This study shows the results of flotation concentration of mica minerals from kaolinised granite taken from the “Bašića bare” deposit – Kobaš, Srbac, The Republic of Srpska (B&H). Mineralogical composition of kaolinised granite is as follows: kaolinite, feldspar, quartz, and mica. After separating >0.630 mm, and <0.043 mm size class where kaolinite is concentrated, the rest is –0.630+0.043 mm class containing quartz, feldspar and mica. The mica concentrate was obtained by the flotation concentration, while feldspar and quartz were in the flotation underflow. According to the mineralogical analysis, the most abundant minerals are mica and chlorite/clays, while quartz and feldspar occur much less, and accessory minerals are represented in trace. The semi-quantitative mineralogical analysis obtained by the X-ray powder diffraction (XRPD) method of the mica concentrate amount to: mica ≈55%, chlorite/clays ≈35%, quartz ≈5%, feldspars (plagioclase and K-feldspars combined) ≈5%.
The region’s development potential is a set of endogenous features that determine the growth of the local economy. It supports the development of knowledge, innovation and eff ective competition on global markets. The publication argues that saturation with potential may not be enough to cause economic growth. The distribution of potential is also important: concentration is its catalyst. The study proposes a method for measuring the concentration of potential. It has also been shown that the size of the regional economy depends on the distribution of potential in the region.
During the cruise of the research ship r/v Oceania owned by the Institute of Oceanology of the Polish Academy of Sciences in Sopot a research on mineral suspension concentration and dispersion distributions was conducted. The research area included the western part of the Baltic Sea, the Danish Straits, the Norwegian Sea, the waters around Spitsbergen and the North Atlantic Ocean. Samples of water were collected from the surface layer. They were subjected to microscopic analysis. Measurements were done with a projection microscope (magnification lOOOx) and using the Burker's table. After counting the particles dispersion distribution was determined. The largest concentration of mineral suspension was noted offshore in the Norwegian Sea and around Spitsbergen and the smallest in the central Atlantic Ocean.
This paper presents the results of studies on functional possibilities of the optimization of geometric sizes and the design development of specialized resonance concentrating link (concentrator-sonotrode) with enlarged radiating surface. Developed theoretical model allows to determine the value of longitudinal and transverse sizes of each part of concentrating link providing the achievement of required features of the ultrasonic vibrating systems (gain factor of the unit and its resonance frequency). To verify the efficiency of designed model, the geometric sizes of resonance concentrating link were determined using the finite-element complex, which showed that the disagreement did not exceed 10%. The efficiency of proposed model at the determining of size and resonance characteristics of concentrating link was proved by the experiments. Theoretical and experimental studies helped to optimize the size of concentrating link while the vi- brating system developed on its base enabled the enlargement of radiating surface without decreasing the radiation intensity for the realization of technologies of cavitation treatment of liquid media
Detection of explosives vapors is an extremely difficult task. The sensitivity of currently constructed detectors is often insufficient. The paper presents a description of an explosive vapors concentrator that improves the detection limit of some explosives detectors. These detectors have been developed at the Institute of Optoelectronics. The concentrator is especially dedicated to operate with nitrogen oxide detectors. Preliminary measurements show that using the concentrator, the recorded amount of nitrogen dioxide released from a 0.5 ng sample of TNT increases by a factor of approx. 20. In the concentrator an induction heater is applied. Thanks to this and because of the miniaturization of the container with an adsorbing material (approx. 1 cm3), an extremely high rate of temperature growth is achieved (up to 500 °C within approx. 25 s). The concentration process is controlled by a microcontroller. Compact construction and battery power supply provide a possibility of using the concentrator as a portable device.
This investigation is concerned with the extraction of nugget copper particles from copper recovery plant slag which recycled of copper scrap. For this purpose, the Falcon concentrator was used because of its enhanced gravity properties. The Falcon concentrator has a fast spinning bowl which creates a centrifugal force to separate fine size minerals on the basis of their density differences. In the tests, the tailings of the copper recovery plant were used and the test sample was divided into two groups and one of them was classified in narrow particle sizes. The operational parameters were determined as particle size, centrifugal force and washing water pressures. The water pressure and centrifugal force have an inversely proportional relationship. Because of this phenomenon, the G/P parameter was created. The test conditions were applied to the whole distribution sample and narrow size distribution samples in the same way. The test results indicate that the average grade was elevated from 1.04% to 6.50% with the recovery of 15.07% and 619% enrichment ratio for narrow sizes, whereas grade was elevated to 4.36% with 13.24% recovery and 415.94% enrichment ratio for the whole distribution. As a result, the recovery and grade values of concentrates are not good enough for gravity concentration process for both samples. However, this process was applied to the double recycled material and the lower recovery, grade values can be tolerated because of concentrate is nugget copper metal. The concentrate can also be washed in cleaning table for increasing the grade value for adding to initial feed of plant. This process can, therefore, supply important earnings not only economically but also environmentally.
