Lithium Sputtering TargetCAS #: 7439-93-2

Synonyms

 N/A

Molecular Weight: 6.941 

Appearance: Silvery 

White Melting Point: 180.54°C 

Boiling Point: 1342°C Density: 0.534 g/cm3 

Solubility in H2O: N/A 

Poisson's Ratio: N/A 

Young's Modulus: 4.9 

GPa Vickers Hardness: N/A 

Tensile Strength: N/A 

Thermal Conductivity: 0.848 W/cm/K @ 298-C.2 K 

Thermal Expansion: (25 °C) 46 µm·m-1·K-1 

Electrical Resistivity: 8.55 microhm-cm @ 0 °C 

Electronegativity: 1.0 

Paulings Specific Heat: 0.85 Cal/g/K @ 25°C 

Heat of Vaporization: 32.48 K-Cal/gm atom at 1342°C

Product Introduction: Potassium Metal (K, CAS #: 7439-93-2)

Potassium metal, with the chemical symbol K and CAS number 7439-93-2, is a highly reactive alkali metal that plays a pivotal role in industrial chemistry and materials science. This soft, silvery-white element, belonging to Group 1 of the periodic table, is defined by its extreme chemical activity, low density, and ability to drive critical reactions that weaker elements cannot. While its reactivity limits direct applications, potassium metal serves as an irreplaceable precursor in the production of high-value compounds and as a powerful reducing agent in specialized manufacturing processes.

Core Chemical & Physical Attributes

Potassium’s behavior is governed by its distinct properties, which set it apart from other metals:

Mechanical Traits: Exceptionally soft (easily cut with a knife), with a Mohs hardness of 0.4. Fresh surfaces exhibit a bright metallic luster that tarnishes within seconds upon exposure to air, forming a protective oxide layer (K₂O, K₂O₂, KO₂) to slow further reaction.

Thermal & Density Properties: Boasts a low melting point of 63.5°C (146.3°F) and a boiling point of 759°C (1,398°F), with a density of 0.862 g/cm³ at 20°C—less than water, causing it to float during aqueous reactions.

Extreme Reactivity: Reacts violently with water, producing potassium hydroxide (KOH) and hydrogen gas (H₂) in an exothermic reaction that often ignites the hydrogen (flame temperature ~1,900°C). It also reacts with oxygen, halogens (Cl₂, Br₂), and even many organic compounds, requiring strict isolation from these substances.

Electrical Conductivity: Conducts electricity at ~14 × 10⁶ S/m, comparable to other alkali metals, due to its delocalized electron structure, making it useful in specialized conductive alloys.

Industrial Applications & Use Cases

Potassium metal’s value lies in its ability to enable reactions and processes that other materials cannot:

High-Purity Metal Extraction

As a powerful reducing agent, it extracts refractory metals like titanium, zirconium, and hafnium from their oxides. For example, in zirconium production: ZrO₂ + 4K → Zr + 2K₂O. This method yields metals with >99.9% purity, critical for aerospace components (titanium alloys) and nuclear reactors (zirconium cladding).

Chemical Synthesis & Pharmaceutical Manufacturing

Facilitates carbon-carbon bond formation in organic chemistry, such as the Wurtz reaction for synthesizing alkanes: 2R-I + 2K → R-R + 2KI. It also acts as a strong base in the production of pharmaceuticals, agrochemicals, and specialty esters, where precise deprotonation is required.

Heat Transfer in Extreme Environments

Sodium-potassium alloys (NaK) containing 40–78% potassium are used as heat transfer fluids in fast-neutron nuclear reactors and industrial furnaces. These alloys remain liquid from -12.6°C to 785°C, offering superior thermal conductivity (~25 W/m·K) and low vapor pressure compared to water or oil-based coolants.

Laboratory & Calibration Standards

Serves as a reference material in atomic absorption spectroscopy (AAS) to quantify potassium levels in biological samples (e.g., blood serum) and environmental analyses (soil, water). It is also used to generate high-purity hydrogen gas for small-scale reactions.

Pyrotechnics & Specialty Alloys

In pyrotechnics, potassium metal contributes to vibrant purple flames in fireworks, though its use is limited by safety concerns. In metallurgy, it forms low-melting alloys with other alkali metals for specialized applications like thermal switches.

