Lianyungang Chemsize International Trading Co., Ltd.

A specialised fused-silica export company in Lianyungang, China — wired into the country's fused-silica production belt, enforcing batch testing and export documentation on every order.

Who we are

Factory-direct material, trader-grade service

China's fused-silica industry is sharply divided: melting plants run electric-arc furnaces, and grinding plants make sized sand and powder — rarely both. Chemsize works with two partner plants that cover both sides:

Donghai Hechuang Silica Materials — ~10 kt/y
Jiangsu Xinda Quartz Co., Ltd. — ~20 kt/y, ISO-certified

Chemsize’s principal holds a 1% equity stake in Hechuang Silica — direct skin in the game, so batch quality there is our own interest, not just a supplier relationship.

Combined capacity of ~30 kt/y means large orders and peak-season deliveries are not a constraint. Our role is to manage the interface: fix the raw-material source, enforce the 12-step QC workflow, test every batch and ship with a COA that matches your purchase specification.

Chemsize partner plant of fused silica grains and powder production

Process

From Donghai quartz lump to batch-tested sand and powder

Every step below exists for one reason: a predictable material that runs in your line without surprises.

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1. Feedstock — Donghai lump

Raw material is 1-5 cm quartz lump from Donghai County, one of China's best quartz deposits. We deliberately do not use imported or inland quartz sand — it tends to produce bubbles, under-fused cores and a milky colour after fusion. The feed is acid-washed, rinsed and dried before melting to remove surface iron and dirt.

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2. Fusion — electric arc furnace

Each 20-tonne batch fuses in a three-phase electric arc furnace at 2200-2500 °C for about 12 hours, yielding roughly 16 tonnes of acceptable ingot (80% yield). Electricity is more than half the cost — a fact we state openly, because it proves no shortcuts on temperature or time.

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3. Grading — manual, visual, exact

After natural cooling, workers break the ingot into 3-10 cm pieces and sort by transparency, black spots and cristobalite into grades A, AB, B, C and C-/D. This step stays manual because machine vision cannot reliably separate the defects that change end-use performance. The grade you pay for is the grade you get.

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4. Sand line — crushed, screened, dust-free

Graded lump goes through a Barmac crusher, impact mill and long screens (rotary vibrating screens) into standard mesh cuts, then a classifier removes fine dust for dust-free stucco sand used in precision casting.

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5. Powder line — iron-free grinding

Powder is ground in a ball mill with alumina-ceramic media and linings — no steel contact, so Fe₂O₃ is not added back. After vibrating screening, PSD is verified by Malvern (D10 / D50 / D90).

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6. Blending, QC, packing

Blending, re-weighing (+2%), final checks against the 12-step QC engineering table, then packing into 25 kg bags or 1 t jumbo bags. Every batch is sampled and tested before shipment.

Partner plant

Hechuang Silica Materials — Donghai production base

One of our two partner plants. Electric-arc fusion, manual grading, in-house lab — the source we route orders through when the spec calls for it.

Hechuang arc-furnace hall — three-phase electric arc furnace used to fuse Donghai quartz lump — Arc-furnace hall — where 20-tonne batches fuse at 2200-2500 °C.

Customers visiting the fused silica production site with Chemsize team — viewing freshly fused silica ingot in the workshop — Customer visit — Chemsize team at the fused silica plant.

Customers visiting the Hechuang fused silica ingot production site — Customers inspecting fused silica ingots on site.

Fused silica grains production lines — Barmac VSI crushers, vibrating screens and finished jumbo bags inside the Hechuang workshop — Grains production lines — Barmac VSI and screening.

Fused silica grains and powder finished-batch warehouse — palletised 1-ton jumbo bags stored in aisle rows — Warehouse aisle — palletised jumbo bags.

Fused silica finished-batch warehouse — 1-ton jumbo bags on wooden pallets with green strapping, ready for export — Wooden pallets, green strapping — ready for shipment.

Quality control

Tested before it leaves — not after it arrives

Our laboratory covers almost all standard tests except XRD: chemical composition by XRF/ICP (SiO₂, Fe₂O₃, Al₂O₃, TiO₂, alkalis), particle-size distribution by Malvern plus standard sieves, whiteness, pH and moisture. For customers requiring XRD amorphous-content verification, partner-lab or third-party (SGS) data is supplied.

Every batch is sampled and tested before shipment. The COA that travels with your order matches your purchase specification — so your incoming inspection is confirmation, not discovery.

Chemsize 14-step QC process table for fused silica — sand and grains line (Barmac VSI, vibratory screen) and powder line (alumina-media ball mill, PSD, blending) with method, standard and pass criterion per step

Testing center

Inside our testing center — equipment, process, retained samples

Our in-house lab in Lianyungang runs XRF/ICP chemical analysis, atomic-absorption spectrometry, sieve grading, drying-oven moisture testing and pre-shipment sampling — with batch-tagged retained samples archived against every COA we issue.

Fused silica testing center — exterior view of the Chemsize quality-control building in Lianyungang housing ICP-OES, chemical analysis and sieve-testing facilities — Chemsize testing center.

Atomic-absorption spectrometer in the Chemsize lab — ICP-OES / AA instrument for trace Fe₂O₃, Al₂O₃ and alkali analysis in fused silica — ICP-OES / AA spectrometer.

Chemical analysis laboratory at Chemsize — chemist performing wet-chemistry titration for SiO₂ composition in fused silica — Wet-chemical analysis.

Analyst workstation — microscopy and data-review station at the Chemsize quality-control department for fused silica grading — Analyst workstation.

Physical testing laboratory — drying oven, refrigerator and bench tests for pH, whiteness and moisture of fused silica at the Chemsize lab — Drying oven + bench tests.

Retained samples and standard test sieves (4/6/16/30/50/100/230 mesh) with precision balance at the Chemsize lab — every batch archived for traceability — Retained samples + test sieves.

Moisture test in drying oven — glass beakers numbered 1 to 4 for loss-on-drying measurement of fused silica powder at the Chemsize lab — Moisture test (drying oven).

Pre-shipment sampling and COA documentation — bagged FS-AB samples tagged with batch code and date alongside signed COA folder and customer specification sheet at the Chemsize lab — Pre-shipment sampling + COA.

Packaging & export

Fused silica export — packing, palletising and shipment worldwide

Every finished batch is packed, weighed and shipped with its batch COA. The photos below are real Chemsize export work: 25 kg bags and 1 t jumbo bags, palletised formats (Euro-style, double-layer, jumbo without pallet), warehouse storage with dust and moisture protection, container stuffing and vessel loading — for deliveries to Italy, Africa, North America, South America and India.