The tendency to abolish, to obtain heat from coal in order to reduce atmospheric pollution, leads to the closure of coal deposits. The alternative for obtaining heat, especially in the category of heating smaller residential buildings, with wood pellets, although acceptable from an ecological point of view, has its drawbacks, if one takes into account the scale of the required amount of energy and the role of the forest in purifying the air. Wood pulp and coal as basic energy carriers have hydrocarbon compounds. So, in both cases COx and NOx gases appear as gaseous products. The difference is in their scale. Unlike wood, coal also contains sulfur compounds, which makes it an environmentally unacceptable fuel. By adding a certain amount of wood pulp and additives to the coal mass, in this work, pyrophyllite shale, the impact on the energy and ecological aspects of heat release of such a complex fuel mixture was investigated. The ecological aspect is accentuated through the release of sulfur from coal. The mixture was subjected to the briquetting process, and the obtained samples were tested with relevant parameters, primarily the obtained lower heat value and sulfur content (SOx) in these products. The obtained results are very optimistic with both parameters mentioned above and can be a guide for further research for this idea. Key words: coal, wood sawdust, briquette, calorific value, sulfur, ecology.

The review and analysis of a timeline work and stoppage/failure of transportational complex on separation in SC coal mine „Gračanica“ LLC Gornji Vakuf – Uskoplje has been given in this work. The work is based on collecting and analysing data. Collecting data lasted for one year and it is analysed and shown in this work. Rightfully determined the state of work and stoppage/failure, allows precautions and choice of strategy for the next period. Conclusions about which stoppage/failure affected the stoppage of transportational system and separation in full are derived from the research, and based on those conclusions, suggestions about activities which would minimize these stoppages on acceptable value are given. Key words: mine, coal, effective work, stoppage, failure, transportational complex, separation, belt conveyor, scraper.

The research relates to determining the dependence of the strength and hardness, as well as the pH factor and solubility in water, of pellets made based on dolomite powder on the type and concentration of the binder. During the research, the technological parameters of the pelletizing device (speed and inclination of the disk, dosing speed of powder and binder suspension, and mixing time) were kept constant. Variations were made in the concentration of starch and molasses binder at values of 1.0, 2.5, and 4.0% and the control sample of 2.0 %. The purpose of pellets made of dolomite powder is to correct the pH factor of agricultural soil. The obtained results indicate that the production of pellets for the stated purpose requires an optimal choice of binder and its concentration due to the influence on the qualitative indicators of the pellet itself from dolomite powder. The research results are a partial extract of the Study: “Investigation of the optimal technology for the production of dolomite pellets from the “Očura” deposit for agriculture, Phase I”. Keywords: pellet, agriculture, binder concentration, strength, hardness, pH of pellets.

This paper sets out the methodology and presents the results of calculation the efficiency of transport system in separation of the OP "Dimnjače", based on the data of monitoring the operating time and downtime/failure. Properly determined state of operation of the transport system, allows preventive measures and selection of maintenance strategy. Data collection lasted a year, and the data were analyzed, and thus the results are given by month for the transport system as a whole.

This paper will demonstrate the methodology and results of analysis the stationary phenomena upon gravitational pipeline transport of brine from the Salt Mine Tuzla to the ultimate consumer. Moreover, it will provide the analysis of reciprocal effects of flow, change in diameter, speed of hydraulic ascent, loss of pressure and density of brine.

Fischer-Tropsch (FT) synthesis in fixed bed micro reactor (high pressure reaction cell) was studied over different wt% Co supported Na-montmorillonite (NaMMT) and Al-pillared montmorillonite (AlMMT) catalysts. The synthesized catalysts were characterized by XRD, TPR, NH3-TPD, TGA, BET and SEM techniques. FT reaction was carried out at temperature 225, 260 and 275 C and pressure of 1, 5, and 10 bar. Co supported NaMMT catalysts showed very lower CO-conversion along with increase methane selectivity while AlMMT supported Co catalysts gave higher CO-conversion and lower methane selectivity. With increase in reaction temperature from 225 C to 275 C methane selectivity and CO-conversion increased and the selectivity towards C5+ hydrocarbons decreased. Decrease in methane selectivity while increase in C5+ hydrocarbons and COconversion was observed when the pressure was increased to 5 and 10 bar.

The present paper analyzes the operation of the plant for washing stone aggregate 0/2 mm. Researches were conducted on a semi fixed plant for washing aggregates at the open pit 'Drenik' in Srebrenik. Positions of exploration works were on dispenser entrance points, hydrocyclones, distribution system for water supply rubber belt conveyors, etc.). The methods for measuring material flow, calculation the capacity of conveyors, laboratory methods for grain-size distribution of the obtained material were used in this work. The research results are present in the form of tabular data and dependence diagrams of filler content (fractions of technical stone aggregate, granulation -0.063 mm) on capacity of dosed material.

This paper deals with the production of limestone at the stable plant separation of the open pit 'Duboki potok-Bijela rijeka'. Besides that, the effects of different levels of production and material flows were researched. Research was carried out in a fixed plant separation of the open pit limestone 'Duboki potok-Bijela rijeka' in Duboki Potok. Positions of research were on the secondary part of separation (impact crusher, routers materials, funnels, rubber conveyors, vibrating screens, etc). In the course of using different methods of measuring material flow, calculating capacity conveyors, laboratory methods where used in measuring size and distribution obtained material, and particle shape. The research results were reported in: - particle size distribution diagrams of the obtained aggregate stone with the best bands of particle size distribution - defining the functional dependence of impact crusher gap size distribution and structure of the obtained materials.