Πέμπτη, 26 Δεκεμβρίου 2013

The Earth as a resource



A contribution to the more than 7.2 billion living humans on this planet, all making daily users of global minerals.

A day of minerals  

We all use and depend on the earth’s mineral resources. Minerals extracted from the earth underpin every aspect of our daily life including the food we eat, the homes we live in, the pow­er we use, where we work and how we travel and communicate with others.
The importance of minerals in everyday life is however hardly recognized by the vast majority of people although, as mentioned earlier, the average person consumes and uses tens of tons of minerals every year. Day after day, from the early morning to the late evening, there will be many activities relied on, and likewise, many products consumed and used, containing minerals.
Turning on the electric light switch in the morning, for example, we need to use copper and aluminium products, whereas for coffee drinking, we use pots made of silica sand or feldspar. Taking a shower requires water supply pipes often made by copper, iron, nickel and chromium. Brushing our teeth with toothpaste we use calcium carbonate, phosphate, gypsum, fluorite and dolomite.
The car we drive on our way to work is composed of many different components that were manufactured from minerals. The tires use calcium carbonate and clay. All the glassy parts are made from silica sand and feldspar. The engine is made out of iron, lead, molybdenum, chromium, nickel and zinc. Getting to the office and turning on the computer we use products manufactured from gold, silica, nickel, aluminium, zinc, iron and thirty other metals, all derived from minerals.
When coming home in the evening, by warming up our meal we use the microwave oven made from silica, copper, gold, iron and nickel. We enjoy our refreshments in a glass or ceramic mug of silica, calcium carbonate and feldspar, watching at the same time the television made of components using silica, iron, copper, aluminium and nickel. 
 
W hat are minerals?

Minerals are naturally occurring substances that have distinctive chemical and physical properties. They are the building-blocks of all rocks that form the Earth. There are more than 4500 recognised minerals; some are very common whereas others are uncommon. Many minerals are used in society in a wide range of applications like construction, manufacturing, agriculture and energy supply. These minerals are called economic minerals.
Minerals are commonly distributed in the Earth's crust in small amounts. But when they are found in sufficient concentrations and in sufficient volumes they may form economically valuable resources, known as mineral deposits. These have formed by geological processes throughout Earth's history. In some places, e.g. at the mid-oceanic spreading ridges and near subduction zones, deposits with economic minerals are still being formed today.

Types of economic minerals

There are two main categories of minerals, Energy and Non-Energy Minerals (NEM.  In the context of this work and in line with the European Raw Materials Initiative, the non-energy minerals have been subdivided into three groups: metallic minerals, industrial minerals and construction minerals.
Metallic minerals are the normal sources of metals which have a wide variety of uses. For example, iron (as steel) is used in cars or for frames of buildings, copper is used in electrical wiring, nickel is used in jet engines and aluminium is used in aircraft and to make drink cans. Precious metals, such as gold, are used in jewellery and electronics, e.g. mobile phones and flat screens.
Industrial minerals are non-metallic minerals used in a wide range of industrial applications including the manufacturing of chemicals, glass and fertilizers. Examples of industrial minerals are salt, potash, quartz, bentonite, feldspar, talc and gypsum.
Construction minerals, and rocks and sediments they form, include sand and gravel, brick clay, crushed rock aggregates and recycled aggregates. Construction minerals are normally produced in large quantities and used in the manufacture of concrete, bricks and pipes and in the building of houses and roads.

