Mina Lonea — Puțul Lonea Petrila · Hunedoara · Romania

Hard coal extraction in the Jieț valley at Lonea has a documented history stretching back to 1869, when opening works for a mine in the Lonea area commenced. By 1873 a connecting gallery between Mina Lonea I and the railway had been excavated, and a shaft in the Jieț zone — later identified as Mina III or the Puț Jieț — was sunk in two stages: the first in 1873 and the second between 1894 and 1895 when works were resumed and completed. Lonea I and Lonea II were progressively closed in 1928 and after 1 April 1930 respectively during the economic crisis of that period, while Mina III (Jieț) continued in operation.

In 1949, following the nationalisation of the mining industry and the establishment of the Soviet-Romanian joint company Sovromcărbune, Mina Lonea I and II were reopened and merged with the active Jieț workings to form a unified Mina Lonea. From that point, the mine entered a phase of intensive Communist-era expansion. During the peak years of the 1980s the Jiu Valley's mines collectively produced around ten million tonnes of coal annually, and Mina Lonea alone was reported to employ several thousand workers, with coal trains running on the Lonea–Petrila railway every fifteen minutes.

The mine's field stretched eastward from Lonea toward Petrila and covered a substantial portion of the eastern Jiu Valley coalfield. A separate operation, Exploatarea Minieră Lonea Pilier, was established in 1986 to exploit a reserve between Petrila and Lonea; it was closed in 1997. After the fall of communism in 1989, the mining sector underwent drastic restructuring.

Regia Autonomă a Huilei din România was established in 1991, and in 1998 it was transformed into Compania Națională a Huilei S.A. — Petroșani. The four remaining viable Jiu Valley mines, including Lonea, were incorporated into Complexul Energetic Hunedoara S.A., formed by government decision in 2011 through the merger of mining and thermoelectric assets. Lonea and Lupeni were identified as uncompetitive mines and targeted for phased closure from 2016 onward under plans approved by the European Commission, though successive deadlines were extended.

CEH entered general insolvency proceedings on 14 November 2019. By 2023 Mina Lonea employed approximately 400 workers, a fraction of its communist-era complement. In late 2024 the European Commission approved state aid of EUR 790 million to cover the exceptional closure costs of the four Jiu Valley mines.

CEH was declared bankrupt on 31 March 2025, and its assets were transferred to the new Complexul Energetic Valea Jiului S.A. for managed closure. Active underground coal extraction at Lonea formally ceased at 31 December 2025, with the process of putting the workings in safety, closing the shafts, and environmental reclamation scheduled for completion by the end of 2026 under EU-approved funding of approximately 3.15 billion lei through to 2032. The Puț Lonea shaft and its surface buildings — several of which had already fallen into disrepair by the early 2020s — face demolition or selective retention as part of the closure and land-reclamation process.

Discussions have noted the potential for some pithead structures to be retained for heritage purposes, following the model of the neighbouring former Mina Petrila, closed in 2015, where selected historic buildings were preserved as the Ansamblul Istoric Mina Petrila.