Potassium Sulfate (K2SO4) — Buying Guide, Specifications, Uses, Dosage Table, Price, Bulk Sales & Export
Potassium sulfate is classified as a mineral compound and is commonly described as a combination of an acidic salt and a basic salt. In practice, potassium sulfate is widely used as a chemical fertilizer to supply the soil with two essential nutrients: potassium and sulfur. In the Iranian market, it is also commonly known under the commercial name SOP / SoluPotash. However, it is important to note that the difference between potassium sulfate and SoluPotash is primarily related to water solubility (and therefore suitability for fertigation and foliar programs).
In Iran, there are numerous suppliers of both imported and locally produced potassium sulfate. Therefore, when purchasing potassium sulfate, it is essential to evaluate the key selection criteria that determine the most suitable supplier and manufacturer, including: quality, price, packaging, and on-time delivery.
In the sections below, you will find: a list of top potassium sulfate suppliers in Iran, a complete buyer’s guide, technical specifications, production methods, applications across industries (especially agriculture), dosage tables (foliar / fertigation / soil application), packaging and handling requirements, safety notes (MSDS), and finally a practical commercial section focused on price, purchase, domestic supply, bulk sales, and export.
Top 10 Potassium Sulfate Suppliers in Iran
Potassium sulfate is a high-demand mineral product that can be sourced from reputable suppliers. A selection of well-known suppliers in the Iranian market is listed in the table below.
| No. | Supplier Name |
|---|---|
| 1 | Yaros Potassium Sulfate |
| 2 | Kimia Pars Shayankar |
| 3 | Shimico |
| 4 | Shimi Store |
| 5 | Southgan Potassium Sulfate |
| 6 | Petro Kimia |
| 7 | Aral Shimi |
| 8 | Arasbaran Potassium Sulfate |
| 9 | Urmia Petrochemical Potassium Sulfate |
| 10 | Mobtakeran Shimi |
Buying Guide for the Right Potassium Sulfate
Product Quality
In any potassium sulfate buying guide, one of the most fundamental factors is product quality. Higher quality potassium sulfate has a direct impact on agricultural results and performance in other applications. This quality depends on several main parameters, explained below in detail:
1) High Purity
One of the clearest signs of a high-quality potassium sulfate is a high purity percentage. Products with 95% purity or higher typically perform better because impurities can negatively affect plants and soil health. High purity is especially important for farmers who prioritize better crop quality and stable nutritional outcomes.
2) Free from Heavy Metals
Heavy metals such as lead, cadmium, and arsenic may exist in some low-grade or contaminated potassium sulfate samples. These contaminants can damage soil and plants and, when accumulated in crops, may pose risks to humans and livestock. Therefore, products that comply with standards limiting heavy metals are generally considered safer and more reliable.
3) Particle Size
Particle size also affects quality and performance. Finer particles usually distribute more evenly in the soil and become more accessible to plant roots. On the other hand, extremely fine particles may cause handling or caking issues in high-humidity environments. Selecting the correct particle size based on your application method is a key decision factor.
4) Water Solubility
High-quality potassium sulfate should dissolve easily in water. This supports faster access to potassium for plants and reduces common operational issues, such as sediment formation and clogging in irrigation systems. If fertigation (injection) is part of your feeding program, solubility and low residue are critical.
5) Product Color and Odor
Premium potassium sulfate is typically odorless and has a light, clean appearance. Unpleasant odor or dull/discolored appearance may indicate impurities, which can reduce fertilizer performance and reliability.
6) Supplier Credibility and Compliance with Standards
Potassium sulfate quality also depends on supplier credibility and adherence to national and international standards. Buying from reputable suppliers that provide documented quality assurance and recognized certificates helps reduce procurement risk and ensures consistency.
Overall, focusing on potassium sulfate quality during purchase improves productivity, reduces operational and agronomic risk, and supports more efficient fertilizer use. For determining the best application timing—especially for granular SOP— consulting a qualified agronomist is recommended.
