Mineweb - TECHNOLOGY - Chinese power company successfully produces alumina from coal ash

 

Although a seeming excursion from the subject of coal-to-liquid technology, we wanted to submit more evidence, as we have previously, that even the by-products of coal use possess value and utility. We had earlier documented developments wherein coal ash was, and is being, combined with other materials to create a lighter, stronger "cement/concrete", which could be used in many construction applications and provides some benefits in addition to weight savings.

 

Joe's mid-Seventies WVU research into coal mine waste accumulations, though focused, as he remembers it, primarily on an assessment of remaining/recoverable organic content, also involved chemical surveys of other materials present in mine wastes. He recalls that aluminum was present in surprisingly high quantities at some of the sites he studied.

 

Though his work dealt with mine wastes, if aluminum is present in those wastes, it's also likely to be present in the coal, and would thus be present, and concentrated, in the coal ash. In fact, the combustion of the coal might affect the aluminum to make it more easily recoverable.

 

We'll not document it, but another reference on the recovery of aluminum from coal plant ash stated that the aluminum content in the ash studied was higher, and more easily recoverable, than in some grades of the standard aluminum ore, bauxite.

 

The excerpt: 

"Chinese power company successfully produces alumina from coal ash

Datang International Power Generation Co says that it has competed construction of a plant for recovering alumina from high alumina content coal ash.

Posted:  Sunday , 11 Jan 2009

BEIJING (Reuters) - 

A Chinese power company has succeeded in producing alumina from coal ash, a step that could help ease China's chronic raw materials shortage, the Economic Daily said.

Datang International Power Generation Co (601991.SS) has completed construction of a plant capable of producing 3,000 tonnes of alumina a year from coal ash, and produced its first batch of alumina, the paper said, citing a company forum on the topic.

Ash remaining after coal is burned typically contains metals, including alumina, the raw material for aluminium, and recapturing and using them could reduce demand for natural resources. The challenge has been to develop the technology to the point where it is cost-effective.

China's aluminium smelters have expanded rapidly over the last few years, straining the country's ability to supply alumina as well as its raw material, bauxite.

Although the economic downturn has idled some aluminium smelting capacity, China's appetite for raw materials is still expected to be formidable in the long term.

The plant is expected to source its fly ash from power plants in Inner Mongolia, where alumina content in fly ash can near 50 percent, much higher than from other coal sources, the paper said."

Coal use doesn't produce wastes, just by-products.