North Mara

Overview

North Mara is an open pit gold mine located in the Tarime District of the Mara Region of Tanzania.

Gold mining in Tanzania in modern times dates back to the German colonial period, beginning with gold discoveries near Lake Victoria in 1894.

The North Mara mine, which opened in 2002, consists of four open pits, a process plant, waste rock dumps, a tailings containment pond, and other associated facilities. The mine is owned by African Barrick Gold Corporation.

In 2011, the mine produced 170,000 oz gold at a cash cost of US$810 per ounce. A waste stripping program also took place during the year preparing the ground for mining better gold grades.

Location

North Marais an open pit gold mine in the Tarime District of the Mara Region of Tanzania. It is around 100 km east of Lake Victoria and 20 km south of the Kenyan border.

Tanzania is a country in East Africa situated on the shores of the Indian Ocean. Its economy is mostly based on agriculture. Natural gas and minerals also contribute to the country’s wealth.

The site is served by the national road system and there is an airstrip 7 km from the processing plant.

The annual average temperature ranges from 16° – 29°C. Average annual rainfall for the region is 1,300mm.

Geology & Mineralization

The North Mara gold deposits are situated in the Mara Musoma greenstone belt. There are several types of gold mineralization including shear-zone-related quartz vein and disseminated gold.

In 2011, the life-of-mine was estimated at around ten years, based on its proven and probable gold reserves of 3,485,000 ounces.

Mining & Operation

The North Mara mine consists of three open pit deposits: Nyabirama, Gokona and Nyabigena and development potential at Komarera. There is also a process plant, together with waste rock dumps, a tailings containment pond and other associated facilities.

The open pits are conventional hard rock operations with drills, hydraulic shovels and mechanical drive haul trucks.

In 2011, North Mara operations mined 21.8 million tonnes of which 2,254,000 tonnes was ore.

Focus for 2011 was a planned and substantial waste stripping program at Gokona and Nyabirama to open higher grade zones for future years. Plans were made to finalize the analysis of potential Gokona lateral pit extension and resulting re-sequencing of the Gokona underground project. Another task to be completed in 2012 was to progress the Nyabirama Underground project into a feasibility study.

Processing

Ore is processed through crushers, an open circuit SAG mill and a closed circuit ball mill. The crushed ore is processed via cyanidation (carbon in leach) and a gravity circuit, followed by electrowinning and gold refining to doré on-site. 

Water is pumped from the Mara River, which is located three kilometers from the processing plant site. The mine has a license to extract 4,200 cubic meters of water daily from the river. 

In 2009, a power transmission line was brought to the site by Barrick and Tanzania’s national power company TANESCO. 

Priorities for 2012 are to complete the upgrades to the gold plant circuit and the detoxification plan and to complete the commissioning of water treatment plant for discharge of the EPO.

Environment & Community

The North Mara Mine operates at zero discharge, meaning that it recycles process water and does not discharge any water from processing into the environment. 

All mine facilities are fenced and tailings impoundment water, and other mine-impacted water, is regularly monitored to ensure that the water quality remains in compliance with the international criteria established to protect wildlife. 

During operations, when disturbed land is no longer required for mining activities, it is reclaimed by re-contouring and re-vegetating the areas. 

North Mara is working to help combat desertification in the region. The mine donated almost 7,000 tree seedlings to various recipients in the local community. 

By bringing the power line to the mine area local businesses and people also benefited from access to electricity.