In general, the raw materials used in potassium sulfate production have a significant impact on final product purity and quality. The physical and chemical characteristics of potassium sulfate are provided in the table below.
Physical and Chemical Properties of Potassium Sulfate
| Property | Value / Description |
|---|---|
| Chemical Formula | K2SO4 |
| Molar Mass | 259/174 g/mol |
| Appearance | White powder or white granules |
| Odor | Odorless |
| Water Solubility | 111 g/L at 20°C 120 g/L at 25°C 240 g/L at 100°C |
| Melting Point | 1069°C |
| Boiling Point | 1689°C |
| Density | 366/2 g/cm³ |
Potassium Sulfate Production Methods
Potassium sulfate (K₂SO₄) can be produced through several industrial methods. The chosen method depends on industry needs, raw material availability, and production cost structure. The main production methods are listed below:
1) Reaction of Potassium Chloride and Sulfuric Acid
This is one of the most common and economical methods for industrial potassium sulfate production. In this process, potassium chloride (KCl) reacts with sulfuric acid (H₂SO₄) to produce potassium sulfate and hydrochloric acid (HCl) as a by-product:
2KCl + H2SO4 → 2HCl + K2SO4
In this method, sulfuric acid and potassium chloride are introduced into a specialized reactor. The reaction typically occurs at high temperatures (around 600°C). The process can be commercially attractive because hydrochloric acid, produced as a by-product, may create additional value. However, corrosion-resistant equipment is required, and HCl gas management is necessary to avoid environmental pollution.
2) Mannheim Process
The Mannheim process is a widely recognized method and is similar to the sulfuric acid route but includes more precise temperature control and reaction conditions. Potassium chloride and sulfuric acid react in a furnace at high temperature, producing potassium sulfate as a solid. Due to better process control, product quality can be higher than other methods. The main drawbacks include longer production time and more complex equipment requirements.
3) Reaction of Potash and Gypsum
This method uses potash (potassium carbonate) and gypsum (calcium sulfate). Because it relies on relatively accessible and lower-cost minerals, it may be economically attractive, especially for local operations. Potassium carbonate and gypsum are dissolved and mixed; potassium sulfate precipitates, while calcium carbonate forms as a by-product. The cost advantage is tied to raw material availability and local economics.
4) Extraction from Natural Mineral Sources
In some countries, potassium sulfate occurs naturally in mineral deposits such as Langbeinite and Globerite. Through mining and processing (extraction, crushing, washing, purification), potassium sulfate can be produced in a usable powder form.
5) Reaction of Potassium Chloride and Magnesium Sulfate
Another common method involves reacting potassium chloride with magnesium sulfate to produce potassium sulfate and magnesium chloride. With proper temperature control and standardized reaction conditions, high-purity potassium sulfate can be achieved. However, the process may require additional separation steps and appropriate equipment to isolate the final product efficiently.
Applications of Potassium Sulfate
Potassium sulfate (K2SO4) is a widely used mineral compound. Due to its chemical stability, appropriate water solubility, and chlorine-free profile, it is applied across multiple industries. Its usage is not limited to agriculture and also includes chemical, food, and laboratory applications.
| Industry | Application |
|---|---|
| Glass Industry | Used in glass formulations to improve physical properties and clarity |
| Agriculture (Fertilizers) | Supplies potassium and sulfur as a chlorine-free chemical fertilizer |
| Military Industry | Used to reduce flash and light in certain propellants and fuel compositions |
| Medical & Pharmaceutical | Limited pharmaceutical applications and historical use for persistent fevers |
| Food Industry | Used as an approved additive in certain formulations |
| Laboratories | Used as an auxiliary substance or catalyst in certain chemical reactions |
Potassium Sulfate in Agriculture
The most important and most widespread application of potassium sulfate is its use as an agricultural fertilizer. By supplying potassium and sulfur simultaneously, it plays a meaningful role in improving crop quality and yield. It is especially valuable for chlorine-sensitive crops.
