A Mineral-Efficient Future
A Mineral-Efficient Future
If we are serious about developing sustainable environmental and economic practices, it is important that we adopt a mineral policy that promotes increased mineral efficiency. A mineral efficiency policy would reduce the energy and water requirements and the environmental impacts associated with mining, by:
- reducing demand of virgin minerals and promoting the reuse/recycling of metals already in circulation, and
- improving mining technologies to reduce the amount of minerals "lost" as pollution.
The use of minerals is heavily concentrated in rich nations, and the disparities in use are most dramatic for metals. The Worldwatch Institute has estimated that residents of the industrialized world comprise only about 20% of the global population, yet consume 86% of the world’s aluminum and 81% of its iron.
In 1995, Canadians comprised only 0.5% of the world’s population, yet we were responsible for 2 % percent of the total global consumption of both nickel and zinc, and 2.4 % of the worldwide consumption of aluminum (Table 1). Translated to a per capita basis, this means that each Canadian consumed approximately 4 times more nickel and zinc, and 4.8 time more aluminum than the average global citizen.
Clearly, Canadian consumption rates of minerals are excessive, from a global standpoint, and are unacceptable due to the associated environmental costs of the extraction and processing of minerals.
Table 1. Mineral Consumption Statistics, 1995.
|Mta||Mt||% of world consumption||rankb|
a one Mt (megatonne) equals one million tonnes; b refers to placement with regard to other countries in worldwide consumption; c 1994 data
The primary objective in increasing mineral efficiency is to reduce the amount of new materials extracted from the earth. To achieve this goal, we will have to optimize our use of the minerals presently circulating in the global economy. There are many technical possibilities for increasing mineral efficiency:
- reduce our personal consumption of mineral-bearing goods
- substitute non-metals for metals
- reuse and recycle metals
The most simple method, on a personal level, is to refrain from purchasing non-essential or luxury items, such as jewelry, (extra) cars and appliances.
Mineral efficiency can also be improved at the product design and manufacturing stages. For example, in the late 1980s there was a significant rise in titanium dioxide prices. Consequently, companies were able to devise ways of manufacturing their products using fewer inputs of titanium dioxide, while still maintaining product quality.
In Germany, proposed legislation would require that manufacturers of products such as cars and personal computers take them back when consumers are finished with them. This type of legislation would encourage manufacturers to design products that are more durable, thereby reducing the need to replace items as frequently.
Manufacturers could be required to substitute benign and/or renewable resources for non-renewable minerals. An example of a more benign substance is the use of glass fibre optic cables in place of copper wires for communications.
If properly designed, products can be easily separated into their component parts. The automobile producer, Audi, is already manufacturing components from used parts and selling them at high prices, resulting in cost savings as well as lower environmental loadings.
An additional, and essential facet of a mineral efficiency policy would involve ensuring that materials are recovered and recycled whenever possible. Metals are ideal for recycling, as they do not lose their mechanical and metallurgical properties when recycled, and therefore can be recycled an infinite number of times. Furthermore, the economic value of metals remains the same regardless of whether or not they have been recycled.
A policy that encourages the use of recycled metals would: reduce the quantity of virgin minerals that must be mined and processed; reduce the environmental impacts associated with new mines; and reduce per capita energy and water. For example, new steel from recycled scrap metal results in:
- 90% reduction in costs compared to steel from virgin materials
- 86% reduction in air pollution
- 40% reduction in water use
- 76% reduction in water pollution
- 97% reduction in mining wastes
- 105% reduction in consumer wastes
Unfortunately, current federal policies do not sufficiently encourage the metals recycling industry. Despite various "commitments" to waste reduction and development of sustainable economies, a 1995 report prepared for the Canadian Council of Ministers of Environment (CCME) concluded that tax expenditures provided by the federal and provincial governments provided a bias again recycling. The authors estimated that, for Ontario, recycled materials should be taxed at a rate 4.5% lower than at present in order to be taxed at the same rate as virgin minerals. Furthermore, to achieve optimal waste management the taxation rate for recycled materials would have to be 13 percentage points less than virgin materials.
Efficiency in Mineral Production
A policy aimed at increasing efficiency in mineral production would address a number of factors, including the efficient use of energy and water (at all stages of production). Furthermore, efficient mineral production would aim to reduce the output of "wastes" (e.g., metals lost as effluent or airborne emissions; as well as the amount of wasterock, tailings, etc.). This brief review focuses primarily on the use of energy in the mining industry.
Though figures are sparse, the mineral industry as a whole is clearly among the world’s largest users of energy, accounting for between 5 and 10% of world energy use. The mining industry, therefore, is a major contributor to the environmental impacts related to energy use, including climate change.
The mining industry in Canada was responsible for approximately 4.4% of the total national energy consumption in 1995. If iron/steel and smelting/refining are included, the share increases to 9.5% of the total energy consumed in that year.
The extraction of ore from the ground is an energy intensive process, which is only going to increase with time. As higher-grade, easily accessible ores are mined, more effort will be spent removing larger amounts of low grade ores and overburden, resulting in higher energy expenditures per unit of metal mined. This trend is already evident in Canada. Between 1990 and 1995, energy intensity increased by 14% in the Canadian mining industry.
Increasing Efficiency in Mineral Production
Where mineral production is concerned, there are a number of methods for improving efficiency. Attention must be paid to the influence of government subsidies and tax expenditure programs; and a greater emphasis should be placed on research and development of more efficient mining technologies.
Some forms of subsidy provided by the government to the mineral and metal mining industries include the protection from environmental liability, as well as the provision of infrastructure, energy and water at less than the full cost. For example, Canadian industries have traditionally enjoyed energy prices that were among the lowest in the world, which has simply encouraged the development of energy-intensive industries such as mining. If energy subsidies are removed in Canada, some mines may be proven to be so inefficient that they become uneconomical.
In 1994, Natural Resources Canada released a study showing that Canada’s taxation of the mining industry ranks in the low-to-middle range on an international scale, particularly when such factors as allowable accelerated capital cost allowances, tax deferrals, tax credits and tax holidays are taken into account. The removal of corporate tax breaks, combined with the use of market-oriented mechanisms such as assessing taxes on the amount of waste material generated and water and energy used, could lead to a more efficient use of resources.
Improvements in mine design and management practices at mines and processing plants can also significantly affect the mineral recovery rates from particular ore types. A few percentage points difference in recovery rates can capture many tons of metal at little extra cost.
At the present time there are few new, market-ready, energy-efficient process technologies, especially for technologies used to process ore concentrates. As mentioned previously, industry research tends to focus on ways to increase mineral production rather than minimize wastes. Here, tax breaks might serve as positive incentives for the mining industry to develop research projects or pilot programs that target more efficient use of water and energy, and minimize wastes.
Given Canada’s considerable consumption of mineral resources, as well as various commitments to sustainable resource use, Canada should play a leading role in finding ways to increase mineral efficiency.
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