Access to the mine Espérance by river via the Maroni River which borders the border with Suriname. An aviation nearly 1000m track allows easy access to the site.
The exploitation of open pit mine type (MCO). It is done using excavators Hyundai 450 (4 units) and transportation of ore by Terex TA35 articulated haulers (4 units). The company exploits only the soft saprolite materials that do not require blasting.
Ore processing is done by two steps: crushing and grinding in two ball mills in closed circuit. The recovery is ensured by centrifugal concentrators Knelson type KC 48. A flotation unit is being mounted to increase gold recovery.
The sector of Espérance Creek is known since 1890 for its wealth in gold. Various studies have summers are undertaken by former miners who left behind traces of their passage, tunnels, railroad, steam engine ...
During the inventory of the mineral resources of Guyana, BRGM perform significant work covering the work of the elders. The results are surprising, it shows a geochemical anomaly over 2 km long and 500 m wide. The three core holes made in the aftermath show mineralization rooted in saprolite and hard rock to at least 150 m depth.
The deposit then emerges as a priority No 1 of the inventory.
In the late 1980s Gérard Ostorero discovers this project forward quickly and meets the necessary means for its commissioning. He founded the Compagnie Minière Espérance in 1991, after obtaining a research permit personal capacity.
The operation starts with the alluvial resource, abundant, helps fund the development of primary mine Espérance.
In 2013, the Espérance mine gives its name to a rock found on Mars by the Opportunity rover; this rock is a proof that Mars has been rich in water and suitable for life in the past. The rock is called Espérance because of the presence in the mission of a member who has done research on the site of the Espérance mine, but also because this discovery gives Espérance of a possible life on Mars.
Rig on Espérance
The Espérance deposit is located in the western part of the greenstone belt (greenstone belt) north of Guyana. It belongs to a larger whole, called Shield Guayana Shield once connected to West Africa.
At Espérance, the mineralization is implemented in tectonic contact between the sedimentary basin of the Maroni and a set of granite massifs. The basin consists of detrital series unconformably on a volcano-sedimentary base (series called "Paramaca"). The area is heavily distorted by shear movements that developed in contact with granites.
Gold is supported by a quartz vein system with a geometry and stockwork hosted in clastic series. The latter consist mainly of sandstone laminae and conglomeratic sandstones. Gold occurs either in association with pyrites or free or inclusion in quartz. The mineralization is very poor in other elements usually accompanying gold: silver, arsenic ...