Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Diffusion between Cu and Cu/Ag contact materials of relays during multiple cycles under AC operation

Hotloś Agnieszka, Boczkal Grzegorz, Karpiński Marcin

Archives of Electrical Engineering

2024

Vol. 73, nr 3

629--642

Mechanisms of contact diffusion during relay-contacts operation were investigated. The contacts with the same geometry but different chemical composition were tested. The 1st relay-contact in a pair was made of copper, and the 2nd had a surface coated with a layer of silver about 500 micrometers thick. Different numbers of work cycles ranging from 8.5 k to 550 k were applied. AC current in the system was limited to 5 A. The closed/open periods were set at 250/250 ms. The resistance of the contacts was measured every 100 cycles. The microstructure of the working surfaces of the contacts after different numbers of operating cycles was investigated. On the surface of Cu contacts eutectic precipitates are formed and on the complementary bimetal contact tiny Cu-rich precipitates were generated on the silver surface. Crossection observations showed mutual material diffusion between the contacts. The depth of silver diffusion into the copper contact after 550 k operating cycles reaches 30 micrometers. The resistance of the contact system was stabilized after 40 k cycles at a level of 0.25 Ohm.

Wstępna ocena możliwości pozyskiwania pierwiastków wartościowych z wód kopalnianych oraz wód termalnych i leczniczych w Polsce

Razowska-Jaworek Lidia, Pasternak Marcin, Karpiński Marcin, Będkowski Zbigniew, Kaczorowski Zbigniew, Wysocka Irena, Drzewicz Przemysław

Przegląd Geologiczny

2022

Vol. 70, nr 6

435--448

Chemical components in groundwater from mine drainage or used in geothermal installations are a potential source of valuable minerals. At the Polish Geological Institute - National Research Institute, a study was carried out to identify the content of elements in mine waters, wells exploiting natural gas and oil as well as geothermal and therapeutic waters in Poland. The aim of the research was to recognize the concentration of potentially useful minerals in groundwater and the possibility of their recovery. It was the first project that focused on the recovery of elements from groundwater on a national scale in Poland. For this purpose, 67 sites were selected, in which 75 water samples were taken and the content of65 chemical components was determined. Then, the amount of minerals that could be recovered from mine waters and geothermal brines was calculated based on the amount of water pumped in each facility. The calculations involved the approximate efficiency and working time of the recovery installation. As a result of this research, it was found that the mine waters and geothermal brines in Poland contain resources of valuable elements in very different amounts. In more than half of the examined sites, the estimated resources of minerals are present in amounts that are not prospective. However, in 29 sites, mine waters and geothermal brines contain elevated concentrations of several elements, including - B, Br, I, K, Li, Mg and Mn. If they were successfully recovered, they could represent a potential additional income for the mining and geothermal industries. Dębieńsko Desalination Plant of mine waters in Upper Silesia is the most promising potential source of recovery of minerals from mine waters, where the total resources of minerals to be recovered from concentrated brine have been estimated as the highest. Rudna Copper Mine in Lower Silesia is in second place, with one of the highest resources and the largest amount of minerals to be recovered from groundwater. Other sites are: the SOLINO Salt Mine, “Olza” mine water collector, mine waters pumped from abandoned coal mines in the Upper Silesia (in Zabrze, Siemianowice Śląskie, Czeladź, Gliwice), and plants producing geothermal energy in Stargard, Pyrzyce and Bańska. Total amount of mineral resources that can be recovered from waters pumped from the most promising sites is over72 000 tonnes annually. Taking into account both the ecological aspect and the potential economic benefits of recovering minerals from mine waters and geothermal brines, it is necessary to continue the studies on the recovery of minerals from highly mineralized waters in Poland.