The manganese- rich smelting is natural alkalinity and does not require the addition of flux. In a few cases, in order to improve the slag fluidity, a small amount of fluorite is added. Therefore, the raw materials for smelting manganese-rich slag are mainly manganese ore and coke . For manganese ore gangue requirements, Al 2 O 3 , the content should be as low as possible, because of the high Al 2 O 3 , increase the viscosity of the slag and increase the melting point of the slag. The ore is required to contain CaO, and the MgO is lower. The increase of CaO and MgO promotes the reduction of manganese. When a high SiO 2 in the ore, manganese-rich slag SiO 2 will be high, the user of metallurgical silicon manganese alloy, with a manganese-rich slag requires a content of SiO 2. For the smelting of carbon ferromanganese, SiO 2 is required to be low. (2) Physical properties of manganese ore Smelting manganese-rich slag is the same as smelting ferromanganese in blast furnace. It requires uniform particle size of manganese ore, preferably 8~40mm, low powder content, less than 5% less than 5mm, and good strength requirement. Improve the gas permeability of the column and reduce the top blow loss. We are through the PP material, the production
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(1) Chemical composition of manganese ore The chemical composition of manganese ore directly affects the yield, quality and consumption of manganese-rich slag. The chemical composition of manganese ore must be Mn, Fe, P, SiO 2 , Al 2 O 3 , CaO, MgO, and the like. When blast furnace slag rich, more than 85% of manganese into the slag, SiO 2, A1 2 O 3 , CaO, Mg0 almost entirely into the slag, Fe, and about 90% P into the pig iron.
When the manganese content of manganese ore is increased, the manganese-rich slag has high manganese content, high yield, and low consumption of coke and ore. When the iron content of manganese ore is increased, the chemical loss of the ore is significant, and the enrichment effect is good, which is favorable for obtaining high-grade manganese-rich slag. Manganese ore has high iron content and good dephosphorization effect. Phosphorus is reduced and then enters pig iron. Manganese ore is too high in iron content, low in iron high manganese-rich slag, high in iron production, high in coke consumption, low in manganese recovery, and difficult to maintain low furnace temperature in operation.
Smelting manganese-rich slag, the requirements for manganese and iron in ore, are usually expressed by two indexes: m(Mn)/m(Fe) and w(Mn+Fe). When m(Mn)/m(Fe) is constant, the higher the w(Mn+Fe), the higher the manganese content of the slag, but the yield of slag decreases with the increase of w(Mn+Fe). This is because w(Mn+Fe) increases and the gangue in the ore decreases. When w(Mn+Fe) is constant, the higher m(Mn)/m(Fe), the more the Mn content of slag and the yield of slag increase. This is because m(Mn)/m(Fe) increases, the amount of iron in the ore decreases, and MnO increases into the slag. Figure 1 shows the relationship between the grade of manganese-rich slag, the amount of slag and the ores m(Mn)/m(Fe) and w(Mn+Fe). 
In order to ensure the quality of manganese-rich slag, when manganese ore m(Mn)/m(Fe) is required to be 0.3~2.5, its w(Mn+Fe) should be 38%~60%, when m(Mn)/m(Fe) When high, w(Mn+Fe) is low. On the other hand, when m(Mn)/m(Fe) is low, w(Mn+Fe) is a high value. Therefore, w(A1 2 O 3 + SiO 2 ) ≤ 35%, m (SiO 2 ) / m (A1 2 O 3 ) ≥ 1.7, m (CaO + MgO) / m (SiO 2 ) ≤ 0.4 is required.
In the production practice, all kinds of manganese ore are blended to adjust the composition of the charge. The mixed mineral components that are finally brought into the furnace can meet the requirements of manganese-rich slag production, and at the same time, good technical and economic indicators can be obtained.
The smelting effects of various manganese ores are shown in Table 1.
(3) Requirements of coke and fluorite Smelting manganese-rich slag requires good coke strength, suitable particle size (20~80mm) and stable quality. Fluorite is required to have high effective CaF 2 content, stable composition, uniform particle size (20-40 mm), and low powder content.