Specifications

Typical factory dimensions are listed below. Dimensions are indicative for selection only; actual products govern.

Low-form Crucibles

Capacity (mL)	Mouth (mm)	Height (mm)	Type
10	35	22	Low-form
15	40	25	Low-form
20	42	28	Low-form
25	44	30	Low-form
30	48	33	Low-form
50	55	38	Low-form
75	60	43	Low-form
100	65	48	Low-form

High-form / Volatile Crucibles

Capacity (mL)	Mouth (mm)	Height (mm)	Type
15	38	38	High-form
25	40	45	High-form
30	42	48	High-form
50	48	55	High-form
25	40	46	Volatile (lidded)
30	42	50	Volatile (lidded)

For equal capacity, high-form crucibles have smaller mouths and taller bodies to reduce spattering; volatile types include lids.

📌 Customization:
• Custom capacities on request
• Special sizes by mold for bulk orders
• Lids available separately

Product Description

1. Overview

Porcelain crucibles are fundamental vessels for high-temperature ignition, widely used for ashing precipitates, determining ash content and fusing samples. The high-temperature fired body is dense and hard, with smooth glazed surfaces, low water absorption and good resistance to cracking.

Three types are available. High-form crucibles heat evenly and reduce sample spattering, ideal for precipitate ignition. Low-form crucibles have wide mouths for evaporation and routine ignition. Volatile-matter crucibles come with lids for tests that require covering. Capacities span 10mL to 100mL in eight sizes.

Economical and durable, porcelain crucibles are a staple for teaching, QC and analytical laboratories. For batch ignition work, keep sufficient stock together with tongs and a desiccator.

🔬 Types & Features:
High-form — even heating, less spattering, first choice for precipitates.
Low-form — wide mouth, routine ignition and evaporation.
Volatile — lidded design for volatile-matter tests.
Smooth glaze — low residue, easy cleaning.

2. Key Parameters

Material: hard porcelain (glazed inside and out)
Types: high-form / low-form / volatile (with lid)
Capacity: 10 / 15 / 20 / 25 / 30 / 50 / 75 / 100 mL
Corrosion: resists common acids and alkalis; not for HF or strong alkali fusion
Accessories: lids, crucible tongs, pipeclay triangles
Applications: muffle furnace and burner ignition

3. Material & Workmanship

Crucibles are formed from quality ceramic stock, fired at high temperature and glazed. The uniform glaze reduces sample residue and moisture uptake. Each batch is inspected for appearance and dimensions to keep lot-to-lot consistency.

Tip: burn off new crucibles empty before first use; carbon deposits after organic samples can be burned away in the muffle furnace.

Applications

Typical Uses

Precipitate ignition

ignition and weighing to constant mass

Ash testing

ash content of food, coal and polymers

Fusion

pre-treatment of samples by alkaline or acidic fusion (no HF)

High-temperature reactions

thermal decomposition of solids

Industries

QC laboratories routine ash and volatile-matter tests
Coal testing ash and volatile-matter determination
Food industry ash content inspection
Teaching laboratories inorganic ignition experiments

Selection Guide

Selection by Type

Requirement	Recommended	Why
Precipitate ignition, gravimetry	High-form	Even heating, less spattering
Evaporation, routine ignition	Low-form	Wide mouth, easy handling
Volatile-matter tests	Volatile (lidded)	Lid reduces volatilization loss

Selection by Capacity

Sample Size	Capacity	Note
Small precipitates (<0.5g)	10~25 mL	Common sizes, efficient heating
Routine samples (0.5~2g)	30~50 mL	Laboratory workhorse
Large fusion loads (>2g)	75~100 mL	Leave expansion room

💡 Tips: 25mL or 30mL low-form crucibles are the most used sizes.
Choose high-form for gravimetric ignition.
Low-form suits ashing with spread-out samples.

Operation & Maintenance

Operation Guide

Standard operating guide for porcelain crucibles. Good habits extend vessel life and ensure ignition quality.

Before Use

Check for cracks and glaze damage
Burn new crucibles empty to constant mass
Confirm samples contain no HF or strong alkali flux
Prepare tongs, pipeclay triangle and desiccator

Procedure

Charge the crucible to no more than half its volume
Place in the muffle furnace and ignite at the set temperature
Remove with tongs and cool briefly on a heat-resistant board
Transfer to a desiccator and cool to room temperature
Weigh, re-ignite and repeat to constant mass
Clean, dry and store after use

Cleaning & Care

Clean after use; dilute hydrochloric acid helps remove residues
Burn off stubborn carbon deposits in the furnace
Avoid scratching the glaze with hard tools
Store dry, protected from knocks

💡 Lab veteran tips: Burn empty first — pre-fire new crucibles before charging.
Never overfill — keep samples below half volume.
Cool gradually — avoid quenching red-hot ware.
Weigh to constant mass — repeat ignition until the difference qualifies.

Care & Notes

Show care & notes

⚠️ Safety Notes

Hot work

always use tongs and heat-resistant gloves

Forbidden media

no hydrofluoric acid or strong alkali fusion

Furnace safety

ensure no flammable vapors before heating

Do not

No quenching: never place red-hot ware on cold metal or rinse with water

Porcelain Crucibles

Specifications

Low-form Crucibles

High-form / Volatile Crucibles

Product Description

1. Overview

2. Key Parameters

3. Material & Workmanship

Applications

Precipitate ignition

Ash testing

Fusion

High-temperature reactions

Selection Guide

Selection by Type

Selection by Capacity

Operation Guide

Before Use

Procedure

Cleaning & Care

Care & Notes

Hot work

Forbidden media

Furnace safety

Need Porcelain Crucibles?

Porcelain Crucibles

Specifications

Low-form Crucibles

High-form / Volatile Crucibles

Product Description

1. Overview

2. Key Parameters

3. Material & Workmanship

Applications

Precipitate ignition

Ash testing

Fusion

High-temperature reactions

Selection Guide

Selection by Type

Selection by Capacity

Operation Guide

Before Use

Procedure

Cleaning & Care

Care & Notes

Hot work

Forbidden media

Furnace safety

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