The minerals value chain

The minerals value chain is the cycle of activities involved in the usage of minerals including exploration, mining, quarrying, mineral processing, metallurgy, recycling and rehabilitation. Here follows a brief description of these main activities:
Mineral exploration is undertaken in order to find mineral deposits that might be suitable for exploitation. A variety of methods and techniques are used, including geological mapping, aerial photography and satellite images, and geochemical surveys (looking at the chemistry of soil and water which may indicate the presence of certain minerals). Sampling of rocks is carried out both at the surface and through drilling boreholes into the ground. The final stage of mineral exploration is a desk-top study that evaluates all factors that are relevant to the decision to mine: geological, mining, environmental, political and economical.
At this stage, the financial aspects are also considered, including the cost of mining, metallurgy, legal and government factors. The initial costs to set up the mine and run it (termed capital and operational costs) are compared to the expected income from the products of the mine over its lifetime. This provides the mining company with a business case that might justify an application for planning permission to extract the mineral.
Mining. A mineral deposit has to be extracted from the ground where it is situated through mining. This may take place at the surface in open pits or underground. Which of these is chosen depends on many factors, such as the shape, orientation and depth of the deposit and the strength of the mineral-bearing and surrounding rock. Surface mining is typically used when the mineral deposit is located close to the surface. It is more economical than underground mining but has a more significant impact on the surrounding environment. In underground mining, the ore is extracted below the surface with as little waste as possible. Operating mines range in size from small underground mines producing less than 100 tonnes of ore per day to large open pits, some of which move thousands of tonnes of mineral and waste rock per day.
Processing. When the minerals have been extracted from the ground they need to be processed o a form that is useful to us. This usually involves removing any unwanted impurities and processing to increase the concentration of the economic mineral.
Metallurgy. After concentrating the mineral, it may be transported to another site for further processing. Metallic minerals may be smelted or refined to extract pure metal from them. Pure zinc metal is, for example, recovered from sphalerite (zinc sulphide mineral) concentrates.
Recycling. Waste materials are by-products from all previous value chain activities. Recycling and re-use of waste materials increase the supply of valuable secondary resources and encourages a more resource-efficient economy. Many critical minerals and metals may be collected through recycling of mining related waste materials. However, even with the important contribution from recycling, minerals extracted from the Earth still supply most of our daily needs.
Rehabilitation. Modern mine rehabilitation begins already at the start of a mining project and aims at minimizing the environmental effects of mining. Rehabilitation is an on-going process throughout the period of mining, and the land is typically restored for further use as recreational or agricultural land. Today, new mines are typically required to have closure and restoration plans in place before mining starts, and they must also set aside the cost for reclaiming the site in a trust. Despite environmental measures, some abandoned mines may continue to be a problem and a negative legacy of the minerals industry. In most cases, however, old mining areas can be successfully rehabilitated and recultivated. There are many examples of reclaimed mine sites which now provide excellent leisure activities such as walking, adventuring, golfing and sporting in general. There are also other examples worldwide where ecologically rich environments have been created by the mining industry, and now are protected from other types of development.

The role of minerals

Our modern society is totally dependent on non-energy minerals (NEM). They are essential for manufacturing and supply of renewable «green» energy. They also provide the materials to build homes, schools, hospitals and the infrastructure needed by sustainable communities. Despite the recent financial downturn across the globe, the demand for raw materials, such as NEM, will increase as attempts are made to boost economies and push the growth of manufactured goods. A continuous supply of minerals will, in other words, be necessary also in the future.
There is no doubt that mining can bring positive benefits to the host countries but these can come at a cost to the environment and local communities if the mines are not managed properly. The fundamental aim must be for the benefits of development to be distributed as widely as possible and for the negative impacts on people and environment to be minimized.
Mining-generated wealth has the potential to improve the economy, infrastructure and quality of life of the host country, region and community, and brings opportunities for economic growth and diversification. Mining generates revenue for governments through royalty and tax income. It also brings skilled employment, technology transfer and training for people, together with further jobs through the multiplier effect. Mining can bring substantial improvements in physical, social, legal and financial infrastructure.
If not properly managed, economic growth and development can come at a cost to the environment. While mining has historically affected its surrounding environment, advances in technology and changes in public attitude and man­agement techniques mean that many negative impacts are now avoidable. Increasingly, mining companies are making efforts to reduce the remaining environmental impact of mining and to minimize the footprint of their activities throughout the mining cycle, including restoration of land and ecosystems after mining.

