iron phosphate, its interaction with hydrogen and carbon monoxide

Thermodynamic interaction of concentrate, sludge and mill scale from carbon

Due to the gradual depletion of reserves of a number of natural minerals, on the one hand, and the accumulation of a huge amount of waste containing valuable useful components, on the other, the problem of developing so-called man-made deposits is becoming increasingly urgent. Of particular interest are currently man-made deposits formed or being formed on the territory of the objects of placement of man-made waste of the metallurgical complex, including the preparation of raw materials (mining, processing, agglomeration, etc.), directly metallurgical processing and related production. The downward trend in iron ore reserves makes it particularly relevant to process manmade waste from ferrous metallurgy in order to obtain man-made iron ore raw materials

Thermodynamic interaction of concentrate, sludge and mill scale from carbon

Due to the gradual depletion of reserves of a number of natural minerals, on the one hand, and the accumulation of a huge amount of waste containing valuable useful components, on the other, the problem of developing so-called man-made deposits is becoming increasingly urgent. Of particular interest are currently man-made deposits formed or being formed on the territory of the objects of placement of man-made waste of the metallurgical complex, including the preparation of raw materials (mining, processing, agglomeration, etc.), directly metallurgical processing and related production. The downward trend in iron ore reserves makes it particularly relevant to process manmade waste from ferrous metallurgy in order to obtain man-made iron ore raw materials

Towards a Better Understanding of the Chemical Reactions Between Iron Carbide and Silicon Carbide

This article contains the research results of the equilibrium interaction of iron carbide (Fe3C) with silicon carbide (SiC) in a temperature interval of 700-2000 K with the formation of iron silicides (Fe3Si, Fe5Si3, FeSi, FeSi2 ), by using the program of the Finnish metallurgical company Outokumpy HSC Chemistryj-5.1 for  Windows with regard to the electrothermal production of ferrosilicium from siliceous and carboncontaining raw materials. On the basis of the received regression equations connecting the Gibbs energy change with the temperature and the silicon content in a ferroalloy, the response surfaces (change of the Gibbs free energy - ∆GT0) and their horizontal sections for three groups of ferroalloys were constructed with the program Mathcad. The silicon content in the first group of alloys is 14.3-23%, in the second group of alloys – 23-33.3% and in the third group of alloys – 33.3-42.8%. It was established, that the reactions between Fe3C and SiC with the formation of iron silicides in the range of temperatures 700-2000 K are possible, and the probability of these reactions increases with increasing the mole ratio Fe3C/SiC from 0.166 to 1.0. As a result of the reactions the low-silicon ferrosilicium can be obtained, answering to a grade FS20 with Si content from 19 to 27% and consisting of a mixture of Fe3Si and Fe5Si3, and also the ferrosilicium corresponding to a grade FS25 with a Si content from 23 to 29% and consisting of a mixture of Fe5Si3 and FeSi. It was found, that at the technological temperature of 1900-2000 K the maximum Si content in the received ferrosilicium can’t be more than 37.7-38.8%. Production of the medium-silicon and the high-silicon ferrosilicium answering to grades FS45- FS90 from the Fe3C-SiC mixture is impossible from a thermodynamic point of view. The received information extends our knowledge about the iron silicides formation during the electrothermal production of ferrosilicium with a silicon content in the alloy from 19 to 90%

"MARKS" SMALL AVIATION-ROCKET SPACE LAUNCH SYSTEM

The problems of delivery of small space vehicles into low earth orbits are pointed out. The up-to-date means for the ascent of small space vehicles into low earth orbits are analysed. The solution for responsive and economical ascent of small space vehicles into low earth orbits in the form of "MARKS" small aviationrocket space launch system is offered. Implementation of the offered idea will provide the price of delivery of 1 kg payload into 500 km sun-synchronous orbit equal to 3750 US dollars

Study of the Chemical Interactions Between Iron Phosphides and Iron Silicides

This article contains the research results of the thermodynamic modeling of interaction of iron phosphides Fe2P and FeP with FeSi2, obtained by a method of the total thermodynamic analysis on the basis of the program HSC-5.1 of the Finnish metallurgical company Outokumpu, developed on both a principle of the Gibbs energy minimization, and also kinetics of the phosphorus release by ferrosilicon from the electrothermal ferrophosphorus – a by-product of the yellow phosphorus production. It was found, that temperature of the beginning of the phosphorus formation in systems iron phosphides – FeSi2 depends on a mole ratio of phosphorus in the phosphides. At the increasing this ratio from 33.3 to 50%, the temperature of the beginning of the phosphorus formation decreases from 1362 K to 1290 K. At lower temperature (773 K) there is the formation of intermediate FeP2 and FeP in a system Fe2P-FeSi2 and intermediate FeP2 in a system FeP-FeSi2, which react with FeSi2 with temperature increasing and form a gaseous phosphorus. The process proceeds in kinetic mode and is characterized by apparent activation energy of 281-389 kJ/mol