How is Silver processed / made – extracted & purified

How is silver processed, made, extracted & purified

How is Silver processed – Silver is most conductive and reflective metal on our earth. People have been making silver jewelry and other objects since about 4000 BC. Silver is not only used in jewelry. As 80% of silver is mined for industrial purposes. It is used mostly in electronic components and in construction as an insulation coating on glass. The mining company produces silver bars, composition of which is 93 – 97%  pure silver. The company sells the bar to a refinery which further purify them for sale to industries.

Silver remains popular today because of its beauty and its affordability compared to gold and platinum. Pure silver is rather soft and its traditionally combined with one or more metals to give it strength and hardness. The silver used in the jewelry is sterling silver. As sterling is composed of 92.5%  silver and 7.5%  alloy. The alloy is usually copper or copper combined with other metals.

How is silver extracted from its ore

The action begins down in the mines where geologists point a light on gun at various spots in the rock face. The electronic device detects the level of 40 different elements including silver. The silver in its natural state isn’t silver colored at all, rather than charcoal grey. Those silver looking deposits are actually zinc and lead. The miners drill holes in the silver rich areas where the geologists pin pointed. Then dynamite stick is inserted for the blast into the rock. After the blast carts hold the chunks of rock called ore to the surface. Geologist then test ore piles and blend them as required, as to achieve a consistent amount of silver content per Kg of ore.

How is silver processed

The silver processed took some time. The ore first goes into the primary crusher. The machines huge steel teeth break up the big chunks into smaller pieces. Then those pieces drop through grades below into the secondary crusher which breaks them down into smaller pieces. Then these pieces goes into a vibrating cone crushers which pulverize them into tiny pieces.

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A conveyor then transports the crushed ore to the ball mill. At this point the ore pieces are roughly 6 mm big. As the mills large cylinder rotates, steel balls bounce around inside grinding the ore into powder. Then a water circulation system flushes the silver rich powder out of the cylinder into the large tanks which keeps the water moving. As to separate and dissolve the metals that powder contains, the worker pour in acid. After 72 hours, the rock waste settled at the bottom.

The solution containing dissolved silver is pumped through filter presses. The filter plate are treated with a zinc based chemical which attracts silver molecules. As the solution passes through, the plates trap particles containing silver forming a layer of black powder called silver precipitate. This precipitate is composed of approximately 50% of silver and 50%  waste. As the waste being a jumbled of various metals dirt and other type of impurities. To separate the silver from the waste, they first dry the precipitate in a gas furnace for a couple of hours.

How is silver purified

In the lab of mining companies, technicians continuously ore samples to determine the grade. The term for the quantity of silver per Kg of ore. Then the workers heat the samples to 1093 degrees Celsius for about an hour to burn off the impurities. As after the burn off, the silver and other metals are left like Lead, Copper, Zinc, Cadmium and Selenium. Then the lab technicians treat the samples with the chemical that prevents silver from burning off and then put them back in the oven. Now when the samples comes out about an hour later, all the other metals have burnt off and only silver is left behind.

The workers then weight the silver and compares it to the weight of the original sample in order to calculate the grade. As the key to running the profitable mind is ti ensure that the grade is consistently with in certain parameters. The workers put the now dried silver precipitate into an oven along with chemicals which prevents silver from burning off. 4 hours later, the silver and waste have separated and melted. Then the workers pour them into bar shaped molds. The silver being heavier settles at the bottom. Finally the workers skim off the waste floating on top. In less than 5 minutes, the molten silver cool and hardens, enabling workers to extract what is now a silver bar. Then the mining company sells the bar to a refinery for processing into industrial grade silver.

In this way the silver processed and available in the big markets around the world.