the earth and geological resourses

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The Earth and Its Mineral

Resources

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Introduction

• When the Earth first form scientists believe it was a mass of rock and ice

• Over time, solar radiation and other sources of heat caused the earth to melt

• Gradually, the surface cooled and formed a thick, rocky crust rich in minerals

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Introduction

• Gradually, the surface of the Earth cooled and formed a thick, rocky crust rich in minerals

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This chapter examines:

• Minerals extracted from the Earth’s crust

• Impacts of this activity• Ways to meet demand for minerals

more sustainably

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The Earth’s Mineral Riches

Minerals

Nonfuel

Metal-yielding

Industrial

Fuel

Construction

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The Earth’s Mineral Riches

• Metal-yielding minerals (aluminum and copper ore) must be processed

• Industrial (lime) and construction (gravel, send) are used directly

• Minerals typically occur in rocks, solid aggregates that usually contain two or more different types of mineral

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1. The Earth’s Mineral Riches

• Geologists divide rocks into three major classes

•Formed when molten minerals cool

•(basalt and granite)

Igneous rocks

•Formed from particles eroded from other types of rock

•( shale and sandstone)

Sedimentary rocks

•Formed when igneous or sedimentary rocks are transformed by heat and pressure

•(schist)

Metamorphic rocks

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The Earth’s Mineral Riches

• Most metal-yield minerals come from igneous rocks

• A concentrated deposit of minerals that can be mined and refined economically is called an ore.

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Mineral Resources and Society

• Minerals are extremely important to our lives

• Scholars delineate the ages of human history by the chief minerals in use at the time:

• Stone• Bronze• Iron

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Mineral Resources and Society

• Minerals are vital to national economies

• More than a hundred nonfuel minerals are traded in the world market These materials worth a billions of dollars to the world economy

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Who Consumes the Worlds Minerals?

• The more developed countries are the major consumers of the minerals

• 20% of the world population consume about 75% of its mineral resources

• Mineral consumption by the industrial nations has leveled off

• World’s mineral consumption of less developed countries is on the rise

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Import Reliance

• World mineral production is widely dispersed

• Some minerals are found in commercially valuable quantities only in specific countries

• Most nations are highly depended on the supplies of others

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Will There Be Enough?

• 75% of the economically vital minerals are abundant enough

• Approximately 18 economically essential minerals will fall in to short supply – some within a decade or two

• Gold, silver, mercury, lead, sulfur, tin, tungsten, zinc are among them

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2. Environmental Impacts of Mineral Exploitation

• Minerals are part of a production-consumption system:

•

Exploration Mining Processing

Transportation End use

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Environmental Impacts of Mineral Exploitation

• Each stage in this system produces major environmental impacts , even in the best regulated countries

• Mining and smelting have created enormous amount of environmental damage

• Rock wastes burying vegetated areas, erode into lakes and streams

• Toxic metals can contaminate nearby reservoirs, killing aquatic life

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Environmental Impacts of Mineral Exploitation

• Sulfur present in tailings may combine with water to form sulfuric acid, creating acid mine drainage

• Globally, copper and other nonferrous smelters produce about 8% of the world’s sulfur dioxide emissions

• Toxic metals and acids from smelters are responsible for huge dead zones – places where all vegetation has perished

• Mineral exploitation is responsible for deforestation, soil erosion, water and air pollution

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Environmental Impacts of Mineral Exploitation

• Around the Sudbury smelter in Canada, 10 400 hectares have been turned into a barren moonscape

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3. Creating a Sustainable System of Mineral Production

• Putting into practice the operating principles of sustainability , especially :

Conservation

Recycling Restoration

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Creating a Sustainable System of Mineral Production

• Recycling is a process in which valuable products such as metals are collected and returned to factories, where they are melted down and used to manufacture new products

• Recycling :- Increases the time a metal remains in use- Helps to stretch limited mineral supplies- Reduces energy demand and water use- Slashes pollution

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Creating a Sustainable System of Mineral Production

• The SEI Group collects used electric wires/cables, optical fiber cables and carbide chips for cutting tools and their plastic cases for recycling as materials for new products.

