Basic Physical and Chemical Characteristics

-Zinc sulfate heptahydrate (ZnSO₄·7H₂O, white vitriol) is a colorless orthorhombic crystal or a white granular powder; it is odorless and has an astringent taste.

- It has a relative density of 1.957 and a melting point of 100°C. It is highly soluble in water and slightly soluble in ethanol and glycerol; its aqueous solution is weakly acidic (50 g/L, 20°C, pH 4–6).

- It readily deliquesces in dry air at room temperature; it gradually dehydrates upon heating: it loses 1 molecule of crystalline water at 30°C, 6 molecules at 100°C, and is completely dehydrated at 280°C to form anhydrous zinc sulfate, which further decomposes at high temperatures into zinc oxide and sulfur trioxide.

- It is stable at room temperature, incompatible with strong oxidizing agents, hygroscopic, and not classified as a flammable substance.

- Product Categories: Zinc sulfate heptahydrate is available in several grades, including industrial-grade, agricultural-grade, rubber additive-grade, electronic-grade, and pharmaceutical-grade. Each grade is available in different particle sizes: 2–4 mm, 1–3 mm, and <1 mm.

- Product Keywords: zinc sulfate heptahydrate 22, zinc sulfate heptahydrate min 22 zn, low heavy metal zinc sulfate.

Product Composition and Specifications

(I) Core Ingredients

Primary Ingredient: Zinc sulfate heptahydrate (ZnSO₄·7H₂O), serving as a highly efficient zinc source (Zn²⁺) for industrial production and the core functional component. No auxiliary agents or fillers are added, ensuring pure composition.

(II) Product Specifications

Zinc Sulphate Heptahydrate
Parameters	Specifications
Zinc Sulphate Heptahydrate Code
Molecular Formula	ZnSO4·7(H2O)
CAS No.	7446-20-0
Country of Origin	China
Molecular Weight	287.58g/mol
Grade	Agricultural Grade / Industrial Grade
Nutrient Levels
Purity % w/w	as ZnSO4·7(H2O) Min.99
Total Zn % w/w	as Zn Min.22.5
Insoluble Matter in Water % w/w	Max. 0.18
Moisture % w/w	Max. 5
Cd %(mg/kg)	2-20
Mg %(mg/kg)	4-100
Pb %(mg/kg)	1-10
Gg %(mg/kg)	<30
As %(mg/kg)	3-50
PH Value	4
Package	25kg. 50kg. 500kg. 1000kg. 1250kg bag and OEM colour bag
Physical Characteristics
Bulk Density(kg/m³) (tapped)	900-1200
Sieve Analysis	<6mm 100% w/w(2-5mm >93% w/w min, <1mm <1% w/w)
Product Appearance	Colorless transparent granules/columnar crystals
REMARKS: 1.FOB Tianjin Port. 2.Payment term: 30% prepayment, the rest need be paid before delivery. 3.MOQ: 24 ton per 20GP. 4.Lead time:20-30 days.

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What is the role of zinc sulfate heptahydrate in water treatment?

Zinc sulfate heptahydrate dissolves in water to release zinc ions (Zn²⁺), which exert their effects through the properties of these ions; it is a commonly used chemical in circulating water, wastewater, and landscape water systems.

Corrosion inhibition (the most common application: circulating cooling water systems)

Zinc ions are a classic inorganic corrosion inhibitor. They form a dense protective film of zinc hydroxide on the surfaces of carbon steel and cast iron equipment, isolating the metal from contact with water and inhibiting corrosion in pipes and heat exchangers.

Scale Inhibition and Dispersing Aid

While its standalone scale inhibition capability is moderate, when used in combination with other agents, it can suppress the precipitation of scale such as calcium carbonate and calcium sulfate; simultaneously, it disperses fine silt and colloids in water, reducing scale adhesion.

Flocculation / Coagulation Aid (Wastewater and Surface Water Purification)

Zinc ions neutralize the negative charges of colloidal particles in water, compressing the double layer and causing suspended solids, turbidity, and some colloidal pollutants to aggregate and settle. They are often used in conjunction with PAC and PAM to enhance coagulation and sedimentation efficiency and reduce effluent turbidity.

Algae Inhibition and Bactericidal Action (Landscape Water, Cooling Towers, Swimming Pools)

Zinc ions exert a toxic inhibitory effect on algae and microorganisms, destroying algal cells and suppressing algal reproduction, thereby preventing water from turning green and the growth of slime. They can also help inhibit heterotrophic bacteria, reducing biological slime blockages in cooling towers.

Heavy Metal / Pollutant Removal (Industrial Wastewater Treatment)

When the pH is adjusted to slightly alkaline, Zn²⁺ can form precipitates with sulfate ions and hydroxide ions in wastewater, simultaneously entrapping heavy metals such as lead, cadmium, and copper for co-precipitation, thereby achieving synergistic heavy metal removal; It can also remove certain sulfide and phosphate pollutants.

Core Advantages of Our Products

Appearance: Colorless, transparent prismatic crystals or white crystals, free from visible impurities and lumps.
Solubility: Easily soluble in water, with no visible suspended particles after dissolution.
Particle Size: Crystalline or granular, facilitating dissolution and dosing; moisture content ≤0.5%, non-caking.

Packaging and Transportation

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Standard Packaging: Double-layer packaging bags with inner plastic and outer woven layers, providing moisture resistance, leak prevention, and abrasion resistance. Standard specification is 25kg/bag; bulk bag packaging can be customized upon request.
Packaging Labeling: Packaging can be customized according to customer requirements.