Modern Mining September 2017

TIN

The increasing numbers of workers at site have necessitated the construction of additional accommodation.

22 heavy earthmoving machines for work at Mpama North and on the access road. Kamstra described the completion of the boxcut on schedule as an “extraordinary achievement” and also noted that a return airway adit, on which work started last year, had recently intersected the orebody “exactly where we expected”. He said that an airstrip would be put in close to the Bisie camp and added that Alphamin would also be giving attention to the Goma-Walikale road which currently has a section which is in a state of complete disrepair. Although the project is now well into con- struction, it is not yet fully funded. Kamstra told the media that Alphamin (which has already spent approximately US$70 million on Bisie), did not anticipate any problem in raising the remaining financing needed and said this process – which would involve both debt and equity in a roughly 50:50 split – could be com- pleted by year end. Finally, it is probably worth pointing out that Bisie will be commissioned at what appears to be a propitious time for tin demand, with the International Tin Research Institute (ITRI) forecasting a probable global shortfall of the metal beginning in 2018. The ITRI further suggests that tin production from many exist- ing mines and mining regions may have peaked and that a gradual decline may be expected in future years. With Bisie able to produce profit- ably at prices well below those being achieved at present, the project certainly looks to have a bright future – provided, of course, that the DRC remains reasonably stable, as Alphamin is confident it will. Report by Arthur Tassell, photos courtesy of Alphamin

on a tin price of US$17 300/ton, which is well below the current (late August 2017) price of approximately US$20 300/ton. The process design is based on recovery of tin into concentrate through conventional – and simple – gravity separation methods. Mined ore will be crushed to 100 % passing 10 mm. The coarse material (10 mm to +1 mm) accounts for 75 % of the mass flow and the tin contained in this size fraction will be recov- ered in conventional jigs. The fine material (-1 mm) makes up the balance of the mate- rial and the tin contained in this stream will be recovered using spirals. The concentrates from both the jigs and spirals will be milled and subjected to flotation to remove sulphide material. The tin rich concentrate will be thickened, filtered and dispatched for trans- port to smelters for further refining. While the plant – which will have a design capacity of 360 to 400 kt/a with an expected tin recovery of 73 % – will only go into construc- tion next year, the mine infrastructure is on the critical path and an early start has been essen- tial if the project is to come on line and start its production ramp-up in the first quarter of 2019. To this end, Alphamin reported in April this year that it had appointed Kongo River SA and VRSC SARL as the project’s earthworks contractors and Reliant Congo SARL as the Phase 1 mining contractor. All three contractors have a track record in the DRC, with VRSC, for example, having worked on the construction of Banro’s two gold mines in South Kivu Province, as well as the Kibali mine of Randgold/AngloGold Ashanti in Orientale Province in the far north-east of the DRC. In all, the contractors have deployed

The process design is based on recovery of tin into concentrate through

conventional – and simple – gravity separation methods.

September 2017  MODERN MINING  25