Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Drilling mud influence on sandstone poroelastic parameters

Knez Dariusz, Rajaoalison Herimitsinjo, Nkunzi Donatille

Journal of Geotechnology and Energy

2022

Vol. 39, no. 1

5--13

Perhaps the most critical challenge faced during drilling operations is related to the stability of the well. Additionally, drilling mud plays a crucial role in wellbore stability, as one of its main uses is to support the wellbore wall during the drilling operation. However, ignorance of the effects of drilling mud on the mechanical properties of rock formation can also lead to well failure. The stability of the wellbore is also influenced by pore pressure during the drilling process. The analysis of changes in rock poroelastic parameters after drilling mud saturation was found to be useful regarding the abovementioned issues. Therefore, the measurement of the dynamic Young’s modulus, Poisson’s ratio and Biot’s coefficient of sandstone samples was carried out to determine their trends of variations with confining pressure in different conditions such as dry, water and drilling mud filtrate saturation. The findings indicate that both the dynamic Young’s modulus and the Poisson’s ratio of the sandstone rock increased after saturation with water and drilling mud filtrate, while the Biot’s coefficient was reduced. Furthermore, the velocity of the P wave, the dynamic Young’s modulus and the dynamic Poisson’s ratio of the sandstone rock were proportional to the confining pressure, while the Biot’s coefficient were inversely proportional to the confining pressure. The results imply that effective stress calculation can be influenced by changes in poroelastic parameters established from geophysical measurements, and risk management of wellbore stability stability was increased.

Extraction of tin by carbon monoxide

Nkunzi Donatille, Szpytko Janusz

Hutnik, Wiadomości Hutnicze

2019

Vol. 86, nr 12

361--363

The Economy of Rwanda nowadays relies on the mining activities, where the mineral exports contribute a lot to the national export revenues. The Government therefore considers mining as one of the key sectors to drive economic development and poverty reduction. The 3T consist of the major mineral resources exported, and the tin occupies the second place among the 3T carried across the country. However, based on the standards of international market, the grade of these mineral is still low due to the artisanal processing methods. It is in this Regard; foreign companies were engaged in mineral smelting to increase the quality using carbon in form of charcoal as reducing agent in the electric arc furnace to separate tin from the associated compound within the concentrate. Despite that, the technology didn’t reach the high result of increasing the grade of tin due to the high affinity of tin with iron. Therefore, the direct reduction of tin by carbon monoxide is suitable to overcome the challenges mentioned. This paper, is discussing the process of using carbon monoxide during tin extraction from cassiterite concentrate.

Gospodarka Rwandy bazuje obecnie na działalności wydobywczej, w której eksport minerałów ma duży wpływ na krajowe przychody z eksportu. Rząd uważa zatem górnictwo za jeden z kluczowych sektorów, który napędza rozwój gospodarczy i ograniczanie ubóstwa: cyna zajmuje drugie miejsce spośród eksportowanych surowców mineralnych. Jakość minerału jest niska ze względu na tradycyjne metody przetwarzania. Zagraniczne firmy były zaangażowane w wytapianie minerałów w celu podniesienia ich jakości przy użyciu węgla drzewnego, jako środka redukującego w elektrycznym piecu łukowym (w celu oddzielenia cyny od powiązanego związku w koncentracie): technologia nie znalazła zastosowania z uwagi na wysokie powinowactwo cyny do żelaza. W artykule omówiono proces stosowania tlenku węgla podczas ekstrakcji cyny z koncentratu kasiterytu.