Comparative Analysis with Other Alkali Metals

Potassium offers unique advantages over lithium, sodium, and cesium:

vs. Sodium: More reactive, enabling reduction of metals that sodium cannot (e.g., hafnium). NaK alloys with potassium have lower melting points than pure sodium, expanding their operational range.

vs. Lithium: More abundant and cost-effective (potassium costs ~\(50/kg vs. lithium’s ~\)150/kg), making it preferable for large-scale industrial processes. However, lithium’s lower reactivity simplifies handling in battery applications.

vs. Cesium: Far less expensive and more stable, while retaining sufficient reactivity for most industrial reducing applications. Cesium’s high cost (~$10,000/kg) limits its use to niche applications.

Production Methods & Quality Assurance

Potassium metal is produced exclusively via electrolysis due to its high reduction potential:

Electrolysis of Molten Potassium Chloride: In a specialized cell, molten KCl (heated to 770°C) is electrolyzed with graphite anodes and iron cathodes. Potassium ions (K⁺) are reduced at the cathode to form molten metal, which floats to the surface for collection, while chlorine gas (Cl₂) is released at the anode.

Purification: Raw potassium undergoes vacuum distillation (1–10 mmHg) at 300–400°C to remove sodium and other impurities, achieving purity levels of 99.5–99.9%.

Quality control includes:

Glow discharge mass spectrometry (GDMS) to detect trace elements (Na <500 ppm, Ca <100 ppm).

Gas analysis to ensure low levels of dissolved hydrogen and oxygen (<0.1%).

Critical Safety Protocols

Potassium’s reactivity demands rigorous handling procedures:

Storage: Must be submerged in dry mineral oil, kerosene, or argon-purged containers. Small quantities are stored in sealed glass ampoules to prevent punctures.

Handling: Requires a Class IIB fume hood, flame-resistant clothing, face shields, and non-sparking tools (brass or Teflon). Never use water to extinguish potassium fires—Class D extinguishers (graphite, sand) or dry soda ash (Na₂CO₃) are mandatory.

Emergency Response: Skin contact requires immediate removal of contaminated clothing and flushing with mineral oil (not water) to stop the reaction. Inhalation of fumes may cause respiratory irritation; seek medical attention promptly.

Disposal: Excess potassium is neutralized by slow reaction with isopropanol (2K + 2C₃H₇OH → 2KC₃H₇O + H₂) under controlled conditions. Waste solutions are treated as hazardous waste.

Packaging & Sourcing Options

Available in forms tailored to industrial and research needs:

Ingots: 10g–1kg in oil-filled steel cans; 5–50kg in sealed drums for metallurgical applications.

Shavings/Powder: 100g–5kg in argon-sealed bags for chemical synthesis, ensuring minimal oxidation.

NaK Alloys: 1–20L sealed containers with pressure relief valves, available in 50/50 or 78/22 K/Na ratios for heat transfer systems.

High-purity grades (99.99%) are available for semiconductor and research applications, with a certificate of analysis (CoA) provided.

For technical specifications, safety training, or bulk inquiries, contact our team specializing in reactive metals and alkali metal derivatives.

Health & Safety Information 

Signal Word: Danger 

Hazard Statements: H260-H314 

Hazard Codes: F,C 

Precautionary Statements: P231+P232-P260-P303+P361+P353-P305+P351+P338-P501 

Flash Point: Not applicable 

Risk Codes: 14/15-34 

Safety Statements: 8-43-45 

RTECS Number: OJ5540000 

Transport Information: UN 1415 4.3/PG 1 

WGK Germany: 2 

GHS Pictogram: Image,Image

Chemical Identifiers 

Linear Formula: Li 

Pubchem CID: 3028194 

MDL Number: MFCD00134051 

EC No.: 231-102-5 

Beilstein/Reaxys No.: N/A 

SMILES: [Li] 

InchI Identifier: InChI=1S/Li 

InchI Key: WHXSMMKQMYFTQS-UHFFFAOYSA-N

Packing of Standard Packing: 

Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 735 gallon liquid totes Special package is available on request.