Wyroby stalowe i żeliwne ze względu na niską cenę i korzystne właściwości znajdują najszersze zastosowanie wśród metali w gospodarce, a ich zużycie stało się wskaźnikiem rozwoju gospodarczego. W artykule przedstawiono charakterystykę surowców żelaza w odniesieniu do obecnych wymagań hutnictwa. Globalizacja handlu i rozwój technologii wytwarzania stali w ostatnim półwieczu spowodowały istotne zmiany w jakości wsadowych surowców mineralnych. Wymusiło to usprawnienie technologii przeróbczych przez zakłady górnicze. Przedmiotem światowego handlu są obecnie standardowe koncentraty o zawartości żelaza ponad 60%, tj. niemal dwukrotnie bogatsze niż rudy przetwarzane w połowie XX wieku w wielu krajach. Udoskonalone zostały sposoby oceny jakości surowców wsadowych i zaostrzono normy jakości. W publikacji dokonano przeglądu wymagań jakościowych najbardziej istotnych surowców: rud i koncentratów żelaza, złomu stalowego, głównych metali stopowych, węgla koksowego i koksu oraz gazu i innych nośników energii. Zwrócono szczególną uwagę na metodykę badania jakości surowców oraz standaryzację surowców wsadowych. Jakość surowców oceniana jest wieloparametrycznie; istotne są zarówno cechy chemiczne, jak i fizyczne. Gorsze parametry jakościowe surowców wsadowych skutkują niższymi cenami uzyskiwanymi przez dostawców w obrocie. Rynki tych surowców są zróżnicowane, kierowane odrębnymi i częściowo nowymi regułami. W obrocie handlowym funkcjonują standardy odniesień cenowych (np. ceny węgla metalurgicznego w Australii czy indeksy cenowe koncentratów żelaza). Część surowców kwotowana jest w systemie giełdowym (niektóre składniki stopowe i złom stalowy). Rezygnacja z powszechnych dawniej kontraktów wieloletnich doprowadziła do dużych wahań cen, które osiągnęły podobną skalę jak inne metale.
The paper presents results of the field tests on membrane biogas enrichment performed with the application of mobile membrane installation (MMI) with the feed stream up to 10 Nm3/h. The mobile installation equipped with four hollow fibre modules with polyimide type membranes was tested at four different biogas plants. Two of them were using agricultural substrates. The third one was constructed at a municipal wastewater plant and sludge was fermented in a digester and finally in the fourth case biogas was extracted from municipal waste landfill site. Differences in the concentration of bio-methane in feed in all cases were observed and trace compounds were detected as well. High selectivity polyimide membranes, in proper module arrangements, can provide a product of high methane content in all cases. The content of other trace compounds, such as hydrogen sulphide, water vapour and oxygen on the product did not exceed the values stated by standard for a biogas as a vehicle fuel. The traces of hydrogen sulphide and water vapour penetrated faster to the waste stream enriched in carbon dioxide, which could lead to further purification of the product – methane being hold in the retentate (H2O > H2S > CO2 > O2 > CH4 > N2). In the investigated cases, when concentration of N2 was low and concentration of CH4 higher than 50%, it was possible to upgrade methane to concentration above 90% in a two-stage cascade. To performsimulation ofCH4 andCO2 permeation through polyimide membrane,MATLABwas used. Simulation program has included permeation gaseous mixture with methane contents as observed at field tests in the range of 50 and 60% vol. The mass transport process was estimated for a concurrent hollow fibre membrane module for given pressure and temperature conditions and different values of stage cut. The obtained results show good agreement with the experimental data. The highest degree of methane recovery was obtained with gas concentrating in a cascade with recycling of the retentate.