Alumina 99.7%     Alumina 60%,80%95%,99.5%     Zirconia     Fused Silica     Agate     High Alumina Porcelain

Alumina 99.7% Labware

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99.7% Alumina Labwares are made from special grade of Alumina imported from ALCOA Germany.

These Labware are made by slip casting and pressure casting. Special care is taken to maintain purity of sintered Alumina to be above 99.7%

Sintered Grain Size is between 2-4 microns.  

Tolerance: +/- 1mm for all dimensions up to 50 mm. +/- 2mm for all dimensions above 50 mm.

Typical Chemical Composition of ALCOA Powder (Sintered Product) by wt %
Al₂O₃ [%]   99.8 (99.7)               SiO₂  [%]    0.015 (0.05)              MgO  [%]   0.04 (0.08)
Na₂O [%]   0.03 (0.03)               Fe₂O₃ [%] 0.015 (0.015)              CaO   [%]   0.01 (0.03)
All date are based upon Ants standard test methods. The typical values are based upon actual averages from production data.

Sintered Density:  above 3.9 gm/cc, above 98%  TD (3.96gm/cc)
   
Lustre and Color: With submicron Alumina powder from ALCOA, Ants create special Vitreous Lustre, Ivory Color and a Translucent high purity Alumina that leaves other Alumina Labware a distant second.

Solubility in boiling HF: 0.1 % by wt after three hours . Solubility in boiling HCL, H₂SO₄ and NAOH after 12 hours: less than 10^-3% by wt

Thermal Shock Behavior: Temperature change rate should not exceed 150°C/Hr 

Maximum Temperature of use without load: 1750°C 

Components of Alumina 99.7% made by Ants have been tested with success for Ultra High Vacuum Compatibility
 
Recommended Usage:    
Ants 99.7% Alumina wares are especially useful to chemists, metallurgists, and others high temperature involved in work demanding contamination-free results. These wares are highly refractory, meant for use in reducing and oxidizing atmospheres. It is inert in hydrogen and carbonaceous atmospheres and offers high resistance to alkalies and other fluxes. Suitable for glass melting, including borosilicate glass.  

Ants has developed a number of lab and industrial solutions with Alumina 99.7 composition. However Alumina forms Low temperature eutectic with compounds of Bismuth, Lead, Silicon, Tin, Antimony and rare earths. So care has to be taken to not use Alumina wares used for heat treatment of one eutectic forming compound with another eutectic forming compound. In cases as this Ants offers a wide range of Platinum wares (Purity > 99.95%) as an alternative.

Alumina 60%, 80%, 95% and 99.5%

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Technical Data (Typical Value)
	AC 60	AC 80	AC 95	AC 99.5
Chemical Analysis by weight %
Al203 Min	60	80	95	99.5
SiO3 Max	35	18	3	0.20
Fe2O3 Max	0.50	0.30	-	-
Na2O Max	1	1	0.50	0.20
Physical Properties
Colour	White	White	Ivory/ White	Pink/Ivory/ White
Sp.Gr. – gm/cc	2.80	3.20	3.80	3.90
Water Absorption	0	0	0	0
Max.Service Temp –0 C	1450	1550	1650	1800
Gas Permeability	Nil	Nil	Nil	Nil
Hardness R45N	68	72	83	83
Chemical Resistivity	Good	Good	Very Good	Excellent
Co-eff. Of Linear Thermal Expansion
(RT-14000 C) x 10-6 /0C Max.	-	-	8.0	8.3
Flexural Strength N/mm2	210	280	350	365
Tensile Strength N/mm2	-	-	188	260

Zirconia

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Several High-Alumina 99.7% items can be provided in a Fully Stabilized Zirconia (ZDY) composition (imported from Tosoh, Japan). Some advantages of Zirconia are:

• Higher maximum use temperature (2400º C – no load).
• Better chemical resistance in certain corrosive environments.
• Slightly better thermal shock resistance.


Fused Silica/Quartz

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When naturally occurring crystalline silica (sand or rock) is melted, the material is simply called fused quartz. When silicon dioxide is synthetically derived, however, the material is referred to as synthetic fused silica.

Most acids, metals, chlorine and bromine are unreactive with fused quartz at ordinary temperatures.  It is slightly attacked by alkaline solutions, the reaction rate increasing with temperature and concentration of solution.

Phosphoric acid will attack fused quartz at temperatures above about 150°C. Hydrofluoric acid alone will attack it at all temperatures. Carbon and some metals will reduce fused quartz; basic oxides, carbonates, sulfates, etc., will react with it at elevated temperatures. For general use, however, it can be concluded that fused quartz is quite unreactive.

Fused quartz is essentially impermeable to most gases, but helium, hydrogen, deuterium and neon may diffuse through the glass. The rate of diffusion increases at higher temperatures and differential pressures.

One of the most important properties of fused quartz is its extremely low coefficient of expansion: 5.5 x 10-7 mm °C (20-320°C). Fused quartz is a solid material at room temperature, but at high temperatures, it behaves like all glasses.

Quartz undergoes phase inversion to cristobalite phase at about 1200°C. This inversion is accompanied by a large change in density and can result in spalling and possible mechanical failure. This inversion is also called Devitrification.  Devitrification is a two step process of nucleation and growth. In general, the devitrification rate of fused quartz is slow for two reasons: the nucleation of the cristobalite phase is possible only at the free surface, and the growth rate of the crystalline phase is low.

Agate

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Agate is a microcrystalline variety of silica, chiefly chalcedony, characterised by its fineness of grain and brightness of color. Although agates may be found in various kinds of rock, they are classically associated with volcanic rocks and can be common in certain metamorphic rocks.

Most agates occur as nodules in volcanic rocks or ancient lavas where they represent cavities originally produced by the disengagement of volatiles in the molten mass which were then filled, wholly or partially, by siliceous matter deposited in regular layers upon the walls. Such agates , when cut transversely, exhibit a succession of parallel lines, often of extreme tenuity, giving a banded appearance to the section. Such stones are known as banded agate, riband agate and striped agate. 

                                                                                                

Physical Properties
Color	White to grey, light blue, orange to red, black, banded
Crystal habit	Cryptocrystalline silica
Crystal system	Rhombohedral Microcrystalline
Cleavage	None
Fracture	Conchoidal with very sharp edges
Mohs scale hardness	6.5 - 7
Luster	Waxy
Diaphaneity	Translucent
Specific gravity (gm/cc)	2.58-2.64

 

High Alumina Porcelain

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High Alumina Porcelain wares have alumina content greater than 50%.

High Alumina content gives these wares a superior finish and lustre, very high chemical and heat resistance.

These wares can be used upto 1150°C (2102°F). Only evaporation dish deep form has upper use temperature limit of 1000 °C.

The wares are autoclavable.

The heating cooling rate should not exceed 200 C/hr.

The Porcelain wares have been glazed at appropriate surfaces to make them impervious.