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High-purity lime powder solutions engineered for water purification and treatment applications
Food Grade Slaked Lime (Calcium Hydroxide) โ Factory Direct Supply for Water & Food Applications
OEM Calcium Hydroxide & Carbonate โ Competitive Prices and Customized Water Treatment Solutions
Precipitated Calcium Carbonate (PCC) โ High-Purity Industrial Grade for Water Conditioning
Ground Calcium Carbonate (GCC) โ Versatile Industrial Grade, 25kg/500kg Packaging Available
Understanding the chemistry and properties behind the world's most widely used water treatment chemical
Calcium hydroxide โ chemically represented as Ca(OH)โ and commonly known as slaked lime or hydrated lime โ is produced by adding water to calcium oxide (quicklime, CaO) in a controlled exothermic reaction. The resulting white powder is mildly alkaline, with a pH of approximately 12.4 in saturated solution, making it an ideal reagent for a broad range of water treatment and purification processes.
In its dry powder form, calcium hydroxide lime powder is highly reactive, cost-effective, and easy to transport and store. Its high surface area and fine particle size โ particularly in high-purity grades โ allow it to dissolve and react rapidly when introduced to water systems. These properties are why it has remained the reagent of choice for municipal water authorities, industrial wastewater plants, and environmental remediation engineers worldwide for over a century.
The global market for calcium hydroxide used in water treatment is experiencing consistent growth, driven by stricter environmental regulations, rapid urbanization in Asia and Africa, and increasing industrial production requiring wastewater compliance. Analysts project the global hydrated lime market to surpass USD 8.5 billion by 2030, with water treatment applications representing one of the largest and fastest-growing demand segments.
World-class manufacturing infrastructure delivering consistent quality at industrial scale
A step-by-step overview of lime powder's critical role in modern water purification systems
Lime powder is dosed into acidic water to raise pH to optimal levels (6.5โ8.5 for drinking water), neutralizing corrosive acids and protecting infrastructure while meeting regulatory standards.
Caยฒโบ ions react with carbonate and hydroxide ions to form insoluble precipitates that bind suspended particles and colloids, forming large flocs that can be easily settled or filtered out.
At elevated pH, dissolved heavy metals such as lead, cadmium, arsenic, chromium, and zinc form insoluble hydroxide or carbonate compounds and precipitate out of solution effectively.
The high alkalinity created by lime treatment inactivates bacteria, viruses, and protozoa, providing a critical layer of disinfection in both drinking water and wastewater treatment facilities.
Calcium hydroxide lime powder serves critical functions across these high-demand water treatment sectors
Lime softening is a proven process for removing hardness (calcium and magnesium) from municipal water supplies. Ca(OH)โ reacts with dissolved bicarbonates and magnesium salts to precipitate them as calcium carbonate and magnesium hydroxide, dramatically reducing scale buildup in pipes and appliances. Municipalities also use lime to adjust pH before chlorination, improving disinfection efficiency and reducing disinfection by-product (DBP) formation.
Factories producing metals, chemicals, textiles, food products, and mining outputs generate highly acidic or alkaline wastewater streams. Calcium hydroxide is the most economical alkali for neutralizing these effluents prior to discharge. Its rapid reaction kinetics and high buffering capacity ensure compliance with environmental discharge limits even with variable influent quality โ a critical advantage in high-throughput industrial settings.
In both industrial and municipal applications, lime precipitation is the dominant technology for removing dissolved heavy metals and phosphorus. Raising pH above 9.5 using Ca(OH)โ causes metals like lead, zinc, copper, nickel, and arsenic to precipitate as metal hydroxides with removal efficiencies exceeding 99%. Phosphorus removal through calcium phosphate precipitation is increasingly important for preventing eutrophication in receiving water bodies.
Calcium hydroxide is widely applied to sewage sludge and biosolids to achieve pathogen reduction and odor control through a process called lime stabilization. Adding sufficient lime to raise the pH above 12 for at least 2 hours destroys pathogens, significantly reduces volatile solids, and produces a stabilized product (EQ or Class B biosolids) suitable for land application as a soil amendment โ creating a valuable circular economy resource.
Mining operations generate highly acidic drainage containing dissolved heavy metals and sulfates. Calcium hydroxide is the primary treatment chemical for AMD remediation โ rapidly raising pH from values as low as 2 to above 9, precipitating metal hydroxides, and neutralizing sulfuric acid. Large-scale lime dosing systems at active and legacy mine sites treat millions of liters per day, preventing environmental contamination of groundwater and surface water resources.
In membrane-based desalination and reverse osmosis (RO) water treatment plants, controlling the pH and hardness of feed water is critical to preventing membrane scaling and biofouling. Calcium hydroxide dosing is used in pre-treatment stages to adjust carbonate equilibrium, reduce scaling potential (Langelier Saturation Index management), and optimize overall system performance โ extending membrane life and reducing operational costs in these high-capital water infrastructure investments.
