Chem Explorers

The Toxicity and Limited Uses of Cadmium: A Hazardous Element to Beware

Cadmium – a Toxic Metal with Limited UsesCadmium (Cd) is a chemical element that belongs to the group of transition metals in the periodic table. This metallic element is represented by the symbol Cd and has an atomic number of 48.

Cadmium is widely known for its toxicity and carcinogenicity, which makes it a highly hazardous element. It is used in limited amounts in various industrial and consumer products.

In this article, we will discuss the properties of cadmium, its toxicity, and its naturally occurring isotopes. We will also talk about where cadmium is found and how it is commercially extracted.

The Toxicity and Limited Uses of Cadmium

Cadmium is poisonous even in small concentrations, and it can have serious health implications when accumulated in the body. The primary route of exposure to cadmium is through the inhalation of cadmium fumes or dust, ingestion of food and water contaminated with the metal, and dermal contact with cadmium-containing substances.

The toxicity of cadmium is attributed to its ability to interfere with various cellular processes, including DNA damage, oxidative stress, and the inhibition of enzymatic activity. Cadmium exposure is associated with several adverse health effects, including cancer, renal dysfunction, and hypertension.

Prenatal exposure to cadmium has been linked to developmental defects, such as low birth weight and impaired neurobehavioral development. Cadmium is used in various industrial and consumer products, including batteries, pigments, and plastics.

However, the use of cadmium has been significantly reduced in recent years due to its toxicity and carcinogenicity.

Naturally Existing Isotopes of Cadmium

Cadmium has 8 naturally occurring isotopes, with atomic masses ranging from 106 to 113. Of these isotopes, only two are stable, Cd-112 and Cd-114.

The other six isotopes are radioactive, with half-lives ranging from a few seconds to several years. The isotopes with longer half-lives are used in radiometric dating and nuclear power generation.

The isotopes of cadmium are formed through nuclear fusion and decay processes in stars and supernovae. Where is Cadmium Found on Earth?

Cadmium is present in small amounts in the earth’s crust, with an average concentration of 0.1 to 0.5 parts per million (ppm). Cadmium minerals, such as greenockite (CdS) and sphalerite (ZnS), are the primary sources of cadmium.

These minerals are found in zinc ores and are often associated with lead and copper deposits. Cadmium can also be found in industrial wastewater, effluent, and soil contaminated with cadmium.

Commercial Extraction of Cadmium

Cadmium is commercially extracted as a by-product of zinc refining. The extraction process involves the volatilization of cadmium at high temperatures to produce cadmium vapors.

The vapors are then collected by cooling and condensation in a recovery furnace. Most of the cadmium produced is used in nickel-cadmium batteries, which account for about 80% of the total cadmium used.

Other uses of cadmium include in pigments, coatings, and alloys.

Conclusion

In conclusion, cadmium is a toxic metal that has limited uses due to its adverse health effects. Although it is present in small amounts in the earth’s crust, it is commonly found in industrial wastewater and effluent.

Cadmium minerals, such as greenockite and sphalerite, are the primary sources of cadmium, and it is commercially extracted as a by-product of zinc refining. The isotopes of cadmium have various applications in radiometric dating, nuclear power generation, and scientific research.

Nonetheless, the toxicity of cadmium underscores the need for proper handling and disposal practices to mitigate its health and environmental impacts.

3) History

Cadmium is believed to have been discovered in 1817 by Friedrich Stromeyer, a German chemist who was working at the University of Gttingen at the time. He was studying the properties of zinc carbonate, which is also known as calamine.

During his experiments, he noticed that a blue-grey metal sample appeared as a residue after heating the calamine. Stromeyer initially thought that this metal was a new form of zinc, but further tests revealed that it was a distinct element.

The element was given the name “cadmium” after the Latin word “cadmia,” which means calamine. Calamine was the primary source of zinc during that time, and cadmium was often found as an impurity in zinc ores.

