Production Of Manganese Ferroalloys Research Articles

Numerical simulation of gas-solid heat transfer and moisture evaporation process in preheating shaft kiln for ferromagnesium pellets

The arc furnace is an important equipment in the production of manganese ferroalloys. In the smelting process, it produces high temperature flue gas above 700 K, which has high utilization value. During the pelleting process, moisture exists on the surface and inside of the pellets, which, if directly fed into the arc furnace, will lower the temperature of the furnace, affecting the production, and will also cause the pellets to burst, resulting in pressure fluctuations in the furnace and other hazards. The preheating shaft kiln reduces the moisture content of the pellet while preheating the pellet by utilizing high temperature flue gas. In this paper, through the establishment of porous media and shrinking core coupling mathematical model, to achieve the prediction of the heating and drying process of the pellets of various particle sizes, which is in good agreement with the production monitoring data. The results show that 9~11 mm pellets have the best preheating effect in terms of tail gas temperature, pellet temperature and preheating time.

Replacing Coke with Noncaking Coal in the Production of Manganese Ferroalloys

Replacing Coke with Noncaking Coal in the Production of Manganese Ferroalloys

Method to determine the decrepitation index of South African manganese ores when heating in a rotary kiln

Manganese ores are the major raw materials utilized in the production of manganese ferroalloys. Decrepitation, which is described as the breakage or disintegration of the ore particles upon heating in a rotary kiln, is an important quality parameter of these ores. The Decrepitation Index (DI), the parameter used to describe the extent of decrepitation, is described as the ratio of the mass of particles <6 mm after pre-heating to the total mass of the sample. After a rigorous review of literature, it was found that the procedure to determine DI of manganese ores in rotary kiln does not exist. This necessitated the development of a method to determine the DI of manganese ores when pre-heated in a rotary kiln. The method was developed through the following steps•The method from the ISO standard 8371 to determine the DI of iron ores in a muffle furnace was studied and the method developed was based on the method.•A literature review on the decrepitation of ores and the factors that cause fines generation during a tumbling test.The method developed can be used to investigate the effect of temperature, rotational speed and size range on the DI of South African manganese ores.

Reaction Rate Analysis of Manganese Ore Prereduction in CO-CO2 Atmosphere

Variations in energy efficiency and climate gas emissions in production of manganese ferroalloys are largely related to the solid-state reduction of the manganese ores used as raw material in the production. The gas-solid reduction is known to be dependent on the ore characteristics, making information on the factors governing the kinetics crucial. A reaction rate analysis of thermogravimetric data obtained for the reduction of Comilog and Nchwaning manganese ores in CO-CO2 atmosphere was performed. Experimental variables were CO partial pressure, ore particle size, temperature regimes (isothermal/non-isothermal), as well as heating rate for non-isothermal experiments. The effects of particle size, CO-concentration, and temperature on the reaction rates were quantified. It was found that the reduction rate of both ores was proportional to the inverse average particle size. Different sensitivities towards the CO-concentration in the gas feed was determined, where the rate of Comilog-ore was proportional to p_{text{CO}}^{0.7} , and Nchwaning to p_{text{CO}}^{1.5} . The activation energy of Comilog ore was estimated to be 17 kJ/mol, whereas 63 kJ/mol was found for Nchwaning ore.

Problem of manganese in Russian metallurgy

Ferrous metallurgical industry is the main consumer of m nese. The production volume of manganese ferroalloys in the world is approximately 1 % of steel production. After the collapse of the Soviet Union, Russian Federation found itself without any manganese ore base. At present, only high-carbon ferromanganese and ferrosilicomanganese are smelted from imported ore in Russia in a limited quantity. The mineral and raw base of manganese ores in Russia is quite large: the balance reserves of manganese ores are about 230 million tons (approximately 2 % of the world), forecast resources – more than 1 billion tons. Quality of the manganese ores is lower than the manganese ores of most major producing countries. Average manganese content in Russian ores is 9 – 23 %. Basis of mineral and raw base of these manganese ores are carbonate ores, share of which is more than 77 %. Manganese ore mining in Russia is sporadic and does not exceed 66 thousand tons per year. Demand of Russian ferroalloy plants, producing manganese ferroalloys, in manganese ores and concentrates is covered by imports. The problem of accelerating the creation of domestic manganese ore base from the position of economic security seems to be very important. It is necessary to solve a number of issues related to the enrichment of poor manganese ores, development of effective technologies for manganese ferroalloys smelting from concentrates obtained after the enrichment of these ores, as well as creation of more advanced methods of manganese concentrates dephosphorization. In the production of manganese ferroalloys from ore to finished alloys, about 50 % of manganese mined from the subsoil is lost; a large number of by-products are formed (sludges of enrichment, slags, screenings of small fractions of ore raw materials and finished products, sludges of smelting process and dust). The use and processing of them allow not only to reduce the consumption of initial mineral raw materials, but also to increase the efficiency of main production and to reduce environmental pollution. Additional extraction of manganese from industrial wastes and improvement of the technological processes for manganese ferroalloys smelting are the ways to increase the through extraction of manganese.

