Experts from State Mine Company, Pernik began the geological research in the Maritsa Iztok Basin in 1948 and it was established that the reserves amounted to over 2.9 billion tonnes of coal. The first development project was prepared in 1951 by GIPROSHAHT, Leningrad and envisaged seven opencast mines. Upon completion of the prospecting and the preparation of the detailed geological map of the region, Decree No 652 dated 16th June 1951 of the Council of Ministers was issued, establishing Maritsa Iztok, a state mining enterprize, residing in the village of Troyanovo.
Item 1 of Decree No 652 dated 16th June 1951 of the Council of Ministers reads, “On the strength of Art. 1 of the State Enterprize Act, the coal deposits in the eastern area of the Maritsa Coal Basin shall be established as a state mining enterprize named Maritsa Iztok with a seat in the village of Troyanovo, Stara Zagora District.” That decision was the logical outcome of the prospecting activities in 1947 and 1948, done by the experts in the Geology and Mine Surveying Service at Pernik State Mines. They came to the conclusion that the discovery of a large lignite basin could be expected. In the Maritsa Iztok coal basin more than 3 billion tonnes of prospected reserves are located over an area of 240 square kilometers. Despite the disadvantageous quality characteristics of the coal – low coalification level, high moisture contents, low calorific value, sulphur contents – the country’s growing fuel and energy demand in the 1950s led to the decision to work the deposit. In March 1951 the preliminary design of the mines working the deposit was ready. It was prepared by Lengiproshaht, Leningrad, with Eng. Mariya Demidova as general designer.
On March 3rd 1952 Yordan Ivanov and Kolyo Petkov, both working for Minstroy State Economic Group, under the supervision of Petko Nikolov, Engineering Manager, turned the first sod for Troyanovo-1 Mine. It was for a banker, and that laid the beginning Mini Maritsa Iztok EAD. The first excavators were delivered in May and the construction of a railroad commenced in June.
The construction of the mine was carried out by Minstroy State Economic Group - Third Building Area with Manager Donyo Pehlivanov. The Group undertook the task to train the workers to operate the excavators because there was no qualified personnel. In 1954 the first qualified excavator operators obtained their certificates: Ivan Mutov, Enyo Mutov, Gancho Tenev, Mihail Yankov, Ilcho Hristov, Dinyo Kishnev and Ivan Angelov. They took part both in the construction of Troyanovo-1 Mine and in the exploitation of the coalfield afterwards.
In March 1954 the first Soviet СЭ-3 excavators arrived at the site of Troyanovo-1 Mine (called Maritsa Iztok then). They were employed in drawing the pioneer cut. On 19th July the same year the first train of overburden was loaded, the external dump site formation started together with the substantial construction of the mine.
In the 1970s a new design for mining operation without any pillar was adopted.Itenvisaged to initially extract the coal pillar between Troyanovo-1 and Troyanovo-3 mines and to form a single production area named Troyanovo-South Mine, with two strips: northern – that of Troyanovo-1 Mine – and southern – the one of Troyanovo-3 Mine. Huge mining and hydraulic engineering construction began simultaneously to prepare for the extraction of the coal pillar between Troyanovo- 1 and Troyanovo-North mines. Part of that project included the redirection of the Ovcharitsa river away from the coal field through canals to the left and to the right, the construction of twodams, twosmalldams, fiveretentionbasins, 31 kilometersofcanals, akilometerofundergroundsyphon, 6 kilometers of underground canals and other smaller water-engineering works. On 21st March 2008 the coal pillar between the two mines was formally cut and production from the most efficient part of the coalfield began.