When sourcing potassium sulfate for industrial or agricultural use, you’ll quickly encounter a variety of potassium sulfate other names that can cause confusion. Whether you call it sulfate of potash (SOP), K2SO4, arcanite, or 0-0-50 fertilizer, understanding the chemical’s identity is critical for precise specification matching and supplier evaluation. This guide clarifies every synonym, trade name, and grade designation so procurement professionals, chemical engineers, and industrial buyers can navigate the market with confidence.
Sulfate of potash is the most prevalent commercial name in agriculture. It emphasizes the product’s potassium content (potash) combined with sulfate ions. SOP is the standard term in fertilizer trading and is intrinsically linked to chlorine-free nutrient formulations for high-value crops such as tobacco, citrus, grapes, and potatoes.
In the geological and mining sector, potassium sulfate is often referred to as arcanite. This name appears in technical literature discussing natural deposits, mineral processing, and extraction methods. While industrial buyers rarely use ‘arcanite’ in purchase orders, recognising it helps when evaluating raw material sources or reviewing analytical reports from mined versus synthetic SOP.
The term 0-0-50 potassium sulfate refers specifically to the fertilizer grade with a guaranteed NPK rating of 0% nitrogen, 0% phosphorus pentoxide, and 50% water-soluble potassium oxide (K2O). This label strictly follows the standard fertilizer analysis convention in North America and parts of Asia. It does not represent a different chemical entity—it is the same K2SO4 with a minimum 50% K2O content. The 0-0-50 potassium sulfate page on our website details typical analytical results and compliance with international fertilizer standards.
In Commonwealth countries and many international contracts, the spelling ‘potassium sulphate‘ is used. Although chemically identical, this orthographic difference can cause indexing issues in databases. Procurement teams should ensure that both spellings are captured in ERP systems and RFP documents to avoid missing relevant supplier bids.
In laboratory specifications and technical datasheets, you will find the formula K2SO4 or the CAS number 7778-80-5. These are the most unambiguous potassium sulfate other names, immune to language or regional variations. Chemical engineers often use ‘dipotassium sulfate’ in inorganic chemistry contexts, though it is less common in trade.
Other less frequent potassium sulfate other names include ‘salt of Lemery’, ‘sal polychrestum’, and ‘tartar vitriolate’. While these are largely obsolete, they occasionally appear in legacy patents or specialized pharmaceutical reference texts. Understanding this nomenclature can prevent misidentification when evaluating older intellectual property or historical literature.
One of the most curious queries that surfaces is, ‘Is potassium sulfate a metal?’ The straightforward answer is no—potassium sulfate is not a metal; it is an inorganic salt. Yet this question often stems from a need to understand the material’s hazard classification, shipping requirements, or elemental composition. Let’s break down the chemistry to eliminate any ambiguity.
Potassium sulfate (K2SO4) comprises potassium cations (K+) and sulfate anions (SO42-). In its solid form, it is a white crystalline powder or granule with no metallic properties such as electrical conductivity or malleability. The potassium component itself is a metal in its elemental state, but when cationic in a salt, it behaves entirely differently. For transport and handling, potassium sulfate is not classified as a metal; it falls under general inorganic chemicals. It is not combustible, not a metal powder requiring special safety precautions, and it is not subject to regulations concerning water-reactive metals. However, some buyers may confuse potassium metal (UN 2257) with potassium sulfate—a critical distinction for safe logistics. Procurement specifications should always reference the correct CAS number and UN number (not regulated as dangerous goods) to prevent shipping delays.
This distinction is particularly relevant when importing into jurisdictions with strict metal-bearing substance legislation. Potassium sulfate is not a heavy metal compound, nor does it contain toxic metals; instead, it is an essential nutrient bearing potassium, calcium, magnesium, and sulfur benefits for agriculture. When you source from a reliable supplier, the detailed potassium sulfate product specifications will clarify its non-metallic nature and safe handling profile.
Beyond the different potassium sulfate other names, industrial procurement hinges on precise specifications. Here are the critical parameters you must verify when evaluating commercial offers, whether for fertilizer, glass manufacturing, or pharmaceutical applications.
The 0-0-50 designation directly ties to the potassium oxide (K2O) equivalent. Although potassium sulfate does not contain K2O per se, the fertilizer industry uses this convention to express potassium nutrient content. A 50% K2O minimum translates to approximately 41.5% actual potassium (K). Our premium SOP consistently achieves 51.5% K2O, a specification detail that ensures maximum nutrient density and reduced freight cost per unit of potassium shipped. When comparing suppliers, always ask for the guaranteed K2O percentage rather than relying solely on the ‘0-0-50’ label, as variations exist between 48% and 52% across global sources.
