Mercury Use In Mining For Gold And Why It Is A Problem:

Mercury is not used in the majority of large-scale, controlled gold mining operations. Mercury is sometimes used by small-scale, illicit gold mining operations to separate the gold from other minerals.

 

Mercury is first combined with gold-containing compounds. Because gold dissolves in mercury but no other contaminants, a mercury-gold amalgam is created as a result. The gold and mercury combination is then heated to a temperature where the mercury vaporizes, leaving the gold behind. Although the method does not produce 100% pure gold, it does remove most of the contaminants.

 

The environmental impact of this method i.e. mercury vapor discharge is a drawback. Some of the vapor may still enter the environment even when apparatus is utilized to trap it. 

 

Gold extraction using mercury dates back at least 3,000 years. According to a source, the practice was widespread in the United States up until the 1960s, and the effects on northern California's ecosystem are still being felt today.

The World Health Organization states that exposure to mercury vapor may be lethal and that it has a detrimental influence on the lungs, kidneys, neurological, digestive, and immunological systems. Mercury may have negative health consequences whether inhaled, consumed, or even simply physically touched. Tremors, sleep issues, memory loss, migraines, and motor skill loss are typical symptoms.

 

Eating contaminated fish is a frequent way to get an infection.

 

The phenomena has a particularly negative effect on the Guyana Shield area (Surinam, Guiana and French Guiana), Indonesia, The Philippines, and a portion of the coast of Western Africa (such as Ghana). Mercury usage is often regarded as the simplest and most affordable method of gold separation given the socioeconomic and political context of small-scale gold mining operations.

 

Alternative techniques often employ motion or water to separate the gold from lighter particles since gold is heavier than the majority of other particles. When you pan, you move water and sediment that may contain gold in a curved pan so that any gold will settle at the bottom and the water and other sediment will fall out. Sluicing is lowering sediment with water from a platform. The platform's bottom is covered with a material that resembles carpet, which will hold the larger gold flakes as the water and other grit wash them away. Magnets, chemical leaching, and smelting are some additional more sophisticated techniques. 

 

Chemical & Physical Properties of Mercury: The only metallic substance that is a liquid at room temperature is mercury. Atomic number 80 and the element symbol for this heavy metal are Hg. This list of mercury facts covers information about the element's atomic structure, electron configuration, chemical and physical characteristics, and history. 

 

•    Symbol: Hg

 

•    Atomic Number: 80

 

•    Atomic Weight: 200.59

 

•    Element Classification: Transition Metal

 

•    CAS Number: 7439-97-6

 

•    Mercury Periodic Table Location

 

•    Group: 12

 

•    Period: 6

 

•    Block: d

 

Discovery: The Chinese and Hindus of antiquity were aware of it. As far back as 1500 B.C., mercury has been discovered in Egyptian tombs.

 

Name: Mercury's name comes from the connection between its usage in alchemy and the planet Mercury. Both the metal and the planet Mercury had the same alchemical sign. The Latin term "hydragyrum," which means "water silver," is the source of the element symbol, Hg. 

 

•    State at room temperature (300 K): Liquid

Appearance: heavy silvery white metal

Density: 13.546 g/cc (20 °C)

Melting Point: 234.32 K (-38.83 °C or -37.894 °F)

Boiling Point: 629.88 K (356.73 °C or 674.11 °F)

Critical Point: 1750 K at 172 MPa

Heat of Fusion: 2.29 kJ/mol

Heat of Vaporization: 59.11 kJ/mol

Molar Heat Capacity: 27.983 J/mol·K

Specific Heat: 0.138 J/g·K (at 20 °C)

To make it easier to extract gold from its ores, mercury is amalgamated with gold. Thermometers, barometers, diffusion pumps, mercury vapor lamps, mercury switches, insecticides, batteries, dental products, antifouling coatings, pigments, and catalysts are all made using mercury. There are several salts and organic mercury compounds that are significant.

 

•    Older writings refer to mercury compounds having the +2 oxidation state as "mercuric." For instance, HgCl2 used to be called mercuric chloride.

 

•    Older writings refer to mercury compounds having the +1 oxidation state as "mercurous." In the past, Hg2Cl2 was referred to as mercurous chloride.

 

•    Rarely does nature contains free mercury. Cinnabar, which contains mercury (I) sulphide (HgS), is a source of mercury. By heating the ore and collecting the generated mercury vapor, it is extracted.

 

•    Quicksilver is another name for mercury.

 

•    One of the very few elements that is liquid at standard room temperatures is mercury.

 

•    Both mercury and its constituents are very toxic. Mercury is easily absorbed via intact skin, the respiratory system, or the digestive tract. It has a poisonous cumulative effect.

 

•    In air, mercury is very flammable. Mercury vapor is saturating the air at room temperature (20°C), well above the hazardous limit. At greater temperatures, the concentration and risk both rise.

 

•    Early alchemists thought that different quantities of mercury were present in all metals. In several trials, mercury was employed to change one metal into another.

 

•    Mercury was a component of various medications because Chinese alchemists thought it improved health and lengthen life.

 

•    One of the heavy metals is mercury. Even though many metals are denser than mercury, they are not categorized as heavy metals. This is due to the fact that heavy metals are both very poisonous and exceedingly dense.