Ferro Niobium Production Process

The Araxa plant of the São Paulo Mining and Metallurgical Company (São Paulo Mining and Metallurgy Company) is the largest ferro-niobium production plant in the world. Ferro Niobium has been produced since 1965 by the traditional aluminum thermal process. At the beginning of the 1990s, a semi-continuous autothermal reduction process for the production of ferro-niobium was built (see Figure 2). The reactor for aluminum-thermal smelting is of the stationary type (Fig. 3) and is equipped with a furnace cover. The slag from the reaction is discharged from the furnace together with the ferro-niobium. The prepared raw materials are separately loaded into designated cylindrical silos using charge tanks. The various furnace materials are weighed according to the dosage and 1/12 of the total amount is loaded at a time (approx. 2500 kg of mix). After mixing in the mixer for 4min, it is unloaded into a small bin, added to the conveyor belt by a screw conveyor and transported to the mixing bin at the top of the aluminum thermal reactor. All bins are connected to an exhaust pipe that passes through a bag filter to maintain negative pressure to minimize dust. Open the valve of the mixing bin and add 10t of mixing material into the reactor. After ignition with magnesium strips, the reaction will start. After the reaction of the furnace material, the rest of the mixture to 1 ~ 3t/min to add. After the reaction, open the slag outlet to release the slag. The slag is granulated with high pressure water. The slag is granulated with high-pressure water. Then the iron outlet is opened to release the ferro-niobium and the ingots are cast (each weighing about 4t). A smelting cycle takes about 1h.