THE EXTRACTION AND UTILIZATION OF

THE EXTRACTION AND UTILIZATION OF

COBALT

INTRODUCTION Cobalt is an element having a specific silvery luster and hard physical properties. Its atomic number is 27 and is found in chemically combined forms due to its high reactivity. It is listed in the D-block of the periodic table and possesses high melting and boiling points.

Extraction Of Cobalt

Cobalt is being used since ancient times. Main uses were pigment related and it was used as a coloring agent in glass and many other materials. Presently, cobalt is being used in large quantities for the manufacturing of powerful magnets, turbine blades, electroplating coatings, high quality enamels and for the treatment of some forms of cancers.

Extraction of Mineral Ore

Crushing and Cleaning of Ore

Cobalt is not found free in the nature. It is found in the form of sulfuric minerals. Other metals are also found in its ores. Deep sea floors also possess considerable amounts of cobalt in the form of manganese minerals.

Beneficiation and Concentration of Ore

Cobalt is also found as arsenic ores and mostly, cobalt is obtained as a byproduct of nickel refining. SULFATING ROAST METHOD

In this method ores are sulfated by roasting on fluidized bed furnace. Cobalt oxides are rendered soluble and iron is converted into insoluble compounds. Sulfuric acid is used for this purpose. A process of electrolysis follows for the separation of copper by using copper cathodes and cobalt is precipitated as cobalt hydroxide. Lime is also used as a pH maintainer for this purpose. Some metallic cobalt is used as a catalyst for the reaction.

Air

Roasting of Ore

Sulphur Arsenic

Core

Reduction

CO2CO2

Smelting

Crude Metal of Cobalt

THE SHERRITT PROCESS

It is a hydrometallurgical process and its early form was developed by Doctor Frank Forward. Matte is produced by smelting the nickel sulfides, which in turn are converted to cobalt by a hydrometallurgical process. After the separation of nickel and other metals, addition of hydrogen gas extracts cobalt as a precipitated product. A purity of 99.6 percent can be achieved by this method.

Electrorefining

Pure Metal of Cobalt

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REFINING BY ELECTROLYSIS

EXTRACTION FROM CU-COBALT OXIDE ORES

An aqueous solution is electrolyzed for the extraction of cobalt. Electro refining yields very pure and desirable form of cobalt. Cobalt purity exceeds 99.9 percent when obtained by this method.

In this method, copper cobalt oxide ores are crushed into fine pieces and enrichment separates the cobalt rich oxides. The method is known as froth flotation. Lime and charcoal is then mixed with the product before heating the mixture under a reducing environment. This removes the impurities along with other undesirable metals. Every step is repeated for the subsequent separation of copper, nickel and iron. Then the 40 percent cobalt rich mixture is treated by a hydrometallurgical method. Blast furnace can also be used for this purpose.

EXTRACTION FROM LATERITE ORES

These ores are also known as nickel-cobalt ores. Two main methods are used for the separation of cobalt from its laterite ores

A

EXTRACTION FORM ARSENIDE BASED ORES

Arsenic ores are rich in arsenide and it is removed by roasting the finely crushed ore over a fluidized bed. This process removes about 65 percent of the arsenic as arsenic oxide. A leach solution is then prepared by the reaction of roasted ore with the sulfuric acid. Hydrometallurgical process is used for further purification of the leach solution. Cobalt is separated in the form of its oxides.

B

Hydrometallurgical method. Ammonia leach solution or a solution of sulfuric acid yields the cobalt by a hydrometallurgical method. Pyro-metallurgical process. Crushing, smelting and subsequent treatment of the products with the respective reactants separates every metal and all the impurities.

UTILIZATION OF COBALT Cobalt has a wide range of its utilization in the modern industry. Only the high demand utilizations are discussed below MAGNETS

Cobalt has a tendency to be magnetized. Cobalt is being used to make advanced and very powerful magnets. Sometimes an alloy POWER STORAGE BATTERIES (Co, Al and Ni) is used for this purpose. A considerable portion of total demand of cobalt for the chemical industry is used in HIGH TEMPERATURE AND STRENGTH the manufacture of power storage batteries. APPLICATIONS Cobalt is used in the production of lithium ion Cobalt is a very strong metal with a very high batteries for electric vehicles (EVs) and those for tolerance for elevated temperatures. Alloys of other electronic gadgets like mobile phones, cobalt are widely used in the manufacturing personal computers and media players etc. of jet turbines and heavy duty parts of some generators. MEDICAL USES Cobalt is a great source of gamma rays, which are projected on the tumors to destroy and Cobalt has a very desirable appearance and contain them. Isotope 60 of cobalt known as physical properties. Being corrosion resistant Co-60 is used for this purpose. Small amount and hard, cobalt is used for electroplating of of cobalt is needed by human body to function properly. various materials. ELECTROPLATING

3

MARKET SUPPLY AND DEMAND Cobalt is much demanded element and with the increasing trend of electric vehicles, its demand is expected to rise above 115000 tons per year by the early twenties. Power storage batteries are made more advanced and useable now leading to the increased demand for cobalt.

KT

4,000

3,400

3,000 2,000

1,500 1,000

1,000

DRC

Australia

Cuba

270

250

Zambia

Russia

230

120

New Canada Caledonia

72

33

29

China

USA

Brazil

Natural resources of cobalt are mostly found in the African copper belt. Over fifty percent of global cobalt supply is produced from the Democratic Republic of Congo. China is also a major controller of cobalt production. Over ninety percent of the total cobalt supplied by Democratic Republic of Congo is refined in China.

300,000

250,000

200,000

150,000

100,000

Cobalt apparent demand

2025

2023 2024

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022

2010

2007 2008 2009

2006

2005

50,000

Total refined output

4

It is estimated that a small-scale cobalt supply deficit will occur by the end of this decade.