801 research outputs found
The producing of lead and elemental sulfur by new technologies from galenite ores
These investigations have developed an effective hydrometallurgical method to recover high-purity lead metal and elemental sulfur from simulated galena synthetic mixures eliminating sulfur gases and lead emissions, in contrast to the current high-temperature smelting technology.
The method consists of different operations: oxidative leaching with production of solution with residue containing elemental sulfur., electrowinning by the solution with metal production.
The obtained results determined the optimal parameters for possible processing of natural domestic galena ores
Cable Distribution systems - an essential element of the global information society
Not long ago, before the advent of cable operators, here in Macedonia, especially in the smaller towns in this area in the developed countries was overwhelming. In Shtip were able to follow only two or three programs in the Macedonian Television. Later, in the nineties of the last century, there have been two more programs to private local television stations. Admission to these programs is done through external antennas. Nevertheless, due to the specific configuration of the terrain and tall buildings, it was not possible quality reception of TV programs in all parts of the city. On the other hand, this way of receiving television programs by external antennas (and several antennas for each family) and brings other problems. Among other things, in terms of aesthetic appearance of buildings resembling a "forest" of antennas. With the advent of cable operators, this picture changes significantly. At the beginning of its development, the cable operators only offered a service to its customers - analog TV. Today, cable operators offer more services, ie services, and are called Multi Service Operators (Multi service operator - MSO). They invest in quality and expensive equipment that receive and distribute to end users a number of TV and radio channels channels with high quality. Users however, relatively inexpensive monthly fee can enjoy the quality of TV channels, radio channels, internet, telephony and other interactive services. Today through KDS can carry more than 70 (seventy!) Analog television and radio programs as well as a much larger number of digital TV and radio channels. Additionally through KDS enables fast digital communication, access to high-speed, broadband Internet and fixed telephony. Modern cable distribution systems represents a form of electronic communication networks. Electronic communications networks other than cable can be partially or completely wireless
The recovery of the biomass waste for industrial pellets by recycling
The biomass as an organic product which may be used as a fuel - biofuel or the raw material in the industry. The bio-fuel may be occurred as a plant or animal origin. These may be used by their direct combustion. The most effectively usefull method for biomass utilization is finalization in the pellet product as combustion product. The pellets have had appropriate parameters with geometry, caloric power, ash and dust. These wood products are rescent fuels produced by wood waste
Logistics of passengers at the domestic airports
As statistics show, air travel is one of the most prevalent in this society of ours from day to day is increasing its use. Characteristic of air travel and transport is his speed but that speed depends from many factors. Some of these factors are: the speed and capacity of the aircraft, the speed of transport of goods to and from the airport warehouses them to planes, the speed of data processing for passengers and their luggage forwarding to the appropriate place for loading the plane, the speed of system transfer the luggage of a passenger to the appropriate place for loading the plane and the speed of the staff handled it. Hereafter will talk about all these factors which affect to a fast and successful air transport
Prilog proucavanju procesa segregacionog przenja u cilju ekstrakcije nikla iz oksidno - silikatnih nikonosnih ruda
Prilog proucavanju procesa segregacionog przenja u cilju ekstrakcije nikla iz oksidno - silikatnih nikonosnih ruda. Obradzena je termodinamika i kinetika heterogenih reakcija na radnoj tempteraturi od 750 stepeni do 950 stepeni, dodatak kalciumhlorida od 2,5%, koks 0,5-1%, sulfidnih dodataka i slicno. Proracunati su izobarni potencijali reakcija segregacije i kineticke konstante pomenutih reakcija na radnim uslovima
Current applications of micro - organisms in the leaching of copper and gold from chalcopyrite low grade ores
