Value-added for the coal industry?

Staff at Quebec-based Orbite Aluminae say it has successfully developed a process for the production of alumina using fly ash.

Created during coal combustion, fly ash typically contains alumina concentrations ranging from five to 35 per cent, the company states, along with significant levels of silica, iron, rare earths and rare metals, depending on the original composition of the coal.

The process will be able to produce smelter-grade or high-purity alumina, according to Orbite.

According to the International Energy Agency, coal generates approximately 41 per cent of the world’s electricity and is a significant fuel source for many industrial thermal processes.

According to Orbite, the International Aluminium Institute says approximately 43 per cent of alumina produced worldwide in 2011 was manufactured using coal as a fuel source.

Fly ash produced by coal-fired thermal power plants is typically stored in reserves or discharged with few options for recycling outside of cement processes.

“Orbite’s unique technology has once again proven to be groundbreaking in its breadth and scope,” chief engineer at Orbite, Denis Primeau, said in a statement. “We have already succeeded in producing alumina samples from source materials including clay, bauxite and red mud, and we have now successfully expanded our family of feedstocks to include fly ash.”

This new application of Orbite’s technology is anticipated to be economically viable, based on different sources of fly ash, with an alumina content as low as 15 per cent.

Orbite says its preliminary evaluation projected recovery rates are expected to reach a minimum of 88 per cent of alumina content and 96 per cent of other metals present (e.g., silica, hematite, magnesium oxide, etc).

The chemical analyses of the test materials were performed by the independent laboratory AGAT Laboratories.

Source: Canadian Manufacturing newsletter