Laiva Mine
Laiva Mine[edit]
| Location | Peihinki,Northern Ostrobothni,Finland |
| coordinates | Lat:64.551113 Long:24.598329 |
| Mine type | Shear hosted Gold Deposit (open pit) |
| Mine owners | Nordic Gold Oy (subsidiary of Firesteel Resources Inc) |
| Gold produced | 78500 oz |
| Exploration activity | 1981-present |
| Production activity | 2011-2014 |
| Resource estimate as of August 2017 | 600000 oz |
| Site expenditure | €220 million |
Overview[edit]
Laiva mine is a gold mine situated on the Laivakangas Gold deposit, the second largest in Finland. The mine is located 15km NW of the ‘city’ of Raahe in the Ostrobothnia province of central Finland. Laiva is maintained and owned by Nordic Gold Oy/Firesteel Resources. The mine is currently in maintenance but is due to start production in August 2018 from its two open pits,with a production target of 100,000oz of Gold per annum.
History[edit]
Laivakangas gold deposit was first discovered when a mineralised boulder was observed by an amateur Geologist skiing in the area, in the early 1980’s. Following this initial discovery Outokumpu laid claim to the area and explored the deposit between 1981 – 1986. Following this Endomines Oy claimed the area and began core drilling. Nordic mines Oy started exploration in the area in June 2005. In October 2009 they gained the mining lease creating Laiva mine,and began production in the third quarter of 2011, The first Dore Gold bar was cast on Dec 27th 2011. Production ceased in 2014 due to a drop in global gold prices. Leading to the mine lying dormant in care maintenance. The mine is now under new management with extensive investments in RC drilling programs, they are also conducting a 1000km magnetic line survey to identify the iron-rich lithology’s associated with the resource. The mine is currently expected to restart production in the August 2018. Historic expenditure on the property is estimated at €220 million including exploration, maintenance, infrastructure and production costs. Laiva mine produced 2225kg of gold (78500oz) during production from 2012-2014.
Geology[edit]
Regional
The Laivakangas (or Laiva) gold deposit is located in the NW of the economically significant metallogenic Savo belt, it is an accretionary orogenic belt, characterised by the presence of numerous shear zones. The Savo belt is associated with several different styles of mineralisation including Kuroko style VMS Cu-Zn mineralisation (Pyhäsalmi, Vihanti), porphyry style Au-Cu mineralisation (Kopsa), Ni-Cu mineralisation associated with mafic-ultramafic intrusives (the Kotalahti nickel belt), and orogenic (shear-hosted or lode) gold style, e.g. Laiva.[1]
Local
The oldest host lithology’s to the Laiva mineralisation are fine-medium grained mafic volcanic rocks representing weakly to moderately metamorphosed lavas and tuffs. These are intruded by quartz diorite rocks ranging from medium to coarse in grainsize. Tectonic contacts are typically characterised by a zone of brittle faulting or increased shearing, often marked by late pegmatite intrusions. The gold is deposited in clustered shear hosted auriferous quartz veins, the gold partials are around 1-50nm in diameter and found as inclusions within Arsenopyrite and Quartz. Gold was precipitated in these veins 1863 ± 26 Ma and thought to originate from older granite intrusions.[2]
Mining Operations[edit]
The mine is comprised of two open pits, North and South. The North pit measures 60m in depth and covers a surface area of…. With narrow benches, the north pit was the main past source of Gold ore. With the strip ratio at around 5.15-1 waste-ore. The south pit is shallower at around 10-15m depth and has a surface area of….the south pit has had extensive RC and Dimond drilling carried out within it but little ore produced as of yet. RC and Dioamond drilling has been carried out between the pits and across the 1694ha mining licence,as well as bedrock surface drilling,RC/Diamond drilling,Geochemical sampling of soil Gold content and Geophysical surveys on other gold prospects within the exploration licence, which are called the new hope area's, which consist of the Otlava,Musunneva and kaukienen Exploration licenses.[3]
Ore Processing[edit]
Ore from the two pits is delivered to the crusher via large dumper trucks where it is crushed firstly to 200mm.The ore is then loaded onto a conveyer belt which leads into two cone crushers, which crush the ore to less than 0.1mm. The ground ore then goes through a leaching process and gold is recovered on a carbon leach (CIL) process. Gold is then recovered from the loaded carbon and separated via electrolysis. Once the gold is recovered it is then melted and poured into Dore bars on site. Plant has the capability to be fed 600tonne of ore per hour.[4]
References[edit]
This article "Laiva Mine" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Laiva Mine. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.
