GENERAL PRINCIPLES OF METALLURGY GENERAL PRINCIPLES OF METALLURGY

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GENERAL PRINCIPLES OF METALLURGY

GENERAL PRINCIPLES OF METALLURGY

GENERAL PRINCIPLES OF METALLURGY ELECTROCHEMICAL PRINCIPLES OF METALLURGY 1. ALUMINIUM

GENERAL PRINCIPLES OF METALLURGY ELECTROCHEMICAL PRINCIPLES OF METALLURGY 1. ALUMINIUM

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø We have seen how principles

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø We have seen how principles of thermodyamics are applied to pyrometallurgy Ø Similar principles are effective in the reductions of metal ions in solution or molten state Ø Here they are reduced by electrolysis or by adding some reducing element

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø In the reduction of a

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø In the reduction of a molten metal salt, electrolysis is done Ø Such methods are based on electrochemical principles which could be understood through the equation ΔG = – n. E F Ø here n is the number of electrons and E is the electrode potential of the redox couple formed in the system Ø More reactive metals have large negative values of the electrode potential

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø So, their reduction is difficult.

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø So, their reduction is difficult. Ø If the difference of two E values corresponds to a positive E and consequently negative ΔG then the less reactive metal will come out of the solution and the more reactive metal will go to the solution, e. g. , Cu 2+ (aq) + Fe (s) → Cu (s) + Fe 2+ (aq)

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø In simple electrolysis, the Mn+2

GENERAL PRINCIPLES OF METALLURGY Electrochemical Principles of Metallurgy Ø In simple electrolysis, the Mn+2 ions are discharged at negative electrodes (cathodes) and deposited there Ø Precautions are taken considering the reactivity of the metal produced and suitable materials are used as electrodes Ø Sometimes a flux is added for making the molten mass more conducting

GENERAL PRINCIPLES OF METALLURGY Aluminium Ø In the metallurgy of aluminium, purified Al 2

GENERAL PRINCIPLES OF METALLURGY Aluminium Ø In the metallurgy of aluminium, purified Al 2 O 3 is mixed with Na 3 Al. F 6 or Ca. F 2 which lowers the melting point of the mix and brings conductivity Ø The fused matrix is electrolyzed Ø Steel cathode and graphite anode are used Ø The graphite anode is useful here for reduction to the metal Ø The overall reaction may be taken as:

GENERAL PRINCIPLES OF METALLURGY Aluminium 2 Al 2 O 3 + 3 C →

GENERAL PRINCIPLES OF METALLURGY Aluminium 2 Al 2 O 3 + 3 C → 4 Al + 3 CO 2 Ø This process of electrolysis is widely known as Hall-Heroult process Ø The electrolysis of the molten mass is carried out in an electrolytic cell using carbon electrodes Ø The oxygen liberated at anode reacts with the carbon of anode producing CO and CO 2 Ø This way for each kg of aluminium produced, about 0. 5 kg of carbon anode is burnt away. The electrolytic reactions are:

GENERAL PRINCIPLES OF METALLURGY Anode Copper clamp + Carbon lining (cathode) Iron Molten Al

GENERAL PRINCIPLES OF METALLURGY Anode Copper clamp + Carbon lining (cathode) Iron Molten Al 2 O 3 + Na 3 Al. F 6 Outlet for aluminium Molten

GENERAL PRINCIPLES OF METALLURGY Aluminium Cathode: Al 3+ (melt) + 3 e– → Al

GENERAL PRINCIPLES OF METALLURGY Aluminium Cathode: Al 3+ (melt) + 3 e– → Al (l) Anode: -2 C (s) + O 2 (molten) → CO 2 (g) + 4 e–

GENERAL PRINCIPLES OF METALLURGY 1) The electrolyte used in the extraction of Aluminium a)

GENERAL PRINCIPLES OF METALLURGY 1) The electrolyte used in the extraction of Aluminium a) Fused cryolite with felspar b) Fused cryolite with fluorspar c) Pure alumina in molten cryolite with fluorospar d) Pure alumina with bauxite and molten cryolite MCQ S

GENERAL PRINCIPLES OF METALLURGY 2) The non-metal present in cryolite is… a) Aluminium b)

GENERAL PRINCIPLES OF METALLURGY 2) The non-metal present in cryolite is… a) Aluminium b) Chlorine c) Bromine d) Flourine

GENERAL PRINCIPLES OF METALLURGY 3) Cryolite and fluorspar is added to electrolyte in electrolytic

GENERAL PRINCIPLES OF METALLURGY 3) Cryolite and fluorspar is added to electrolyte in electrolytic refining of aluminum is because … a) To increase the conductivity of the electrolyte b) To decrease the conductivity of the electrolyte c) To get 100 % pure metal d) To remove all the impurities from the electrolyte