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Creating a Sustainable System of Mineral Production

• Conservation – decreasing product size, increasing product durability

• Conservation – using only what we need and using it efficiently

• Cheapest, easiest, and quickest means of stretching mineral resources:

• - making smaller automobiles• - finding ways to design products using less

material

•

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Creating a Sustainable System of Mineral Production

• Conservation and recycling measures combined:

• - will slow down depletion, giving us more time to develop new mining technologies and fined substitutes

• - minimize our impact on environment

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Creating a Sustainable System of Mineral Production

• Restoration and Environmental Protection

• New laws and tighter enforcement of existing laws could improve mining practices and reduce pollution from smelters

• Requirement to prepare an EIA• Cooperation in cleaning up abandoned mines

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Expanding Reserves

• Future demand cannot all be satisfied by conservation efforts. • New deposits need to be discovered and mined• Reserves – deposits which is fairly certain exist and feasible to

mine at current prices • Price is one of the most important factors determine the size of

mineral reserves • Rising prices – economically feasible to search for and

produce more minerals – expend of mineral reserves• But mineral resources are finite. Resources will simply run out

or become so costly to mine that they will be unaffordable

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Expanding Reserves

• Rising supplies• Prices• Technological

improvements

• Reduce supplies• High labor costs• Interest rates• Energy costs• Env. protection

costs

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Expanding Reserves

• Technological improvements make it feasible to mine less concentrated ores, which helps expend reserves

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Minerals From The Sea

• The minerals deposits on land are finite, they have been heavily exploited

• Antarctica and the floor of the world’s oceans are potential sources for new minerals

• Superficially promising, these options face serious economic, environmental, and social barriers

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Minerals From The Sea

• Pros• Vast resource of

minerals• Important minerals on

the sea floor• Mineral –rich nodules

“manganese nodules”

• Cons• Many of resources are

dissolved, generally in low concentration

• Issue of ownership• Environmental impact

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Minerals From The Sea

• Manganese nodules contain:

• Several vital minerals

• Manganese 24%• Iron 14%• Copper 1%• Cobalt 0,25%

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Finding Substitutes

• Historically, the substitution of one resource for another one that has been depleted has been a useful strategy for industrialized nations

• Substitution could help find alternatives to some minerals, replace environmentally damaging materials

• Critics argue that it creates unreasonable faith among the public

• Many substitutes have limits themselves

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Personal Actions

• Personal actions are essential to building a sustainable future

• Buying durable products, recycling, and choosing recycled materials are three steps people can take

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Prof. Sanga-Ngoie K.Done by Bekenova G. (ID № 51211620)

Hazardous and Solid Wastes : Sustainable

Solution(chapter 23)

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Introduction

• This chapter discusses solid and hazardous wastes

• It shows how individuals, business and governments have addressed the problem

• Chapter shows more sustainable approaches, measures that make sense from social, economic, and environmental perspectives

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1. Hazardous wastes: Coming to Terms with the Problem

• Hazardous wastes are waste products of homes, factories, businesses, military installations, and other facilities that pose a thread to people and the environment

• Toxic, carcinogenic, or mutagenic• The signs of unsustainable

practices

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The Dimensions of the Problem

• Each year countries worldwide produce millions of tons of hazardous waste

• This waste ended up in abandoned warehouses; in rivers, streams, and lakes; in fields and forests, and along high ways

• No current estimates are available

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The Dimensions of the Problem

• Effects of improper waste disposal

Ground water

contamination

Well closures Habitats destruction

Human disease

Soil contaminatio

n Fish kills Livestock

disease

Sewage treatment

plant damage

Town closures

Difficult or impossible cleanups

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Managing Hazardous Wastes

• Two problems:• How to clean up existing wastes

sites?

Required immediate actions• How to deal with enormous

amounts of hazardous waste produced each year?

Required long-term preventive measures that eliminate the production of wastes

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The Superfund Act: Cleaning Up Past Mistakes

• CERLA – Comprehensive Environmental Response, Compensation and Liability Act (Superfund)

• Established in 1980, $16.3 billion fund financed by state and federal governments, and by taxes on chemical and oil companies

• To clean up leaking underground storage tanks, hazardous wastes dumps, landfills, contaminated factories, mined and mils

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What to Do With Today’s Waste: Preventing Future Problems

• The more sustainable approach involve steps that reduce or eliminate hazardous waste output

YOU DON’T HAVE WASTE

IF YOU DON’T MAKE IT

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What to Do With Today’s Waste: Preventing Future Problems

• In-plant options include:• 1. Process manipulation – alterations in

manufacturing process to cut waste production

a) substitution - the use of nontoxic of less toxic substitutes in manufacturing

b) monitoring of manufacturing processes to locate and fix leaks

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What to Do With Today’s Waste: Preventing Future Problems

• 2. Reuse and recycling strategies• Companies can capture toxic waste

and, with little or no purification, reuse them to manufacture other products or sell them to other companies fore reuse

