Lithium Mining

LITHIUM :

Lithium is a chemical ingredient with the symbol Li and infinitesimal number 3. It is a squashy alkali metal with a shade of silver-white color. Under normal conditions, it is the lightest metal and the lesser intense concrete element. Like all alkali metals, lithium metal is very imprudent, corroding rapidly in the presence of moist air to shape a black discolor. For this reason, lithium metal is characteristically stored beneath the cover of oil.

With reference to theory, lithium was one of the little amounts of elements synthesized in the Big Bang, even though its measure has vastly decreased. The reasons for its disappearance and the process by which new lithium is fashioned persist to be significant matters of learning in astronomy. Lithium is the 33rd largest part of the abundant constituent on Earth, but due to its sky-scraping reactivity only appears in nature in the form of compounds. Lithium transpires in a quantity of pegmatite minerals, but is also commonly achieved from brines and clays on a profit-making scale, lithium metal is secluded electrolytically from a concoction of lithium chloride and potassium chloride.

Mark out amounts of lithium is in attendance in the oceans and in a quantity of organisms, though the constituent serves no noticeable genetic function in humans. On the other hand, the neurological consequence of the lithium metal ion Li+ produces some lithium salts functional as a class of disposition stabilizing drugs.

Lithium and its composites have quite a few other profitable applications, counting heat-resistant glass and ceramics, high strength-to-weight alloys utilized in aircraft, and lithium batteries. Lithium also has significant links to nuclear physics the parting of lithium atoms was the 1st man-made form of nuclear rejoinder serves as the combination fuel in dramatic thermonuclear weapons.

HOW IS LITHIUM OBTAINED?

It may seem like lithium is a rare metal but that is not completely true. Lithium is found in many places on our planet which includes the oceans from where it is extracted and processed. This Lithium ore or brine with added hydrochloric Acid, using the process of electrolysis splits the compound to give out the lithium separately to form lithium hydroxide.

MINING AND PROCESSING:

Lithium is historically known to be produced from two sources brines and hard rock mining. Lithium produced from brines is a cost-efficient process. Also, Lithium is processed from brine, spodumene, and clay. Salar brines are underground reservoirs that contain high concentrations of dissolved salts, such as lithium, potassium, and sodium. They are found below the surface of dried lakebeds, known as salars.

These brines containing lithium are derived entirely from the leaching of volcanic rocks. They range from highly concentrated lithium deposits in the high altitude salars of Chile, Argentina, Bolivia, Tibet and China where lithium concentrations are found to be really high; to mid-level brines like Silver Peak, Nevada and Searles Lake, California, to lower concentration brines like the Great Salt Lake, Utah. The brines with lower concentration have modest evaporation rates with constant dilution containing lithium in less concentration.

The effectiveness of producing lithium carbonate from salt brines is quite a significant task and compared to hard rock mining is less time consuming and favourable. Lithium brines are currently the only lithium source that support mining to have a not so tedious process.

Certain reports reveal to find that lithium recovery from brines may lead to a significant carbon footprint reduction because of a nearly zero-waste mining method.
Decades ago, commercial lithium production depended on mineral ore sources such as spodumene, petalite, and lepidolite. But today, lithium extraction from such sources is crucially more exhausting than extracting the metal from brines. Also the cost of lithium produced from hard rock mining is double than that of what is extracted from brines containing the metal.


 

EXTRACTING AND REFINING :

Lepidolite also known as lithia mica, the petalite, spodumene, the triphylite and the amblygonite- are all ores of lithium. Lithium is an alkali metal and is very reactive in nature and also considered to be a very strong reducing agent. In case of lithium, the regular methods of the mineral extraction cannot be used since:

(1) Lithium cannot be separated by the reduction of its oxides despite being a very strong reducing agent.

(2) It cannot be extracted from its ores by the process of electrolysis of aqueous solutions as the resultant metals will end up producing their hydroxides on immediate reaction with water.

(3) Lithium and all other alkali metals tend to react violently with water and thus it cannot be prepared from the aqueous solution of its salt by the normal metal displacement method.