The Problem of Phosphorus in the Production of Manganese Ferroalloys

Ferrous metallurgy is the main consumer of manganese. The mineral resource base of manganese ores in Russia is quite extensive: the reserve of manganese ores amounts to 283.7 million tons (~2% of the world’s), and the expected reserves amounting to more than 1 billion tons. The quality of manganese ores in Russia is lower than that of manganese ores in most major producing countries. The average manganese content in Russian ores ranges from 9 to 23%. The Russian domestic manganese ores contain an increased amount of hazardous impurities, which are primarily phosphorus (from 0.2 to 0.8%). To involve domestic manganese ores into production, it is necessary to develop perfect methods for dephosphorizing manganese concentrates. Studies regarding a novel method for the dephosphorization of manganese-containing products are underway. In order to eliminate the manganese loss together with associated metal, as occurring in the case of the currently used dephosphorization method, this method consists in phosphorus reduction from the oxide melt by using gaseous carbon monoxide CO blown through the oxide manganese-containing melt, rather than using solid carbon. A novel process has been developed for smelting high-carbon ferromanganese and ferrosilicomanganese based on manganese concentrates with an increased phosphorus content. The process is carried out in a two-zone furnace equipped with a third zone intended for dephosphorization. Exhaust gases from the reduction zone containing 80–85% of carbon monoxide serve as the source of carbon monoxide required for performing dephosphorization. Methods have also been developed intended for smelting medium-carbon and low-carbon ferromanganese, as well as metallic manganese. These methods are based on a similar way for the phosphorus reduction from the oxide melt.

Manganese Problem in Russian Metallurgy

The main manganese consumer is ferrous metallurgy. The global volume of manganese ferroalloys production is ~1% of the volume of steel production. After the collapse of the Soviet Union, Russia was cut off from a manganese ore base. Currently, only high-carbon ferromanganese and ferrosilicomanganese are smelted in Russia from imported ore in a limited amount. The mineral resource base of manganese ores in Russia is quite large: the balance reserves of manganese ores are about 230 million tons (~2% of the world), the projected resources are more than 1 billion tons. The quality of the manganese ores in Russia is lower than that of manganese ores in most of the main producing countries. The average manganese content in Russian ores is 9–23%. The mineral resource base of the manganese ores is made up of carbonate ores, which account for more than 77%. Recovery of manganese ores in Russia is carried out irregularly and does not exceed 66 thousand tons/year. The demand of Russian ferroalloy plants producing manganese ferroalloys for manganese ores and concentrates is covered by imports. The acceleration of the creation of the domestic manganese ore base from the standpoint of economic security is quite a pressing issue. It is necessary to solve a number of issues related to the following: the treatment of poor manganese ores, the development of effective technologies for smelting manganese ferroalloys from concentrates obtained after the treatment of these ores, as well as the creation of more advanced methods for dephosphorization of manganese concentrates. In the production of manganese ferroalloys from ore to finished alloys, about 50% of manganese extracted from the subsoil is lost, a large amount of by-products is formed (treatment sludge, slags, screenings of fine fractions of ore raw materials and finished products, sludge from the smelting process and dust), its utilization makes it possible not only to reduce the consumption of raw mineral materials, but also to increase the efficiency of the main production, as well as to reduce environmental pollution. Additional recovery of manganese from industrial waste and improvement of technological processes for smelting manganese ferroalloys are ways to increase the through manganese recovery.

Utilization of Manganese in Russian Metallurgy

Abstract—Although Russia has considerable reserves of manganese, the quality of its manganese ore is relatively poor. (Its mean Mn content is 9–23%, with a high content of harmful impurities, primarily phosphorus). In terms of economic security, it is essential to create a Russian source of manganese. This entails enrichment of the lean manganese ore; the development of effective technology for producing manganese ferroalloys from the resulting concentrates; and improved methods of removing phosphorus from manganese concentrates. In the production of manganese ferroalloys from ore, about 50% of the manganese is lost. Numerous byproducts are formed in this process. The processing of such byproducts not only reduces the demand for the initial ore but also increases the efficiency of ore processing and decreases the environmental impact.