GENERAL PRINCIPLES OF METALLURGY COPPER FROM LOW GRADE ORES AND SCRAPS 1. OXIDATION &

GENERAL PRINCIPLES OF METALLURGY COPPER FROM LOW GRADE ORES AND SCRAPS 1. OXIDATION & REDUCTION

GENERAL PRINCIPLES OF METALLURGY Copper from Low Grade Ores and Scraps Ø Copper is

GENERAL PRINCIPLES OF METALLURGY Copper from Low Grade Ores and Scraps Ø Copper is extracted by hydro metallurgy from low grade ores. It is leached out using acid or bacteria Ø The solution containing Cu 2+ is treated with scrap iron or H 2 Cu 2+ (aq) + H 2 (g) → Cu (s) + 2 H+ (aq)

GENERAL PRINCIPLES OF METALLURGY Question At a site, low grade copper ores are available

GENERAL PRINCIPLES OF METALLURGY Question At a site, low grade copper ores are available and zinc and iron scraps are also available. Which of the two scraps would be more suitable for reducing the leached copper ore and why? Answer: Zinc being above iron in the electrochemical series (more reactive metal is zinc), the reduction will be faster in case zinc scraps are used. But, zinc is costlier metal than iron so using iron scraps will be advisable and advantageous.

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø Besides reductions, some extractions are based on

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø Besides reductions, some extractions are based on oxidation particularly for non-metals Ø A very common example of extraction based on oxidation is the extraction of chlorine from brine (chlorine is abundant in sea water as common salt) 2 Cl– (aq) + 2 H 2 O (l) → 2 OH– (aq) + H 2 (g) + Cl 2 (g) Ø The ΔG for this reaction is + 422 k. J

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø When it is converted to E (using

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø When it is converted to E (using ΔG = – n. E F), we get E = – 2. 2 V Ø Naturally, it will require an external e. m. f. that is greater than 2. 2 V Ø But the electrolysis requires an excess potential to overcome some other hindering reactions Ø Thus, Cl 2 is obtained by electrolysis giving out H 2 and aqueous Na. OH as by products

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø Electrolysis of molten Na. Cl is also

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø Electrolysis of molten Na. Cl is also carried out Ø But in that case, Na metal is produced and not Na. OH Ø As studied earlier, extraction of gold and silver involves leaching the metal with CN– Ø This is also an oxidation reaction (Ag → Ag+ or Au → Au+)

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø The metal is later recovered by displacement

GENERAL PRINCIPLES OF METALLURGY Oxidation Reduction Ø The metal is later recovered by displacement method 4 Au(s) + 8 CN–(aq) + 2 H 2 O(aq) + O 2(g) → 4[Au(CN)2]–(aq) + 4 OH–(aq) 2[Au(CN)2]– (aq) + Zn (s) → 2 Au (s) + [Zn(CN)4]2– (aq) Ø In this reaction zinc acts as a reducing agent

GENERAL PRINCIPLES OF METALLURGY 1) Cyanamide process is used for the extraction of a)

GENERAL PRINCIPLES OF METALLURGY 1) Cyanamide process is used for the extraction of a) Ba b) Al c) B d) Ag MCQ S

GENERAL PRINCIPLES OF METALLURGY 2) The metal is extracted by leaching with a) cyanide

GENERAL PRINCIPLES OF METALLURGY 2) The metal is extracted by leaching with a) cyanide b) chloride c) bromide d) fluoride

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 1. DISTILLATION 2. LIQUATION

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 1. DISTILLATION 2. LIQUATION

GENERAL PRINCIPLES OF METALLURGY ORES CONCENTRATION EXTRACTION REFINING PURE METAL General procedure to extract

GENERAL PRINCIPLES OF METALLURGY ORES CONCENTRATION EXTRACTION REFINING PURE METAL General procedure to extract a metal…. REFINING

GENERAL PRINCIPLES OF METALLURGY DI 1 ON TI LA N O TI UA Q

GENERAL PRINCIPLES OF METALLURGY DI 1 ON TI LA N O TI UA Q IL ST LI EL EC Definition 2 R TR 3 EF O Purification of the INcrude metal by LY I N T non-metallic PO removing metallic and G IC 4 LI impurities is known Nas G refining of metal ZO NE 5 RE FIN IN G 6 VAPO UR P HASE REFI NING 7 CHROMATOGRAPHY REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY PRINCIPLE This method is used to remove the non volatile

GENERAL PRINCIPLES OF METALLURGY PRINCIPLE This method is used to remove the non volatile from impurities metals DISTILLATION e. g. : Zinc, Cadmium and mercury Impure metal is heated in the RETORT pure metal vaporises condenses separately non volatile impurities left in the furnace

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY PRINCIPLE In this process, the low melting metal forms fusible

GENERAL PRINCIPLES OF METALLURGY PRINCIPLE In this process, the low melting metal forms fusible liquid on heating and flows down. LIQUATION This method is employed when Impurity HIGHER melting point Required metal LOWER melting point Metals like bismuth, tin, lead and mercury are separated from their crude form by Liquation.

