Emerald Mining Jobs

Emerald is a large, modern country town that was established in 1879. The town is named after a lush emerald green hill 'Emerald Downs Hill', located just north of town. Emerald is considered as the 'gateway' to the Sapphire Gem fields; the largest, and one of the richest, sapphire fields in the southern hemisphere. In 1972, the construction of Fairbairn Dam and the Emerald Irrigation Scheme and its associated Lake Maraboon allowed for the significant development and expansion in large-scale coal mining within the Bowen Basin in 1977, which at present, produces a significant proportion of Queensland's total coal exports.

One of Queensland's new generations of underground mines, Crinum produced its first longwall coal in June 1997. Located 62km north east of the regional centre of Emerald, it was planned as replacement capacity for the Gregory opencast operation. Crinum’s installed capacity is 4.25Mt/y of metallurgical coal, with the Gregory operation retaining some 1.25Mt/y of output.

Development

Access to the underground workings at Crinum is via twin declines and an 85m-deep, 6m-diameter vertical ventilation shaft. Contracts for the decline and shaft development were awarded to Thiess Contractors. Development of the main in-seam infrastructure is carried out using three remote-controlled Joy continuous miners in conjunction with crawler-mounted mobile bootends that advance the panel conveyor behind the miner and allow continuous development. The miners are fitted with ARO roof and rib bolters, permitting simultaneous gateroad driveage and support.

Safety Aspects

A major concern at Crinum is the inflow of water. Water management programmes have proved successful, with five 60l/s submersible pumps and three 80l/s portable units in place. Computer-linked systems are used to monitor excess water inflows. On a personal level, all underground miners are equipped with oxygen self-rescuers and each operator can be contacted in case of emergency through a receiver connected to the caplamp battery.

Surface Handling And Preparation

Run-of-mine coal from Crinum is moved by a 1,000t/h, 15km-long overland conveyor to the Gregory preparation plant. The entire conveying and coal-handling system, including the underground decline conveyor, was designed by the Brisbane-based consulting engineers, CMPS&F. The plant uses heavy medium cyclones, spirals and flotation to produce hard coking, soft coking and thermal coal products for the export market. Products are held in a 100,000t-capacity stockpile before being transported 380km by rail to Gladstone.

Coal Quality

Typical Gregory Joint Venture coking coal quality parameters are:

Total moisture: 8.0% Volatile matter: 33.5% Ash: 6.5% Sulphur: 0.65% Crucible swelling number: 9