Paper 4 final

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  1. 1. By Nikhat.S.Hussain MSc Part II,Paper4 S.I.E.S
  2. 2. Properties Occurence Extraction Applications
  3. 3. LUSTRE HARD DENSITY;13.29g/cm ;MP=2200C;BP=5000C 2 forms -form -form
  4. 4. Hf + 4HF HfF + 2H Hf + AquaRegia HfCl Resistant to Bases Hf + 2H 300C HfH
  5. 5. 0.002% IN EARTHS CRUST ALVITE MALAEON CRYTOLITE
  6. 6. Zircon Thiocyanite Arc Furnace CO,SiO2 ZrCN,HfCl4 Cl2 Chlorinating furnace,500 C ZrCl4,HfCl4 Condenser,100 C Condensate crude ZrCl4,HfCl4 H2 Sublimation Residue-FeCl2 Purified (ZrCl4,HfCl4-2-7 %)
  7. 7. NH4OH ZrCl4,HfCl4 mixture H2O NH4CNS Solvent (Methyl iso butyl ketone) Liquid -Liquid Extraction Zirconyl chloride Hf rich solvent HCl Stripping Hafnyl chloride H2SO4 Scrubbing Solvent recycle NH4OH Precipitation Heat Calcining Hf Oxine
  8. 8. Kroll Process De-Boer or hot wire method
  9. 9. Hf(OH)4 cake Rotary oven H2O HfO(OH)2 Electric muffle furnace H2O 300 C HfO2 Cl2, Chlorinator CO2 Purification Furnace Resublimed HfCl4 Mg(excess) Reduction Furnace(850 C) Hf+MgCl2 Vacuum Distillation furnace Hf sponge Arc melting Furnace Hf metal
  10. 10. (Zr +Hf)+H2O+2H2SO4Hf ppt +Zr(SO)4+2H2 HfI4Hf +2I2
  11. 11. 1. HfCl4+4NaHf+4NaCl 2. HfI4Hf+2I2 3. HfO2+2MgHf+2MgO HfO2+4NaHf+2Na2O HfO2+2CaHf+2CaO
  12. 12. Applications Electroni cs Control rods Special Glasses Hf-Ti alloys lamps Radio tubes TV tubes
  13. 13. Discovered:1801 by Charles & Hatchet
  14. 14. Hard grey metal M.P=1927 C B.P=4925 C Density=8.5 g/cm3 Superconductor at low temperature
  15. 15. 2Nb+air Nb 2 O 5 2Nb+5Cl 2 2NbCl 5 2Nb+N 2 2NbN 2Nb+H 2 2NbH 2Nb+3F 2 2NbF 3 2Nb+5Cl 2 2NbCl 5 Nb+4HFNbF 4 +2H 2
  16. 16. Minerals Columbite (Fe,Mn)(Ta,Nb)2O6) Euxenite (Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6) Pyrochlore (Na,Ca)2Nb2O6(OH,F) Fergusonite
  17. 17. Solvent Extraction Mineral Fusion with K 2 CO 3 Extraction with H 2 O Filtrate Residue (K 3 [NbO 4 ] &K 3 [TaO 4 ]) (Insoluble hydroxide of Fe & Mn ) Treated with CO 2 Filter off Filtration Filtrate Precipitate (Nb 2 O 5 & Ta 2 O 5 ) Removed Dissolved in HF acid containing KF Fractional Crystallisation Less soluble K 2 TaF 7 More soluble K 2 NbOF 5 Electrolysis
  18. 18. Krolls Method 2NbCl 5 +5Mg2Nb+5MgCl 2 Nb NbCl 5 +NaClNb-metal Nb 2 O 5 +AlNb-Al alloyNb 5NbC+Nb 2 O+7Nb+5CO
  19. 19. Rocket missiles Optical glass Air welding rods Petroleum equipments With steel Nuclear reactor Gel engines Electronics
  20. 20. General and inorganic chemistry by R.Sarkar