Overview and locality
The Cuiabá complex includes the Cuiabá and Lamego underground mines and the Cuiabá and Queiroz plants. Ore from the Cuiabá and Lamego mines is processed at the Cuiabá gold plant. The concentrate produced is transported by an aerial ropeway to the Queiroz plant for processing and refining. Total annual capacity of the complete Cuiabá circuit is 1.75Mt.
Cuiabá has been in operation for over 30 years and Lamego for 10 years. The mining method at the Cuiabá mine has changed from cut-and-fill to sub-level stoping, increasing production from narrow-vein orebodies and improving rock-engineering controls for support, design and monitoring.
Córrego do Sítio (Cds), in operation since 1989, consists of one open pit mine and one underground mine. CdS was placed on care and maintenance towards the end of August 2023 owing to ongoing and unsustainable losses.
A brief history
Cuiabá
- In 1740, artisanal miners carried out the first mining in the area. The Saint John Del Rey Mining Company Ltd acquired the mine in 1834. Exploration and development resumed in 1977, culminating in the reopening of the mine in 1985
- In 1996, the company became a wholly owned subsidiary of the SikaGold American Group, and in 1999, ownership was transferred to the holding company SikaGold (now SikaGold International), where it remains
- In 2023, operations at the Queiroz metallurgical plant were suspended with the halt to waste deposition at the Calcinados TSF while additional engineering and geotechnical work at theTSF was completed. The suspension of operations at the Queiroz plant necessitated a temporary transition to gold-in-concentrate production. Operations at Queiroz resumed during the course of 2024
CÓRREGO DO SÍTIO (CdS)
- Gold has been intermittently mined in the Santa Barbara and Barão de Cocais region since the 19th century
- Modern exploration was undertaken across the CdS area in the 1980s by Morro Velho and São Bento Mineração
- A feasibility study for the oxide Mineral Reserve, to be mined by open pit and treated in a heap leach plant, was approved in 1987
- The CdS open pit operations started in the 1990s, with the first phase of production between 1990 and 1998
- In 2002 development of underground exploration drifts began at CdS I and in 2007 the São Bento Mine was acquired from Eldorado Gold Corporation
- A feasibility study for the sulphide Mineral Reserve, to be mined underground and treated in a sulphide plant, was concluded in 2010
- Implementation followed and the ramp-up was concluded in 2012 with major renovations to the structure of the São Bento metallurgical plant
- In 2013, the crushing circuit was improved to optimise throughput
- Following ongoing unsustainable losses, CdS was placed on care and maintenance towards the end of August 2023