Fused Quartz Technical Information

Fused quartz is produced through a specialized melting process that eliminates impurities and crystalline structures of quartz sand, resulting in a material that has purity above 99.995% and exhibits excellent thermal, optical and mechanical properties.

Thermal Properties

Fused quartz products feature excellent thermal shock resistance due to its low coefficient of thermal expansion. Quartz products can work under a wide thermal operating range and withstand rapid temperature changes.

The recommended maximum operating temperature of our quartz products is 1200°C (2192°F).

Thermal Conductivity		1.38(W/m°K)
Coefficient of Thermal Expansion (0~1000°C)		0.55 (10^-6/°C)
Normal Operating Temperature	Continuous Usage	~1050°C
	Non-continuous Usage	~1250°C
Strain Point		~1075°C
Annealing Point		~1180°C
Hot Processing Temperature		~1700-2100°C
Devitrification Temperature		Starting at ~1000°C. High temperature accelerates devitrification, esp. with surface contaminants such as alkaline solutions, salts and vapors

Chemical Resistance

Compared to most other materials, quartz products offer excellent chemical resistance to most acid, alkaline and neutral substances. The only exceptions are hydrofluoric acid which attacks quartz products at all temperatures, and phosphoric acid which attacks quartz at temperatures above 150°C.

Engineering Properties

	Units of Measure	Value
Density	gm/cc (lb/ft³)	2.2
Porosity	%	0
Tensile Strength	10⁶ Pa	48.3
Young's Modulus	10⁹ Pa	71.7
Hardness	Kg/mm²	600
Thermal Conductivity	W/m°K (BTU·in/ft²xhr·°F)	1.38
Coefficient of Thermal Expansion	10^-6/°C (10^-6/°F)	0.55
Specific Heat	J/Kg·°K (Btu/lb·°F)	740
Dielectric Strength	Ac-kv/mm (volts/mil)	30
Dielectric Constant	@ 1MHz	3.82
Index of Refraction @587.6m		1.4585

Guidelines for Cleaning and Drying

Quartz products should be cleaned prior to use to ensure optimal performance. Begin by using distilled or deionized water to remove dirt, grease, or stains. For products that are heavily contaminated, will be subject to high temperatures, or need to be reprocessed, it is recommended to wash them with the detergent, followed by thorough cleaning with distilled or deionized water, and then rapid drying.

A commonly used detergent solution is prepared by mixing 40% hydrofluoric acid and water in a 1:2 to 1:3 ratio. Dip the quartz products in the acid solution for no more than 5 minutes, then rinse thoroughly with deionized water and dry quickly.

To prevent recontamination, the products must be dried in a clean, dust-free environment or with specialized drying equipment.

Guidelines for Transport and Storage

After cleaning, quartz products must be either used immediately or packed with clean, continent-free materials. Always wear gloves when handling quartz products to prevent contamination from oils or residues on bare hands. Use high-quality cushioning materials for packaging to protect the products from impact. Since quartz products are fragile, handle them with extreme care to prevent collisions during packing, transportation, storage and use.

Guidelines for Use

High temperatures accelerate devitrification, especially in the presence of alkaline solution, salts, vapors or oxidizing environments. To minimize devitrification, clean the quartz surface with the hydrofluoric acid detergent (as described above), rinse it thoroughly with deionized water, and dry it rapidly.
Compared to other materials, quartz exhibits minimal thermal expansion when heated. As a result, special care should be taken when connecting quartz products with materials that have significantly different thermal expansion rates.
For large and thick quartz products or irregular shapes, avoid rapid heating or cooling to minimize thermal stress.
When subjected to high temperatures under heavy loads, using thicker quartz components is recommended for enhanced durability.