Native sulfur deposits occur in the vicinities of Tarnobrzeg (Osiek, Baranów, Machów and Jeziórko deposits), Staszów (Solec and Grzybów deposits) and Lubaczów (Basznia deposit) in the northern part of the Carpathian Foredeep (map).
The native sulfur output has been significantly declining in the world economy for the last couple of years. It is the result of the growing recovery of sulfur from the sour gas and oil fields. In Poland there are 4 sour gas and oil fields documented. Sulfur is recovered from BMB (Barnówko – Mostno – Buszewo), Cychry, Zielin and (from time to time) Górzyca fields.
Native sulfur is a product of a volcanic origin, nevertheless in the majority it is being created in the process of the sulfates reduction (mainly gypsum and anhydrite) with the participation of bacteria and hydrocarbons.
Sulfur occurs in the above mentioned areas in the form of fillings of fissures and small cavities in Tertiary (Miocene-Torton) rocks, mainly post-gypsum limestones. The content of sulfur in these rocks may reach up to 70% at the most, ranging from 25% to 30% at the average. The output of native sulfur is at present limited only to Osiek deposit where sulfur is mined from the surface using the Frasch hot water method. The Osiek mine remains the last large native sulfur mine in the world. In 2017 there was the concession for the exploitation and the deposit development plan issued for Basznia-1 deposit which was allocated from the abandoned Basznia deposit. Thus, the sulfur economic resources increased by about 6 million tonnes. Except for the exploitation from underground deposits, native sulfur is in small amount being obtained from the volcanic deposits.
The recovery of sulfuric acid in the processing of copper ores and zinc and lead ores is of the limited economic importance, being conducted mainly for the protection of the natural environment.
Table 1 shows resources and the current state of exploration and development of sulfur deposits.
When documenting sulfur deposits the limit values of the parameters that define the anticipated economic resources are: the minimum sulfur content in the sample contouring the deposit of 10%, the minimum average sulfur content in deposits bed of 10%, the minimum deposit richness of 75m% and the maximum depth of deposit base of 400 m.
Anticipated economic resources amounted to 503.85 million tonnes in 2017. The output of sulfur in 2017 amounted to 686 thousand tonnes (Table 2). This volume includes 663 thousand tonnes of sulfur from the only mine under exploitation (Osiek) and 23 thousand tonnes of sulfur which was a by-product of desulfurization of sour natural gas.
The figure given below shows changes in domestic resources and production of sulfur in Poland in the years 1989-2017.
Prepared by: Robert Bońda