Chemical Equations

........This chemical process is divided into several steps. The first step involves mixing silver sulfide with salt (NaCL). For the reaction to work properly the reactants have to have access to free oxygen and if possible sunlight. When combined the silver sulfide reacts with oxygen to form silver chloride. The following is the chemical equation for the first step in the Patio Process.

Ag2S + 2NaCl + 2O2 = Na2SO4 + 2AgCl

Now that silver chloride has been produced mercury must be added to produce a pure silver metal. The reaction is as follows.

2AgCl + 2Hg = 2Ag + Hg2Cl2

........This final step in the process is based on a concept named amalgamation. Amalgamation is defined as two metals that are dissolved into each other. Mercury is a unique metal primarily because when mixed with some other metals, mercury dissolves into them. In the case with silver the mercury would coat the silver particles very gradually dissolving into them. When exposed to heat and open air mercury evaporates into the air and leaves behind some of the pure silver particles. The silver that has been partially dissolved by the mercury is left behind in the form of black powder waste. Overall amalgamation is a fairly simple method of refinement but it is not entirely efficient.

Figure 3(above): A sample of amalgamtion. In this diagram gold is being filtered andrecovered. Notice that final results shows a loss of gold.