In the arsenal of any laboratory there is a great variety of different utensils used for a wide variety of needs. Often in the process of analytical work, tanks are needed that have increased resistance to temperature, pressure and corrosive chemicals. Quartz crucibles, the properties of which are very useful in analytical work and in various industries, can be attributed to such utensils.
What is it and in what areas is it applied?
A crucible is a container designed for heating, burning, evaporating, drying, hardening, or melting all kinds of materials under extreme thermal conditions.
All types of tableware made of quartz glass are united by their characteristic resistance to high temperature and caustic acids of different origin. Exceptions are only hydrofluoric and phosphoric acids, preheated to 300 ° C.
This vessel is used not only in the process of laboratory experiments and analysis. Oversized versions of crucibles also exist. They are used in chemical, metallurgical and other industries.
A quartz crucible is the best suited for working with chemicals of varying degrees of causticity. The vessel has an extremely high resistance to caustic acids. He is not afraid of high temperature indicators (up to 1250 ° C inclusive) in combination with high pressure. Vibration and other dynamic effects will not cause damage, as well as sudden cooling after overheating. With strongly alkaline reagents, things are worse due to the high hygroscopicity, the consequence of which is high electrification.
Where is it used?
The applications of quartz crucibles are quite extensive. As mentioned earlier, this capacity is widely used in laboratory research, when working with different acids and in heavy metallurgy. But the functionality of crucibles is not limited to this. Without the use of crucibles, for example, the production of semiconductor silicon is impossible. Capacity is indispensable even in dentistry and orthopedics, because the manufacture of dentures, crowns and bridges is impossible without its use.
The advantage of quartz over other materials
These factors together give an idea of the significant advantage of the quartz crucible over any other.
- First, quartz glass crucibles are currently cheaper to produce than their platinum counterpart.
- Secondly, this material is more resistant to aggressive environments than, for example, porcelain, from which laboratory glassware, including crucibles, is also produced.
- Thirdly, the production of quartz crucibles is not as labor-intensive as, for example, platinum or porcelain.
Composition and method for the production of quartz glass
Quartz, or silicate, glass is made from prepared silica. The process is that the silicon oxide in the feed is brought to an amorphous state. It is this feature that gives quartz glass such good resistance to acids and temperature jumps. Numerous tests have shown that the containers do not deform and do not crack even after a twenty-fold repetition of sharp thermal fluctuations.
Quartz crucibles are made by obtaining a suspension of high concentration quartz raw materials. The following is the molding of containers using blanks, drying of raw materials, firing in a muffle furnace at a temperature of about 300 ° C. The firing process lasts about 3 hours, then the obtained form is impregnated with methylphenylspirosiloxane. The last step in the manufacture of quartz glassware is the application of an inner layer consisting of silicon nitride.
The resulting batch is tested for stability and compliance with GOST 19908-90. After the final certification, the products are ready for use.