The name “cadmium” reflects the element’s close association with zinc minerals, specifically with calamine. Stromeyer’s discovery was not immediately accepted by the scientific community, and it was not until several years later that others independently confirmed his findings.

Karl Meissner, a German chemist, and Karl Karsten, a German mineralogist, both reported the discovery of cadmium in 1818.

4) Identification

Atomic Properties of Cadmium

Cadmium has the atomic number 48 and the chemical symbol Cd. Its CAS number is 7440-43-9. In the periodic table, it is located in Group 12, which is also known as the zinc group.

This group consists of elements that have similar properties, including a high melting and boiling point and the ability to form divalent cations.

Physical Properties

Cadmium is a silvery-white metallic element that is soft and malleable. It has a density of 8.65 g/cm3 and a melting point of 321.07C.

It has a boiling point of 767C, which is lower than that of zinc. Cadmium is a good conductor of electricity and heat.

It also has a high corrosion resistance and is not affected by water or air at room temperature.

Chemical Properties

Cadmium has two valence electrons and belongs to the d-block in the periodic table. It has an oxidation state of +2, which is the most stable state.

It can also form other oxidation states, such as +1 and +3, but these are less common. Cadmium has an ionization energy of 8.99 eV, which is relatively low compared to other metals.

This low ionization energy makes it easy for cadmium to lose electrons and form cations. Cadmium reacts readily with oxygen in the air, forming cadmium oxide (CdO) or cadmium hydroxide (Cd(OH)2).

It also reacts with most non-metals, such as sulfur, selenium, and phosphorus, to form binary compounds. Cadmium can form complexes with a variety of ligands and is often used as a catalyst in organic synthesis.

Conclusion

Cadmium is a chemical element that was discovered in the early 19th century by Friedrich Stromeyer. It was named after the Latin term “cadmia,” which means calamine.

Cadmium has an atomic number of 48, and its atomic symbol is Cd. It is a soft, silvery-white metal that has a high corrosion resistance and good conductivity. Cadmium belongs to Group 12 of the periodic table and has two valence electrons.

It has an oxidation state of +2, which is the most stable state. Cadmium reacts readily with oxygen, sulfur, and other non-metals, forming binary compounds.

It can also form complexes with a variety of ligands and is used as a catalyst in organic synthesis.

5) Properties and Characteristics of Cadmium

General Properties

Cadmium is a chemical element with the atomic number 48 and the symbol Cd. Its atomic mass is 112.411 grams per mole, and its molar mass is 112.411 g/mol. It belongs to the group of transition metals in the periodic table of elements and is a member of the zinc group.

Cadmium is a soft, blue-white metal that is ductile and malleable. It has a low melting point and can easily be cut with a knife.

Physical Properties

Cadmium has a silver-white color and a lustrous finish. It is a relatively rare element and is generally found in small quantities in association with other minerals or ores.

Cadmium is a solid at room temperature and has a melting point of 320.9C. Its boiling point is 765C, and it has a low thermal conductivity.

Cadmium also has a low coefficient of thermal expansion, which makes it useful in applications that require a stable material over a wide temperature range.

Chemical Properties

Cadmium has a unique atomic structure that makes it chemically reactive. It has a radius of 154 pm, which is smaller than the other elements in the zinc group.

Its covalent radius is 144 pm, which is the distance between two atoms that share a pair of electrons. Cadmium has a total of 48 electrons, two of which are valence electrons.

These outermost electrons make cadmium a moderately reactive element. 6) What is Cadmium Used for?

Corrosion Resistance in Plating

One of the primary uses of cadmium is in plating. Cadmium provides excellent corrosion resistance and is widely used in the aerospace and automotive industries.

It is also used in marine applications, such as boat hulls and underwater structures. Cadmium is preferred over other metals because of its ability to withstand saltwater corrosion and its low coefficient of friction, which prevents wear and tear on moving parts.

Rechargeable Batteries

Cadmium is a key component in nickel-cadmium (NiCd) batteries, which are a type of rechargeable battery. These batteries are widely used in portable electronic devices, such as cameras and cell phones.

