0
Novel Electrowinning Technologies:The Treatment and Recovery of Metals                from Liquid Effluents               ...
ELECTROWINNINGElectrowinning, also called electroextraction,  is the electro-deposition of metals from  their ores that ha...
History of Electrowinning… It is the oldest industrial electrolytic process. In 1807, for the first time an English chem...
Electrowinning Process  In Electrowinning, direct current is passed from  an inert anode through a liquid leach solution  ...
Types of Electrolytic Cells used :-                                Electrolytic                                    cell   ...
Two-dimensional (2D) arrangements of cylindrical electrode cells : Cells where electrode is essentially in sheet form. T...
Two novel solution treatment and electrowinning technologies are :-• EMEW Technology• RenoCell technology
EMEW TechnologyEMEW Technology was developed by Electrometals TechnologiesLtd. of Australia to overcome a number of signif...
RenoCell TechnologyRenoCell is a patented electrochemical cell technologydeveloped by EA technology. The RenoCell is curre...
Electrometallurgy for Selected MetalsAluminum ElectrowinningMost of the aluminum metal, alumina derived from bauxite. Both...
Hall-heroult process
There are two types of electrochemical cells orpots in use today :-1. The Soderberg Cell, based on a continuousanode that ...
HORIZONTAL STUD SODERBERG (HSS)
Pre-bake electrolytic cells
Copper Electrorefining and ElectrowinningThe main industrial use for copper is for electrical conductivity purposes and th...
Lead ElectrowinningThe process involves ferric leaching of galena concentrate in afluoboric based solution, electrowinning...
Magnesium Electrometallurgy Magnesium has two major raw materials –• Dolomite from the lithosphere, and• contained Magnesi...
Electrowinning from Chloride ElectrolyteThe electrowinning of nickel from chloride electrolyte is used in aprocess to trea...
Electrowinning from Sulfate Electrolyte Nickel electrowinning from sulfate electrolyte is used in a process to treat groun...
Titanium electrometallurgyTi not produced commercially by electrowinning.   It was thought that the history of Ti producti...
Ti electrowinning cell in molten fluorides.
Zinc ElectrowinningAs the zinc deposition process is carried out from acidic solutions, theprocess is sensitive to trace i...
Alternative anodes for metal electrowinning  The main disadvantages of lead anodes are elevated power  consumption, corros...
Advantages of EMEW Technology•   Continous and easy control of copper concentration below 3000 ppm•   Recycling of acid•  ...
THANKYOU 
Upcoming SlideShare
Loading in...5
×

Novel electrowinning technologies.ppt copy

2,653

Published on

Novel electrowinning technologies are now a days has great talks among todays scientist. I heartily thanks to the behind this ppt.Namely- bhagyashree,neelu sheoran,pranitha geedigunta. thanks gls...

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
2,653
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
86
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Novel electrowinning technologies.ppt copy"

