Zinc oxide (ZnO, CAS 1314-13-2, mp 1975°C) is one of the highest-volume specialty inorganics globally, consumed across an unusually wide range of industries — rubber and tyre vulcanization at 3–5 phr loading, paint and coating UV-shielding pigments, glass-ceramic glaze formulation, USP and EP pharmaceutical actives for sunscreen and dermatology, food-grade fortification and feed-additive zinc supplementation. The same crystalline ZnO can serve all these markets but only when produced under the right purity discipline — pharma and cosmetic applications demand ≤10 ppm heavy metals (Pb, As, Cd) and tightly controlled particle size, food and feed grades require GMP traceability and pathogen-free handling, while rubber and ceramic grades trade purity for cost-per-tonne. SEMITECH’s ZnO portfolio recognises this segmentation explicitly with eight purpose-built grades, each manufactured in dedicated production lines to prevent cross-contamination.
SEMITECH’s ZnO supply chain is integrated with one of China’s pioneer zinc-oxide manufacturers — operating since 1995 with annual capacity above 72,000 metric tonnes, more than 30 patents covering process intensification and quality stability, and a “six-step inspection” QC protocol covering raw material → reaction → milling → blending → sieving → packaging. This vertical integration delivers two structural advantages versus traders: (1) direct grade-to-grade specification matching, allowing SEMITECH to respond to non-standard customer specs (e.g., D90 cuts, controlled BET, low-Pb cosmetic grade) without margin-stacked subcontracting; and (2) consistent batch-to-batch quality at production-scale volumes — important for downstream rubber and tyre buyers running multi-shift formulation lines where ZnO inconsistency translates directly to cure variability.
Rubber-grade ZnO is the highest-volume application globally — every passenger tyre, truck tyre, conveyor belt, and rubber compound uses ZnO at 3–5 phr loading as the activator for sulfur vulcanization. The ZnO reacts with stearic acid and the sulfur accelerator (CBS, MBT, TBBS) to form the active zinc complex that catalyses crosslink formation. Particle size and surface area drive the cure efficiency: D50 0.5–2 µm with BET 4–10 m²/g is the standard tyre-compound specification. SEMITECH supplies indirect-process (French process) ZnO with 99.7%+ purity, low-Pb (≤10 ppm), and consistent BET — qualified at major tyre buyers in China, Southeast Asia, and Europe. Loading: 3–5 phr in passenger tyre tread, 5–7 phr in TBR truck tyre, 2–4 phr in EPDM weatherstrip.
Paint-grade ZnO serves three coating roles simultaneously: opacifying pigment (refractive index 2.0, behind only TiO₂ at 2.7), UV-shielding additive (absorbs strongly below 380 nm), and anti-corrosion booster in zinc-rich primer systems. SEMITECH coating-grade ZnO is supplied at D50 0.3–1 µm for premium architectural and automotive coatings, and at 1–3 µm for industrial maintenance and powder coatings. Surface treatment (silane, stearate, or amino-silicone) is available on request to improve dispersion in solvent-borne and waterborne resin systems. Typical loading: 1–3% in white architectural paint, 5–15% in zinc-rich epoxy primer for marine and offshore steel, 0.5–2% as UV-shield in clear-coat over wood substrates.
Ceramic-grade ZnO is the workhorse flux additive in glass and ceramic glaze formulation — it lowers the melting point of silicate glass mixtures by 50–100°C, raises the fired surface gloss, and improves chemical durability of architectural ceramic tile. ZnO also stabilises crystalline phase in soft-magnetic ferrites (used in transformer cores, inductors, and EMI shielding). SEMITECH supplies ceramic-grade ZnO at 99.5%+ purity with controlled trace iron (typical <50 ppm) — the key parameter for white-glaze formulations where iron staining is intolerable. Loading: 5–15% in glass frit, 2–8% in ceramic glaze, 8–25% in soft-magnetic ferrite formulations.
