This is a picture of the electric car charging station at the local MEC store. Never seen a car here, in spite of the many outdoors-men who shop for expensive clothes and gear to climb mountains, ride bikes, and hike in the woods.
Here are the four e-resources that I found in a search of the first twenty pages of a Google-search using the terms mine energy balance:
- Water and Energy Balances in Mineral Processing Plants by Osvaldo Bascur and Ales Soudek on OSIsoft.
- Energy Efficiency Opportunities: Eneergy-Mass Balance: Mining from the Australian Government, Department of Resources, Energy and Tourism.
- Energy Use Benchmarks for Open Cut Coal Mines by D. Cooke and C. Randall in NSW.
- Mining the energy savings at Xstrata Brunswick Mine from efficiency NB.
- Optimized Mine Ventilation from ABB.
You too can find them easily via a Google-search.
The best is that from Australia on energy mass balances. More than fifty pages of details, including lists of mine facilities and components and how they consume energy and how you can monitor the consumption of energy. The introduction is a bit dull, but does say why the document was compiled:
Mining consumed 450 PJ of energy in 2007–08 or 11% of national energy end use. Energy consumption and intensity in mining is rising at around 6% annually due to deeper and lower grade ores, and greater liquefied natural gas production. Mining operations use energy in a variety of ways, including comminution, excavation, materials transfer and haulage, ventilation and dewatering. This guidance document outlines the key considerations and potential approaches for the development of an energy–mass balance (EMB) for a mining operation to meet the requirements of the Energy Efficiency Opportunities (EEO) program, as detailed in the EEO legislation. This document focuses on open pit and long wall mining operations for the extraction of mineral and fossil fuel resources rather than oil and gas extraction.
But do not be fooled; the document is detailed, starting with the definition of an Energy Balance:
|An energy balance is a mathematical statement of the conservation of energy, and a systematic accounting for energy flows and transformations in a system. The theoretical basis for the energy balance is the first law of thermodynamics, which states that ‘energy cannot be created or destroyed, only modified in form’. Contrary to mass balances, a system can only have one energy balance that describes it, since different types of energy are considered, mathematically, to be interchangeable. Specifically, the change in energy for a system equals the heat transferred into the system minus the work done by the system plus the net energy input associated with mass flows. Mass flows carry enthalpy, kinetic and potential energies.|
As for most mining activities, the objective of an energy balance is to reduce energy consumption and hence increase profits. Here is how the NSW papers describes it:
A range of energy efficiency benchmarks and targets have been established, which, when applied across coal mines, will assist in leading to a significant improvement in energy efficiency in the coal mining industry in NSW, thereby leading to an improvement in environmental performance. Typically, energy efficiency improvements of 20 per cent and higher appear possible at many mines leading to a commensurate reduction in this controllable operating cost, i.e. energy. On the basis that annual energy costs and net profit are similar for many mines, a reduction in energy costs by 20 per cent will lead to increase of 20 per cent in net profit.
The Xstrata case history is fascinating, as it describes this success:
Energy—the majority of which is generated by electricity and bunker C oil—represents about 13% of Brunswick’s operating costs, using the equivalent of 600 million kilowatt hours each year. Parent company, Xstrata Zinc, has a target is to reduce average energy consumption by 1% each year, while Brunswick has reduced its energy intensity by 2% each year since 2005.
Finaly the OSI document is a well-illustrated PowerPoint presentation that describe a computer code they have for quantifying mine energy mass balances. Below is one of the images I was able to copy.
I found no suppliers, consultants, or specialists when I tried a search of the InfoMine databases for the search term: energy balance. Can it be that there are no consultants or suppliers dealing with this. Please let me know if you know of some.
I found a few articles in the InfoMine Library that touch on the subject, but which cannot be said to be definitive. Is prudent energy balance management being done at mines and hence this is a topic of no significance? Or is this a gaping hole waiting to be filled? I would appreciate your insight.