Straits Resources (ASX:SRQ) has almost doubled Ore Reserves at...

Straits Resources (ASX:SRQ) has almost doubled Ore Reserves at the Murrawombie deposit of its Tritton Copper Operations in New South Wales to 51,500 tonnes of copper from 23,300 tonnes.

The company has now added 51,400 tonnes of copper to the Ore Reserves at the project since the start of July 2013, meeting the obligation it has with Standard Chartered Bank as part of the debt restructure announced in September 2013.

Murrawombie is a sulphide copper gold deposit that has a long history of mining commencing with small scale underground extraction of oxide copper ores from 1891 to 1910.

In recent times open pit mining extracted the oxide and transitional sulphide (chalcocite) ore from 1992 to 1998. Copper ore from the open pit was processed by heap leaching with acid and a SXEW plant producing copper cathode.

The pit was mined to a depth of about 130 metres where the ore changed to majority sulphide mineralogy that is not suitable for heap leach processing.

Development of an underground mine to extract the sulphide deposit that extends below the pit was started and then aborted in 2008.

A portal, decline and parts of two levels were developed before the project was suspended.

The Ore Reserve assumes that the ore will be mined by a combination of open pit and underground methods.

Murrawombie ore will be trucked 25 kilometres by sealed road to the Tritton ore processing plant.

Ore is treated by flotation to recover copper, gold and silver to a copper concentrate product at the existing Tritton sulphide ore processing plant.