Potassium Sulfate Other Names, Specifications, and Procurement Insights for Industrial Buyers
When sourcing chemical raw materials, clarity in nomenclature is essential to avoid costly mistakes. Potassium sulfate other names such as sulfate of potash (SOP), arcanite, and K2SO4 can cause confusion among procurement professionals who must verify exactly what they are purchasing. Whether you are an importer of specialty fertilizers, a glass manufacturer, or a pharmaceutical producer, understanding the full range of synonyms and the corresponding quality specifications is the first step toward a reliable supply chain. This buyer-focused guide decodes the multiple identities of potassium sulfate, clarifies its chemical nature, examines industry-standard specifications, and provides actionable criteria for selecting a trusted supplier.
What Are the Most Common Potassium Sulfate Other Names?
Because potassium sulfate serves both agricultural and industrial sectors, it appears under various chemical, commercial, and historical names. Awareness of potassium sulfate other names helps buyers cross-reference technical data sheets, customs documentation, and supplier certificates without ambiguity. The following table lists the most widely recognized synonyms, along with the context in which each is used.
| Synonym | Typical Usage Context |
|---|---|
| Sulfate of potash (SOP) | Agricultural fertilizer trade, especially chlorine-free formulations |
| Potassium sulphate | British English spelling, common in EU and Commonwealth markets |
| K2SO4 | Chemical formula, used on safety data sheets and lab documentation |
| Arcanite | Mineralogical name; occasionally seen in niche industrial references |
| Salt of Lemery | Historical pharmaceutical name, rarely used today |
| Tartarus vitriolatus | Archaic alchemical term; may appear in legacy pharmacopoeias |
| Sulfuric acid dipotassium salt | Systematic IUPAC name; prevalent in chemical registries and patents |
In international trade, sulfate of potash (SOP) dominates the fertilizer sector, while K2SO4 and potassium sulfate are standard across technical documentation. Buyers encountering potassium sulfate other names on a supplier’s certificate of analysis should always verify that the CAS number 7778-80-5 matches, as this unique identifier eliminates any doubt about the material identity.
Understanding Potassium Sulfate: Chemical Nature and Molecular Weight
A fundamental question often arises among newcomers to chemical procurement: “Is potassium sulfate a metal?” The short answer is no. Potassium sulfate is an inorganic salt composed of potassium cations (K+) and sulfate anions (SO42−). It is a white crystalline solid at room temperature and is highly soluble in water. Its metallic constituent, potassium, is an alkali metal, but the compound itself is not a metal; it does not conduct electricity in solid form, nor does it exhibit metallic luster or malleability. This distinction is critical for logistics teams that must classify materials for safe transportation and storage.
From a quality control standpoint, one of the most important physical constants is the molecular weight of potassium sulfate. The molecular weight (or more precisely, the formula mass) of K2SO4 is 174.259 g/mol. This value is indispensable when preparing gravimetric standards, calculating molar concentrations for pharmaceutical buffer systems, or verifying batch consistency through stoichiometric analysis. A reputable supplier will list the molecular weight on the certificate of analysis alongside other physicochemical data such as melting point (1,069°C) and relative density (2.66 g/cm³).
When evaluating a commercial sample, the molecular weight itself does not change, but impurities may alter the apparent molar mass in titration methods. Buyers should always request a full potassium sulfate product specification that includes purity percentage, as this directly impacts the utility of the molecular weight in industrial formulations.
Potassium Sulfate Specification: Key Parameters for Industrial and Agricultural Grades
Procurement teams rely on precise potassium sulphate specification sheets to ensure that the delivered material meets end-use requirements. Although the chemical formula remains constant, the permissible levels of impurities, particle size distribution, and packaging vary significantly depending on the application. The table below outlines typical specifications for premium-grade potassium sulfate.
| Parameter | Typical Value / Range | Relevance |
|---|---|---|
| K2O content (water-soluble) | 50.0% minimum | Defines fertilizer grade; often labeled 0-0-50 potassium sulfate |
| Chloride (Cl) | ≤ 0.5% | Critical for chlorine-sensitive crops and pharmaceutical use |
| Moisture | ≤ 0.5% | Prevents caking during storage and improves flowability |
| Water-insoluble matter | ≤ 0.05% | Ensures clarity in glass melts and pharmaceutical solutions |
| pH (5% solution) | 2.5–4.0 | Acidic nature due to slight hydrolysis; buffering considerations |
| Heavy metals (as Pb) | ≤ 5 ppm | Pharmaceutical and food-grade compliance |
| Particle size (mesh) | Customizable: fine powder (200 mesh) to crystalline granules | Adjusts dissolution rate and blending homogeneity |
The fertilizer grade 0-0-50 potassium sulfate is a standard designation in North America, indicating zero nitrogen, zero phosphorus, and 50% soluble potash (K2O). This high-concentration, chloride-free formulation makes SOP the preferred choice for tobacco, citrus, grapes, potatoes, and other high-value crops that are sensitive to chloride toxicity. When reviewing a potassium sulphate specification, agricultural importers must confirm that the K2O content is expressed on a water-soluble basis, as this directly influences nutrient availability.
For industrial users such as glass manufacturers, the particle size and purity levels dictate the melting behavior and the optical quality of the final product. Hailei Chemical’s potassium sulfate is produced to meet both standard and customized specifications, with uniform granularity that ensures consistent furnace feed.
Is Potassium Sulfate a Metal? Common Misconceptions Clarified
While we’ve established that potassium sulfate itself is not a metal, the persistent question “is potassium sulfate a metal” arises because it contains the element potassium, which is an alkali metal. In its pure elemental state, potassium is a soft, silvery-white metal that reacts violently with water. However, in potassium sulfate, potassium exists as a cation (K+), completely stripped of its metallic properties. The compound is an ionic salt, not a metal, and it dissolves in water without producing free electrons. This distinction matters for handling, transport classification, and material compatibility: potassium sulfate does not require the same precautions as metallic potassium, which must be stored under oil to prevent oxidation.