  1. 1. Novel Electrowinning Technologies:The Treatment and Recovery of Metals from Liquid Effluents Neelu sheoran Bhagyashree Pranitha Geedigunta
  2. 2. ELECTROWINNINGElectrowinning, also called electroextraction, is the electro-deposition of metals from their ores that have been put in solution or liquefied.
  3. 3. History of Electrowinning… It is the oldest industrial electrolytic process. In 1807, for the first time an English chemist Humphry Davy obtained sodium metal in elemental form by the electrolysis of molten sodium hydroxide . James Elkington patented the commercial process in 1865 and opened the first successful plant in Pembrey, Wales in 1870. In 1883, the first commercial plant in the US was the Balbach and Sons Refining and Smelting Company in Newark, New Jersey.
  4. 4. Electrowinning Process In Electrowinning, direct current is passed from an inert anode through a liquid leach solution containing the metal so that the metal is extracted as it is deposited in an electroplating process onto the cathode.The resulting metals are said to be electrowon.
  5. 5. Types of Electrolytic Cells used :- Electrolytic cell Cylindrical Rectangular tank/ electrode cell Rectangular electrode cellTwo- dimensional Three- dimensional(2-D) arrangement (3-D) arrangement
  6. 6. Two-dimensional (2D) arrangements of cylindrical electrode cells : Cells where electrode is essentially in sheet form. Three- dimensional (3-D) arrangements of cylindrical electrode cells : Cells where the electrode is constructed to provide opportunities for electrochemical reaction from three axial source
  7. 7. Two novel solution treatment and electrowinning technologies are :-• EMEW Technology• RenoCell technology
  8. 8. EMEW TechnologyEMEW Technology was developed by Electrometals TechnologiesLtd. of Australia to overcome a number of significant limitationsinherent in conventional rectangular electrowinning technology,particularly the restricted window process characteristic ofconventional hardware.This technology has been shown to achieve high performanceunder chemical conditions well outside the limits required forefficient operation of conventional cells. At the core of the technology is a specially designed cell thatimproves electrowinning performance by providing a physicalmechanism by which the metal ions are delivered to the cathodesurface efficiently and continuously.
  9. 9. RenoCell TechnologyRenoCell is a patented electrochemical cell technologydeveloped by EA technology. The RenoCell is currently beingcommercialized by Renovare International, Inc. Thetechnology takes advantage of the extremely high surface areaprovided by a special 3-D position.
  10. 10. Electrometallurgy for Selected MetalsAluminum ElectrowinningMost of the aluminum metal, alumina derived from bauxite. Both low and highsilica bauxite are refined using the Bayer Process and the product is aluminapowder which is then electrolytically reduced to aluminum metal by the Hall-Heroult process.There have been many advances made in the Hall-Heroult production processwhich have resulted in significant improvements in productivity, energyefficiency and its impact on the environment. However, the process used todaythat is based on a consuming carbon anode, a cathode metal pool and fluoridebased electrolyte is fundamentally the same as the process, originally developedby Charles Hall and Paul Héroult 125 years ago.
  11. 11. Hall-heroult process
  12. 12. There are two types of electrochemical cells orpots in use today :-1. The Soderberg Cell, based on a continuousanode that is made from carbon paste that is fedto the cell and baked in-situ. This celltechnology accounts for around 10% of theworld Al production.2. The Pre-bake (PB) Cell, based on multipleanodes that are made from coke and pitch whichare formed and baked in furnaces outside of thecell accounts for the rest of the metal production.
  13. 13. HORIZONTAL STUD SODERBERG (HSS)
  14. 14. Pre-bake electrolytic cells
  15. 15. Copper Electrorefining and ElectrowinningThe main industrial use for copper is for electrical conductivity purposes and thisrequires very pure copper product that can only be produced on a large scale throughelectrolysis. Historically large scale refined copper production occurred almostexclusively via electrorefining after the smelting of sulfide ores. Over the past fourdecades, there has been growth in the large scale hydrometallurgical recovery ofcopper by low cost heap leach, solvent extraction and electrowinning. Electrowon copper capacity growth has been in those regions where there isleachable copper at mine sites in the Southwest USA, Chile and central Africa.Electrorefining, now accounts for 70-80% of the worlds refined copper withelectrowinning producing the rest. Electrorefining is the older and still dominatemethod to produce copper cathode. Technology development in ER has focused onproductivity, automation and quality. Electrowinning due to its inherent higher electrical energy consumption hasfocused on electrical energy reduction as well as improvements in productivityautomation and quality. Often improvements can be utilized for both ER and EWoperations.