The molecular weight of potassium sulfate is 174.259 g/mol. This value is fundamental for industrial formulators and chemical engineers involved in precise blending, stoichiometric calculations, and quality control. For example, to supply 1 kilogram of pure potassium (K), you need 2.228 kg of K2SO4 (2 × 39.0983 / 174.259 = 0.4487, so inverse 2.228). In glass manufacturing, the molecular weight determines the amount of potassium sulfate required as a refining agent to achieve the desired melting behaviour and bubble removal. In pharmaceutical excipient applications, the exact molar mass is essential for master formula records and regulatory submissions. Reputable suppliers will state the molecular weight clearly in their certificate of analysis, often alongside moisture content (max 0.5%), chloride (max 0.1–0.5%), and pH (7–9). These data points together validate the product’s purity and suitability.
| Parameter | Specification |
|---|---|
| Appearance | White powder / granular |
| K2O content | 50.0% min (typical 51.5%) |
| Chloride (Cl) | ≤0.5% |
| Moisture | ≤0.5% |
| Water solubility (20°C) | 120 g/L |
| Bulk density | 1.2–1.3 g/cm³ (granular) |
| pH (1% solution) | 7.0–9.0 |
| Molecular weight | 174.259 g/mol |
| CAS number | 7778-80-5 |
| Sulfur (S) content | 18% min |
This typical specification sheet represents a chlorine-free potassium sulfate grade suitable for both fertigation and industrial processes. Buyers should request samples and full analysis alongside the commercial offer to confirm batch-to-batch consistency.
In international trade, inconsistent nomenclature can lead to serious quality disputes. When drafting or responding to a request for quotation, align all potassium sulfate other names with an unambiguous reference—preferably the CAS number and the chemical formula K2SO4. Here are practical steps to eliminate ambiguity:
Procurement managers are encouraged to use a dedicated line in the contract: “K2SO4 (Sulfate of Potash, SOP, Potassium Sulfate), 0-0-50 fertilizer grade, CAS 7778-80-5, minimum 50% K2O, chlorine-free, granular.” This single sentence captures all relevant potassium sulfate other names while setting clear technical boundaries.
The ambiguity surrounding potassium sulfate other names has real economic consequences in agriculture. Many specialty crop programs demand chlorine-free potassium sources to avoid toxicity in chloride-sensitive plants. Mistaking SOP for MOP (muriate of potash, potassium chloride) due to sloppy naming can result in severe crop damage and financial loss. The 0-0-50 potassium sulfate designation is particularly important in fertigation schedules because it quantifies the nutrient input precisely: applying 100 kg of 0-0-50 delivers 50 kg of K2O—far different from a 0-0-52 SOP that would alter the nutrient formula. Growers and fertilizer importers must demand that every shipment is accompanied by a label clearly stating “Sulfate of Potash (Potassium Sulfate) 0-0-50” and not generic ‘potash’, which could be mistaken for potassium chloride.
Furthermore, organic certification bodies such as OMRI and ECOCERT have strict rules about the origin and processing of potassium sulfate. They recognize the product only when referred to as sulfate of potash derived from natural langbeinite ores, for example. Using incorrect potassium sulfate other names on organic input documentation can lead to decertification of entire crop lots. Thus, precise language is a regulatory compliance issue as much as a commercial one.
Different industries have developed their own preferred potassium sulfate other names, reflecting the product’s role in their processes:
Glassmakers typically order ‘potassium sulfate’ or ‘K2SO4’ as a refining agent and flux. They focus on purity, iron content below 200 ppm, and particle size uniformity to ensure homogeneous melt behaviour. In this sector, you will almost never see the term 0-0-50; instead, technical grade potassium sulfate or pure K2SO4 appears on bills of lading.
In aluminum dross processing and scrap remelting, potassium sulfate is introduced as a salt flux to protect the melt from oxidation and improve metal recovery. Here, it is commonly called ‘fluxing grade potassium sulfate’ or simply ‘K2SO4 flux’. The sulfate ion plays a different role than in fertilizer, so the name often drops any agricultural connotation entirely.
Pharmacopoeia monographs list the substance as ‘Potassium Sulfate’ (USP) or ‘Potassium Sulphate’ (Ph. Eur.). For regulated industries, the only acceptable potassium sulfate other names are the official compendial titles. Brokers should not substitute terms like SOP when dealing with pharmaceutical purchasing departments, as this could trigger audit non-conformities. The premium sulfate of potash from Hailei Chemical can be supplied with necessary pharmacopoeia compliance documents on request.
Wallboard manufacturers use potassium sulfate as an accelerator or additive to control setting time. Again, the material is simply called potassium sulfate or K2SO4, often with a specific particle size and purity that differs from agricultural grades. The 0-0-50 label is irrelevant here, but the same chemical entity is being consumed.
This industry-by-industry mapping underscores why buyers must communicate clearly using the name that matches the intended use and required certification, while always linking back to the same chemical identity.
With all the potassium sulfate other names clarified, the final challenge is supplier selection. A trustworthy partner like Hailei Chemical offers:
Whether you import potassium sulfate under the name SOP, arcanite, or 0-0-50 fertilizer, the supplier’s ability to align the delivered product with your exact specifications matters most. Request samples, evaluate the molecular weight and purity data, and verify that all potassium sulfate other names used in your contracts point definitively to K2SO4 CAS 7778-80-5.
Ready to source high-quality potassium sulfate? Request a quote today and let our experts help you match the right grade to your exact application requirements.