TABLE  1 - POTENTIAL AND REALIZABLE ORES FROM THE GREAT ORME MINE

 

 

Main/Minor Ore Minerals

Trace Minerals

Tonnage, Grade, Continuity

Beneficiation and Results

Metals in ‘Smelter Charge’

Bronze Age Ores

 

 

 

 

 

1a Copper-veins

 

 

 

 

 

1b Copper-vugh infilling

 

 

Chalcopyrite, malachite, copper-bearing limonite.

Coarse-grain size.

Few intergrowths

Copper sulphide-digenite, djurleite, covelline, spionkopite.

Copper-oxides – Cuprite, tenorite. Native copper, sphalerite, manganese oxides.

 

High Tonnage, continuous.

Approx. 10% Cu metal.

 

 

High tonnage, discontinuous.

10% Cu metal or less.

 

 

High grade chalcopyrite-malachite ± Cu-bearing limonite concentrate by hand-cobbing.

Cu, Fe, trace Ni, Ag, Mn

By-product Bronze-Age Ores?

 

 

 

 

 

2a Copper ddu

Amorphous iron-copper-bearing oxides/hydroxides. Minor malachite. Powdery

None

Tonnes, locally, discontinuous. <5% Cu metal?

Beneficiation not possible.

Fe, Cu, trace Co, Mn, Ni As.

2b Azurite-shales

Azurite nodules <1cm, minor malachite.

Chalcopyrite, pyrite.

Very local.

Continuous.

< 2% Cu.

High grade Azurite concentrate.

Cu, trace Fe.

Non Copper Ore Assemblages

 

 

 

 

 

3a Polymetallic disseminated sulphides

Chalcopyrite, galena, siegenite, pyrite, marcasite. Fine-grained, complex intergrown sulphides.

Cobaltite/gersdorffite, malachite, azurite, tennantite, sphalerite.

Very little?

No in situ ore seen.

<5% Cu

Fine-grained separate copper concentrate not possible.

Fe, Cu, Co, Pb, trace Ni, Zn, As.

3b Galena-veins

Galena, minor chalcopyrite.

Coarse-grained galena.

Malachite, nickeliferous pyrite, marcasite, millerite, sphalerite.

Little tonnage. Continuous but localized.

<1% Cu metal.

Lead concentrate by hand cobbing. Copper concentrate not possible.

Pb, Cu, Fe, trace Ni, Co, Ag, Zn.


Return to Document