NiCd batteries are also used in medical devices, such as pacemakers, and in emergency lighting systems. Cadmium is used in the electrode of NiCd batteries, which allows for the production of a highly efficient and long-lasting battery.

Helium-Cadmium Lasers

Cadmium is used in the production of helium-cadmium lasers, which are used in various applications, including spectroscopy, microscopy, and holography. These lasers emit light in the ultraviolet-visible spectral range, making them ideal for applications that require high-energy radiation.

Cadmium is used in the construction of the laser tube, which is the heart of the helium-cadmium laser.

Control Rods in Nuclear Reactors

Cadmium is used in the control rods of nuclear reactors. These rods are used to regulate the flow of neutrons in the reactor core.

By absorbing some of the neutrons, the rods slow down the rate of the nuclear reaction, making it easier to control. Cadmium’s high neutron-absorbing capacity makes it an ideal material for use in control rods.

Low-Melting Solder

Cadmium is also used in the production of low-melting solder. Solder is a metal alloy that is used to connect two or more metal surfaces.

It has a lower melting point than the metal it is connecting, which allows it to fuse the metals together without melting them. Cadmium is used in some solders because it lowers the melting point of the alloy, making it easier to work with.

Conclusion:

In conclusion, cadmium is a chemical element that has a wide range of applications despite its toxicity and carcinogenicity. Cadmium has several unique properties that make it a valuable material for various industrial and scientific applications.

Some of the primary uses of cadmium include providing corrosion resistance in plating, being a key component of rechargeable batteries, being used in the production of helium-cadmium lasers, and being used in the control rods of nuclear reactors. Cadmium is also used in low-melting solder, which is a metal alloy used to connect diverse metals.

7) Toxic Effects of Cadmium

Health Hazards of Inhalation and Ingestion

Cadmium is highly toxic to humans and can have serious health hazards if inhaled or ingested. Inhalation of cadmium fumes or dust is a primary route of exposure in occupational settings where cadmium is used or produced.

When cadmium particles are inhaled, they can enter the respiratory system and reach the lungs, causing a variety of adverse effects. Ingestion of food and water contaminated with cadmium is another common route of exposure in the general population.

Cadmium can accumulate in plants and animals through the soil and water, leading to contamination of the food chain. Chronic exposure to low levels of cadmium through diet can have cumulative toxic effects in the body.

Specific Effects on Organs

Cadmium has a particular affinity for certain organs, including the lungs, kidneys, and liver. Inhalation of cadmium can cause lung damage, leading to a condition known as cadmium pneumonitis.

This condition is characterized by inflammation of the lung tissue, coughing, and difficulty breathing. Long-term exposure to cadmium fumes can also result in the development of fibrosis, a condition where scar tissue forms in the lungs, impairing their function.

The kidneys are another target organ for cadmium toxicity. Cadmium is absorbed into the bloodstream and filtered by the kidneys.

Prolonged exposure to high levels of cadmium can cause damage to the renal tubules, leading to a condition called cadmium-induced renal dysfunction. This condition is characterized by proteinuria (presence of protein in the urine), tubular dysfunction, and impaired kidney function.

In severe cases, cadmium exposure can lead to kidney failure. Cadmium toxicity can also affect the liver.

The liver plays a vital role in detoxifying harmful substances in the body, including cadmium. However, prolonged exposure to high levels of cadmium can overwhelm the detoxification capacity of the liver, leading to liver damage.

Cadmium-induced liver damage can manifest as hepatotoxicity, inflammation, and impaired liver function.

8) Interesting Facts

Past Uses of Cadmium

Cadmium has had various historical uses, particularly in the 20th century. One notable application of cadmium was in the phosphor coating of cathode ray tubes (CRTs), which were commonly used in older television sets.

The cadmium-based phosphors emitted light when excited by electron beams, allowing for the display of images on television screens. However, due to concerns about the toxicity of cadmium, alternative materials have been developed for phosphor coatings in modern displays.

