GABORONE (miningweekly.com) – The modular tailings treatment project (MTTP) which is currently being built at Debswana’s Jwaneng diamond mine in Botswana, is expected to begin initial commissioning in the next few months.

A substantial volume of diamond tailings has accumulated at Jwaneng since operations began in 1983, before diamond recrush facilities were introduced.

The MTTP, which will treat 2.4-million tons of old tailings a year, is expected to yield 18-million carats over 20 years.

This will add 900 000 ct/y to Jwaneng’s current output of 13-million to 15-million carats a year, which contribute a disproportionate 70% of Debswana’s total earnings because of their high value.

Debswana group manager process engineering Ben Baeletse told last week’s Botswana Resource Sector Conference in Gaborone that the MTTP was being set up as a concept for replication at other mines in the Debswana group, which is owned jointly by De Beers and the government of Botswana.

Jwaneng had been chosen first because of its better resource and the availability of power and water.

“We see this as a new frontier for marginal resources going forward,” Baeletse said, adding that the concept had been tried at other sites in the past.

The idea behind the compact modular plant design was to reduce project costs and have a low environmental impact compared with previous processing plants.

“It presents itself as a low-cost facility,” he said.

The material has degraded as a result of the long time that the material has been dumped.

Mechanical completion of the plant is expected in November, with ramp up in July 2014.

Delays have centred on Jwaneng’s Cut 8 project requiring site accommodation for longer that expected and the late issuing of issue-for-construction drawings.

It will serve as a facility to demonstrate the economics and capability of the modular plant concept and has been made to harmonise with the site’s completely automated recovery plant or Carp plant.

“From now on, we will have a copy-and-paste-type template which we can use going forward,” Baeletse added.