With all the reasons kept aside, it is clear that lithium cannot be obtained in any of the ways mentioned above. Hence, lithium is obtained through electrolysis process of its fused metal halides which is done in two steps. But firstly, the minerals are required to be converted into lithium chloride by any one of the two methods as follows:

1. The Acid treatment method: In this method, the ore is finely powdered and boiled with sulfuric acid solution. The insoluble waste formed in the process is removed by simple filtration. The acidic solution is treated with sodium carbonate in order to precipitate iron and aluminum. Secondly, excess of sodium carbonate is added to the filtrate in order to precipitate lithium in the form of lithium carbonate. This is filtered and dissolved in hydrochloric acid to acquire lithium chloride, which is then purified by extraction with alcohol.

2. The Fusion method: In this method, the ore is finely powdered and blended with a mixture of barium carbonate, barium sulfate and potassium sulfate. The blended mass is segregated into two layers, with the upper layer consisting of lithium, sodium and potassium sulfates and the lower layer consisting of barium sulfate, alumina and silica. The upper layer is taken apart dissolved in water and then treated with barium chloride solution. As a result, barium sulfate gets precipitated while the chlorides of lithium, sodium and potassium remain in solution. The precipitate of barium sulfate is filtered and the filtrate is evaporated to dryness. The residue formed consists of the mixture of alkali metal chlorides, and then lithium chloride is dissolved out in pyridine. Lastly, the pyridine is distilled, leaving the lithium chloride behind.

This dry lithium chloride is mixed with potassium chloride for electrolysis in an electrolytic cell. Potassium chloride is added to lower the temperature and increase the conductivity of lithium chloride. The electrolytic cell operates at the temperature of about 720 K and a voltage of 8 to 9 volts is passed through. The reactions take place as follows:




LiCl -------------> (Li+) + (Cl-)

(Li+) + (e-) ---------------> Li

2(Cl-) + 2(e-) ------------> Cl2



As a result of the process, the chlorine gas is liberated and leaves the cell whereas the molten lithium metal rises to the surface of the fused electrolyte and collects in the cast iron enclosure surrounding the cathode. The lithium can now be removed and made available in the market for our daily usages.

TOP LITHIUM PRODUCING COUNTRIES :

 

production of lithium

USES OF LITHIUM:

* It is effective in curing bipolar disorders, major depression, schizophrenia and other mental disorders.

* It is used in rechargeable batteries for mobile phones, laptops, digital cameras and electric vehicles.

* It is made into alloys with aluminium and magnesium for specific uses where magnesium-lithium alloy is used for armour plating and aluminium-lithium alloys are used in aircraft, bicycle frames and high-speed trains.

* Lithium oxide is used in special glasses and glass ceramics.

* Lithium stearate is used as an all-time lubricant.

*Lithium hydride is used as a means of storing hydrogen for use as a fuel.

 

ANNUAL LITHIUM USAGE :

 

 

LITHIUM PRODUCTION IN THE WORLD:

Lithium, mined from its ores is found to have deposits in the USA, Canada and China. Since it is also majorly obtained from lake brines , the USA and Chile play important sources in contributing lithium obtained from brines. The wordly production of lithium is known to be around 36,000 MT. The five topmost lithium producing countries are as follows where Australia known to be the leading producer of lithium and other countries like Chile, Argentina, Australia and Zimbabwe follow accordingly. Unlike Australia, where lithium is extracted from hard-rock mines, Chile's lithium is found in lithium brine deposits. Argentina's Salar del Hombre Muerto district holds sufficient lithium brines reserves from ages. Most of the lithium produced in Australia goes to China, whereas on the other hand the fifth top country-Zimbabwe maintains a constant production of 1,000 MT.

 

Rank

Country/Region

lithium mine production (metric tonnes)

------

  World

36,000

1

 Australia

14,300

2

 Chile

12,000

3

 Argentina

5,700

4

 China

2,000

5

 Zimbabwe

1000

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