The calcium hydroxide water treatment sector is evolving rapidly โ here's what's shaping its future
Governments worldwide are tightening discharge limits for heavy metals, nitrogen, phosphorus, and suspended solids. The EU's updated Urban Wastewater Treatment Directive, the US Clean Water Act enforcement, and China's GB 18918-2002 revision have all dramatically increased demand for reliable chemical dosing solutions like calcium hydroxide. This regulatory pressure is forecast to sustain market growth at a CAGR of 4.5โ5.8% through 2032.
Asia-Pacific, the Middle East, and Sub-Saharan Africa are experiencing unprecedented urban population growth, driving massive investments in municipal water and wastewater infrastructure. China alone has committed over $200 billion to water treatment infrastructure upgrades through 2025. These developments represent enormous growth opportunities for high-quality calcium hydroxide lime powder suppliers with the scale and quality consistency to serve large government contracts.
Modern water treatment facilities are increasingly designed around resource recovery โ extracting phosphorus for fertilizer, recovering metals from sludge, and converting biosolids into energy. Calcium hydroxide plays a central role in enabling these circular processes, particularly in struvite precipitation for phosphorus recovery and in conditioning sludge for anaerobic digestion. This shift toward resource-positive water treatment is creating new value-added applications for premium-grade lime products.
The integration of AI-driven process control, real-time water quality sensors, and automated lime dosing systems is transforming water treatment plant operations. Intelligent dosing systems optimize calcium hydroxide consumption, reduce chemical waste, and ensure consistent effluent quality โ all while lowering operational costs. Suppliers who can provide consistent, high-purity lime powder with tight particle size specifications are best positioned to serve this emerging smart water infrastructure market.
The challenge of treating per- and polyfluoroalkyl substances (PFAS), microplastics, pharmaceutical residues, and other emerging contaminants is reshaping water treatment chemistry. While advanced oxidation and activated carbon dominate PFAS treatment, calcium hydroxide plays a supporting role in pH optimization for these processes. R&D is ongoing into lime-based co-precipitation methods that could offer cost-effective solutions for legacy contamination sites and smaller treatment facilities with limited capital budgets.
The lime industry is investing heavily in decarbonization โ from next-generation kilns capturing COโ for carbonation products, to renewable energy integration in production facilities. Shandong Useen Calcium's ongoing R&D collaboration with leading Chinese universities is aligned with these sustainability imperatives, developing lower-emission production processes and high-performance calcium products that help customers reduce their overall environmental footprint while meeting increasingly demanding water quality standards.
Shandong Useen Calcium Co., Ltd. specializes in a range of products, including nano-scale calcium carbonate, food-grade calcium carbonate, calcium oxide, calcium hydroxide, and light calcium carbonate. Our company owns 17 fully automated calcium oxide production lines, three calcium hydroxide production lines, and nine calcium carbonate production lines.
Its annual output is 200,000 tons for nano-calcium carbonate, 200,000 tons for calcium hydroxide, 160,000 tons for light calcium carbonate, 360,000 tons for heavy calcium carbonate, and 1 million tons for calcium oxide โ delivering the scale, reliability, and consistent quality that global water treatment customers require.
Our materials are used across a wide range of industries including PVC pipes, automotive primers, paper, printing inks, wires and cables, sealants, rubber products, tyres, and more. Our clients rely on us for consistency, tailored solutions, and support in scaling their operations without compromising on quality. Our company is the first in China to apply nano calcium carbonate to PE blow molding products, replacing traditional filling materials with superior performance.
Innovation is at the core of everything we do. In recent years, we have made significant investments in R&D, focusing on the development of new technologies and next-generation calcium products. Our company has established close "industry-university-research" cooperation relationships with:
Through our industry-university-research partnerships, we have established strong capabilities in applied research, product development, and advanced process engineering. These collaborations allow us to continuously evolve, improve our formulations, and meet the changing demands of global industries.
Partnering with China's leading calcium product manufacturer for your water treatment needs
Our calcium hydroxide is manufactured under rigorous quality control protocols, achieving Ca(OH)โ purity levels exceeding 95%, with tightly controlled particle size distributions optimized for rapid dissolution and maximum reactivity in water treatment dosing systems.
With 200,000 tons of annual calcium hydroxide production capacity and flexible packaging options (25kg bags to bulk tanker), Useen Calcium reliably supplies municipal authorities, EPC contractors, and industrial water treatment operators across Asia, the Middle East, Europe, and beyond.
Our R&D team works directly with customers to develop tailored calcium hydroxide grades โ adjusting particle size, surface treatment, and blending ratios to optimize performance for specific water chemistry conditions, treatment goals, and dosing equipment configurations.
Welcome to Useen โ Where Calcium Science Meets Industrial Innovation
Our materials are used across a wide range of industries including PVC pipes, automotive primers, paper, printing inks, wires and cables, sealants, rubber products, tyres, and more. Our clients rely on us for consistency, tailored solutions, and support in scaling their operations without compromising on quality.
Our company is the first in China to apply nano calcium carbonate to PE blow molding products, which can replace traditional filling materials and has excellent performance โ demonstrating our commitment to pioneering new applications for calcium-based materials across industries.
High-quality calcium carbonate, hydroxide, and nano-scale products for water treatment and diverse industrial applications
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