Everything you should know about Cobalt Commodity.

Once the named Goblin metal now known as Cobalt, which was commercially explored in 1920, made a massive impact in the late 20th century. Cobalt is a ferromagnetic metal that is essential for humans in many ways. It is the 27th essential element for human lives. Cobalt can be found on both land and sea with a substantial abundance, but then also ranked 33rd. Cobalt is mainly used in batteries, alloys, tools, magnets, wings of airplanes, catalysts et., In overall, Cobalt is one of the critical commodities and everyone from mineral mining and the metal sector should be aware.

This scope of this blog is limited to know about the basics of Cobalt, its mineralogy, global distribution, current process of metal extraction, price prediction, and challenges. We are not going through the each a bit of process, but if you required detailed review, send an email to me: sachinasra21@gmail.com. So without wasting much time, let us get to know the goblin of the periodic table!

Introduction of Element Cobalt

Cobalt is a lustrous, greyish-silver, brittle metal. It is tough and sturdy and can take a high polish. It retains its strength at high temperatures and has relatively low thermal and electrical conductivity, a high melting point, and multiple valences. Cobalt is ferromagnetic and is, therefore, capable of being magnetized. Other important useful properties are its ability to form alloys with many other metals (e.g., chromium, molybdenum, nickel) and to maintain its magnetic properties at high temperatures (up to 1121°C). (Click on the following image to pay me for this article)

Mineralogy of Cobalt

From a mineralogical viewpoint, it is present in the earth's crust with an average of 15 to 30 ppm (parts per million). Although the pure form of Cobalt is not found, nearly 100 Cobalt bearing mineral has been found. It is mostly found with Iron, Nickel, Copper, and sulfur (Some times it can be found with zinc also). However, it can also be found in the form of oxides, hydroxide, and carbonate. It mostly found in Ni--Cu-Co(pentlandite, pyrrhotite, and chalcopyrite), Ni-Co(goethite, hematite, asbolane, lithiophorite, and heterogeneity), Cu-(Co), and Co-(As). Cobalt can be found in economic concentrations in three principal deposit types: stratiform sediment-hosted copper-cobalt deposits, nickel-cobalt laterite deposits; and magmatic nickel-copper (-cobalt-platinum-group element (PGE)) sulfide deposits. Other deposits are Cobalt-copper-gold deposits in metasedimentary rocks, Polymetallic and other cobalt-rich vein deposits, Iron-oxide-copper-gold deposits, Black shale-hosted nickel-copper-zinc-cobalt deposits, Volcanogenic massive sulfide deposits, Skarn and replacement deposits, etc., (Following flow diagram to denote major Co bearing)

 

Ore distribution.

As per the recent geological exploration, 10MT Cobalt is a reserve on land, and approximately 600MT is reserved in the sea. Approximately 49% of Cobalt is found in a single state that is the Democratic Republic of Congo. Australia has the second most cobalt reserve, with nearly 17.5% global share. The other major players are Cuba, Philippines, Canada, Russia Madagascar, China, the USA with 7.,4.1,3.6,3.6,2.0,1.2,0.6, respectively.

Home to some of the biggest cobalt mines in the world, Congo produces Cobalt majorly from its Katanga Province, which hosts mines such as Tenke Fungurume, Mutanda, and Ruashi, among others. The country has approximately 3.4 million tonnes of cobalt reserves.

Nearly 50% of world cobalt production came from Sediment Hosted deposits. Ore minerals can characterize primary deposits contained organic-rich pyritic shales and sandstone. The following are some of the cobalt bearing deposits found on earth.

Sediment Hosted

The Central African Copperbelt is the world's most crucial cobalt resource. It runs more than 500 kilometers across north-western Zambia and the south-east part of the Democratic Republic of Congo. It is estimated to contain about six million tonnes of Cobalt (Cailteaux, 2004), generally at grades between 0.17 percent to 0.25 percent cobalt. The mineralization processes are not fully understood, but the most widely accepted model of ore genesis is that metal concentration began with the erosion of Palaeoproterozoic and Archaean basement terrains rich in Cobalt, copper, nickel and gold and the influx of these sediments into a basin.

The European Kupferschiefer also contains significant sediment-hosted base metal deposits. They are rich in copper and silver, with cobalt contents typically 20-30ppm and 100-300ppm in cobalt-enriched zones. The Upper Permian (around 250 to 256 million years ago) Kupferschiefer extends from north-east England across the North Sea to Poland, with most deposits in central Germany and Lower Silesia, Poland. Other valuable sedimentary cobalt deposits include Mount Isa, Australia, and Kilembe, Uganda which are both also worked for their gold content 

Hydrothermal and Volcanogenic

Precipitation of hydrothermal fluids which passes through the host rock often sourced from or powered from volcanic activity. Ores can detect where minerals have been remobilized along with the place, fissures and cracks, and in veins. Major deposited in this kind can be found in several countries. In Kristi Finland, Demi, China

Magmatic Sulphide.

When mafic and ultramafic melt becomes saturated in crustal derived sulfur, then the immiscible liquid sulfide phase will convert into nickel, Cobalt, and platinum group, which is elemental preferentially partition. Following are the common types:

1. Stratabound Deposits: (Merensky Reef, South Africa)
2. Basal deposits (Norilsk, Russia)
3. Deposits in extrusive ultramafic rocks. (Kambalda, Western Australia)

There are other types of deposits, either in very small in abundance or the deep seawater.

