Parys Mountain Mine - historical outline up to 2007
Parys Mountain has been confirmed as a site of prehistoric mining, has some indications of Roman activity and became probably the world's largest copper mine in the 1780s. Until 1800 most mining was by open cast but from 1810 Cornishmen opened up significant underground workings. By 1900 all significant mining activity had ceased.
Modern exploration began in the 1960s - Canadian Industrial Oil and Gas drilled extensively in the 1970s and Cominco found the polymetallic zones in the early 1980s. Anglesey Mining was formed in 1984 and floated on the Stock Exchange in 1988. Extensive work was done on site between 1988 and 1990. The site was mothballed in late 1991 due to adverse economic conditions. Further surface drilling and major geological studies took place from 1997 culminating in a series by Micon from 2007 onwards.
Property and land rights
From its formation in 1984, Anglesey Mining had a mining lease, dating from 1971, entitling it to mine base metals at Parys Mountain. In 1997 the company purchased the freehold of the land and the minerals on the western portion of Parys Mountain where its identified mineral resources are located. It then entered into a new lease for the land and minerals in the eastern half. In 2002 it surrendered this lease and in 2006 it signed a new lease over the same area on terms it considered to be more satisfactory.
All the Parys base metal minerals are subject to a royalty, on much the same terms as the original lease, that is to say 6% of taxable profit attributable to base metals sold.
Gold and silver are leased by the company from the Crown and a standard royalty is due on their extraction. This lease expired in 2019 and negotiations on a renewal continue.
Planning permission for a 1,000 tonne per day mine was obtained in 1988, reviewed in 2006 and remains current. The local authority strongly supports the project because of the jobs it would provide in an area with high unemployment.
Between 1988 and 1990 a shaft was sunk to a depth of 300 metres and about 1,000 metres of lateral development were completed on the 280 metre level. Approximately 2,000 tonnes of development ore were hoisted and 700 tonnes were processed through an on-site pilot plant - concentrate production of about 200 tonnes was sold to the smelter at Avonmouth. All of the facilities are on the land now owned by the company.
Feasibility Study - Kilborn 1990
In 1990 Kilborn Engineering completed an independent feasibility study of the project that confirmed the technical and economic viability of a 1,000 tonne per day (300,000/350,000 tonnes per year) mining and milling operation producing zinc, copper, lead and gold concentrates. Kilborn estimated the capital cost of the mine in 1992 at UK pounds 22 million.
This study was based on a mineable reserve of 1,963,000 tonnes at a grade of 6.43% zinc, 1.30% copper, 3.32% lead, 75 grams of silver and 0.51 grams of gold per tonne and a mine life of seven years. This mineable reserve covered the shaft development area in the extreme west of the property, being only a portion of the overall geological resource of 6.5 million tonnes. There are also unexplored prospective areas to the east of these resources.
The Kilborn study was independently reviewed by two separate firms of consultants, SRK in Cardiff and WGM in Toronto, for project loan purposes, and a loan from Swiss Bank Corporation was approved and documented but not drawn down.
For information on further studies since 1995 see other sections of this website.
Local issues and project timing
After the feasibility study, detailed mine and plant designs were prepared and further more detailed planning permissions were granted.
If economic conditions were favourable, the directors believe it would be possible for the Parys Mountain mine to go into production in less than 2 years from financing. This was the time frame to completion of construction set out in the banking agreements of 1990.
Mining conditions are good, metallurgy presents no problem and planning permission has been obtained. Some aspects of the tailings arrangements might require further consents. A review of new regulatory requirements introduced since 1991 has not revealed any major hurdles for the project.
There is strong local support for a mine. The company's relationship with the Amlwch Industrial Heritage Trust, which takes a keen interest in the site, is excellent. There are no requirements at all to restore any of the old workings and mine dumps on the property - in fact generally these must be preserved and not disturbed or landscaped.
Geology in the late 1990s
From 1997 to 1999 the company concentrated its efforts towards resolving some of the geological uncertainties at Parys Mountain so as to to be able to better predict the occurrence of economic reserves. This work has been very successful and is outlined in the Annual Reports and covered in more detail in the geological and lithogeochemical reports on this website.
The company believes that there is potential for significantly increasing the level of resources, especially in the eastern area of Parys Mountain. An expansion of reserves would enable the production rate to be increased, with consequent transformation of the economics of the project.
In addition to the massive sulphide deposits which the company is currently targeting, CIGOL, a former holder of the mining lease, outlined the Northern Copper zone, estimated to contain 30 million tonnes at 0.7% Cu in the north central part of the property. This has not been one of the company's targets although the 1997-99 work has shown potential for higher grade areas within this zone and the occurrence of over 200,000 tonnes of copper metal in this area, not far from the potential sulphides, is obviously of interest.
From June 2005 - drilling and new plans
Diamond core drilling recommenced in June 2005 with AMC15, a 632m deep hole which intersected 2.5m of 40% combined base metals and 886 grams per tonne of silver. Other holes led to the identification of several important mineralised zones in the Garth Daniel area more than 700m from the Morris Shaft.
Having demonstrated a significant increase in the potential extent of the deposits, drilling much closer to the Morris Shaft in the shallow White Rock area commenced in 2005 and resulted in a JORC compliant indicated resource estimate of 1.75 million tonnes at 6.9% zinc equivalent. Although of much lower grade than the deeper resources previously identified, these resources were significant because they were shallow enough to mine economically through a decline and because they were JORC compliant.
In July 2007, Micon International produced a scoping study demonstrating the viability of mining the White Rock area at 500 tonnes per day with capital expenditures of UK pounds 15 million and operating costs of UK pounds 30.25 per tonne mined.
There are many fascinating aspects of Anglesey Mining plc as a company and of the Parys Mountain mine which are worth reviewing here.
The mine's lunar landscape has been used in a number of films, including Mortal Kombat II. Allegedly it was the world's largest copper mine and the person most responsible for its development, an Anglesey lawyer named Thomas Williams, was one of the first industrialists and a contemporary of James Watt. He was also one of the first to create a vertically integrated operation in which he controlled mining, smelting, distribution, warehousing and some fabrication work.
It is a much studied piece of ground, providing a rich source of unusual features for geologists, biologists, environmentalists, archaeologists, industrial historians and many more specialist disciplines. The slimes and algae growing in the old underground workings and the surface copper ponds are scientifically interesting and very colourful. There are uncommon minerals, orchids growing in contaminated soil and streams which carry enough acid to eat through one quarter inch steel in three months.
Although there is presently a great fashion for land reclamation and environmental improvement, the pollution at Parys Mountain has been there for centuries and has now become a feature in itself. Much of the surface of the mountain is protected in one way or another rather than being subject to landscaping schemes.
The possibility that bronze age man mined underground at Parys Mountain has, thanks to carbon dating, now become a certainty and further prehistoric discoveries are being made. These finds tend to indicate that our bronze age ancestors were considerably more advanced than had previously been thought.
Anglesey Mining plc was floated in 1988 at 70 pence per share, went to 220 pence (it was in the top ten performers of 1990, when zinc prices were at a real peak) and has since seen the share price come back as low as 1.0 pence. During this time the mineral deposit, the company's chief asset, on which all of its value is based, has not, physically speaking, changed at all. Of course the extent to which the asset can be demonstrated to exist and its measurable value have changed as our understanding of the geological processes which lead to the formation of the mineral deposits has improved.
Historically gold is not a metal associated with Parys Mountain. However it is present in the zones identified during the 1988 to 1992 development programme. From a production of 350,000 tonnes of ore a year, about 75 kilograms of gold could be recovered on site and sold to the jewellery trade as Welsh gold.