Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie Number 06/2021

In industrial activities, the contents of water can work as positive or negative agent. The content of water in industrial and technological oils, operating fluids, lubricants provides an example. Due to its physical and chemical properties, the contents of water is a natural factor limiting the flammability of some lubricants, what is positive. In the case of its content as a result of the use or improper storage of lubricants, it plays a negative role and proves the deterioration of the functional properties of the agents used, contributing to the formation of metal corrosion, erosion and the growth of microorganisms (bacteria, molds, fungi) and - in this way - to failures of devices and machines. The article presents the diversity of water impact in the area of lubricants, paying attention to its specific nature and effects that its participation may cause.

This work presents two technologies of longwall entry liquidation after the passing of the longwall front. The traditional one is based on the use of friction steel props (Valent type), while the other one utilizes URW Panda liquidation unit. Advantages and disadvantages of both technologies have been described alongside changes that have been made to Panda unit. Benefits of the use of Panda unit such as reduction of accident rate and improvement of reusability rate of steel sets’ segments have also been described.

Pursuant to the Geological and Mining Law [8], deposits and excavations in mining plants are to be classified into one of two degrees of landslide risk, in accordance with the provisions of the Regulation [7]. This requirement applies, among others, to 46 Lower Silesian granite mines located in the Carboniferous Granitoid Massifs of Strzegom-Sobótka and Strzelin (Figure 1). The granite deposits of the massifs in question are characterized by the presence of joints (Fig. 2) and the presence of faults and associated granite waste. The deposits are mined with explosives, which may affect the loss of stability of the scarps or slopes. Even at the beginning of the 21st century, there was a common view that landslides did not occur in granite mines. However, for about 20 years, their excavations have increased in depth, while maintaining a relatively small surface area. This necessitated a review of this notion. A landslide that took place in 2018 in the "Borów 17" Granite Mine confirms this assumption (Figures 3 and 4). This event points to the need to monitor the risk of landslides and structured prevention in order to adapt it to the specific characteristics of a particular mining plant and the geological makeup of the rock mass. It is also important to shape the awareness of miners performing work in the face of existing or potential threat.