Chromic acid

Chromic acid is used in the process of chrome plating and in the manufacture of wood preservatives.

Setting the standard

Elementis offers two chromic acid products: Flake and CA ULTRA™. Both products have similar specifications and can be used in any applications requiring chromic acid. However, chromic acid flake is used primarily in applications requiring fast dissolving rates, like wood preservation. It is also used in conjunction with Elementis’ proprietary sparger systems, which transports dry chromic acid in totes, trucks or railcars to the customer, is then dissolved in-situ and off-loaded into a customer tank as liquid chromic acid.

The environmental and safety benefits, in combination with greater efficiency, make the sparger systems desirable for any application.

CA ULTRA™ is a specially designed chromic acid that is virtually dust free, has a long, stable shelf life, a fast dissolving rate and low sodium content. This product is used primarily in metal finishing, surface finishing and catalyst production applications which generally require a low dusting and low sodium product.

Plating applications

Chromium plating is the most visible of the applications using chromic acid as an ingredient. A wide range of metals and plastics are electro-plated to produce a durable, tarnish resistant and high luster “chrome” finish. Uses include domestic appliances, plumbing fixtures, automobile accessories and hospital equipment where hygienic, wipe-clean surfaces are essential.

Functional chrome plating, some times referred to as hard chrome plating, is applied in much thicker layers for heavy industrial applications. Hard chrome has exceptional wear and corrosion resistance and typically used in metal working machinery, engine cylinders, cutting tools and hydraulic ram coatings.

Preservation properties

Chromic acid is also used extensively as an ingredient in formulating industrial wood preservatives. Here it acts as a fixative, binding vital biocides to the wood which gives protection against insect and fungal attack. In certain climates untreated wood lasts only six months in ground contact, whereas treated wood can extend this to over 30 years. In fact, estimates show that chromium-based timber preservatives prevent the destruction of 250 million trees every year.