- Improved crop quality: better fruit color, taste, size, and uniformity
- Higher stress tolerance: nutritional support for drought, heat, and cold tolerance
- Better growth performance: supports enzymatic activity and improves photosynthetic efficiency
For these reasons, potassium sulfate holds a key role in nutrition programs for field crops, orchards, and greenhouse production, and is frequently chosen as a practical alternative to chloride-based potash fertilizers.
What Is SoluPotash and How Is It Different from Potassium Sulfate?
In the Iranian market, “SoluPotash” is commonly used as a commercial label for potassium sulfate with higher water solubility, typically intended for fertigation and foliar application. From a chemical standpoint, both products are related to potassium sulfate (K2SO4). However, the market uses separate naming primarily due to: solubility level, fine particle size, impurity control, and compatibility with irrigation systems.
If your main goal is soil application (basal application / pit application), granular or crystalline potassium sulfate can be a logical choice. However, for pressurized irrigation systems and precise feeding programs, a product that is genuinely water-soluble and low-residue can reduce clogging risk and improve nutrient delivery efficiency.
Potassium Sulfate Forms and How to Choose the Right One (Powder, Granular, Liquid)
Potassium sulfate is commonly supplied in three main forms. The correct choice depends on your application method. If you operate pressurized irrigation systems, prioritize real-world solubility and low sediment performance—not just label claims.
1) Granular / Crystalline
Suitable for soil application, basal fertilization, and programs where gradual nutrient release is preferred. It is generally easier to handle, store, and transport, and generates less dust.
2) Powder (Fine)
Better suited for solution preparation, fertigation, and foliar spraying. However, practical performance depends on: complete dissolution and low residue. Poor quality or unsuitable particle size increases clogging risk.
3) Liquid
Used for faster uptake and specialized feeding programs. It is more common in certain niche applications and smaller-scale use cases.
Application Timing, Method, and Dosage (Decision Framework)
Application timing depends on crop type, growth stage, and soil/water test results. However, a general framework commonly used includes:
- Early growth / start of vegetative growth: to strengthen the nutritional base
- Before fruit set and during fruit development: to support quality and fruit filling
- After environmental stress (nutritional support): to help restore nutritional balance
Important operational note: In very light soils (sandy / sandy-loam) or under heavy irrigation/rainfall, nutrient leaching risk is higher. It is often better to split applications into several lighter doses rather than one heavy dose. This can improve efficiency and reduce salt accumulation risk.
Potassium Deficiency Symptoms in Plants
Potassium is a mobile element within plants. Therefore, deficiency often appears first on older leaves and becomes more severe if deficiency persists. Common symptoms include:
- Yellowing followed by leaf edge scorching
- Weak stems and reduced structural strength
- Lower fruit quality (smaller size, weaker taste/color)
- Higher sensitivity to stress and diseases
Note: Accurate diagnosis is best confirmed through soil and leaf tests and field condition assessment, because other nutrient deficiencies may produce similar symptoms.
Mixing, Compatibility, and Common Mistakes
- Before injection into fertigation systems, dissolve in a separate container and then filter the solution.
- Avoid incompatible mixtures that form sediment—especially in programs where calcium enters the same irrigation line.
- When combining multiple fertilizers, perform a small-scale compatibility test first.
