Gold collection with mercury is typically used for very fine free gold and not gold in ores. Essentially the gold sticks to the mercury and mercury sticks to itself. Put a bit in a pan with your materials, mercury like gold sinks to the bottom, and pan it normally. Afterward remove the mercury and now you need a device called a retort to separate the mercury from the gold safely. There are other ways, like the potato method, but I suggest a retort as you'll get your mercury back and you'll not be polluting the enviroment with waste mercury. Mercury has a low boiling point so when its boiled off it leaves the gold that was attached to it behind, the retort cools and recollects the mercury. But the method has its hazards so I dont suggest it unless you take precautions and study this method of extraction carefully.