Underground mining development is directly related to face drilling rig performance. Reducing operating costs and improving productivity are current and crucial topics for mining projects around the world within the development phase. Unlike past approaches, this article is based on variations of equipment availability and utilisation, and their impact on development plans success and costs decrease. To assess the influence of these parameters, daily field data were collected to identify major downtimes in normal cycles and apply adequate corrective measures to mitigate them. Additionally, this article presents the reader with a graphic illustration of the correlation between utilisation and development, including historical data. This paper was developed from October 2017 to March 2018. The result of this study seeks to identify when projects generate profits by comparing four situations with constant productivity, but variables such as the possession rate, maintenance fee, production and utilisation. Finally, it is demonstrated that success in mining projects, related to equipment, is proportional to the utilisation of the fleet, with the correct management of productivities.

In the paper presented is a novel concept to utilize the heat from the turbine bleed to improve the quality of working fluid vapour in the bottoming organic Rankine cycle (ORC). That is a completely novel solution in the literature, which contributes to the increase of ORC efficiency and the overall efficiency of the combined system of the power plant and ORC plant. Calculations have been accomplished for the case when available is a flow rate of low enthalpy hot water at a temperature of 90 °C, which is used for preliminary heating of the working fluid. That hot water is obtained as a result of conversion of exhaust gases in the power plant to the energy of hot water. Then the working fluid is further heated by the bleed steam to reach 120 °C. Such vapour is subsequently directed to the turbine. In the paper 5 possible working fluids were examined, namely R134a, MM, MDM, toluene and ethanol. Only under conditions of 120 °C/40 °C the silicone oil MM showed the best performance, in all other cases the ethanol proved to be best performing fluid of all. Results are compared with the "stand alone" ORC module showing its superiority.

A procedure has been proposed for proceeding with homogeneous chemicals being technical products or reagents stored in unlabelled packages, in order to classify these substances to particular categories of wastes. A series of simple tests belonging to a classical analysis of chemical compounds, complemented with instrumental methods in needed cases has been proposed. The requirements have been established for equipment and necessary qualification of personnel in a laboratory in which identification is to be carried out. Attention has been drawn to risk accompanying this procedure and necessary precautions, which should be undertaken, especially due to possible explosive, inflammable and toxic properties of these substances. The worked out procedure was verified in tests and applied during cleaning the central chemical storage rooms.

The study evaluated physicochemical properties of bio-waste as a potential biofuel in the form of leaves from ‘Regent’ grapevines grown on six different rootstocks and a control grown on its own roots for three years of cultivation. An elemental analysis was carried out, determining the content of carbon, hydrogen, nitrogen, and sulphur in the leaves tested. A technical analysis of the biofuel was also carried out to determine the content of moisture, volatile matter, and ash. The calorimetric method was used to determine the higher heating value for the material. Fixed carbon and oxygen carbon was calculated based on the elemental and technical analyses. The study showed that the type of rootstock and the year of cultivation influence the amount of leaves obtained from the cultivation area. Leaf entrustment per hectare ranged from 1,140,868.02 in rootstock 161-49 to 1,265,286.7 Mg∙ha–1 in rootstock SO4. Regardless of the year of the study, shrubs grafted on 125AA rootstock and the control had the highest combustion heat of 17.5 MJ∙kg–1 and 17.6 MJ∙kg–1 respectively, while 5BB rootstock had the lowest combustion heat (16.4 MJ∙kg–1). Statistical analysis showed no significant effect of test year on the elemental and technical parameters evaluated. It was observed that regardless of the evaluated parameter and the type of rootstock in most parameters, the values in 2022 were the highest, while in 2021 they were the lowest.

