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Abstract
The dependence of parameters of rock massif and drilling-blasting parameters, on the one hand, and individual fractions as well as the size of the middle portion, is the basis for the development of mathematical model and software’s programs are crucial for the management (prediction) and
to analysing the granulation of the blasted material.
In blasting of any kind of rock mass in order to achieve physical crushing to certain granulation, the need for simple and fast estimation of the granulation of the material blasted are inevitable.
Abstract
“P2A” ore body is one of three active ore bodies in Jama Bor underground mine. Copper ore is extracted by Swedish variant of sublevel caving.
However, due to poor ore properties, central part of ore body couldn’t be extracted regularly. Significant ore reserves were left in this part of ore body.
Analysis of current situation in central part of ore body, led us to conclusion that it is possible to extract ore reserves in this area, by application of different mining method. Considering the layout, dimensions, ore properties and existing drifts and equipment in the central part of “P2A”, we suggest application of block caving.
This paper gives main parameters of method design, block development and loading and haulage of drawn ore, together with expected results of application of block caving.
Abstract
Size of grinding media (balls) in ball mill strongly affect on specific mill capacity and grain size of mill product which further play great role in efficiency of applying concentration method of useful minerals, particularly in flotation.
Experimental results from dry grinding of quartz, as a monomineral material, were presented in this paper. Quartz samples were prepared in form of four particular size fractions such as: (-0.8+0.63) mm;
(-0.63+0.5) mm; (-0.5+0.4) mm and (-0.4+0.315) mm. In the other hand the balls were prepared in form of four charges with uniform diameters for each charge, as like: 20mm, 15mm, 11mm and 6mm. The grinding was
performed in mutual combination of each quartz size fraction with each uniform ball charge. Based on grinding kinetics from above combination of quartz size fractions to uniform ball diameter charge, the optimal ball diameter for certain quartz size fraction were obtained. Consequently to these results a model for optimal ball charge with all diameters was defined and verifed.
The experiments of quartz grinding were carried out in the laboratory steel mill with steel balls in dry environs. Degree of mill feed was maintained on 40% of mill volume in all experiment as well as mill revolution was constant at value 85% of mill critical speed.
Abstract
Because of changed printing technologies and increased recycling quotas in the paper industry, demands on flotation deinking have increased considerably, particularly in the last few years. Today, in the paper
industry, flotation deinking is the dominating process worldwide for the removal of printing inks from recovered paper. The focus of this paper will be the deinking flotation process. The deinking process includes a number of processes in succession dipending on the particle size of the ink particles
liberated from the newsprint. Experimental studies have been conducted to evaluate different operating conditions, including temperature of liquid phase, concentration of solid in flotation, etc. The efficiency of the process is evaluated in terms of brightness and filthiness. The paper shows results of
investigation the influence of the temperature of liquid phase on quality of recycled waste newspaper and on efficiency in removing the ink from newspaper by flotation.
Abstract
Apart from a high concentration of iron, mine water can also contain a higher concentration of manganese. Extraordinarily high concentrations can be found in acid waters from the surroundings of ore deposits, e.g. the water from the sulfitic ore deposits in Smolník contain up to 40 mg.l-1 of manganese. The legislation ordains discharge of water into surface water with a maximum concentration of manganese of 1 mg.l-1, and therefore it is vital to reduce the content of manganese in the mine water to
a permissible value. Within the research work, a variety of demanganization methods were tested. In conclusion of the paper, so far most optimal method of manganese removal from acid mine water is suggested.
Abstract
Ceramic glazes are used for the layer protection, coating and decoration of various ceramic products such as: porcelain, majolica, faience, sanitary ceramics, artistic ceramics, electro-porcelain. The
application of colorless or colored glazes creates the possibility for restoration and decoration of ceramic products. Every ceramic type has a certain specific characteristic and it requires a particular type of glaze which must be in compliance with the tile.
This study describes the application of basalt ores from the bearing “Vrelo” on Kopaonik for faience ceramics. Investigation was performed in the aim of finding a correlation between specific characteristics of coating glazes based on basalt.
Abstract
In this paper authors consider changes of mineralogical composition depending on firing temperature of Smederevska Palanka brick clay. Research of the influence of firing temperature on mineralogical
composition was performed on fraction samples with particle size up to 5μm of studied clay and subjected to thermal treatment at temperature of 600 oC, 800 oC, 1000 oC and 1200 oC. The samples were then subjected to x-ray diffraction analysis (XRD) and to examinations by scanning electron microscopy (SEM).
It was found that during firing Smederevska Palanka brick clay had the characteristic to develop mineralogical phases of hematite, melilite, monticellite, wollastonite and mullite. In this clay the decrease of porosity by increase of firing temperature was found as well as some presence of glassy phase which also was proportional to the increase of firing temperature.
