How to make silver?

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Silver was first obtained in sixteenth-century Mexico by a method called the courting process. It consisted of mixing silver ore, salt, copper sulfide and water. The resulting silver chloride was raised by adding mercury. This inefficient method was superseded by the Von Patera process. In this process, the ore was heated with rock salt, producing silver chloride, which was precipitated out with sodium hyposulfite. Today, several processes are used to extract silver from ores.

A method called cyanide, or heap leach, the process has gained acceptance within the mining industry because it is a low-cost method of processing low-grade silver ores. However, the ores used in this method must have certain characteristics: the silver particles must be small. The silver must react with the cyanide solution. The silver ores must be relatively free of other mineral contaminants and/or foreign substances that are present in the cyanidation process. and must be free of silver sulfide minerals. The idea of ​​cyanidation actually dates back to the eighteenth century, when Spanish miners siphoned acid solutions through large piles of copper oxide ores. The process evolved into its present form during the late nineteenth century. The cyanide process is described here.

preparation of ore

1 Silver ore is crushed into pieces to make the material sieve, typically with a diameter of 1-1.5 inches (2.5–3.75 cm). About 3–5 lb (1.4–2.3 kg) of lime is added per ton of silver ore to create an alkaline environment.

Silver

ore must be completely oxidized so that the precious metal is not confined to sulfide minerals. Where fines or clays are present, the ore is agglomerated to form a uniform leach pile. The process involves crushing the ore, adding cement, mixing, adding water or cyanide solutions, and curing in dry air for 24-48 hours.

2 Broken or crushed ores are piled on impermeable pads to eliminate the loss of the silver cyanide solution. Pad material can be asphalt, plastic, rubber sheeting, and/or clay. These pads are slanted in two directions to facilitate drainage and collection of solutions.

Adding cyanide solution and curing

3 A solution of water and sodium cyanide is added to the ore. Solutions are delivered to the pile by scintillation systems or by ponding methods, which include perforation, injection or seepage from the capillary.

Recovering silver

4 Silver is recovered from a piled leach solution in one of several ways. The most common is Merrill-Crow precipitation, which uses fine zinc dust to hide the precious metal from the solution. The silver platter is then filtered, melted, and made into bullion bars.

5 Other methods of recovery are activated carbon absorption, where solutions are pumped through tanks or towers containing activated carbon, and the addition of sodium sulfide solutions, which form silver pores. In another method, the solution is passed through a charged resin material that is attracted to the silver. The recovery method is generally decided on the basis of economic factors.

Silver is rarely found alone, but mostly in ores containing lead, copper, gold and other metals that may be commercially valuable. Silver emerges as a byproduct of processing these metals. To recover silver from zinc bearing ore, the Park process is used. In this method, the ore is heated until it becomes molten. As the mixture of metals is allowed to cool, a layer of zinc and silver forms on the surface. The flake is removed, and the metals undergo a distillation process to remove the zinc from the silver.

To extract silver from copper-containing ores, an electrolytic refining process is used. The ore is placed in an electrolytic cell, which consists of a positive electrode, or anode, and a negative electrode, or cathode, in an electrolyte solution. When electricity is passed through the solution, silver, along with other metals, is deposited as a sludge at the anode while copper is deposited at the cathode. To collect the sludge, it is then roasted, leached, and smelted. The metals are formed into blocks that are used as anodes in a second round of electrolysis. As electricity is sent through a solution of silver nitrate, pure silver is deposited at the cathode.Advertisements

Silver was first obtained in sixteenth-century Mexico by a method called the courting process. It consisted of mixing silver ore, salt, copper sulfide and water. The resulting silver chloride was raised by adding mercury. This inefficient method was superseded by the Von Patera process. In this process, the ore was heated with rock salt, producing silver chloride, which was precipitated out with sodium hyposulfite. Today, several processes are used to extract silver from ores.



A method called cyanide, or heap leach, the process has gained acceptance within the mining industry because it is a low-cost method of processing low-grade silver ores. However, the ores used in this method must have certain characteristics: the silver particles must be small. The silver must react with the cyanide solution. The silver ores must be relatively free of other mineral contaminants and/or foreign substances that are present in the cyanidation process. and must be free of silver sulfide minerals. The idea of ​​cyanidation actually dates back to the eighteenth century, when Spanish miners siphoned acid solutions through large piles of copper oxide ores. The process evolved into its present form during the late nineteenth century. The cyanide process is described here.

preparation of ore



1 Silver ore is crushed into pieces to make the material sieve, typically with a diameter of 1-1.5 inches (2.5–3.75 cm). About 3–5 lb (1.4–2.3 kg) of lime is added per ton of silver ore to create an alkaline environment.

Silver

ore must be completely oxidized so that the precious metal is not confined to sulfide minerals. Where fines or clays are present, the ore is agglomerated to form a uniform leach pile. The process involves crushing the ore, adding cement, mixing, adding water or cyanide solutions, and curing in dry air for 24-48 hours.

2 Broken or crushed ores are piled on impermeable pads to eliminate the loss of the silver cyanide solution. Pad material can be asphalt, plastic, rubber sheeting, and/or clay. These pads are slanted in two directions to facilitate drainage and collection of solutions.

Adding cyanide solution and curing

3 A solution of water and sodium cyanide is added to the ore. Solutions are delivered to the pile by scintillation systems or by ponding methods, which include perforation, injection or seepage from the capillary.

Recovering silver

4 Silver is recovered from a piled leach solution in one of several ways. The most common is Merrill-Crow precipitation, which uses fine zinc dust to hide the precious metal from the solution. The silver platter is then filtered, melted, and made into bullion bars.

5 Other methods of recovery are activated carbon absorption, where solutions are pumped through tanks or towers containing activated carbon, and the addition of sodium sulfide solutions, which form silver pores. In another method, the solution is passed through a charged resin material that is attracted to the silver. The recovery method is generally decided on the basis of economic factors.

Silver is rarely found alone, but mostly in ores containing lead, copper, gold and other metals that may be commercially valuable. Silver emerges as a byproduct of processing these metals. To recover silver from zinc bearing ore, the Park process is used. In this method, the ore is heated until it becomes molten. As the mixture of metals is allowed to cool, a layer of zinc and silver forms on the surface. The flake is removed, and the metals undergo a distillation process to remove the zinc from the silver.

To extract silver from copper-containing ores, an electrolytic refining process is used. The ore is placed in an electrolytic cell, which consists of a positive electrode, or anode, and a negative electrode, or cathode, in an electrolyte solution. When electricity is passed through the solution, silver, along with other metals, is deposited as a sludge at the anode while copper is deposited at the cathode. To collect the sludge, it is then roasted, leached, and smelted. The metals are formed into blocks that are used as anodes in a second round of electrolysis. As electricity is sent through a solution of silver nitrate, pure silver is deposited at the cathode.

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