Fume Formation from Oxidation of Liquid SiMn Alloy

Thermally generated fumes from the production of manganese ferroalloys are mostly composed of metallic oxides generated due to reaction between high-temperature molten metal and ambient oxygen in the air. In the current study, the fume characteristics (particle morphology, compositions and particle size distribution) from the exposure of a SiMn alloy under an impinging air jet, in the temperature range 1400–1700 °C, were experimentally investigated. Combinations of manganese- and manganese/silicon oxide particles were found in the system, displaying both crystalline and amorphous structures. The governing generation mechanisms of fume from both a thermodynamic and a kinetic perspective are discussed.

Improving manganese utilization in the production of manganese ferroalloys

To extract manganese from the tailings slag produced in the furnace smelting of manganese with silicon, a possible approach is to reduce the slag by means of melts of iron, high-carbon ferromanganese, or ferrosilicomanganese. Thermodynamic analysis of this process is undertaken. The reaction of these melts with the slag is also studied experimentally. It is found that the reduction of manganese from such slag by carbon from hot metal is promising for practical purposes. Hence, the overall extraction of manganese may be increased if the tailings slag from furnace smelting of manganese is used to alloy hot metal with manganese.

Carbon reductants for the production of manganese ferroalloys

Carbon reductants for the production of manganese ferroalloys

Computer simulation of equilibrium relations in managanese ferroalloy production

The complex heterogeneous equilibria associated with the production of manganese ferroalloys have been simulated using recently developed thermochemical databases. Over 600 measured equilibrium data have been used to verify and calibrate the model calculations. Good agreement is obtained for many important technical relations such as carbon solubility, equilibrium diagrams and phase relations, and element distribution as a function of temperature and composition. Experimental slag/metal and slag/metal/gas equilibria in MnO-SiO2 binary, MnO-SiO2-CaO and MnO-SiO2-Al2O3 ternary, MnO-SiO2-CaO-Al2O3 quaternary, and MnO-SiO2-CaO-Al2O3-MgO quinary systems can be reproduced within experimental uncertainties. The influence of temperature, CO partial pressure, and slag chemistry on the Mn- and Si-distribution equilibria has been quantitatively evaluated. This leads to a sound basis for optimizing the manganese ferroalloy production processes.

Reaction equilibria in the production of manganese ferroalloys

A laboratory investigation has been carried out to determine slag/metal and slag/metal/gas equilibria relevant to production of manganese ferroalloys. The metal phase was normally composed of MnSi-Csat alloys, but in some experiments, the alloys contained up to 15 wt pct Fe. Different slag systems were used: MnO-SiO2, MnO-SiO2-CaO, MnO-SiO2-Al2O3, and quaternary MnO-SiO2-CaO-Al2O3 with fixed CaO/Al2O3 weight ratios of 1.5 and 3. The experiments were normally made in CO gas atmosphere at temperatures ranging from 1450 °C to 1600 °C. The results give comprehensive information about equilibrium relations.Partial andcomplete equilibria are illustrated in equilibrium diagrams. Partial equilibrium is a situation in which equilibrium is established with respect to certain variables but not to others, in this case, between slag and metal but not with the gas phase. The effect of temperature was found to be of minor importance for the partial slag/metal equilibrium, whereas the complete slag/metal/gas equilibrium is considerably influenced by both temperature and CO pressure. As expected, increasing temperature and decreasing CO pressure will reduce the equilibrium MnO content of slags. The influence of alumina addition to the slag phase and of iron to the metal phase is also discussed.

A decision support system for the integrated production of manganese ferro alloys : G.R. Mateus, A.M.M. Almeida, pp 219–227

A decision support system for the integrated production of manganese ferro alloys : G.R. Mateus, A.M.M. Almeida, pp 219–227

A Decision Support System for the Integrated Production of Manganese Ferro Alloys

Abstract The manganese ferro alloys are basic raw materials for steelmaking. A nonlinear model for the production of manganese sinter, high-carbon ferromanganese and silicomanganese is proposed. The model is solved by three different approaches: nonlinear methods, constraint linearization and a heuristic composed of three linear subproblems. Their Computational implelnentation, the results obtained and their influence on management and process control are discussed. Based on the results we present a simplified design for a decision support system.