Pharma-grade ZnO is the active mineral UV-blocker in physical sunscreen formulations — non-nano grades (≥100 nm D50) provide broad-spectrum UVA + UVB protection without nanoparticle skin-penetration concerns, and nano-grades (10–50 nm) deliver transparent finish for daily-wear cosmetic sunscreens. SEMITECH USP / EP-compliant ZnO meets ≥99.9% purity, residual heavy metals ≤10 ppm (Pb / As / Cd), and microbiological pathogen-free per Ph.Eur 2.6.13. Same grade serves dermatological zinc-oxide ointment (calamine), diaper-rash creams, antimicrobial skin formulations, and cosmetic foundation/loose powder applications. Packaging in food-grade lined drums under nitrogen blanket; per-batch CoA includes the full pharmacopoeia panel (assay, identification, residual solvents, microbiological).
Food-grade ZnO is used as a zinc fortification additive in cereals, flour, infant formula, and vitamin-mineral supplement tablets — meeting FCC (Food Chemical Codex) and JECFA specifications with ≥99.5% purity, low-Pb (≤2 ppm), and pathogen-free certification. SEMITECH food-grade ZnO is produced in a dedicated GMP-compliant production line, packaged in food-contact-approved liners, and shipped with full traceability documentation including batch records, supplier-of-supplier audit references, and HACCP control-point evidence. Typical fortification levels: 1–10 mg Zn/100 g for cereal products, 10–50 mg Zn/serving in nutritional supplement tablets.
Feed-grade ZnO is supplied as a veterinary-grade zinc supplement for poultry, swine, ruminants, and aquaculture — correcting zinc deficiency, supporting gut health, and improving feed conversion ratio at 50–200 ppm of zinc per kg of compound feed. SEMITECH feed-grade ZnO meets FAMI-QS standards with ≥99% purity, complies with EU 1831/2003 on additives in animal feeds, and includes per-batch CoA with residual heavy-metal and pathogen testing. Note: post-2022 EU restrictions on therapeutic high-dose ZnO (>2,500 ppm in piglet weaning diets) have driven a market shift toward zinc chelates and lower-dose nutritional ZnO supplementation; SEMITECH supports both transition pathways.
Granule ZnO is pre-densified into 0.5–3 mm pellets to eliminate dust handling on production lines — critical for tyre, rubber, and powder-coating compounders running automated dosing systems where airborne ZnO powder creates worker-safety, equipment-fouling, and yield-loss issues. SEMITECH granule ZnO maintains the same 99.7%+ purity and reactivity as the powder grade after dispersion in the polymer matrix; the pelletisation uses a small percentage of polymer-compatible binder that disintegrates during compounding. Premium pricing 8–15% over equivalent powder grade — payback is typically rapid where dust-handling overhead dominates production cost.
Nano ZnO (D50 10–50 nm, BET 30–80 m²/g) serves transparent UV-blocker applications in clear cosmetic sunscreen, automotive clear-coat photo-stabilisation, and antibacterial functional textile finishes — where the ≥100 nm pharma-grade would be visually opaque. Surface-treated nano grades (silane, silica-coated, or polymer-encapsulated) prevent agglomeration and improve dispersion stability in waterborne and solvent-borne carriers. SEMITECH nano-ZnO is also supplied as photocatalyst grade for self-cleaning surface coatings, water-treatment photodegradation systems, and dye-sensitised solar cell (DSSC) photoanode formulations.
Zinc citrate (Zn₃(C₆H₅O₇)₂, CAS 5990-32-9 dihydrate) is the chelated organic-zinc companion to inorganic ZnO — used where higher bioavailability is required in pharmaceutical zinc supplementation, oral-care toothpaste (anti-plaque, anti-gingivitis), and food fortification. SEMITECH supplies USP-grade and food-grade zinc citrate trihydrate (≥97% purity, ≤2 ppm Pb / As) from the same dedicated high-purity manufacturing line as the ZnO portfolio. Buyers integrating zinc supplementation systems often specify both ZnO and zinc citrate from the same supplier to consolidate qualification overhead and supply-continuity risk.
