WOLFF & MÜLLER Minerals is a German-Bulgarian Joint Venture company with vermiculite production facilities in Bulgaria founded in 2006. 
WOLFF & MÜLLER Minerals Bulgaria has the concession for exploiting and developing of vermiculite deposits «VERONA» and «BELITZA» situated near the capital of Bulgaria – Sofia for the period of 35 years. These are the only deposits of vermiculite in Europe which have an industrial size and volume. This fact gives an important advantage concerning logistic and communication relations with European companies using this mineral and its sales price.

WOLFF & MÜLLER has an opencast mineral extraction. The produced ore is processed in a modern vermiculite concentration factory, which has the capacity of 20 000 T of concentrated crude vermiculite per year.
The factory operates with brand new machines and qualified personnel, which gives us maximum effectiveness and high achievements. The factory works 24/7 and it takes maximum 4-5 days after dispatch to deliver any client in Europe and the region.


contact form



Zlaten rog str.22, fl. 2, office 3
1407 Sofia / Bulgaria

tel.: +359 2 962 6900
fax: +359 2 868 0342


Before starting mining operations geologist analysis are made.
If the results are positive the mining process is started by first removing the soil on top of the rocks (the overburden).

This soil is moved aside for its future usage. The resulting heap of loose rock are scooped up and dumped into trucks, which carry the ore to our nearby processing plant. There the vermiculite is separated from the surrounding rocks and grit.
The separation is conducted until the vermiculite flakes are 90% pure. Since vermiculite is extracted from different sections of the mine it is blended together before further processing to ensure uniformity of the product. During the cleaning process depending on the size of the flakes they are separated in our two products Micron and Super Fine.

Some vermiculite may form high percentage of large flakes and these are slightly crushed to reduce their size. The process is finished by filling the graded vermiculite into Big Bags and shipped to clients.

Our product undergoes constant laboratory analysis throughout the whole process and stands behind a consistent quality.


WOLFF & MÜLLER is environmentally oriented and the mining process takes in consideration the filling up of the open mine after the extraction of the available vermiculite is completed. 
From the beginning of the mining process the hummus of the excavated earth is set aside. After a geologist determines that there is no more vermiculite, the mine location is covered back with land to 23 degrees slope and at the top the original hummus is laid back. The hummus helps the environment to recover to its normal biological condition and the tilt of the slope is at this degree level so that there are no earth slides. The revitalization is supported not only by planting trees as they were before, but also through the extraction of the vermiculite. When vermiculite is processed a percentage of the vermiculite remains in the residual mass, which is laid back when the field is being covered back. This vermiculite that remains in the earth is major support of revitalization.