Price

In the past, we can see that the prices of the Cobalt highly fluctuate; one of the reasons is immerging technology building to replace the cobalt use. Cobalt is using to produce chemicals (58 percent), superalloys for gas turbine blades and jet aircraft engines, special steel, carbides, diamond tools, and magnets. From the known data of pricing cobalt, cobalt price in the summer of 2010 was $40852.13, and in 2012 recession its drop to $22606. In the past, we have seen record high pick point of cobalt prices emerge on March 23, 2018, with $94385. The current rate is $28500, and forecasted prices can be varied from $26000 to $16000. With the new research of Prof. John B. Goodenough to make supper batteries with minimal content or no Cobalt content with highly cheap may be made a sudden drop in terms of price.  (All prices are in per MTone)

However, new batteries are making without Cobalt, some other metals, and alloys to replace the Cobalt. There are other factors for reduction in prices: government rules in DRC, decrease in grade of Cobalt bearing ore, increase in the use of chemicals in the hydrometallurgical plant, which could be a potential threat for the environment. It is also found that Cobalt-based batteries can catch fire quickly than phosphate-based batteries.

On the other hand, some of the industries made endowments in this commodity. For example, Tesla agreed with Glencore Plc. To buy Cobalt up to 2025. Samsung and other cell phone making companies are ready to buy Cobalt. This is happening because Cobalt contained batteries that can work more time than lithium-iron-phosphate batteries.

COVID-19 is affecting the global supply chain. Currently, the DRC is not stuck in COVID-19; however, the other Cobalt consuming countries are not ready to open. Moreover, the airlines which are significant consumers of Cobalt are not working in its full strength. The demand is dropping in the continued quarter of the year, but on the other hand, supply is steady. The bigger picture is a bit in an ambiguity.

Extraction Process.

In a mineralogy section, we discussed that percentage cobalt in the cobalt bearing ore is very low. Cobalt is not an original product of any mine, in there were two mines which are now ceased but run to produce Cobalt as a primary product: 1] Bou-Azzer mine 2]Outocampu mine, Switzerland. For the production of high-grade Cobalt five general unit operations that are used.

1. Concentration
2. Roasting
3. Smelting 
4. Hydrometallurgical refining
5. Final purification- metal refining.

Concentration:

Before removing sulfur and other desirable minerals, we need to preconcentrate the ore for further processing. Therefore, we have two options: Gravity separation and the other one is flotation. Gravity separation is one of the most cost-effective and energy effective processes that could handle coarse feed. However, enhanced gravity separation can separate the fine constituent. Jigs, shaking tables, and dense media separation can be used. Primary gangue material in the ore is quartz, talc dolomite, and limonite with lower density, so dense media separation is an appropriate choice. In downstream, we will get other heavier minerals of Cu-Ni-Co, etc.

Cobalt associated with sulphides readily floats with the copper sulphides using xanthate-type collectors. In the flotation, there are two options: 1) single product as Cobalt in product and others are depressed, they could then be separately processed, and 2) Cobalt sulphite with the copper-rich product which is done by employing differential flotation. In the non-ideal case, it is impossible to separate copper from Cobalt completely. So in Cobalt reach product Cobalt reach assay range between 2-3% and copper assay between 6-13%.

The flotation of oxide mineral, primarily malachite and heterogeneity, is mostly employed by sulphidisation using NaHS or Na2S.9H20 as a conditioning step. In this type of flotation, dolomitic gangue is hard to remove, whereas siliceous gangue is relatively easy to remove.

Smelting:

If the copper is present after the flotation step, then smelting is done o produce blister copper, cast into anodes and electro-refined to produce high-grade copper. Cobalt is mixed with the slag and then clean by using specific cobalt recovery furnaces. The concentration of Cobalt bearing mineral will be above 60% after smelting. If the Nickel sulfides are present, then smelting produces PGM- bearing nickel matte.

Roasting:

When the sulfides content in the ore is high, then roasting is employed, which used between 650 and 710 °C in a fluidized bed. This is achieved by carefully controlling the temperature in the range of 680 and 710 °C. Above 650 °C, Fe2O3 is the dominant iron product. At 680 °C, 93% of the copper is formed by copper sulphate, and this drops to 50% at 720 °C. About 90% of the Cobalt remains in the sulphate form at 720 °C.

Hydrometallurgical processing of ores and concentrates

Approximately 70% of Cobalt is produced in a hydrometallurgical way. The central leaching technology for Cobalt's primary production includes reduction by using ammonia leaching with solvent extraction. Currently, in several parts of DRC, Whole Ore Leach plants are used, which were conventionally inefficient. Other newly researched concepts are coming, for example, nitric acid leach, atmospheric acid leach, hydrochloric leach.

Purification of Cobalt :

It is the last step to get high-grade Cobalt, which is beyond the scope of this article. Nevertheless, traditionally, this done by using precipitation techniques.

Extraction methods from primary cobalt ore.

Down below are the extraction process flowchart.

State-of-the-art technology in cobalt production:

1. High-temperature/pressure Leach of Cobalt arsenide
2. Improvement of conventional Heap Leach 
3. The advent of heap Bio-Leach
4. Bio Leaching of Cobalt ferous pyrites.
5. Cobalt Recovery from copper smelter slag. 
6. Molecular Recognition technology 
7. Rein - In-Pulp
8. Cobalt Electrowinning
9. Briquettes-Hydrogen Reduction. 
10. Cobalt Sulphate -Crystallisation 
11. Hydroxy - oxides - Strong oxidants

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About the Author

Sachin Urade is a recent graduate student from IIT(ISM) Dhanbad, major in Mineral processing. He is dedicated to spreading his knowledge and skills to society. Writing blogs on mineral processing and extractive metallurgy is a freelancing work for him. He is open to the opportunity to be part of magazines and journals as a freelance editor and writer.  

Declaration: The author is taking some of the images from some research papers that are not here to make any money, and the author is not claiming these images. He took these images to make readers visible to what he is talking about. He also wants to show gratitude for to there work(credits are given to each one)