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This article presents the results of scientific investigations on the thermal regeneration process of a sorbent of mineral origin sorbent using a retort burner. Diesel oil, a petroleum liquid, most often pervades the environment during different catastrophes. The investigated sorbent of mineral origin was used in the standard way that the Fire Service removes such petroleum liquids from the environment during disasters. For research purposes, a regeneration chamber with a retort burner was constructed. The first phase of the investigation was aimed at defining the physico-chemical features of the sorbent after subsequent cycles of the regeneration process. The second phase involved an analysis of the energy and ecological effects of the regeneration process. The results showed that the first three cycles of the regeneration process occurred under low emission conditions. The proposed regeneration method achieved a positive energetic effect with a functional heat stream with an average value of 12.4 kW (average efficiency of the regeneration chamber was 68 %). The method is very efficient, with regeneration rates between 7.2 kg/h and 8.4 kg/h. It requires only a short amount of time for the start-up and extinction of the regeneration chamber, and it is also flexible to changes in the process conditions.

Biogas plants are one of the most stable sources of renewable energy. Currently, there is a noticeable increase in the amount of post-production residues from agricultural production and agri-food processing (fruit and vegetable processing, fermentation, beet pulp, or lignocellulosic waste), which, can be used for biogas production after appropriate pretreatment. The aim of this study was to examine the possibility of using the biomass produced during the cultivation of grapes on a selected farm as a substrate for a biogas plant, taking into account the production process. The research was carried out in 2018–2020 in a vineyard located in the Sandomierz Upland in the south-eastern part of Poland. Own rooted vines were grown as a single continuous string with a trunk height of 40 cm and a length of one fixed arm approx. 0.9 m, on which six pivots were left every year after applying a short cut, from which 12–16 fruit shoots were derived, the so-called grapevines. Leaves were collected at random from three locations on the fruiting shoot, a total of 30 leaves in each replicate. Each sample consisted of 1/3 of the leaves collected at the bottom, 1/3 in the middle, and 1/3 at the top of the canopy. Leaf area was estimated with a model 3100 area meter on a sample of 30 leaves from each replicate. Both the quantity and quality of the obtained material as a substrate for methane fermentation were evaluated. Biogas yield tests in optimal conditions for mesophilic bacteria were conducted on three substrate samples referred to as ‘Regent’, ‘Seyval Blanc’, and ‘Solaris’. The yields of the tested material ranged from 51.0 to 59.0 Nm ³ biogas per Mg of biomass.

This paper discusses the configuration of a space-effective rack cell for storing a given set of heterogeneous items. Rack cells are the primary components of rack storage areas. A rack cell configuration problem (RCCP) for heterogeneous storage is formulated as a combinatorial mathematical model. An effective heuristic for solving the RCCP in practical cases is presented. The proposed heuristic consists of multistage brute force searching of defined sets of feasible solutions and solving linear integer assignment problems by the branch-and-bound method. The developed algorithm was implemented and tested, and the rack cell obtained meets the modularity requirements in the design and operation of heterogeneous storage areas.

In this research, the high arsenic content dust of copper smelting, as a raw material, the extraction of copper and arsenic from the high arsenic content dust in the leaching system containing acidic and alkaline compounds was investigated. Meanwhile, the effects of acid/alkaline initial concentration, liquid to solid ratio, leaching temperature, leaching time on the leaching rate of copper and arsenic were studied. The optimum conditions for the leaching of high arsenic content dust and preparation of copper arsenate were determined. The results showed that acidic/alkaline leaching of high arsenic content dust was particularly effective. 93.2% of the copper, and 91.6% of the arsenic were leached in an acidic leaching process and 95% of the arsenic, while less than 3% of the copper, less than 5% of the antimony, less than 2% of the bismuth was also leached in an alkaline leaching process. A new method (the parallel flow drop precipitate method) was developed in the synthesis of copper arsenate process. The parallel flow drop method was employed to adjust the molar ratio (copper to arsenic) of the mixed solution of the acid-leaching solution and the alkali-leaching solution by taking the drop acceleration of an acidic leaching solution and an alkaline leaching solution at 10 mL/min and 12 mL/min, at a temperature of 60°C and a reaction time of 1 h. Copper arsenate was prepared by mixing an acidic leaching solution and an alkaline leaching solution. The main phases of copper arsenate were CuHAsO4·1.5H2O and Cu5As4O15·9H2O. Copper arsenate contained 30.13% copper and 31.10% arsenic.