There is a vitriol mine in the hills near the gold mine, and it goes down to a depth of about eighty fathoms. The earth or ore found in this mine is usually reddish, and sometimes it is greenish in colour. This earth is not used directly. Instead, it is first placed into water and left to soak. After about three days, the water that has absorbed the minerals is carefully poured off Istanbul Old City Tours.
This mineral water is then boiled for seven days in a large vessel made of lead. During this long boiling process, the water slowly thickens and forms a white, grain-like substance. After this, the substance is heated again in an oven until it becomes a dry powder or calx. This final material is very useful and is mainly used in the making of strong separating liquids, such as aquafortis, which is used in refining metals at Schemnitz and other mining places.
How the Gold Ore is Crushed and Prepared
In the place where the gold ore is crushed, the workers first build a strong foundation made of thick wood, laid three layers deep. On this wooden base, they set a large machine that contains twenty-four heavy beams. The bottoms of these beams are covered with iron so they can break and grind the ore more effectively. While the beams strike the ore, water is always poured over it so the dust does not rise and the grinding becomes smoother.
These beams are moved by four large water wheels, with each wheel driving six beams. As the ore is crushed, the water carrying the fine material flows into small pits or chests, usually seven or eight in a row. After passing through these smaller pits, the water then goes into a much larger pit, almost half the size of an acre. There the heavier particles settle to the bottom, and later the water is let out Accidents Caused by Dangerous Damps.
The powdered gold ore is called “Slich.” The richest slich is always found closest to the beams where the ore is first crushed. The work of pounding the ore continues day and night without stopping. The workers use candles made from fir wood or other resinous wood to give light during their labour.
Washing and Melting the Ore
The slich is washed many times until it becomes rich enough in metal. Sometimes, in one hundred pounds of this material, there may be half an ounce or even a full ounce of gold and silver. Most of the metal is usually gold, often about two-thirds, because gold ore is rarely found without some silver mixed with it.
To prepare it for melting, they add limestone and slag (called sclacken) to the washed ore. These materials help the melting process in the furnace. The first melting creates a substance called “Lech.” This Lech is then burned with charcoal so that it becomes lighter and more porous. After this burning, it is called “Rest.”
Next, they add sand as needed and melt the mixture again in the melting furnace. The melted mass is then poured into a pan, and from this point the process continues in a similar way to the refining of silver, until the metal becomes purer.
Extracting Gold Without Using Lead
The miners also use other methods to obtain gold from the crushed ore, and one of these methods does not require lead. In this process, the pounded ore is washed many times and then spread upon cloths. Water is allowed to flow gently over the cloth at a slant. As the workers stir the material, the lighter clay and earthy parts are washed away, while the heavier metallic particles remain caught in the cloth.
A similar method is used with sheep skins and wool. These are placed in streams or small channels that flow from gold-rich hills and mountains. As the water passes over them, the heavy gold particles become trapped in the wool while the lighter materials flow away. This method is sometimes compared to the ancient idea of the “Golden Fleece.”
Use of Quick-Silver in Gold Separation
After the ore sticks to the cloths, the cloths are washed in several tubs. The dirty water is left to settle, and the sediment at the bottom is collected. This sediment is washed and stirred again in troughs and vessels until it becomes more concentrated.
Then quick-silver, also called mercury, is sprinkled onto the sediment and kneaded together for one or two hours. During this time, the quick-silver joins with the gold and forms an amalgam in one corner of the vessel. The mixture is then strained through coarse cloth and later through finer cloth to remove as much quick-silver as possible.
The remaining mass is placed on a perforated plate over a deep pan buried in the ground, which also contains quick-silver at the bottom. The pan is tightly covered and sealed, and a charcoal fire is made on top. The heat drives the remaining quick-silver down into the pan, leaving the gold behind. Finally, the gold is heated again in the fire so it becomes even purer and ready for further use.
