Mixing the tailings of gold and silver ores with a cyanide solution, or simply spraying the tailings with a cyanide solution, would cause a chemical reaction to take place. When gold and silver come in contact with cyanide, they it liquefy. Now the gold-silver-cyanide solution can be drained off and processed further.
Another chemical reaction is put to work to separate the cyanide solution from the liquid gold and silver. Zinc is mixed with this solution, which causes the gold and silver to return to a solid form.
Now there is a solid of gold, silver, and zinc. Yet another chemical reaction is used to remove the zinc. Sulphuric acid dissolves the zinc and leaves just the gold-silver mixture.
From this gold-silver solid, gold and silver are separated by further processing.