Alastair Hodder Z3407978 MINE8110 Major Assignment Essay

Submitted By Alastair-Hodder
Words: 2371
Pages: 10

STUDENT NO: Z3407978
DUE: Friday 26th October 2012

1. Overall mining scenario

Scenario selected is a 5km strip coal mine situated in the Hunter Valley between Singleton and Muswellbrook.

1.1 Resource

The mine site is estimated to have 175 Million tonnes of thermal coal with an average strip ratio of 7.8:1.

1.2 Markets Coal from the mine is distributed proportionally to the following markets:
Japan - 37%
Mexico - 16%
Korea - 10%
Australian Domestic, Malaysia, Italy, UK, Scotland, Netherlands, and Chile - 37%

1.3 Mine outputs (costs, grade/quality, tonnages etc)
Given an average projected cost of approximately $120 per tonne, the expected revenue from the resource is estimated at approximately $19 Billion.

Target grade for the finished product coal is 10% ash, and expected finished product output is 7 Million tonnes per annum.

1.4 Method(s) of extraction
Over/Interburden is handled by dragline with dragline pre-strip by Truck and shovel. Coal is loaded by wheel loader into coal fleet trucks, and then transported to the ROM pad and washery bins.

1.5 Mine plan/layout
All coal seams have an approximate down-dip of 1 and 40 to the southwest. To best suit dragline operation, the mine strip has a north/south orientation and advances in the direction of the down-dip.

Figure 1. Aerial Photo of Mine Layout
1.6 Mine development
Initial pre-strip is completed by dozer/excavator/ADT due to the hilly terrain and high clay content. Box cut and subsequent dragline pre-strip is carried out by truck and shovel operation. Interburden is hauled back and placed over dragline spoil dumps. Dragline operates in cut/strip with moderate amount of re-handle to access the lower seams. Seven seams are within the lease, and are depicted in figure 2 below.

Figure 2. Mine site coal seams

2. Systems and processes

The proposed mining process is comprised of six sub systems. The sub systems are defined as follows:

2.1 Topsoil removal
Topsoil removal and transportation equipment.

Inputs for the system: approved ground disturbance permit, labour force, fuel supply, and serviced equipment. Weather conditions also have an impact on this system with respect to dry dusty conditions as well as conditions that are too wet and slippery.

The main outputs of the system: cleared and levelled area suitable for drilling, and a supply of topsoil for newly rehabilitated areas. If no rehabilitation operations are currently taking place, the topsoil is stockpiled.

Model/flowchart/process map
See figure 3 below for corresponding system diagram

Figure 3. Topsoil removal system diagram
Impact on overall system (mine) output
Any delays in this process will have minimal effect to the ongoing mining operation, due to the infrequency that the strip will advance at the natural surface.

2.2 Drill and blast
The successful operation of the drill and blast (D&B) system is very important to the overall mining operation. There needs to be a considerable buffer of blasted material planned into the mining process to allow for inherent delays (relocation, servicing and maintenance) in the D&B system. Without this buffer, there is risk of having equipment on standby waiting for blasted material, to recommence digging.

Inputs of the system: design and supply of the blast pattern specifications, prepared drilling surface, drilling equipment, explosive consumables (detonators, boosters, etc.), blast hole loading equipment, labor, and environmental considerations. Any storm activity will prevent drilling from taking place due to the danger of lightning strikes on drills.

Outputs of the system: fragmented material is the one major output of the drill and blast system.

Model/flowchart/process map
See figure 4 below for corresponding system diagram.

Figure 4. Drill and blast system diagram
Impact on overall system (mine) output
Whilst the output of