Potassium Sulfate Dosage (Foliar, Fertigation, and Soil Application)
Important: The values below are general guidelines and may vary based on soil/water tests, growth stage, cultivar, tree age, and deficiency intensity. To reduce sediment or irrigation clogging risk, verify solubility and filtration performance.
| Crop Group | Foliar Spray (kg per 1000 L water) | Fertigation (kg/ha per application) | Soil / Basal (kg/ha) | Best Application Windows |
|---|---|---|---|---|
| Field Crops (wheat, barley, canola, corn) | 2–4 | 8–15 | 50–120 | Active growth, pre grain/ear formation, grain filling |
| Open-Field Vegetables (tomato, cucumber, watermelon) | 2–5 | 10–20 | 80–150 | Pre-flowering, post fruit set, fruit development |
| Greenhouse Crops (vegetables, strawberry, intensive cultivation) | 2–4 | 10–25 | — (fertigation is usually preferred) | Light and frequent applications, especially during fruiting |
| Pome Fruits (apple, pear) | 3–6 | 10–20 | 120–250 | Post fruit set, fruit sizing, color/storage improvement |
| Stone Fruits (peach, nectarine, apricot, plum) | 3–6 | 10–20 | 120–250 | Fruit development, pre-coloring, quality-sensitive stages |
| Grapes | 3–5 | 10–18 | 100–200 | Pre cluster formation, berry sizing, sugar increase |
| Citrus (orange, lemon) | 3–6 | 12–22 | 150–300 | Post fruit set, sizing, improved taste and peel quality |
| Pistachio, almond, walnut | 3–6 | 12–25 | 150–350 | Kernel filling, post heat/drought stress (within nutrition plan) |
| Ornamental / Houseplants (solution use) | — | — | — | Light diluted solutions; depends on ready-to-use product |
Packaging and Storage of Potassium Sulfate
Proper Packaging
Potassium sulfate is available in multiple forms, including liquid, granular, and powder. In general, solid potassium sulfate should be packaged in moisture-resistant bags. These bags are typically manufactured from polyethylene with an inner liner to prevent air and moisture penetration. 50 kg bags are among the most common packaging formats in the market.
Storage, Loading, and Delivery
Potassium sulfate should be stored in a cool and dry environment. Loading must be handled carefully to avoid damaging packaging. Using pallets and stacking bags in a stable, organized way helps prevent product loss and packaging failures.
Fast and on-time delivery is particularly important for farmers because fertilizers are needed during specific seasonal windows. Therefore, delivery planning can be a critical part of procurement.
Safety and MSDS of Potassium Sulfate
Potassium sulfate is typically classified as non-flammable. However, dust can irritate eyes, skin, and the respiratory tract. When handling, use gloves and safety goggles and follow standard industrial hygiene practices. For transport and storage, keeping the product dry and away from moisture helps preserve quality and prevents caking.
Potassium Sulfate Price and Domestic Agricultural Purchase
If you are looking to buy potassium sulfate at a competitive price for domestic agricultural use, the correct choice is not limited to the price tag alone. In Iran’s market, the quality difference between potassium sulfate products is often determined by: real solubility, particle uniformity, impurity level, and supply consistency— factors that directly affect fertilizer performance and your total cost.
For farmers, orchard owners, and greenhouse operators, an appropriate potassium sulfate product should be:
- Chlorine-free and suitable for chlorine-sensitive crops
- Low sediment / low clogging risk in fertigation and foliar programs
- Stable in repeated supply cycles (consistent quality across orders)
Key Factors That Influence Potassium Sulfate Price (Agricultural Grade)
- Product form (powder, granular, high-solubility)
- K₂O percentage and bioavailable sulfur content
- Packaging (25 kg, 50 kg, jumbo bag)
- Order volume (retail, wholesale, bulk/tonnage)
- Transport and delivery cost to the consumption location
Practical purchasing note: In many cases, cheaper potassium sulfate with poor solubility ultimately causes irrigation clogging, lower nutrient uptake, and higher hidden costs. Therefore, the lowest price is not always the most economical option.
To request today’s potassium sulfate price, place a bulk order, or receive guidance on selecting the correct agricultural grade, you can connect with Shimico experts. Comparing multiple suppliers, reviewing technical specs, and selecting a more cost-effective option becomes easier when the decision is based on both quality and delivery conditions.