• Waste output can be dramatically reduced

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What to Do With Today’s Waste: Preventing Future Problems

• Conversation to Less Hazardous of Nonhazardous Substances

• Not all waste can be eliminated, reused, and recycled

• Remaining waste be destroyed or detoxified

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What to Do With Today’s Waste: Preventing Future Problems

• Detoxification can be accomplished for certain types of waste by land disposal, applying them to land

• Land treatment is an expansive option, requiring care to avoid polluting ecosystem, poisoning cattle and other animals, and contaminating groundwater

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What to Do With Today’s Waste: Preventing Future Problems

• Another option available for organic wastes is incineration

• High-temperature furnaces at stationary wastes disposal site, on ships that burn waste at sea, and on mobile incinerators

• Disadvantages: release of toxicants during transport, possibility of long-term exposure, producing carbon dioxide

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 A conceptual diagram of the Incineration

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What to Do With Today’s Waste: Preventing Future Problems

• Low-temperature decomposition • Wastes are mix with air and maintained under

high pressure while being heated to 450 C to 600 C

• Organic compounds are broken into smaller, biodegradable molecules

• Advantage – uses less energy

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What to Do With Today’s Waste: Preventing Future Problems

• Perpetual storage• 25 to 40% of the waste stream will remain even after a

best efforts• Residual waste could be dumped in secured landfills,

excavated pits lined by impermeable synthetic liners • To lower the risk of leakage, landfills should be placed in

arid regions • One of the cheapest option

• Growing public opposition, problems for future generation

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Disposing of Radioactive Wastes

• High-level of radioactive wastes are the most hazardous of all wastes

• Generated by nuclear power plants, weapon production, research laboratories and hospitals

• Deep underground disposal site• Radioactive waste can be bombarded with

neutrons in special reactors to convert some of it into less harmful substances

• Seabed disposal has been used, but now is forbidden (effects are difficult to predict)

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Some Obstacles to Sustainable Hazardous-Waste Management

• One of the main problems was that much of it was highly diluted in water released by industrial processes

• Removing the hazardous substance from the water is extremely costly

• 11% of total release - underground injection

• 60% - release occurs in the air

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Solid Wastes: Understanding the Problem

• Each year, human society produces mountains of municipal solid wastes

• The problem are especially acute in the more developed nations

• In 2003, Americans generated 212 million tons of municipal solid waste

•

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Solid Wastes: Understanding the Problem

• Municipal solid waste is the product of many interacting factors

Large population High consumption

Low product durability

Heavy dependence on

disposable products

Low reuse and recycling rates

A lack of personal and governmental

commitment to reduce waste

Relatively cheap energy and

abundant land for disposal

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Solving a Problem Sustainably

• Output approach - incinerating trash or dumping it in landfills

• Input approach – reduce the amount of materials entering the production-consumption cycles

• Throughput approach – direct materials back into production-consumption cycle, creating cyclic system

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The traditional strategy

• The output approach• The most widely used• Open dump has been replaced by sanitary landfill• Landfill require land and grate deal of energy for

excavation , filling and hauling trash• They can pollute ground water• Low social acceptability• Locating them away from ground water supplies,

collecting and treating toxic leachate, capturing methane gas

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Sustainable Options

• The input approach• Source reduction include:• - increase product life span (high quality, more

durable goods)• - reduce the amount of materials in goods and

packaging (make products smaller and compact)• - reduce consumption (buy what you need)

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Sustainable Options

• The throughput approach: reuse, recycling, composting

• Recycling refers to the return of materials to manufacturers

• Recycling conserve recourses, reduce energy demand, cuts pollution, saves water, decreases solid waste disposal and incineration

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Sustainable Options• Reuse is the return of operable and repairable goods

into the market system for someone to use• Reuse :• - reduces land area needed for solid waste disposal• - provides job• Provides inexpensive product for the poor• Reduce litter• Decreased the amount of consumed materials• Help reduce pollution and environmental degradation

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Sustainable Options

• Composting - the process in which nutrients from organic wastes return to the soil

• Form of nutrient recycling• Organic matter is collected from various sources ,

stockpiled, mixed with some dirt , and then allowed to decompose

• Compost - nutrient rich organic material that can be used as fertilizer

• Reduce the need for landfilling, helps nourish soils, creating cycle system

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The economic benefits

• Taking together, source reduction, reuse, and recycling can not only cut waste but also foster more flexible and self-reliant economies. Decentralized collection and processing of secondary materials can create new industries and jobs