METHOD OF CHLORINATION OF FERRONIOBIUM AND DEVICE FOR ITS EMBODIMENT Russian patent published in 2002 - IPC

FIELD: metallurgy of rare metals, particularly, methods and devices for chlorine decomposition of tantalum- and niobium-containing natural and technogenic raw materials. SUBSTANCE: method includes loading of ferroniobium in the form of pieces with size of 10-100 mm in a layer 200-250 mm thick into chlorinator. Chlorination is carried out at temperature of 1100-1200 C and chlorine consumption of 1:(1.7-1.9) kg/kg. Melt is additionally chlorinated with introduction of sodium chloride into it. Ratio of chlorine quantity used for chlorination to that used in final chlorination is (9.5-10):1, and sodium-chloride-ferrous chloride weight ratio is 1:(4-4.5). Device for method embodiment has a vertical water-cooled chlorinator lined with graphite with branch pipe for chlorine introduction; melting pot for collection of ferrous chloride provided with branch pipe for introduction of sodium chloride; condenser furnished with scrapers; branch pipe for withdrawal of vapor-gas mixture; chamber for final chlorination with branch pipe for tangential introduction of chlorine and installed on melting pot and connected with chlorinator by means of conical bottom with hole for discharge of chlorination products. Bottom is filled with packing from melted quartz. Diameter of holes is 45-50 mm. Chlorinator height-final chlorination chamber height ratio is (2.5-3):1. Invention makes it possible to increase degree of chlorine use up to 95-98%, recovery of niobium and tantalum into higher niobium and tantalum chlorides due to reduced degree of reduction of niobium and tantalum to lower degrees of oxidation and decreased content of nonvolatile lower chlorides of niobium and tantalum with their withdrawal from process with the help of ferrous chloride and to improve chlorinator by improved gas distribution and absence of local overheating due to upper introduction of chlorine into vertical chlorinator. EFFECT: higher efficiency. 2 cl, 1 dwg, 1 tbl, 1 ex