Significant investments in production
During the year, Terrafame invested heavily in the development of production. As a whole, investments were in excess of EUR 84 million when taking into account the purchase of the lime plant and laboratory.
Terrafame began preparatory work in the commercialization of copper in 2016, and aims to begin its sale in 2017. Copper sulphide precipitation is the first step of the production process at the metals production plant. In bioheapleaching, however, copper leaches from the ore at a later stage than zinc and nickel, so its commercialization is of interest now, since production has already been at the ramp-up phase for some time.
During the year under review, the design work and procurements of the copper commercialization investment project were brought to completion. Construction work will be carried out in 2017. As a whole, copper commercialization is an investment project reaching almost EUR 1 million.
Secondary leaching a substantial investment
The construction of the base structures of the new secondary heaps 3 and 4 was continued during 2016. Capital expenditure totalled EUR 35 million. The heap 3 base structures were brought to approximately 70 per cent completion and the heap 4 base structures to approximately 40 per cent.
Secondary heap 3 will be ready for production in the spring of 2017 and secondary heap 4 at the turn of 2017 and 2018. When the secondary bioleaching cycle, lasting for 3–4 years, has been brought to completion, the leaching heaps will function as final disposal place for dissolved ore.
Waste rock area under construction
Waste rock has so far been utilised in the construction of bioleaching areas, but from 2017 onwards it is to be transferred to a separate waste rock area located east of the Kuusilampi open pit. In an area located within the vicinity of the Kuusilampi ore body, two areas – KL2 and KL1 – have been planned. In the autumn of 2016, Terrafame applied for an environmental permit for KL2, whereas KL1's permit will become relevant later.
Earth removal in area KL2 was initiated in 2016, and the preparation of the base structures is continuing by compacting and coating as well as with construction work of a pumping station in 2017. During the year, investments in the waste rock area totalled approximately EUR 1.7 million.
Eight million to centralised water treatment plant
The construction work related to the centralised water treatment plant was completed by the end of 2016, and trial use of the plant began in November 2016. The centralised water treatment plant will simplify the water purification process, making purification more cost-efficient and providing consistent quality in purification results.
The purification process of the new plant is automated and its capacity is 1,400 cubic metres of water per hour. The purification technology represents the best available technology and is based on lime neutralization. Metals present in the water are precipitated and the water is purified. The centralised water treatment plant represented an investment of EUR 8 million.
Terrafame acquires a lime plant, laboratory and geodata
In July, Terrafame announced the acquisition of the lime plant situated in the mining area in Sotkamo, in addition to a laboratory and mine-related geological data from Talvivaara Mining Company Plc.
After the acquisition, process improvements were made to the lime plant in the early autumn, and as part of this work the limestone silos were renewed. As a whole, improvement investments amounted to EUR 1.8 million.
Third hydrogen sulphide line brings more operational reliability
In October, the second production line was started at the metals production plant. The use of two production lines as well as the increase in metal production volumes will require more capacity from hydrogen sulphide production. For this reason, engineering work began in August on the third hydrogen sulphide line, which will be commissioned in the beginning of 2018.
During the year, several small-scale improvement investments were made to production. For example, the efficiency of the sulphur pulper was increased.