Scientific Mining Journal

 Longwal mining is one of the most used methods to mine out coal in underground. This method contains some hazard factors in relation to the area of production and coal formation. In this study, risk analysis of longwall production method is made using Fine-Kinney risk analysis method. The potential hazards that may occur in the face are handled, these potential hazards are classified by using FineKinney risk analysis method and according to results obtained, measures are listed to prevent these hazards in the face. The applied operations in longwall production are classified and R risk points of these operations are calculated using Fine-Kinney risk analysis method. It is pointed out that especially in mines where methane explosion may occur, countermeasure and control should be taken in order to prevent methane explosion.

 Copper ore sample collected from Siirt-Madenköy, was used in experimental studies. The results of microscopic analysis on the samples used in tests showed that the ore contains pyrite, chalcopyrite, sphalerite, galena, hematite, limonite, calcite and quartz. In the Siirt-Madenköy copper plant Aerophine 3418 A (50 g/ton) is used as collector, as well as zinc sulphate (120 g/ton) and sodium silicate (1000 g/ton) as depressants. In this study, collector type and dosages were investigated. A series of flotation tests were accomplished for obtaining concentrates assaying 20 % copper as well as decreasing the zinc content of concentrate below 4 %. Therefore, the effects of collector type, collector dosages, pH and particle size were investigated. In flotation tests, Aerophine 3418A (Sodium Isobutyl Dithiophosphine), KEX (Potassium Ethyl Xanthate) and Aerofloat 211 (Sodium Isopropyl Dithiophosphate) were used as collector and MIBC (Methyl Iso Butyl Carbinol) were used as frother. The effects of depressants caustified starch, sodium meta bisulphite, sodium silicate, zinc sulphate were investigated. As a result of flotation experiments, the best collector type is Aero 3418 A , optimum collector dosage is 50 g/t, and the optimum particle size is below 53 µm. Aerophine 3418 A provides acceptable recoveries and metal contents at pH 12 for copper. Sodium meta bisulphite is more effective depressant compared to zinc sulphate to depress zinc in copper concentrate. When 4000 g/ton meta bi sulphite is used as a depressant, a copper concentrated is produced with 71% recovery and 17.93 % Cu content where zinc content decreases to 3.39 %. These results could be adapted to plant where zinc sulphate is used to depress zinc, sodium silicate to depress gangue minerals. Alternatively, meta bisulphite could be used in the plant for the depression of zinc.

 This paper reviews current state to the art to rotary drill bit selection and operation and also introduce a new method for optimizing this process. The research done so far are examined those are the rock properties affecting the drillability, the full scale laboratory studies, the observation of field practice and the regression analysis of this data to develop penetration rate estimation models. In the new method introduced at this paper; the physical and mechanical parameters of rock samples are firstly determined. Then, systematic drilling tests are carried out in Horizontal Drill Rig using real bits recommended by different manufacturers according to rock conditions. The relation between the penetration rate and the bit design and operational parameters are investigated to find the most suitable bit. In the light of data produced the detailed analysis are carried out to define the specific penetration rate, specific wear rate and specific energy consumption for different bits.

 An important efficiency criterion of the blasting operations in mine production is the degree of fragmentation. Different methods have been used to determine the fragmentation up to the present, however some difficulties such as measurement error and long operation times were encountered. In the study, size distribution analysis using terrestrial laser scanning technology (LiDAR) was firstly applied to laboratory scaled broken rock pile, and then, the method was applied to aggregate pile and blasted rock pile in a quarry. Particle size analysis process contains; obtaining point cloud data of the piles using terrestrial laser scanner, creating three-dimensional computer models of the piles through the various filters and related software, defining the fragments and determining the particle size distribution. It is concluded that LiDAR technology can be used effectively in the determination of the size distribution of the piles for evaluating the blasting results.