Growing needs and demand

The society has become more and more dependent on a range of minerals. In the past, the extraction of minerals has allowed the standards of living to continuously improve around the world. Earlier societies, such as the Stone Age, through the Copper, Bronze and Iron Ages, are classified by their use of minerals and derived metals. Today we take developments in our standard of living for granted, and there are clear signs that the need for minerals is growing fast. There are obvious indications that this trend will continue, takes into account the facts that,
·         about 60 tonnes of aggregate are used to build an average house. If we include the associated infrastructure, such as roads, this can be as high as 400 tonnes. Minerals are used in build­ing houses, schools, libraries, hospitals, offices and shops but also in building bridges and tun­nels,
·         in every car there are over 15,000 components made from minerals,
·         most of the environmental technologies and applications (e.g. wind turbines, photovoltaic cells, electric and hybrid vehicles) allowing energy production from renewable resources will use, so called, high-tech metals (e.g. Rare Earth Elements-REE, Platinum Group Metals-PGM, niobium, lithium, cobalt, indium,  vanadium, tellurium, selenium) that were derived or refined from minerals, which Europe is strongly import dependent on.
·         every year, around the world, we use about 45 billion tonnes of natural resources. On average, each person uses 16 tonnes of all kinds of min­erals, e.g. ores, stones, ceramics etc., per year. People in rich countries consume up to 10 times more natural resources than those in the poorest countries,
·         by 2050, the world population is predicted to reach almost 10 billion and the demand for natural resources will also increase from 45 billion tonnes to 140 billion tonnes.
Our standard of living has, however, its price and we need to be aware of the true costs. The production of the minerals we need in and for our daily life is associated with negative impacts although the related research community is working hard to minimize these. The extraction and processing of natural resources is often very intensive in the use of materials, energy, water and land. These activities therefore often bring about environmental problems. Social problems are also often linked to extraction and mining activities, including poor working conditions and low wages. We must be prepared to embrace the principles and practices of sus­tainability in all aspects of minerals extraction, processing and use.

Potential of European mineral resources

The EU is highly dependent on imports of mineral raw materials that are crucial for a strong European industrial base, a sustainable and competitive growth and a thriving society. There is a particular importance and an increasing demand for a specific group of minerals and metals characterized as critical raw materials. The EU is self-sufficient in the production of construction minerals, including aggregates (sand, gravel and crushed natural stone), various brick clays, gypsum and natural ornamental or dimension stone. The EU also has a large production of industrial minerals supplying a very wide range of industries. For some minerals, such as magnesite, fluorspar, bentonite, kaolin and potash, Europe is an important global producer. In contrast, the European economy is highly dependent on the import of ores and metals. Only a small number of metal ores are extracted within the EU, but is still a relatively important producer for some, such as chromium, copper, lead, silver and zinc. This production is, however, totally insufficient to meet the European demand. For several metals, including rare earth elements and platinum group elements used in electronics and green technologies industries, the EU completely relies on imports. The resulting annual shortage is about €11 billion, of which 90% corresponds to metallic minerals, particularly those of major high-tech applications. Recycling of metal scrap represents around 40% to 60% of the input to EU's metal production, according to industry estimates.
At the same time, Europe’s mineral potential is under-explored, both with regard to the subsurface (particularly deeper than 150 meters) and the sea-bed in the EU member states' exclusive economic zones. Major opportunities of access to raw materials exist within the EU today, especially for mining at greater depths or in small deposits. The ocean bed could also contain valuable raw materials, such as copper, zinc, gold, silver and rare earth metals, leading to growing world-wide competition for marine mineral deposits. A framework of stable economic and technological conditions makes a sustainable and resource efficient exploitation possible in Europe.
A four-year (2009–2013), EU co-funded project, ProMine (http://promine.gtk.fi/), has created and provided a well documented knowledge base of Europe's non-energy raw material resource potential (see attached map). The database demonstrates that Europe hosts a large number of mineral deposits ranging from precious metals (gold, silver, platinum group elements), base metals (aluminium, copper, lead, zinc, tin), iron and metals used to make steel (cobalt, chromium, manganese, nickel, vanadium, tungsten), high tech and rare metals (bismuth, germanium, gallium, mercury, lithium, rare earth elements, antimony, tantalum, titanium, zirconium), minerals for chemical use (e.g. barite and fluorite) to fertilizer minerals (e.g. phosphate), building material and several other industrial rocks and minerals.
The high import dependence of strategic and critical minerals has a serious impact on the sustainability of the EU manufacturing industry. This problem can only be solved by more intense and advanced exploration for new mineral deposits on land and the marine environment. As a matter of fact, mineral resources on the seafloor receive a growing European interest with respect also to the exploration potential of rare earth elements, cobalt, selenium, tellurium and other high-tech metals.