The conventional flotation technologies cannot provide fair results when applaid to very low grade ores or to "refractory" ores. This class includes intimate and nonuniform mineral associations, with partialy oxidized minerals and high secondary mineral content and also high soluble salt content, pre-activated minerals because of the excessive permeability of the deposit and of the intense circulation of waters with heavy metal ions etc. Bacterial oxidation as a means to the recovery of metals from sulphidic deposits has been used for thousands of years. One of the major use of biooxidation is the leaching of copper or the liberation of refractory gold where this is encapsulated in pyrite. In the Bucim copper mine Macedonia, porphiritic type, the final product from flotation is the copper concentrate consisting 20% Cu, 21g/t gold and 25g/t silver, with recoveries: 88% for copper, 60% for gold and 35% for silver. The carried out investigations of the leaching in the agitated tank involve micro-organisms, thiobacillus ferro - oxidans and thiobacillus thio-oxidans. The achieved results are following: Copper recovery 95%, gold recovery from 70-85% and silver recovery from 70-80%
Physical therapy approaches in treatment of sacroiliac joint dysfunction
Introduction: Through the ages sacroiliac joint (SIJ) dysfunction as a source of low back pain (LBP) has been evolved from unrecognized and neglected to a main source in 13% of the population (Schwarzer et al., 1995) or 19% (1995) and 15% (Bogduk et al., 2002). Although there is no widely adopted treatment protocol, the preferred approach is conservative including: electrotherapy, laser therapy, ultrasound, medications, rest, exercise, manual mobilizations and/or manipulations, acupuncture. Aim: The aim of this study was to compare the effects of two treatment programs. Material and methods: Total of 64 patients with pain in the lumbosacral region due to SIJ dysfunction were treated. Divided in two group B (experimental n=41) and V (controlled n=23). The controlled group underwent treatment consisting of classic massage, core stability exercise on stable surface, home exercise program auto-mobilization and for the experimental – manipulative massage, manual mobilizations of SIJ, core stability exercise with fitness ball. Results and conclusion: The positive influence of the therapy was common for the both groups but more noticeable in the experimental. This method demonstrate the normalizing effect on the dysfunction of the pelvic girdle, reduction of muscle imbalance, decreased subjective complaints and symptoms of pain -(VAS ±0.43, SEP ±0.23 and LP ±0.70)
Application of dispersion analysis for determining classifying separation size
The paper presents the procedure of mathematical modelling the cut point of copper ore classifying by laboratory hydrocyclone. The application of dispersion analysis and planning with Latin square makes possible significant reduction the number of tests. Tests were carried out by D-100 mm hydrocyclone. Variable parameters are as follows: content of solid in pulp, underflow diameter, overflow diameter and inlet pressure. The cut point is determined by partition curve.
The obtained mathematical model and the values of the coefficients make it possible to find the classifying cut point for variable factors
The treatment possibility of mining drainage from horizon 830 in the Sasa Mine, Macedonia
The drainage system on mining area Sasa consists of surface water from the rivers Crvena, Svinja and Kozja which are flowing from field of ore deposit, and
with other small mountain tributaries that flow into the River Kamenichka. The results of the measurements show that in all samples from surface waters are detected
increased concentrations of heavy and toxic metals, except for the water of the River Crvena. These increased concentrations are a consequence of historical
anthropogenic impact of acid mine drainage from old inactive pits, as well as the impact of current activities in mine SASA primarily from the mining drainage from the
active horizon 830. The paper shows results of the treating mining drainage samples from horizon 830, by applying the method of passive treatment “diversion wells”. The
results show that the use of combined treatment of diversion well and treatment with flocculants gives satisfactory results in terms of reduced concentrations of metals,
dissolved and suspended solids
Adsorption of copper ions from aqueous solutions on natural zeolite
The adsorption of copper ions from synthetic aqueous solutions on natural zeolite (clinoptilolite)
was examined. In order to determine the rate of adsorption and the copper uptake at equilibrium, a series
of experiments were performed under batch conditions from single ion solutions. Equilibrium data
were evaluated based on adsorption (Langmuir and Freundlich) isotherms. The adsorption kinetics is
reasonably fast. In the first 20 min of the experiment, approximately 80% of Cu2+ ions is adsorbed from
the solutions. Data obtained from the kinetic experiments have been described by the pseudo-second
order kinetic model as well as by the Weber–Morris and Furusawa–Smith models
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