GENERAL PRINCIPLES OF METALLURGY Working Impure metal LIQUATION Sloping hearth Impurities left behind Pure

GENERAL PRINCIPLES OF METALLURGY Working Impure metal LIQUATION Sloping hearth Impurities left behind Pure molten metal

GENERAL PRINCIPLES OF METALLURGY MCQ S 1) Liquation method is used to refine following

GENERAL PRINCIPLES OF METALLURGY MCQ S 1) Liquation method is used to refine following crude metal a) Copper b) Tin c) Znc d) All metals

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 3. ELECTROLYTIC 4. POLLING METHODS

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 3. ELECTROLYTIC 4. POLLING METHODS

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY IC T LY O PRINCIPLE TR NING E EL EFI

GENERAL PRINCIPLES OF METALLURGY IC T LY O PRINCIPLE TR NING E EL EFI R Impure metals are refined in an 99. 99% electrolytic bath containing aqueous Cu Cu+2+ 2 e– solution of their salts. Impure metal anode pure metal cathode.

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY IN L O P Scum PRINCIPLE G Thishydrocarbon method is

GENERAL PRINCIPLES OF METALLURGY IN L O P Scum PRINCIPLE G Thishydrocarbon method is generally employed in The gases liberated from the green purification of copper tin which wood reduce theor metal oxide contain oxide impurities. into metal. Stirring with green log of wood Molten metal Impure metal

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY G E N O Z NIN I F E R

GENERAL PRINCIPLES OF METALLURGY G E N O Z NIN I F E R PRINCIPLE When an impure molten metal is melted and allowed to solidify, the impurities move away from the solid region and prefer to be distributed in the molten region.

GENERAL PRINCIPLES OF METALLURGY MCQ S 1) The method for the purification of impure

GENERAL PRINCIPLES OF METALLURGY MCQ S 1) The method for the purification of impure metals which is based upon the phenomenon of electrolysis is called a) Electro-refining b) hydrometallurgy c) polling d) liquation

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 5. ZONE REFINING 6. VAPOUR PHASE 7. CHROMATOGRAPHY

GENERAL PRINCIPLES OF METALLURGY REFINING METHODS 5. ZONE REFINING 6. VAPOUR PHASE 7. CHROMATOGRAPHY

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY ASE PH R U O NG P I A N

GENERAL PRINCIPLES OF METALLURGY ASE PH R U O NG P I A N I V REF The volatile compound PRINCIPLE is then thermally decomposed to give the pure metal. The metal is converted Monds process Ni + 4 CO & Impurities Ni(CO)4 Van Arkel method Zr + 2 I 2 & Impurities Zr. I 4 into a volatile compound and collected elsewhere. Heat Ni + 4 CO Heat Zr + 2 I 2

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 H O DS ME T

GENERAL PRINCIPLES OF METALLURGY C mn HY u P l o A C GR

GENERAL PRINCIPLES OF METALLURGY C mn HY u P l o A C GR O T MA O R H PRINCIPLE Twsett This method is based on the selective adsorption of the components of a mixture. The different components of a mixture adsorbed to different extents on an adsorbent.

GENERAL PRINCIPLES OF METALLURGY CH RO COLU MA M TO N GR A adsorbent

GENERAL PRINCIPLES OF METALLURGY CH RO COLU MA M TO N GR A adsorbent PH Y

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI

GENERAL PRINCIPLES OF METALLURGY DI CHROMATOGRAPHY ON 7 TI VAPO UR P HASE REFI NING LA IN G 1 IL ST 6 FIN N 5 RE O NE 2 TI ZO UA Q LI EL EC R TR 3 EF O IN L IN YT PO G IC LI 4 NG REFINING 7 OD H T ME S

GENERAL PRINCIPLES OF METALLURGY Magn Hy dr etic S aul ic epara ORE Fl

GENERAL PRINCIPLES OF METALLURGY Magn Hy dr etic S aul ic epara ORE Fl Wa y lur l a et th ing Fro Leach shin g tion Cal cina ound to met tion al oxide Roasting EXTRACTION g Electrolytic Refinin g M l ox eta y etallur m Electro g inin f e ng R Refini e e s n a h Zo Vapour P Dis till atio Liqu ation n n Poli y me e ur l e l r eta to f om ide r yd H om yr P CONCENTRATION Comp ion at oat REFINING PURE METAL Chromatography tal METALLURGICAL PROCESS Al Cu Zn Fe General procedure to extract a metal….

GENERAL PRINCIPLES OF METALLURGY 1) Mond’s process is used for the purification of a)

GENERAL PRINCIPLES OF METALLURGY 1) Mond’s process is used for the purification of a) Ni b)Zr c) Fe d) Cu MCQ S

GENERAL PRINCIPLES OF METALLURGY 2)Van Arkel process is used for the purification of a)

GENERAL PRINCIPLES OF METALLURGY 2)Van Arkel process is used for the purification of a) Ni b) Zr c) Fe d) Cu

GENERAL PRINCIPLES OF METALLURGY Thank you…

GENERAL PRINCIPLES OF METALLURGY Thank you…