Niobium mineral deposits are primarily ferroniobium (manganese) ore, etc., and the extraction of niobium mainly includes the process of differentiation of concentrate, separation of tantalum niobium, preparation of compounds and metals, and essence. The ore can be differentiated by differentiation, melting and chlorination. The separation of tantalum and niobium can be carried out by solvent extraction (the commonly used extraction agents are methyl isobutyl ketone, tributyl phosphate, sec-octanol and acetamide, etc.), fractional crystallization method and ion exchange method. The industrial production methods of the metal niobium include carbon thermal reduction, sodium thermal reduction and aluminum thermal reduction.
Niobium has many advantages such as corrosion resistance, good cold processing function and good electrical function of oxidized film. Niobium is used as an iron and steel additive to produce carbon steel and high-strength low-alloy steel. The primary effect of niobium in steel is to control the size and distribution of de-dissolved niobium carbide, so as to improve the abrasion resistance, corrosion resistance, grain refinement and then improve the function of steel. Adding niobium to cast iron can separate the solid and wear-resistant niobium carbonide phase, and then improve the strength and extend the service life. Niobium and niobium alloys can be used as high-temperature resistant structural materials for spacecraft and their re-entry into the atmosphere, as well as for atomic reactors, as well as for acid-resistant equipment, heat exchangers and heaters in the petroleum and chemical industries. Superalloys containing niobium, nickel and cobalt can be used to make parts for jet engines. Niobium and titanium, tin, zirconium, aluminum, germanium alloys or metal compounds, niobium titanium alloys and niobium tin compounds are now used as the leading superconducting materials. Lithium niobate is an excellent piezoelectric crystal used for color TV filter and radar delay line. Niobium carbide makes super hard things and molds. Niobium disulfide powder can be used as self-lubricating filler for electric machinery and surface equipment.
There are two main types of chlorite, carbonate and pegmatite. The chlorite carbonate deposit is an important deposit type with large scale and high content of niobium. Due to the different types and contents of minerals in the ore, two processes are adopted: gravity separation, magnetic separation, flotation and roasting magnetic separation. Pegmatite xanthochlorite is roughed by multi-stage ore crushing and graded gravity separation process. Magnetic separation is used to eliminate tailings and chlorite concentrate is obtained by flotation. Zircon is sometimes removed from the crude concentrate by electrical separation or flotation. Yichun tantalum and niobium concentrator is located in yichun city, jiangxi province, China. The ores used are granite polymetallic deposits. The content of raw ore (Ta, Nb) 2o50.03% (Ta: Nb= 1.8:1). The scale of concentrator is 1500t/d; The mineral processing process consists of washing, crushing, screening, grinding, grading, magnetic separation and reseparation combined process and reseparation process. After ore rod grinding to -0.5mm, a combined process of magnetic separation and reseparation is adopted to obtain some tantalum and niobium concentrates. Fine grain tantalum and niobium concentrate was obtained by grinding the tailings to -0.2mm with a re-separation process. The tantalum niobium concentrate contained (Ta, Nb) 2o 544.91% and the recovery was 45.6%.