Cadmium was also used in the production of pigments, most notably in the form of cadmium sulfide (CdS). Cadmium pigments provided vibrant and stable colors, making them popular for use in artists’ paints and, at one point, household paints.

However, the use of cadmium pigments in paints has been restricted or phased out in many countries due to environmental and health concerns.

Softness of Cadmium

Cadmium is a relatively soft metal, which means it can be easily cut, shaped, and molded. Its malleability and ductility make it suitable for applications that require flexibility, such as plating and soldering.

However, the softness of cadmium also means that it is not as durable as harder metals, and it can be susceptible to damage or wear over time.

Conclusion:

In conclusion, cadmium is a highly toxic element that can have detrimental effects on human health. Inhalation and ingestion of cadmium can lead to various health hazards, including lung damage, kidney dysfunction, and liver damage.

Cadmium has historically been used in phosphor coatings for cathode ray tubes and as pigments in paints; however, due to its toxicity, the use of cadmium in these applications has been restricted or phased out. Despite its toxicity, cadmium’s softness makes it useful in certain applications that require malleability, such as plating and soldering.

It is essential to recognize the dangers of cadmium exposure and take necessary precautions to minimize the risks associated with this toxic metal.

9) Cadmium Price

Cost of Pure Cadmium

The cost of pure cadmium can vary depending on several factors, including availability, demand, and purity. Cadmium is not as abundant as other metals, and its extraction and refining processes can be costly, contributing to its price in the market.

As of [current year], the average price of pure cadmium is approximately [price per kilogram]. However, it is important to note that this price is subject to fluctuations in the global market.

Factors such as changes in mining and refining operations, economic conditions, and environmental regulations can all influence the price of cadmium. The demand for cadmium is primarily driven by its applications and uses in various industries.

Despite its toxic properties, cadmium continues to be utilized in niche markets where its unique properties are advantageous. This includes its use in rechargeable batteries, plating, and as a component in certain lasers.

The price of cadmium is also influenced by its availability. Cadmium is generally obtained as a byproduct of zinc refining, and the production levels of zinc can impact the supply of cadmium.

Additionally, geopolitical factors and trade policies can introduce volatility into the market, affecting the availability and price of cadmium. The purity of cadmium can also affect its price.

Higher purity cadmium, which is often used in critical applications such as electronics and semiconductors, can be more expensive due to the additional refinement processes required to achieve a higher level of purity. Conversely, lower purity cadmium, which may contain impurities, can be less expensive.

It is important to keep in mind that the price of cadmium can vary regionally. Factors such as transportation costs, import/export duties, and local market conditions can all play a role in determining the price of cadmium in different locations.

Overall, the price of pure cadmium is influenced by a complex interplay of factors, including availability, demand, purity, and market conditions. As such, it is subject to fluctuations, and individuals or industries seeking to acquire cadmium should consult with suppliers or market experts for the most up-to-date pricing information.

Conclusion:

In conclusion, the cost of pure cadmium can vary depending on factors such as availability, demand, and purity. Cadmium is not as abundant as other metals, and its extraction and refining processes can be costly, contributing to its price in the market.

The demand for cadmium is driven by its applications in various industries, while its availability is influenced by factors such as zinc production and geopolitical factors. Additionally, the purity of cadmium can affect its price, with higher purity cadmium generally commanding a higher price.

It is important for individuals or industries interested in acquiring cadmium to consider these factors and consult with market experts to obtain accurate and up-to-date pricing information. In conclusion, cadmium is a toxic metal with limited uses due to its hazardous effects on human health.

It is important to be aware of the toxicity and potential sources of exposure to cadmium. The element is found naturally in the earth’s crust and is commercially extracted as a by-product of zinc refining.

Cadmium has various applications, including corrosion resistance in plating, rechargeable batteries, and control rods in nuclear reactors. However, its use has been reduced due to health and environmental concerns.

It is crucial to handle and dispose of cadmium properly to mitigate its adverse effects. Remember, cadmium’s toxicity underscores the urgency of responsible usage and proper disposal practices.

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