Technical

Mining and output

Method Wet mining
Expansion of mud-flush drilling plants < 160 m length / < 120 m width / <125 m height
Number of currently active mud-flush drilling plants 30
Daily mining progress in the mud-flush drilling plant approx. 1 cm upward
Usable mining height in the mud-flush drilling plant 100 m
Operating duration of a mud-flush drilling plant approx. 30 years
Brine yield per mud-flush drilling plant during the entire operating duration approx. 1.300.000 m³
Brine yield of the Salt Mine per annum approx. 900.000 m³
Daily freshwater requirement for the Salt Mine approx. 2.000 m³ per day


 

Expansions for the Berchtesgaden deposits

Open

From southwest to northeast 4,5 km
From northwest to southeast 1,5 km

 

Being mined

From southwest to northeast 2,5 km
From northwest to southeast 1,5 km
Proven deposit depth 500 m bellow the valley floor
Presumed deposit depth 1.000 m below the valley floor
Salt content in the mountain approx. 50 %

 

 

Tour

Visitors per year approx. 350.000
Route length of the visitor mine train 1.400 m
Temperature below ground +12 degree
Length of the first slide   34 m
Length of the second slide 40 m
Duration of the tour (incl. putting on and taking off mine clothing) appropx. 1,5 hrs.

 

 

Terms

Wet mining

In Berchtesgaden, the salt is extracted using so-called "wet mining". With this, the freshwater is fed into the mountain, which removes the salt from the composite rock. Brine is created, i.e. a concentrate salt solution with 26.5% salt content. Nothing has changed to this day regarding this principle. The brine is extracted in the so-called mud-flush drilling plants.

 

Core drilling
Down to 400 m depth below the mining route level, samples are taken by drilling in order to ascertain the minimum salt content in the rock.

 

Mud-flush drilling plant
For extracting brine using wet mining, a hollow space is first developed. This is filled with freshwater. The water has the function of removing the water-soluble components from the mountain face, i.e. also the salt on ceilings and walls. The non-soluble components of the rock sink to the bottom and settle on the bottom. The hollow space is enlarged through constantly newly fed-in freshwater. This process is repeated until a 3,500 to 5,000 cubic metre so-called initial hollow space is completed.

 

Brine extraction
The continuous brine extraction begins when the ceiling area of the hollow space has reached approx. 3,000 m2. Approx. 1 cm of rock is removed from the ceiling space per day. With a mining height of 100 m, a mud-flush drilling plant can be used for approx. 30 years; during this time, we create more than 1.3 million cubic metres of saturated brine.

 

Brine
Saturated salt solution, i.e. salt water, which contains the maximum possible share of 26.5% salt. In Berchtesgaden, brine is created by feeding the freshwater into the mountain and removing the salt from the rock there. The Berchtesgaden brine is pumped to the Salt Works Bad Reichenhall further processed into industrial salts there.