Another related misconception involves the term “potash.” Potash broadly refers to potassium compounds, often carbonates or chlorides, but in commercial fertilizers “potash” is measured as K2O equivalent. Thus, 0-0-50 potassium sulfate contains 50% K2O by weight, even though the compound itself is K2SO4, not the oxide. Understanding that the K2O percentage is a conventional expression of potassium content helps avoid confusion when comparing different potassium sources such as MOP (muriate of potash, KCl) and SOP.
Potassium Sulfate in Fertilizer: Decoding 0-0-50 and Its Crop Benefits
For specialty fertilizer importers, the designation 0-0-50 potassium sulfate is more than a label; it’s a promise of chloride-free potassium nutrition. Many high-value crops exhibit leaf burn, reduced yield, or poor fruit quality when exposed to chloride ions. SOP delivers potassium and sulfur—both essential macronutrients—without the chloride stress associated with muriate of potash.
- Chloride-sensitive crops: Tobacco, tea, coffee, many fruits (grapes, citrus, berries), vegetables (potatoes, tomatoes, peppers), and ornamentals.
- Sulfur provision: With 18% sulfur in the sulfate form, SOP serves as a ready source of this secondary nutrient, which is vital for oilseed and protein synthesis.
- Low salt index: Compared to potassium chloride, SOP has a lower salt index, reducing the risk of osmotic stress in fertigation systems.
- Compatibility: SOP can be blended with most other fertilizers and is suitable for both soil application and soluble foliar sprays.
Global demand for SOP continues to rise as farmers shift toward chloride-free programs to meet export quality standards for fruits and vegetables. This trend makes premium potassium sulfate a strategic procurement item for distributors serving protected horticulture and organic farming markets (where allowed by local regulations).
Industrial Applications: Beyond Fertilizer – Glass, Aluminum, and Pharmaceuticals
While agriculture consumes the largest volume of potassium sulfate, industrial applications demand high purity and consistent physical properties. Glass manufacturers use potassium sulfate as a refining agent and flux. It lowers the melting temperature of silica, improves the workability of the glass melt, and enhances brilliance. In aluminum recycling, potassium sulfate serves as a flux to protect the molten metal from oxidation and to remove impurities, increasing metal recovery rates.
The pharmaceutical industry utilizes potassium sulfate as an excipient in tablet formulations and as an electrolyte replenisher in certain preparations. The strict requirements of pharmacopoeia monographs (e.g., USP, EP) call for exceptionally low heavy metals and a defined molecular weight. Here, the molecular weight of potassium sulfate (174.26 g/mol) is critical for accurate dosing and analytical standardization.
An emerging application is the use of high-purity potassium sulfate as an additive in gypsum board production. The potassium sulfate acts as an accelerator, reducing the setting time of gypsum plaster without compromising the final board strength. This application requires a fine, free-flowing powder that disperses evenly, a specification that Hailei Chemical can meet with micronized grades.
Sourcing Potassium Sulfate: What Buyers Should Look for in a Supplier
Selecting a potassium sulfate supplier goes beyond comparing unit prices. B2B buyers must evaluate the entire value proposition, from technical capability to logistics reliability. The following checklist can serve as a framework for due diligence:
- Consistent quality: Request three to five consecutive certificates of analysis to verify batch-to-batch uniformity. Pay special attention to K2O content, chloride level, and heavy metals.
- Customized packaging: Depending on your market, you may need 25 kg bags, 1,000 kg supersacks, or bulk shipments. Ensure the supplier can accommodate labeling, palletization, and moisture-proof packaging.
- Regulatory documentation: Confirm that the supplier provides full REACH registration (for EU markets), SDS compliant with GHS, and any required fertilizer registrations.
- Supply security: As a manufacturer rather than a trader, direct producers offer better transparency into production schedules and raw material sourcing. Check production capacity and inventory buffer.
- Logistics expertise: Export-oriented suppliers must demonstrate experience with ocean freight, dangerous goods declarations (if applicable), and customs clearance in your destination country.
- Technical support: A supplier that can advise on formulation compatibility, solubility curves, or alternative grades adds value beyond the product itself.
At Hailei Chemical, we understand that every shipment of potassium sulfate must arrive on time and on spec. With a dedicated export team and in-house quality control laboratory, we provide full traceability from raw material intake to container loading. Our potassium sulphate specification documents are shared proactively during the negotiation stage, empowering buyers to make informed decisions without ambiguity. Additionally, our technical staff can assist in translating between the potassium sulfate other names found in different national standards, ensuring that you order exactly the grade you need.
Conclusion: Turn Potassium Sulfate Knowledge into Supply Chain Confidence
Mastering the vocabulary of potassium sulfate—from its common synonyms to its precise specification parameters—enables B2B buyers to communicate effectively with suppliers and avoid discrepancies that lead to shipment rejections or formulation failures. Whether you know it as sulfate of potash, arcanite, or simply SOP, the same molecular weight and quality benchmarks apply. By focusing on critical data such as the 50% K2O guarantee, chloride content, and particle size, procurement professionals can secure a consistent supply that meets the demands of fertilizer blenders, glass furnaces, aluminum recyclers, and pharmaceutical formulators alike.
Ready to source high-purity potassium sulfate with complete documentation and reliable logistics? Request a quote or explore the technical details of our potassium sulfate product page to find the grade that fits your industrial or agricultural requirements. Hailei Chemical’s experts are available to discuss your specifications, packaging preferences, and delivery schedules.