SEMITECH ZnO is sourced from a 30-year-established Chinese manufacturer operating multiple production lines totalling 72,000 metric tonnes annual capacity — one of China’s pioneer ZnO producers with documented pioneering work on indirect-process (French process) ZnO since 1995. The manufacturing infrastructure includes more than 30 patents covering particle-size control, low-Pb processing for pharma and cosmetic compliance, surface-treatment routes for coating-grade dispersion, and energy-efficient calcination processes. ISO 9001 quality system, ISO 14001 environmental management, and FAMI-QS for feed-grade are maintained. The “six-step inspection” QC protocol covers (1) raw zinc metal traceability; (2) reaction kinetics monitoring in-process; (3) post-reaction milling and BET measurement; (4) blending homogeneity; (5) sieving and particle-size distribution; (6) packaging integrity and final CoA testing. Per-batch CoA covers ZnO assay (acid titration), residual chloride and sulphate, heavy metals (Pb / As / Cd / Hg / Cr), particle size (laser diffraction D50, D90), specific surface area (BET), and microbiological count for pharma / food / feed grades.
Standard packaging is 25 kg multi-wall paper bags (palletised 1 t / 24 bags) for industrial and feed grades; 25 kg fibre drums with food-grade liner for pharma, cosmetic, and food grades; and 1-tonne polypropylene bulk-bags for high-volume industrial buyers. MOQ is 25 kg for sample qualification, 1 tonne for production-scale supply, and 25-tonne FCL for bulk container shipments. Lead time ex-Zhejiang is 2–3 weeks to Asia and 4–5 weeks to Europe and North America. SEMITECH provides full regulatory documentation per shipment including REACH compliance statement, GHS / SDS / MSDS, FDA Drug Master File reference for pharma-grade buyers, and FAMI-QS / GMP+ certification for feed-grade buyers.
All eight ZnO grades (plus zinc citrate companion product) are inventoried with CoA per shipment. Industry-standard equivalencies provided for buyer cross-qualification.
| Tier | Grade | Purity | D50 / BET | Compliance | Primary Application |
|---|---|---|---|---|---|
| 1 | Rubber & Tyre Grade | ≥99.7% | 0.5–2 µm / 4–10 m²/g | REACH / RoHS | Tyre, EPDM, conveyor belt vulcanization |
| 1 | Paint & Coating Grade | ≥99.5% | 0.3–3 µm | REACH / VOC | Architectural / industrial coatings, zinc-rich primer |
| 1 | Glass & Ceramics Grade | ≥99.5% | 1–5 µm | low-Fe (<50 ppm) | Glass frit, ceramic glaze, soft-magnetic ferrite |
| 2 | Pharma / Cosmetic Grade | ≥99.9% | 0.1–1 µm (non-nano) | USP / EP / Ph.Eur | Sunscreen, dermatology, cosmetic foundation |
| 2 | Food Grade | ≥99.5% | 1–3 µm | FCC / JECFA | Cereal / infant formula / vitamin tablet fortification |
| 2 | Feed Additive Grade | ≥99% | 1–5 µm | FAMI-QS / EU 1831/2003 | Poultry, swine, aquaculture feed supplement |
| 3 | Granule (Pelletised) | ≥99.7% | 0.5–3 mm pellet | REACH / RoHS | Dust-free dosing for tyre / rubber / powder coatings |
| 3 | Functional / Nano | ≥99.5% | 10–50 nm / 30–80 m²/g | REACH | Transparent UV-block, photocatalysis, antibacterial |
| 3 | Zinc Citrate Trihydrate | ≥97% | D50 5–15 µm | USP / FCC | Zinc supplementation, oral-care, dental |