recycling

Zinc brings a multitude of economic and social benefits to society. Man has found a wide range of uses for this versatile natural element whose properties are valued in many industries.

The most important application of zinc is protecting steel from corrosion by hot-dip galvanizing. Steel is one of the most widely-used materials on the planet and, thanks to zinc, steel's durability can be prolonged. Both steel and zinc are 100% recyclable. The zinc-steel combination has significant economic benefits in terms of life-cyle costs. Improved air quality in many industrialized countries, with diminishing levels of sulfur dioxide (SO₂), means that today zinc coatings provide even longer protection for steel.

Increased attention to life-cycle costing is motivating designers, specifiers and investors to opt for zinc-coated steel in many traditional and new applications, from construction to automobiles, from electricity distribution poles to safety barriers, from farm gates to ski-lifts.

Zinc, the 27th most common element in the Earth's crust, is fully recyclable. At present, approximately 70% of the zinc produced originates from mined ores and 30% from recycled or secondary zinc. The level of recycling is increasing in step with progress in zinc production technology and zinc recycling technology.

Today, over 80% of the zinc available for recycling is recycled. Zinc is recycled at all stages of production and use - for example, from scrap that arises during the production of galvanized steel sheet, from scrap generated during manufacturing and installation processes, and from end-of-life products. The pie chart below describes the percentage of recovered zinc from various products manufactured with zinc.

The life of zinc-containing products is variable and can range from 10-15 years for cars or household appliances, to over 100 years for zinc sheet used for roofing. Street lighting columns made of zinc-coated steel can remain in service for 40 years or much longer, and transmission towers for over 70 years. All these products tend to be replaced due to obsolescence, not because the zinc has ceased to protect the underlying steel. For example, zinc coated steel poles placed in the Australian outback a hundred years ago are still in excellent condition.

The presence of zinc coating on steel does not restrict steel's recyclability and all types of zinc-coated products are recyclable. Zinc coated steel is recycled along with other steel scrap during the steel production process - the zinc volatilizes and is then recovered.

The supply of zinc-coated steel scrap is expected to double over the next five years, as more zinc-coated vehicles enter the recycling stream. By 2005, half of the world steel output is expected to come from electric arc furnaces (EAF). As a result, growing quantities of EAF flue dust with higher zinc contents will be treated and more recycled zinc will become available.