Mr Peter Robinson, Chairman, British Fluorspar Ltd ...

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www.britishfluorspar.com

Mr Peter Robinson, Chairman, British Fluorspar Ltd

Fluorspar Mining and Processing in the Peak District National Park

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Fluorspar Mining and Processing in the

Peak District National Park

October 2013

Presented by

Mr Peter Robinson, Chairman, British Fluorspar Ltd

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Fluorsid Group Structure

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Location Plan

British

Fluorspar

The Peak District National Park

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Processing Plant Cavendish Mill

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British Fluorspar Operational Areas

Arthurton West

Tailings Dam

Longstone Edge

Cavendish Mill

Milldam Mine

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A History of Mining in the Peak District

• Peak District has a long mining history dating back to

Roman Times.

• Evidence of lead workings in the vein systems goes

back to the 13th Century.

• Lead from Derbyshire was an important source of

armaments for the defence of the realm from the 17th

Century.

• Fluorspar was first mined at the beginning of the 20th

Century initially for steel making and then for the

chemical industry.

• Modern Flotation processing plant was constructed at

Cavendish Mill in 1965 and operated continuously until

2010.

• Following a period of Care and Maintenance the mining

operation and plant were purchased by British

Fluorspar in 2012.

• Following refurbishment Cavendish Mill became

operational again in April 2013.

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The Peak District National Park

• Peak District National Park was established in 1951.

• The Park covers an area of 1,437 square kilometres

in an upland area of central northern England

between Manchester, Sheffield and Nottingham.

• Peak District is the most visited Park in the UK with

over 10 million visitors per year.

• The Peak District is a Living Landscape with a

combined community totalling over 40,000 people,

many local families go back for generations in the

area.

• Mining in the Peak District is an important part of both

the landscape and communities of the area.

• British Fluorspar is the only remaining miner in the

Park extracting strategically important Fluorspar from

the vein structures.

• British Fluorspar makes a significant contribution to

local employment, environmental management and

the economy of the Park.

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Geology

Fluorite Mineral Resources

• Fluorite Mineralisation in the Peak District orefield

is contained within a series of near vertical veins

hosted in limestone from the Carboniferous

period.

• Hydrothermal mineral enriched veins are formed

in the cracks of fissures within the limestone fault

systems.

• The east-west trending fluorite veins extend from

surface or the base of the overlying shale to the

underlying volcanics.

• The primary veins range in thickness from 2 to

over 15 metres in width and grade from 15 to

over 40% CaF2.

• Stockwork, minor veins and replacement

mineralisation are also recovered from the

openpit operations.

• Mineralogy of the veins is predominately Fluorite,

Barytes and Galena.

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Underground Mining Operations

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• British Fluorspar operates an underground Drift Mine in the Hucklow Edge Vein system – Milldam Mine.

• The vein has been worked for over 300 years by the “Old Man” Lead Miners.

• Existing underground development at Milldam extends along a 2,000 metre strike/110 metre depth/5-15 metre width of fluorite vein which provides access to over 2 Million tonnes of good quality ore.

• There is potential within the Hucklow Edge vein to extend the mine further west which could double the known ore resource.

• Milldam is a modern Track-less mine which utilises mobile underground equipment.

• Ore is mined from a series of sub level open stopes (20 metre intervals). Access to the orebody and haulage is from parallel drives in the host limestone which require minimal support.

• Cross-cuts (slits) are driven at 10 metre centres into the vein system. Long hole fans are drilled and fired from the slits to blast the ore to a series of drawpoints in the stopes.

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• Remote controlled scoop trams are used to load the ore from the drawpoints into dump trucks for haulage to surface.

• An Artificial Crown Pillar will be constructed at the upper shale contact to optimise ore recovery and prevent subsidence.

• Crown pillar is a series of grouted rock bolts which are meshed and shot-creted.

• Milldam operates a two eight hour shift pattern with a periodic third night shift for long hole drilling.

• The mine is being redeveloped to produce 100 to 120,000 tonnes of ore per year for at least the next 20 years.

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Western Area

Development

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Milldam Mine Plan

Western Area Development

Sub level.

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Milldam Sub-level open stoping

direction of working

Crown

pillar

Sub

levels

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Openpit Quarry Operations

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Openpit Operations

• Mineralised veins are mined from deep narrow openpits which extend along strike.

• The veins which range in thickness from 2 to 4 metres pinch and swell laterally and horizontally. It important to maintain minimum working void for mining flexibility and to reduce environmental impact.

• Openpit batters average 65 – 70 degrees and are made steeper in places by the use of smooth wall blasting/rock bolting techniques.

• Depth of openpit workings range from 50 to 100 metres. Strip ratios are between 4 and 8 tonnes of rock to 1 tonne of ore.

• Openpit production faces are loosened by drill and blast.

• Ore/rock is excavated by hydraulic backhoes.

• Ore is transported to the Cavendish Mil and rock is placed to backfill by articulated dump trucks.

• Excavated rock is directly backfilled into the preceding worked out areas to facilitate progressive restoration.

• Dried tailings waste from Cavendish Mill are backfilled into the openpit working areas to create a sustainable restoration landform.

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Longstone Edge and Tailings Dam

Progressive Restoration

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Longstone Edge and Tailings Dam

No.4 Tailings Lagoon

Deep Rake

Bow Rake

High Rake

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Mineral Waste (Tailings) Disposal

• The disposal of Mineral Waste in a National Park is controversial, sensitive and strictly

controlled in accordance with European Waste Directive.

