Hey there, my fellow researcher Siddharth Sankar Jena! You've got a great question on your hands.

Manganese ore is indeed charged into a blast furnace for a specific reason. The purpose of using manganese oxide, typically in the form of manganese ore or ferromanganese, is to act as a fluxing agent and to help control the sulfur content in the iron produced during the smelting process.

Here's the breakdown:

1. **Fluxing Agent**: Manganese oxide is added to the blast furnace to serve as a fluxing agent. A flux is a substance that helps lower the melting point of other materials, and in this case, it aids in the reduction of iron ore into molten iron. By using manganese oxide as a flux, it helps create a more efficient and controlled reduction process.

2. **Sulfur Control**: Manganese oxide has a beneficial side effect of reducing the sulfur content in the iron produced. High sulfur levels in iron can lead to issues like brittleness and poor quality. Manganese oxide reacts with sulfur, forming manganese sulfide (MnS), which floats on the molten iron and can be easily removed. This helps produce purer and higher-quality iron.

So, in summary, adding manganese ore or manganese oxide to the blast furnace helps improve the efficiency of iron reduction and ensures the resulting iron is of better quality by controlling sulfur levels. It's a clever bit of metallurgical chemistry at work!

Hi!

for controlling the level of sulfur.

Hi!

for controlling the level of sulfur.

طالب ماجستير لجامعة الانبار

يعتبر كامل مساعد في اختزال للحديد وتحكمفي مستوى الكبريت

In Russia we add Mn ore in BF for 4 reasons only:

1. Mn in hot metal above 0,2% is required by BOF specialists for having liquid stellmaking slag (via MnO);

2. MnO is reduced inside BF hearth by solid carbon so removing small C particles = hearth cleaning/drainage capability increase;

3. MnO in BF slag makes BF slag liquid - sometimes we need that;

4. Mn in BF hot metal makes hot metal liquid - sometimes we need that.

1.The Desirable amount of Mn in hot metal helps to reduce the melting point of primary slag by 10° to 30° C.

2.Shifting Up by cohesive Zone 0.1 to 0.30 meter.

3.Liquid phase filtration begins through deadman coke earlier.

4.Primary high acid slag melt increases an average 2 to 5%

5.The highest gradient of manganese concentration in hot metal is observed not in the melt filtration zone, but deeper, just above tap hole level.

6.Mn-containing materials expands the possibilities of carbon gasification in the lower part of hearth where is experiencing a deficiency of bound oxygen for reaction with crashed particles of coke (coke debris) and PCI unburnt char:

MnO + C = Mn + CO - 288.29 MJ, (5)

Therefore, due to the arrival of additional oxygen in the form of (MnO), the washing effect is enhanced.

7.The melting point mobility of primary slag decreases,

8.The mobility of intermediate slags is improved, carbon debris is oxidized due to the reduction of (MnO) by solid carbon,

9.The mobility and desulfurization capacity of the final blast furnace slag is also improving.

10.Manganese oxides reduce the viscosity of intermediate slags and reduce the melting point of the mixture of iron-bearing part of burden,

11.Mn containing material reduction by furnace gas occurs only to Mn monoxide. When (MnO) enters the lower high temperature zone of BF.

12.Part of manganese is reduced, helping to accelerate the renewal of Deadman coke and stabilize the thermal state of the smelting process.

It is suggested that, to ensure the washing effect, the rational number of Mn-containing materials is determined by maintaining [Mn] content in hot metal in the range of 0.25–0.35% (BF-2 data shows that 0.4 range is better), in some periods it is allowed in the range of 0.20 to 0.30%

Mn ore is added to the blast furnace charge materials. In its ore, it is mainly present as dioxide, MnO2. It is very unstable and forms Mn3O4instantaneously as it is charged. Mn3O4 is reduced in the shaft by the reaction

Mn3O4 + CO= 3MnO+ CO2 ; - 4420 cal/gm atom of Mn

The equilibrium CO/CO2 ratio in the temperature range of 700-900oC is 0.001-0.002 which is very much lower than that exists in the shaft. It means that Mn3O4 is completely reduced to MnO in the upper or middle zones before reaching the lower zone. Reduction of MnO is difficult since, at 1200oC the equilibrium CO/CO2 is 104. No such effective concentration gradient exists in the shaft or bosh. Hence, MnO is reduced directly by carbon (coke). In compare to the formation of gaseous SiO and other sulphurous compounds, manganese does not form any gaseous species. Some of it is reduced in the bosh or belly when the liquid manganese slag flows over the incandescent coke. Some further reduction from the slag occurs in the hearth. During the descent of the burden some MnO always combines with silica to form less reducible manganese silicate. MnO is very helpful in keep in mind the fluidity of acid slags. It reduces the viscosity of slags of basicity CaO/SiO2= 0.6-0.8 by 2-5 times.