Acid etching of concrete

Acid etching will remove the weak, milky layer of cement dust, lime and sand fines that can rise to the surface with over-wet concrete, poor curing or over-trowelling. It involves allowing the reaction of a diluted solution of hydrochloric acid to the concrete surface, then rinsing off with water. The acid will chemically react with the surface, and will dissolve it, allowing it and other water-soluble contaminants to be washed away. By removing the top layer, coatings can firmly adhere to sound concrete giving much longer service life.

10 Uses of Hydrochloric Acid

Did you know that the human stomach contains Hydrochloric Acid?  It is found in Gastric Acid which is a key part of the human digestive system.  Gastric Acid works by activating digestive enzymes in the stomach which help to break down food contents.
The stomach itself is protected from damage by a secretion of a thick layer of mucous and by a hormone called secretin which acts as a neutralising buffer.  Cells in the stomach and small intestine produce bicarbonate which also acts as a buffer and neutralises any potential damaging effects of the acid.
In some people, these mechanisms don’t work properly and they may suffer from indigestion, heartburn or have a peptic ulcer.  Such people may need the help of antacids to neutralise the Gastric Acid in the stomach.
Hydrochloric Acid is a strong mineral acid.  It is highly corrosive and is used in a wide range of industrial processes.

Here are 10 uses of Hydrochloric Acid:-
1. To ‘pickle’ steel.  This is a process whereby rust and scale is removed from steel sheet or coil with the use of a dilute solution of Hydrochloric Acid.  The metal can then be processed
2. To manufacture organic compounds such as Vinyl Chloride and Dichloroethane which are used to produce PVC (Poly Vinyl Chloride)
3. To regulate the pH level in a wide range of manufacturing and treatment processes including the production of drinking water, pharmaceuticals, beverages and foods
4. In the processing of additives for the food industry including fructose, citric acid and hydrolyzed vegetable protein
5. To produce inorganic compounds for water treatment including drinking water and waste water
6. To neutralise the water in swimming pools making it safe for bathers
7. To regenerate ion exchangers
8. To process leathers in the tanning industry
9. To purify common salt
10. In North Sea oil production where it is used to facilitate oil well acidizing

Hydrochloric Acid varies in strength.  If you are working with this chemical you must read the MSDS provided before starting a job.  Always wear PPE (Personal Protective Equipment) including approved eye protection, compatible safety gloves, safety boots and safety coveralls.  Concentrated Hydrochloric Acid should be handled under fume extraction.  This chemical is also known as Muriatic Acid or Spirits of Salt.  It is commonly referred to by its chemical formula HCl.

 

from our friends at The Chemical Blog

common uses for Hydrochloric AcidWhen used with safely in mind, Hydrochloric acid has many common household applications. The website eHow has produced an article highlighting the many common uses for Hydrochloric acid in and around the home. Read about them here.