• Containment of waste in National Parks must be environmentally sustainable and have the

capability of being restored within a landform that has a long term beneficial after use.

• The containment of waste must not be a risk or health hazard to the local community.

• Traditionally Cavendish Mill has pumped its waste tailings to dams in a 5% water suspension at

a flow of 400 cubic metres/hour.

• Once the suspended soils (tailings) have settled the water is recycled to the mill.

• This type of tailings disposal is no longer sustainable in a National Park.

• British Fluorspar is undertaking a two year project to install tailings processing facilities in the

mill to create a filtercake tailings material.

• The silica-sand filtercake will be used to provide long term restoration material for Longstone

Edge

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Environmental Management

Key Objective is to Minimise Adverse Impacts

Visual Screen Workings

Noise Equipment Sound Protection

Dust Water Suppression

Vibration Limit Scale of Blasting

Open Pit Footprint Minimum Working Area/Void

Public Hazards Boundary Treatment

Pollution Contained Surface Water Drainage

Vein mineral extraction by openpit method is a temporary land use.

Openpits are progressively restored to return the land to beneficial after use once the mineral has been extracted.

Restored landforms are drained, seeded and planted before being returned to grazing pasture or public amenity heathland.

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Restoration

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Openpit Restoration Phases

Final quarry working void

Restored Land form

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Fluorspar Processing

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Fluorspar Processing

Ore from each minesite is placed into stock at the

Mill where it is blended to create a composite ore

feed.

There are Five Separate processes within the Mill.

•Crushing

•Heavy Media Separation

•Grinding

•Flotation

•Filtration

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Process Flowchart

Crushing

• Reduce the maximum size of the ore to 15mm

• Separate the fine mineral rich material

• Remove the coarse non mineral limestone gravel

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Process Flowchart

Dense Media Separation

• Heavy liquid separation of

limestone/rock from

mineral rich material.

• Floats – Rocks

• Sinks – Minerals

• Remove fine non mineral

limestone gravel

Grinding

• Combine the fine material flows and

deslime by (centrifugal force)

hydrocyclones to remove the ultra

fine material (minus 100 microns).

• Reduce to mineral liberation size in

a Ball Mill

• Create a consistent feed to Flotation

e.g flow, density and material size

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Process Flowchart

Filtration

• Each mineral in water suspension is

pumped to a separate thickener before

passing over a drum filter to reduce the

moisture.

• Filtercake produced at 10% moisture

• The Fluorspar, Barytes and Lead filter

cakes are separated before distribution

and sale.

• Some fluorspar is dried to be tankered

or bagged for sale as a dry powder.

• Mill operates in a series of seven day

campaigns over 168 operating days per

annum.

Flotation

• Liberated mineral sands

pass through a series of

Froth Flotation Cells.

• Pulp frothed and reagents

added to separate each

mineral

• First – Lead

• Second – Fluorspar

• Third – Barytes

• Waste tails are pumped to

the tailings dam in water

suspension of 5-6% solids.

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Annual Production

Mining Operations – Crude Ore

Tonnes per Year

Milldam Mine 100 000

Openpit Quarries 130 000

Independent Suppliers 70 000

Total 300 000

Cavendish Mill – Mineral Products

Tonnes per Year

Fluorspar – Acid grade 65 000

Barytes 10 000

Lead 1200

Construction Aggregates 125 000

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Planning Issues in the

Peak District National Park

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Planning Issues

• Vein mineral workings are a temporary

land use.

• Working within the confines of the

highly regulated Peak District National

Park regulations.

• A high emphasis on ecological

mitigation and minimising visual impact.

• A constant balance between

operational efficiency and

environmental impact.

• Sustainable after use of restored

openpit workings.

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Landscape Management

Community Relations

• The long term landscape management

plans as part of the restoration process.

• High quality restoration schemes to provide

landscape and ecological gains after mineral

working.

• The landscape management of Sites of

Special Scientific Interest.

• Financial sponsorship of local festivals.

• Land availability to local community groups.

• Education to demonstrate sustainable

landscape management and

environmentally sensitive working practice.

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Vein Mineral Mining for the Future

• Peak district has a substantial resource of unmined Fluorite rich vein systems which have the economic potential to contribute to the long term strategic NEED for FLUORSPAR.

• Ore will be mined from a combination of underground drift mines and narrow steep openpit quarries.

• Cavendish Mill being refurbished to become a long term supplier of good quality fluorspar per annum.

• Tailings Waste to be processed at Cavendish Mill to generate a silica sand restoration material to facilitate sustainable restoration of the Tailings Dams.

• Process water to be recycled in a closed circuit within the Mill.

• Fluorspar quarries are a Temporary Landuse which are progressively restored to a beneficial afteruse.

• Mineral waste is an asset to be used to facilitate the restoration of past and future quarry activities in the Park.

• Vein mineral mining is an integral part of the Living Landscape and the Local Community within the National Park.

• Challenge is to develop the partnership between the Park and the Mining Industry to manage the growing conflict between an economical viable mining industry and the Environmental objectives of the Park Authority.

• Aim is to continue to develop an environmentally sustainable and economically viable vein mineral industry in Partnership with the National park and its local community.

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British Fluorspar

Great British Minerals

Mr Peter Robinson, Chairman, British Fluorspar Ltd ...

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