Bulk Sales and Export of Potassium Sulfate (Bulk & Export)
In bulk sales and export operations, buyers (domestic and international) focus primarily on consistent quality, transparent technical specifications, and reliable delivery. Export-grade potassium sulfate should be controlled for particle size, moisture, element percentages, and impurity thresholds to avoid rejection or price penalties in destination markets.
Requirements for Bulk Sales and Export of Potassium Sulfate
- Valid COA (Certificate of Analysis) and consistent technical specifications
- Continuous supply capability (monthly / seasonal)
- Export-grade packaging (laminated bags, moisture-resistant jumbo bags)
- Clear delivery terms (EXW, FOB, CIF)
- Coordinated logistics and loading schedule
Potassium sulfate is a high-demand fertilizer in regional and international markets, especially for countries producing chlorine-sensitive crops. Therefore, working with a supplier who can guarantee quality + volume + delivery timeline becomes a major competitive advantage.
For bulk sales or potassium sulfate export, requesting a formal proforma invoice and evaluating long-term cooperation terms can be initiated through Shimico. This enables direct negotiation with suppliers and review of international delivery options.
Why Shimico for Buying, Selling, and Exporting Potassium Sulfate?
Shimico focuses on the B2B marketplace model for chemicals and fertilizers, simplifying potassium sulfate procurement, sales, and export. Instead of relying on a single limited source, users can compare multiple options based on price, quality, packaging, and delivery conditions, enabling more informed decisions.
This approach helps:
- Reduce procurement risk
- Compare prices more transparently
- Select the best product based on application method (domestic agriculture vs export)
Potassium Sulfate FAQ
How is potassium sulfate price determined?
Potassium sulfate pricing depends on multiple factors, including product grade (agricultural vs industrial), purity percentage, product form (powder vs granular), packaging type, order volume, and transportation cost. For an accurate and up-to-date quotation, direct supplier inquiry is recommended.
Which potassium sulfate grade is more suitable for purchase?
The best grade depends on the application method. For fertigation and foliar spraying, a product with high solubility and low residue is generally preferred. For soil application or pit application, granular or crystalline potassium sulfate is often a better option.
Is buying potassium sulfate in bulk more cost-effective?
In many cases, bulk purchasing reduces per-unit cost. However, cost-effectiveness should be evaluated alongside quality consistency, delivery reliability, packaging suitability, and application performance. A lower unit price is not always the lowest total cost.
What conditions apply to tonnage (bulk) potassium sulfate sales?
Bulk sales typically depend on supply capacity, packaging type (bags or jumbo bags), delivery terms, loading schedule, and quality documentation such as COA. Buyers usually request consistency in technical specs across shipments.
Is potassium sulfate export possible?
Yes. Potassium sulfate export is feasible, especially to markets that demand chlorine-free potash fertilizers. Export success depends on quality control, stable specifications, appropriate packaging, and logistics readiness.
What documents are required for potassium sulfate export?
Common export documentation includes COA, technical datasheet/specifications, packing list, commercial invoice, and shipping documents aligned with the agreed Incoterms (EXW/FOB/CIF). Additional documentation may be required depending on destination regulations.
What is the difference between potassium sulfate and SoluPotash?
The key difference in the market is typically solubility. SoluPotash usually refers to a more water-soluble potassium sulfate variant designed for fertigation and foliar application, while standard potassium sulfate products may be more commonly used for soil application.
Is potassium sulfate suitable for chlorine-sensitive crops?
Yes. One of the main reasons potassium sulfate is widely used in agriculture is that it is chlorine-free, making it more suitable for crops that are sensitive to chloride-based fertilizers.
What is the minimum order quantity for purchase or export?
Minimum order quantity depends on the supplier, packaging format, and product availability. Retail and small wholesale quantities may be possible in bags, while export and bulk operations typically require tonnage volumes.
How can I receive the best potassium sulfate price?
The best method is to compare multiple suppliers simultaneously based on price, quality, packaging, and delivery terms. The lowest price is not always the most economical choice if solubility and performance are weak.