Coloured gemstone miner Gemfields today unveiled a new ruby sort house at its Montepuez ruby mine in Mozambique. The $15 million sort house, which the company says is the first of its kind in the coloured gemstone industry, will be on a par with the best diamond facilities in the world.
The facility itself will raise production levels significantly. It works by using the natural properties of rubies as a means of automated sorting. The process starts with washing of the raw material, before passing it under ultra-violet (UV) light.
Rubies naturally fluoresce under UV light, meaning optical sorters can detect the fluorescence and employ blasts of air to direct individual rubies to separate channels for further sorting and grading.
The use of programmable logic controllers and data software under the UV light to conduct this process is faster, more reliable and more efficient than the human eye. It also allows the identification of a finer material component than before. A greater number of washing plants — the equivalent of washing 10,000
tonnes of ore per day — combined with UV optical sorting account for how throughput will increase exponentially, translating into significantly higher production figures, Gemfields said.
The company added, however, that the introduction of automation will not mean a reduction in workforce, but will in fact result in quite the opposite. Firstly, the greater throughput of the sort house means an expansion of the current active mining area, which will require an increase in workforce.
Secondly, the manual part of the sorting process — categorisation and grading the rubies themselves — will require a greater volume of highly skilled employees.
Rather than import this expertise, MRM is creating the first group of Mozambican gemmologists specialised in the selection and classification of rubies, which marks a substantial step for the ruby industry.
Gemfields said 2019 will be a significant year of investment and growth for its ruby mine, as the new sort house will be complemented by the implementation of a new thickener to the wash plant, increasing capacity to 150 tonnes per hour (from 125 tonnes per hour).
Two high capacity pre-screen plants will be brought on-line to remove the finer particle material prior to it being fed to the wash-plant, which will result in a greater concentration of the desired size material, further enhancing the wash plant feed capacity.
Sean Gilbertson, CEO, Gemfields stated, “We are proud of our pioneering approach and leadership position within the sector and continually work to improve the provision of responsibly sourced coloured gemstones.”
He added, “We are delighted to inaugurate this state-of-the-art, industry-leading ruby sort house today and will continue to strive to deliver best-in-class operations and promote transparency, trust and sustainable mining practices.”