Petroleum, Metallurgy, and Chemical Products: Uses and Impacts
Petroleum: Formation and Uses
Oil is a mixture of hydrogen and carbon (hydrocarbons) formed by the decomposition of the remains of marine animals and plants that were buried at the bottom of the sea, subjected to elevated temperatures and the action of bacteria for millions of years. It is a dark brown, oily liquid with a characteristic odor.
Fractions Obtained by Distillation:
- Refinery gas: Similar in composition to natural gas.
- Petrol: Used as a solvent and as fuel in spark-ignition engines.
- Kerosene: Used as fuel for aviation.
- Diesel, gas-oil: Used as fuel in diesel engines.
- Lubricating oils: Very toxic substances used to avoid friction problems in machines.
- Paraffin and vaseline: Used in lubrication and in the manufacture of candles, creams, and ointments.
- Tar: The solid residue obtained after distillation.
Metallurgy: Extraction and Processing of Metals
Metallurgy is the scientific discipline that deals with the extraction of metals from their ores, as well as their subsequent treatment. Minerals that contain metal in a way that makes the extraction process cost-effective are called ores. Ores are accompanied by other materials, which constitute the gangue.
Metallurgical Operations
- Concentration of the ore: The process by which the ore is separated from the gangue.
- Reduction: The chemical process that allows for the extraction of the metal from the ore.
- Refining: The raw metal produced in the above process contains various impurities that must be eliminated.
- Alloy: The solidification of a liquid solution of two or more metals.
- Blast furnace: This is where raw iron (pig iron) is burned to remove impurities and make steel.
Sulfuric Acid: Properties and Uses
Sulfuric acid is a strong and fixed acid, so it is used to obtain other acids. It behaves as a dilute acid and, when hot and concentrated, as an oxidizing agent. It has a great avidity for water, with which it mixes in all proportions in a highly exothermic process that can boil the water and project the mixture abroad. Its dehydrating power is so intense that it can remove hydrogen and oxygen from organic substances.
Fertilizers: Enhancing Soil Fertility
Fertilizers are substances that increase soil fertility. The most important nitrogen fertilizers are ammonium nitrate, sodium nitrate, potassium nitrate, and urea. Among phosphorus fertilizers, calcium and ammonium phosphates are included, and among potassium fertilizers, chloride, sulfate, and nitrate of potash.
Plastics: Versatile Materials
Plastics are artificial polymers of variable composition. They get their name because they possess a property called plasticity, under which they can be stretched into threads, laminated, or easily molded.
Advantages: They are very light and strong, inert in the presence of a large number of reagents, do not conduct electric current (so they can be used as insulators), and are cheap and versatile. Drawbacks: Their high pollution potential. If they soften when heated and can be molded, they are called thermoplastics, and if they are rigid, they are called thermosets.
Medicinal Products: Modifying Biological Functions
Medicinal products are products that are used to correct or modify certain functions in living things.
- Antibiotics: Substances that prevent the growth of bacteria and other pathogens (e.g., penicillin). They can be bacteriostatic (inhibiting bacterial growth and metabolism) or bactericidal (killing the organisms).
- Analgesics: Drugs that produce a decrease or disappearance of pain (e.g., aspirin).
- Vitamins: Substances that play an important role in many reactions and help maintain the balance of vital functions. They can be fat-soluble or water-soluble.
Industrial Waste: Management and Disposal
Industrial waste includes all those waste materials that cannot be disposed of in a landfill, either because of the excessive amount that is generated or because of their toxicity. They are stored in suitable geological formations or subjected to physical-chemical treatments to neutralize their toxicity, or destroyed by incineration in special ovens.
- High-activity waste: Emits high doses of radiation.
- Medium- or low-activity waste: Emits moderate or low doses of radiation.