Iron Extraction

Ca. 1550

Georgius Agricola, De Re Metallica Libri XII, 1556

Copyright Peter H. Kunz. CH-8200 Schaffhausen

Searching for Veins

Georgius Agricola, De Re Metallica Libri XII, 1556

Using:

• Divining Rods

• Open Pit Mining

• Digging of Exploration Tunnels

Arrangement of Shafts

Georgius AgricolaDe Re Metallica Libri XII, 1556

Agricola writes: “It is advantageous if a shaftconnects with a tunnel, for then, the minersand other workmen carry on more easily thework they have undertaken: but, If the shaft isnot so deep, it is recommended to drift fromone er both sides of it. From these openings,the owner or foreman becomes acquaintedwith the veins and stringers that unite with theprincipal vein or cut across it, or divide itobliquely.”

Entry into the Mine and Mining

Georgius AgricolaDe Re Metallica Libri XII, 1556

Various methods of entry:

• Use of a ladder• Vertical repelling with a hoist• Repelling via a slide with a hoist• Descent via a stairway• Use of a mule

Ventilation

Georgius AgricolaDe Re Metallica Libri XII, 1556

Woodcut from the manuscript “De Re MetallicaLibrI XII from Georgius Agricola, 1556

The so-called Wetterfuehrung provided theVentilation to the tunnels by blowing fresh air intothe tunnels through pipes:

• A horse sets in motion a vertical drive shaft, theteeth on the wheel activates the bellows with alever

• A horse works the bellows by treading a treadwheel

• The bellows are pushed together by workers

Transport of Ore from the Tunnels

Georgius AgricolaDe Re Metallica Libri XII, 1556

The term ‘fahrnis’ describes the transportationequipment used, to move the mined ore fromthe mining tunnels:

Several horses set a vertical drive shaft in motion• The gear wheel with wooden teeth driven over

a smaller gear drives a vertical shaft • At the end of the drive shaft, a chain is wound

to hoist up a bucket with ore from the shaft • In the middle of the horizontal shaft, there is a

brake wheel • With a lever System, a miner can activate the

brake

Delivery of the Ore to the Smelter

Georgius AgricolaDe Re Metallica Libri XII, 1556

• With 2 or 4 wheeled carts, the ore is drivento the smelter

• The paths are made with gravel or woodenplanks

• The master of the works marks the numberof carts on a stick

• The ore Is unloaded from the carts andready to be processed

Upgrading of the Ore in the Blast Furnace

Georgius AgricolaDe Re Metallica Libri XII, 1556

• The furnace is heated with charcoal

• The coarsely prepared ore and fuel arelayered

• Ventilation is provided by bellows

• At a temperature of 1200 degrees Celsiusto 1499 degrees Celsius, the iron isreduced to its solid form and the slag isseparated

• To melt the iron, a temperature of morethan 1540 degrees Celsius Is avoided

• Slag containing iron clumps remain andare forged for further processing

Forging of the iron Clumps

Georgius AgricolaDe Re Metallica Libri XII, 1556

• From the pile of raw material the ore is putinto the refining furnace and cleaned bymelting it

• The contamination is separated as slagand exits the refining furnace on the side

• The still brittle iron lumps are broken upwith a large hammer

• With a large water powered hammer, thelumps are compacted and the quality ofthe iron is improved

End