  16. 16. Lead ElectrowinningThe process involves ferric leaching of galena concentrate in afluoboric based solution, electrowinning, and treating ofresidues for possible by-product recovery. The electrowinningportion of the process uses divided cells.Lead is deposited on permanent stainless steel cathodes. Theelectrolyte passes through a porous diagram to the anode whereferric ion is regenerated for return to leaching. The anode isreported to be graphite.
  17. 17. Magnesium Electrometallurgy Magnesium has two major raw materials –• Dolomite from the lithosphere, and• contained Magnesium in saline waters of the hydrosphere.The lithospheric dolomite is calcined to calcium-magnesium oxide, and reduced with ferrosilicon at above 1250oC. One of the methods of the reduction is by an electro- thermal approach developed during the 1960’s in France, which is called Magnetherm Process. Here an electroslag melting approach is used where a pool of partly molten slag containing 50% Ca2SiO4, 18%Al2O3, 14% MgO, and 18% CaO is formed from the continuous feed of calcined dolomite and low grade ferrosilicon. The Electro-winning process is used to extract magnesium from the hydrosphere raw material magnesium chloride in the saline waters of lakes or oceans, as well as marine evaporites found in the lithosphere such as carnalite [KCl.MgCl2.6H2O], or kainite [MgSO4.KCl. 3H2O] . It should be noted that the earliest known isolation of magnesium was done by Humphrey Davy in 1808; incidentally Davy used an electrolytic approach to isolate most of the metals from their compounds.
  18. 18. Electrowinning from Chloride ElectrolyteThe electrowinning of nickel from chloride electrolyte is used in aprocess to treat ground matte. Chlorine gas is generated at theanode and is used in matte leaching. Plants that performelectrowinning from chloride electrolyte are located in France,Japan and Norway. Nickel electrowinning from chloride electrolytes use divided cellswith the anode typically placed in a frame wrapped in a polyesterdiaphragm. The frame and diaphragm allows for chlorine capture. Nickel is commonly plated on starter sheets which had beengrown previously on titanium blanks for 1 to 2 days. Nickel canalso be plated on masked titanium cathodes to produce nickelcrowns. Chlorine evolves from coated titanium mesh anodes.
  19. 19. Electrowinning from Sulfate Electrolyte Nickel electrowinning from sulfate electrolyte is used in a process to treat ground matte and has been demonstrated for laterite processing. The acid generated during oxygen evolution at the anode is used during atmospheric and pressure leaching. Plants that use this technology are located in Canada, Finland and South Africa.
  20. 20. Titanium electrometallurgyTi not produced commercially by electrowinning. It was thought that the history of Ti production would follow that of aluminum – beginning with as primitive thermochemical process with expensive limited production for a few decades, and then evolving to a large-scale industrial modern electrowinning process.Ti electrowinning technology is related to conceptual confusion.
  21. 21. Ti electrowinning cell in molten fluorides.
  22. 22. Zinc ElectrowinningAs the zinc deposition process is carried out from acidic solutions, theprocess is sensitive to trace impurities necessitating an efficientpurification process. The purification process is based on cementing theimpurities onto zinc dust.As the kinetics of cementation were not favourable, high quantities ofzinc dust were required to remove the impurities. In addition, the zincelectrolysis was initially labour intensive necessitating high labour forharvesting the zinc from the aluminum cathodes.
  23. 23. Alternative anodes for metal electrowinning The main disadvantages of lead anodes are elevated power consumption, corrosion products fouling the cathode deposit, and generation of a hazardous by-product. If lead-alloy anodes are to be replaced, the alternative anodes must be economically justifiable. Currently, DSA (dimensionally stable anodes) are used in electrowinning in chloride-based solutions and recovery of metals from dilute solutions. Recently, implementation of the titanium coated anodes has been made in the copper electrowinning.. The advantages of using DSA anodes in zinc electrowinning are:• the ability to operate at higher current densities,• the elimination of sludge, and• the ability to operate at a reduced anode voltage (300 mV less than Pb-alloy anodes).
  24. 24. Advantages of EMEW Technology• Continous and easy control of copper concentration below 3000 ppm• Recycling of acid• Reduction of effluent• Lower operating cost• Production of high purity (> 99.99%) copper cathode.• Reduction in acid consumption, handling and transportation• Improved safety• No lead contamination• No requirement for regular replacement of cathodes• Small and compact footprint
  25. 25. THANKYOU 
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×