Native sulphur deposits mined using the underground melting method are characterized by a complex structure, which is the result of the many geologic processes which led to their formation.
The resource utilization rate and the consumption of hot water per ton of sulphur are the main criteria of mining effectiveness. They depend on the porosity and permeability of the rocks forming the deposit, the content and mode of occurrence of sulphur (ore texture), and the distribution of rocks with these varying features. Good recognition of geological and hydrogeological deposit features, exploitation results, is important for formulating the rules of controlling the course of exploitation in order to achieve the best recovery of sulphur with the lowest possible water consumption and to reduce operating costs.
Sulphur deposits are characterized by great local and directional variations in their structure and hydrogeological parameters. This makes the melting process irregular. The flow of hot water and melted sulphur is facilitated in certain directions. As a result, the shape, and distribution and form of exploited parts of the deposit are highly variable. Full information about the deposit is necessary for the proper understanding and prediction of processes that occur in the deposit during sulphur melting, for forecasting its effects, and for controlling the exploitation process. This information is obtained through the lithological description of core samples from exploratory and exploitation boreholes, geophysical borehole logging, and surface seismic surveys.

Currently available field rock mass deformability determination methods are rather difficult to perform, due to their complexity and a time-consuming nature. This article shows results of a suitability assessment of a Pen206 borehole jack (a hydraulic penetrometer) for field rock mass deformability measurements. This type of the borehole jack is widely used in Polish hard coal mining industry. It was originally intended only for quick rock mass strength parameters determination. This article describes an analysis and scope of basic modifications performed mainly on a borehole jack head. It includes discussion of results with possible directions for future development of the device.

Badano wpływ osadu ściekowego na aktywność enzymatyczną pokrywy glebowej na terenie po otworowej kopalni siarki w celu oceny możliwości jego wykorzystania w leśno-łąkowej rekultywacji terenów Kopalni Siarki "Jeziórko". Wyniki, uzyskane po sześciu latach od zastosowanych zabiegów rekultywacyjnych wskazują, że osad ściekowy, dodany w odpowiedniej dawce, wpływał na ogól korzystnie na właściwości biochemiczne i chemiczne gleby. Oznacza to, że zastosowany osad może być brany pod uwagę, jako jeden ze środków służących do rekultywacji gruntów toksycznych.

Badano wpływ osadu ściekowego na aktywność enzymatyczną pokrywy glebowej na terenie po otworowej kopalni siarki w celu oceny możliwości jego wykorzystania w leśno-łąkowej rekultywacji terenów Kopalni Siarki "Jeziórko". Wyniki, uzyskane po sześciu latach od zastosowanych zabiegów rekultywacyjnych wskazują, że osad ściekowy, dodany w odpowiedniej dawce, wpływał na ogól korzystnie na właściwości biochemiczne i chemiczne gleby. Oznacza to, że zastosowany osad może być brany pod uwagę, jako jeden ze środków służących do rekultywacji gruntów toksycznych.

Mining-induced sinkholes are a common feature in underground mines. Sinkholes usually disrupt mining operations and associated infrastructure when they occur. This paper presents a case study of the Lubambe copper mine, where nine (9) sinkholes have been reported on the eastern and southern limbs. The development of sinkholes has resulted in increased mining costs due to the closure of the 182 mL decline on the eastern limb and the 175 mL truck route on the southern limb. This study establishes the influence that poor ground formation, rock stability, geological structures, and inappropriate mining practices have on the formation of surface sinkholes. Assessment of ground condition was done by core logging, and borehole analysis was conducted using GEM4D-BasRock software to classify the rock mass quality based on RQD, RMR, Q-System and GIS. Assessment of the mining operational environment was focused on the effects of varying stope designs and sequencing on ground stability. Results of the study indicate that the formation of surface-induced sinkholes is attributed to historical mining in weak rock formation and weathered rock coupled with subsequent failure of unsupported stopes with stope height between 8 and 25 metres and less stand-up time of 7 days.

The main task of mathematical modelling of thermal and flow processes in vertical ground heat exchanger (BHE-Borehole Heat Exchanger) is to determine the unit of borehole depth heat flux obtainable or transferred during the operation of the installation. This assignment is indirectly associated with finding the circulating fluid temperature flowing out from the U-tube at a given inlet temperature of fluid in respect to other operational parameters of the installation.

The paper presents a model of thermal and flow processes in BHE consisting of two analytical models separately-handling processes occurring inside and outside of borehole. A quasi-three-dimensional model formulated by Zeng was used for modelling processes taking place inside the borehole and allowing to determine the temperature of the fluid in the U-tube along the axis of BHE. For modelling processes occurring outside the borehole a model that uses the theory of linear heat source was selected. The coupling parameters for the models are the temperature of the sealing material on the outer wall of the borehole and the average heat flow rate in BHE. Experimental verification of the proposed model was shown in relation to BHE cooperating with a heat pump in real conditions.