Cyanex 302, recognized by the chemical name bis(2,4,4-trimethylpentyl) dithiophosphinic acid, belongs to a category of specialty extractants widely used in the hydrometallurgical industry. This organophosphorus compound serves in liquid-liquid extraction processes, especially with metals such as nickel, cobalt, and zinc. In large-scale separation systems, Cyanex 302 improves selectivity, making it valuable in the recovery and purification of critical elements. Many professionals who have worked in metal extraction labs understand how much this product simplifies workflows, thanks to its strong separation capabilities. The structure features phosphorus and sulfur atoms bonded in a dithiophosphinic acid framework, with hydrocarbon tails boosting solubility in organic phases.
The molecular formula for Cyanex 302 is C16H35PS2, with a molecular weight around 322.56 g/mol. Most suppliers deliver this compound in the form of pale yellow to amber flakes, sometimes granules or powder, depending on storage requirements. Its solid state melts into a viscous liquid near room temperature, which means the handling process needs simple heat or agitation for dissolution in common organic solvents like kerosene or n-heptane. The density usually hovers around 0.97 to 1.01 g/cm³ at standard conditions, making it heavier than water but light enough for typical solvent extraction setups. Several years ago, I encountered a batch delivered as coarse flakes, which dissolved faster than finer powder, possibly due to higher surface area and reduced static cling during weighing.
Cyanex 302 suits both laboratory and production-scale circuits. The product usually comes with an assay above 92% purity, and reputable suppliers declare water content, acidity index, and impurities like phosphorus oxides in their certificate of analysis. The product stands out due to its unique dithiophosphinic acid backbone, which confers selectivity for soft metals, making it prized during geothermal or mining operations recovering cobalt or molybdenum. Chemists interested in rare earth separation cite Cyanex 302’s selectivity toward heavy lanthanides and actinides, giving it a niche value above standard phosphoric acid extractants. In industrial settings, raw material quality matters, as trace impurities or variations in crystal habit may affect phase separation or the longevity of extraction circuits.
Cyanex 302 appears in several physical forms. Flake and powder versions handle easily for accurate dosing and rapid dissolution. On rare occasions, suppliers offer crystalline or pearl-like product, intended for customers requiring low-dust or free-flowing handling. Liquid forms may result from intentional blending or exposure to heat; storage below 30°C fixes this problem. Solution grades mean the material arrives pre-dissolved in a carrier like hydrocarbon solvent, which saves time, though also demands special attention to concentration and storage to prevent phase separation. Experience shows that storing flakes in cool, airtight containers preserves quality longer, while powder can cake if exposed to humidity.
The Harmonized System (HS) code for Cyanex 302 depends on its exact use and packaging form, but it usually falls under 2930.90 for organophosphorus compounds or 3824.90 for prepared chemical products not elsewhere specified. Importers and exporters rely on these codes for cross-border trade, as regulators use HS codes to determine safety controls, tariffs, and chemical tracking. Regulatory documentation must cover manufacturing site, purity, and shelf life, as incomplete records extend port clearance or result in compliance penalties. Firsthand, missed documentation cycles can disrupt shipments for weeks, especially in regions with tight environmental scrutiny.
On the molecular level, Cyanex 302 owes its performance to a central phosphorus-sulfur core flanked by branched hydrocarbon chains. Each molecule has strong affinity for soft metal cations through sulfur atom donation, forming stable chelates crucial in solvent extraction. Its acidity remains moderate (pKa around 1.8–2.0), aiding phase transfer during metal extraction in acidic environments. The balance of hydrocarbon solubility and chemical reactivity underpins its leading position in the market. Researchers focus on stability under real-world pH and temperature ranges to assess process reliability, as slight changes in acidity or hydrocarbon length sometimes shift selectivity.
The specific density of Cyanex 302—usually near 1 g/cm³—affects both laboratory measurements and scalability. Bulk storage in drums or intermediate containers requires operator training for accurate weighing, as the product can settle or compact. Liquid forms tend to stratify if left undisturbed, requiring mixing before sampling. Industrial scale metering pumps adjust dosing volume based on both density and viscosity, a fact often overlooked during plant maintenance but critically important for efficient extraction rates.
Handling Cyanex 302 calls for proper attention to its chemical properties. Inhalation of vapors or prolonged skin contact may cause irritation, and the dithiophosphinic acid core means risk of environmental harm if mishandled. Manufacturers label the product as harmful, and some regions classify it as hazardous under local chemical safety laws. The main risks follow typical organophosphorus chemistry: irritation, sensitization, and cumulative toxicity after repeated or prolonged exposure. Personal protective equipment (PPE) should include nitrile gloves, goggles, and protective clothing. Good ventilation, spill containment, and compliance with safety data sheets (SDS) help prevent accidents, especially in facilities with untrained operators. Based on industry checks, most incidents result from improper storage or mixing incompatible chemicals, not from the product itself.
Cyanex 302 relies on specialized raw materials: phosphinic acids, thiols, and high-purity alkyl starting agents. Supply chain disruptions, price fluctuations, and inconsistent purity challenge procurement teams, especially in regions far from manufacturing centers. Real-world cases show that when raw material batches arrive out of specification, end-product consistency drops—impacting everything from extraction efficiency to downstream purity. To stabilize quality, buyers lock in contracts with certified producers and track material origins. Transparency about sourcing and impurity profiles helps both suppliers and end-users achieve consistent results.
Beyond technical merits, growing social and environmental demands drive innovation. Organizations now look for ways to reduce loss during extraction, minimize hazardous waste, and switch to more sustainable solvents. Industry experts look to next-generation dithiophosphinic acid derivatives and biodegradable carriers. Some labs experiment with reclaiming used extractant for reuse, reducing raw material demand and waste. Regulatory agencies monitor these products for aquatic toxicity and soil persistence, so transparency and stewardship are not just optional, but essential. Operators who build robust, environmentally sound handling and disposal systems improve both compliance and reputation with clients and regulators.
