In steel***, used as deoxidizer and alloy additive, is the most ferroalloy dosage. Smelting with manganese ore general requirement femn with manganese 30 to 40%, ferromanganese than more than 7, phosphorus manganese ratio is less than 0.003. Before the ***elting, carbonic acid manganese ore to the first pellets, powder grinding need to the sintering made piece. Iron ore high phosphorus of general only can match the use, or through selective reduction tried to low iron low phosphorus of manganese residue rich. Smelting in coke as a reductant, and some factory also equiped with thin coal or anthracite. Auxiliary materials mainly for lime, ***elting manganese silicon alloy usually with addition to silica.

Carbon ferromanganese international standard for with manganese 75 ~ 80%, China in order to adapt to the low grade manganese ore material condition, the provisions with manganese lower grades (electric furnace femn with manganese 65% above, blast furnace femn ***elting with manganese above 50%). Carbon ferromanganese ***elting blast furnace mainly with the past, along with the de***pment of the electric power industry, electric furnace with the increasing. At present China and Western Europe in the blast furnace is given priority to, Norway, Japan all use the electric stove, the Soviet union, Australia, Brazil and other countries new ferromanganese factory also USES the electric stove.

Smelting blast furnace

General use of the 1000 m 3 the following the blast furnace, equipment and production process in blast furnace iron*** and same. Manganese ore in the top of the decline of the stone in the process, the high cost of oxidation manganese (MnO2, Mn2O3, Mn3O4) increases with temperature, be CO gradually returned to a MnO. But MnO can only under high temperature through direct reduction of carbon into metal, so need higher furnace femn ***elting temperature cylinder, for blast furnace femn refined by using the higher coke rate (1600 kg/tons) and wind temperature (1000 ℃ above). In order to reduce the loss of manganese, slag should keep high basicity (CaO/SiO2 is greater than 1.3). Due to high and indirect coke rate reduction rate is low, refined femn blast furnace gas production rate and the blast furnace iron*** is containing CO than for high, top with higher temperature (350 ℃ above). Rich oxygen drum wind can improve the hearth, temperature, lower coke rate, increase the yield, and because of a reduction of the gas stove can reduce the temperature, femn ***elting to h***e significant improvement action.

Smelting furnace

Femn ***elting reduction h***e flux method (also called low manganese residue method) and no flux method (high manganese residue method) two kinds. Flux principle and method of ***elting blast furnace is same, just based on the power instead of on heating coke. With addition of lime fed by high basicity slag (CaO/SiO2 is 1.3 ~ 1.6) in order to reduce the loss of manganese. No flux method without ***elting lime, f the basicity low (CaO/SiO2 is less than 1.0), containing manganese high and low iron low phosphorus manganese residue rich. This method slag quantity is little, can reduce power consumption, and because of low temperature slag can reduce evaporation loss of manganese, at the same time by-product manganese residue rich (including manganese 25 ~ 40%) can make silicon alloy ***elting manganese of raw materials, to achieve a higher manganese comprehensive recovery (more than 90%). Modern industrial production is used mostly without flux method carbon ferromanganese ***elting, and with manganese silicon alloy and medium, low carbon ferromanganese ***elting composition of joint production flow chart.

Technology situation

Modern large ferromanganese reduction furnace capacity of 40000 ~ 75000 kv, generally for fixed enclosed. The power consumption of the flux method ***elting general for 2500 ~ 3500 kw/tons when, and no flux method for the consumption of 2000 ~ 3000 kw, when/ton.

Manganese silicon alloy with closed or close partly reduction ***elting furnace. Generally USES contain silica high, low phosphorus of manganese ore or other for raw material with addition of silica. Manganese residue rich low phosphorus, including silica high manganese silicon alloy ***elting is good material. The power consumption ***elting about 3500-5000 kw commonly, when/tons. Charging raw material first as pretreatment, including the whole grain, preheating, prereduction and powder sintering, electric furnace operation and technology to economic index up significant improvement action.

Electric furnace in the refining, low carbon ferromanganese generally with the 1500 ~ 6000 kva furnace to take off silicon refining, manganese, rich in silicon manganese ore and lime as raw materials, the reaction for:

MnO MnSi + 2 + 2 CaO ─-3 Mn + 2 CaO • SiO2

Using high basicity slag can make the slag containing manganese reduces, by reducing the loss caused by abandon slag manganese. The joint production of low residue alkalinity (CaO/SiO2 is less than 1.3) operation, high income with manganese (20 to 30%) for ***elting slag manganese silicon alloy. Burden preheating or load liquid manganese silicon alloy help shorten the time, to reduce the consumption ***elting. Refining the power consumption is in commonly 1000 kw, at around. Medium, low carbon ferromanganese also use hot against the law, the liquid silicon alloy and manganese manganese ore stone, lime mutual hot melt confirmed for the production.

Oxygen blowing with pure oxygen converting process of refining liquid carbon ferromanganese or manganese silicon alloy can be tried as well, low carbon ferromanganese. This method after years of experiment research, in 1976 into the industrial production.