Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie Number 07/2023

Hard coal mining in Poland is accompanied by the hazard of rockbursts. Over the years, methods of this hazard preventing have been developed. They effectively reduce the frequency of rockbursts occuring or minimize the magnitude of the effects of tremors,. The article characterizes, on the basis of data obtained from mining plants conducting mining works in rockburst hazard, the scope of application of individual methods of active rockburst prevention, taking into account the period of 2017-2021. The analysis of the collected data idicates that despite the availability of many possible methods of combating the rockburst hazard, in the mining practice the vast majority of methods are used aimed at disintegration of the rock environment in the vicinity of endangered excavations with the use of explosives are used. The most commonly used are long-hole destress blastings and shock blastings.

Mining shaft hoistings are relatively rarely equipped with drum winders with multilayer rope winding. To prevent the rope from jamming when winding in this way, for example, LEBUS-type liners with parallel grooving of the drum on part of its circumference with two oblique passes are used. With this system, the rope is wound and unwound smoothly, in a way that increases its durability up to four times. However, incorrect installation of liners with parallel and inclined grooving arrangements can result in rope destruction. Correct installation of these means that the inclined groove zones must be opposite each other and all wedges must be properly made and installed. Drum machines with multilayer winding require the use of special wire rope designs. The preferred ropes are those with significant lateral stiffness, based on IWRC-type steel or plastic cores resistant to lateral deformation. All the conditions for use on the drum of a machine with LEBUS lining are met by ropes of construction 34 x 7- - FC or 35 x 7- - WSC, as well as ropes of construction NOTORPLAST and Turboplast ropes.

In the Polish lands sulphur was known as early as the 10th century. The first place of its extraction was found in the area of Swoszowice near Cracow. Between 1415 and 1921, there were four sulphur mining centres on Polish territory, with total production estimated at around 200,000 tonnes. After the Second World War, exploration led to the discovery of sulphur deposits in the Tarnobrzeg area. This led to the commencement (in 1966) of sulphur mining by underground smelting method, using the Frasch method, adapted to the seam deposits, among others at the Grzybów mine. In this method, the structure of the production well consists of five elements: casing columns: initial and technical, and production columns: water, sulphur and air. A water column is used to pump process water at a temperature of approximately 160°C at a pressure of 0.8-0.9 MPa. The sulphur column receives smelted sulphur at a temperature of 140-150°C. The production wells are drilled in a 45 x 45 m triangular grid and, in the case of re-exploitation, 45 x 60 m. Stress relieving of the deposit is carried out by stress relieving boreholes located at the front of the exploitation front. The main criterion in determining the reservoir stress relieving rate is the balance between reservoir pressure and the pressure generated by the overburden rocks. For the Osiek mine, the stress relieving rate should be between 35-70% of the amount of water injected into the deposit.