gold
Ancient civilizations used gold as a monetary unit for their trade and economic transactions, and entered the jewelry industry. The metal is a very precious metal, a chemical element of its atomic number 79 in the periodic table. It is called “Au” and can be found in nature in the form of granules, which exist within the rocks and in river bottoms, and its natural state before human intervention is the taper, and can be found in the ground in the form of veins.
Its characteristics
The gold element has been of great importance since antiquity to the present time, because of its distinctive characteristics of other minerals. It is worth mentioning that gold was used in ancient times in the Pharaohs, in royal coffins, cars and masks.
- Gold is characterized by its bright yellow color, or light, yellowing depends on the amount of silver mixed with it.
- Retractable metal element and knocking.
- Gold is characterized by low corrosion.
- The gold element is a high density element.
- Gold is smooth.
Its uses
- Gold is entered into jewelry and ornamentation, and is made of yellow gold.
- Used in the manufacture of gold teeth, and in dentistry in general; due to its resistance to corrosion in the mouth.
- Gold enters the treatment of bone infections, using rheumatism and surgery.
- Used in the treatment of cancer, especially radioactive gold 198.
- Used in the manufacture of high-end cylinders as a reflective layer.
- Gold is stored in the form of alloys, or coins to invest.
- Insoluble in acids.
- Soluble in royal water, which is a solution or acid mixture, consisting of hydrochloric and nitric.
Gold mining
Gold is subject to a number of processes that lead to its extraction from its mines and places of existence, using certain techniques, and has evolved from primitive methods to very sophisticated methods at present. It is worth mentioning that the gold prospectors used the method of placing the river mud in a metal container and is called “the bowl” and is filled with water, and be stirring in a circular, and measured purity of gold carats, and the gold is pure when the equivalent of twenty four carats.
Methods of extraction
Gold extraction methods are classified as follows:
- Cyanide method: This method is the best method of extracting gold, because of its efficiency in the extraction process by 96%, and the amount of pollutants harmful to the environment resulting from this method less than others, and cost less, and can be recycled materials used in the extraction process again.
- The method of royal water: This method is very dangerous; because of the gases used, they need to know the process of gold deposition of metals.
- Method of lead: This method is 100% in terms of efficiency, but one of the most significant disadvantages of high cost, and the seriousness of the process of recovery of gold.