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Estimation of Rock Quality Designation (RQD) distribution with low value of error is crucial for mining excavation based on geomechanical data. This paper proposes an application of an Inverse Distance Weighted Anisotropic Method (IDWAM) based on combined variograms to construct RQD block model in Kahang Copper-Molybdenum (Cu-Mo) porphyry deposit, Central Iran, using subsurface data. To do this, an appropriate voxel size was calculated and then RQD variography was carried in horizontal and vertical directions. In addition, Deere and Miller rock classification was used to classify RQD block model for a final open pit interpretation. Finally, correlation between results for RQD estimated derived via the IDWAM and raw data was carried out using jackknife method. The results obtained by the combination of IDWAM and experimental variogram showed that the excellent RQD zones are located in the central and North Western parts of this area.
This study reports the recovery of bitumen concentrate from Ondo tar sand by alkaline leaching stripping of the associated sand. Bitumen was extracted from the tar sand as received in un-stirred and stirred state in the oven and on the magnetic stirrer hotplate, respectively, at varying 32 factorial design combinations of temperature and sodium hydroxide molar concentrations at 40 g/dm3 pulp density. The tar sand was further subjected to bitumen dissolution test and recovery of bitumen at varying pulp density. The results obtained showed that bitumen was optimally stripped from the tar sand with initial bitumen content of about 34% in the stirred condition to produce a concentrate with grade and recovery percents of 98.82 and 99.41% of bitumen, respectively. The optimal leaching stripping was obtained at 2 M sodium hydroxide concentration, at 90 °C temperature and 25 minutes contact time. The ultra-clean bitumen obtained can serve as raw material input for petroleum products recovery and as a coking additive in blend formulation of coals for metallurgical coke making.
In geopolymer reactions, with lime rich compound addition, the strength parameter is dependent on the molar ratios of (Si/Al) and (Ca/Si), such that (Si/Al) ratio contributes to short period and (Ca/Si) ratio contributes to long period strength development. In the present study a mathematical model has been proposed to identify the role of each on compressive strength development through exponential mathematical relationship, such that, N1 is an exponent of (Si/Al) ratio and N2 is an exponent of (Ca/Si) ratio indicating short period and long period strength development parameter respectively, while C is the compressive strength developed on keeping the samples for different extended time periods. The values of N1 and N2 can be found out by solving linear equations relating (Si/Al) ratio, (Ca/Si) ratio, and compressive strength values of different experimental batch compositions. Calculated and selected additions of sodium silicate, sodium hydroxide, lime and GGBS in iron ore mine tailing samples indicated that the values of N1 and N2 merged with each other after 7 days reaction period, but after 28 days reaction line due to N1 is found above that of N2. It is concluded that for long period strength development (Si/Al) ratio is more important in comparison to (Ca/Si) ratio.
The paper examines the resistance to the effect of cavitation of glass-ceramics based on basalt. Two types of samples were investigated: cast and sintered samples based on basalt.The cavitation erosion test was performed using the ultrasonic vibratory method with a stationary sample. To measure the cavitation resistance, a change in sample mass in function of the cavitation time was monitored. The change in the morphology of the surface with the test time was followed by scanning electron microscopy. The level of the surface degradation of the samples was quantified using the image analysis. Samples were tested under the same conditions. A comparison of the properties of the resistance to the effect of cavitation was performed in relation to the calculated cavitation rates. The results showed the high degree of cavitation resistance of the tested samples and the possibility of their application in conditions of high cavitation loads.
The modification of structural chemical properties of natural fluorite, scheelite and calcite under the impact of high-power electromagnetic pulses (HPEMP–treatment) were studied with help of adsorption of acid-base indicators. It was determined that the HPEMP–treatment during of 30 seconds (3 x 103 pulses) resulted in the intensification of fluorite surface ‘electron-donating ability and acceptor properties of calcite and scheelite surfaces. Single mineral flotation tests has allowed to determine that treatment by high-power electromagnetic pulses resulted in the improvement of the calciferous minerals floatability. The rising of the scheelite recovery was 10 – 12%, for fluorite it was 5 – 6%, for calcite 7 – 8%.
This paper presents the results of mineralogical and flotation studies on the copper ore from the deposit „North Revir“ in the Copper Mine Majdanpek, using different collectors. XRD and ore mineralogical analysis showed that the most common minerals are pyrite and chalcopyrite. Chemical analysis confirm that it is a complex low-grade copper ore with average copper content of 0,273%. The content of precious metals (Au and Ag) was 0.2 g/t and 1.2 g/t, respectively. The main aim of flotation studies have been the effect of collector type on the recovery and concentrate grade in the copper flotation process. Various collectors and combinations of them were used in the rough flotation tests of copper ore. The copper recovery was in the range from 79.43% (test no. 4) to 84.96% (test no. 7). The best flotation results were obtained with mixture collectors of sodium isopropyl xanthate (Z11), dialkyl dithiophosphinates (Aerophine 3404) and SKIK BZ 2000. The collector’s dosages of 20 g/t Z11, 8 g/t AP3404 and 8 g/t SKIK BZ 2000 produced the copper recovery (84.96 %) with copper concentrate grade of 1.52%
The environmental pollution is a major problem over the world. The large amount of pollutants formed during various industrial processes reaches the ecosystem. Thus, heavy metals, oils and other organic compounds are responsible for water contamination. It is known that heavy metals have toxic effect on the environment. Additionally, they are non-degradable and have ability to reach the living organisms through the food chain. Among different methods, the adsorption is widely used in wastewater treatment due to simplicity of the process and efficiency in the removal of pollutants. Natural zeolites from different deposits have shown good selectivity for heavy metal ions. Additionally, they are environmentally friendly, low-cost and have high ion exchange capacity.
