Social Content

.

Get a quote

Chemical Resistance

Chemical Resistance

The type of Corrosive substance along with the Temperature determines the effect of concentration. Concentrated acids are less corrosive than diluted acids with the exception of Phosphoric Acid. Different factors, such as the type of corrosive substance, its Concentration, pH, Temperature and Agitational forces affect the rate of corrosion.
Temperature
  • Temperature has a strong effect on corrosion for both acids and bases. Generally, the rate of corrosion for bases double with every 10˚c increases in temperature. At pH 14 (NaOH) the maximum permissible limits are 57˚c.
  • Time of exposure also plays significant role in process. The effect of exposure time on corrosion varies, depending upon the nature of corrosive substance. In case of acids when the time of exposure is increased the rate of corrosion tends to diminish. Bases however, display a constant corrosion rate with time.
Substance
  • Ceracoats (CERA 9011-Cobalt Blue) provides a high degree of resistance to Acids, Bases, Solvents, Gases, Uncondensed Vapors, Melted Salts of Acidic, Natural or Anhydrous Nature, at Relatively high Temperature and at all Concentration.
Acids
  • CERA 9011 (Cobalt Blue) exhibits excellent resistance to all acids - organic and inorganic, oxidizing and reducing. The iso corrosion curves are established for most common acids. Reagent grade acids are used in laboratory test that produced these curves. In actual practice other factors such as velocity, phase type, chemical grade etc can affect the corrosion rate.
  • Only hydrofluoric acid causes rapid destruction of Glass Lining at all concentrations. When phosphoric acid concentration is increased, it becomes more aggressive towards glass. At 85% concentration the maximum useable temperature is 95°c.

VOLUME TO SURFACE AREA RATIO (V/S)=20

SULFURIC ACID

VOLUME TO SURFACE AREA RATIO (V/S)=20

HYDROCHLORIC ACID

VOLUME TO SURFACE AREA RATIO (V/S)=20

NITRIC ACID

VOLUME TO SURFACE AREA RATIO (V/S)=20

PHOSPHORIC ACID

Bases
  • Bases are of more corrosive nature than acids. As concentration increases rate of corrosion increases. Also, the rate of corrosion increases with increase in temperature. An increase of 10% doubles the rate of attack of Glass Lining. Therefore, it is important to be cautious while using hot alkalis.

SODIUM HYDROXIDE

POTASSIUM HYDROXIDE

Water
  • Water can cause severe corrosion which increases with water purity. Our CERA 9011 is competent enough to combat corrosion in vapor phase environment. Condensed water droplet on the colder surface of the glass in vapor phase, tend to leach out the alkali ion from the glass network. Therefore, it is recommended that the vessel contents be slightly acidic. It also recommends that Unjacketed top dish be insulated to reduce condensation
Effect of hydrofluoric Acid on Glass
  • It is well known that hydrofluoric acid (HF) will completely destroy Glass Lined Vessel. Even at concentration as low as 20ppm, fluorides in acid environment have a devastating effect on Glass surface, specifically in continuous reactions where the fluoride as HF are repeatedly replenished. Hydrofluoric acid reacts with silicon dioxide main ingredient in glass, destroying the SiO2, structure and producing a rough surface.
  • Preventing fluorides attack on Glass Lined surface requires constant vigilance by the users. Reactants which can contain fluoride impurities must be carefully analysed to determine the fluoride level before they are used. In particular technical grade phosphoric acid and its salts are often fluoride contaminated and other mineral acids.
Corrosion Inhibition
  • Chemical reactions are sometimes so severe that they cause a rapid wear of glass lining. The use of additives to the reacting substances can inhibit this corrosion permitting the use of glass-lined equipment. When using acids, several hundred ppm of silica protests the glass lining and considerably reduce the rate of corrosion in liquid phase.
  • The same result can be obtained in vapour stage by adding silicon oils. Generally, the higher the temperature, the greater the quantity of silica required and the more concentrated the acids are, the less silica needs to be used. In presence of fluorine, silica also has a favourable influence. With alkalies, a few hundred ppm of calcium, aluminium or zinc may reduce corrosion, especially in dilute solutions.

UNIT - I

C-1,1-53, Phase-IV, GIDC Estate,
V.U.Nagar, Anand
Gujarat - 388121, India

UNIT - II

Block No, 833, Rajnagar Road
Khadol, Anand Gujarat - 388 350,
India

Contact Info

Address

Block No, 833, Rajnagar Road Khadol, Anand Gujarat - 388 350, India

Company

Marketing

Phone

+91 98252 28948

Email

mkt@ceracoats.net
tanmay@ceracoats.net

Download Brochure

Copyright © 2024 Ceracoats All Rights Reserved.

Get Quote Now

It’s Free and Faster. Your details will be secure with us.