Dr. Michael Coley and Dr. Anthony Greenaway

Dr. Coley and Dr. Greenaway conducting experiments.
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Bauxite is one of Jamaica’s most important natural resources. There are large deposits of bauxite in the parishes of St. Ann, Manchester, St. Elizabeth and Trelawney and smaller amounts in St. Catherine and Clarendon. These deposits are mined to support the operations of Jamalco in Clarendon, Alpart in St. Elizabeth and the Windalco plants at Ewarton in St. Catherine and Kirkvine in Manchester. These plants process bauxite to produce alumina for export whereas the fifth bauxite plant, St. Ann Jamaica Bauxite Partners exports raw bauxite ore for processing overseas.

ECONOMIC IMPACT

The Bauxite-Alumina industry is very important to the Jamaican economy. Over 3,400 workers are employed to the industry when all five plants are in operation. In addition, up to recently the industry accounted for over 50% of Jamaica’s total export and was the country’s second largest foreign exchange earner.

MARGINAL BAUXITE QUALITY

Jamaica has been exporting bauxite and alumina since 1952 and for many years Jamaica was the leading bauxite producer in the world. During the more than fifty years of bauxite mining, most of the high quality, easily processed bauxite has already been mined. Much of the reserves that remain is of marginal quality and must be blended with higher quality ore if it is to be processed. In some cases, these contain impurities(such as silica, phosphate and iron-containing minerals) at concentrations that are as much as 100 times higher than bauxite from other countries.

Dr. Greenaway and Dr. Coley.
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If these bauxites are processed using current technologies, the alumina produced may not meet required purity standards. The challenge therefore is how to process bauxite that has high impurity levels and obtain alumina that is till suitable for the export market. This must be done while keeping the cost of production low so that Jamaican alumina will remain competitively priced

THE EXPERIMENTAL APPROACH

In response to these challenges, the UWI Bauxite Process Research team worked closely with industry experts to design a project to tackle the problem. Working along with our graduate students, we examined data for over 19,000 bauxite samples that were taken from areas that will be mined in the future. We compared these mostly marginal bauxites with thousands of samples taken from current mining areas from which bauxite was being satisfactorily processed into alumina. We documented the properties of bauxite from both current and future mining areas and selected about 100 samples from each for detailed study.

In our laboratories, each sample is processed in a way that gives information on how it would behave during processing in the industrial bauxite plant. WE then measure the amounts of impurities that dissolve and study the various reactions that occur. From these, we develop ways to control the effects of certain impurities. We also use the information to predict how bauxite with different properties would behave during processing in the industrial plant.

Dr. Greenaway and Dr. Coley viewing results.
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ECONOMOMIC IMPACT

As a result of our work, engineers at industrial bauxtie plants can use the information we generate to select bauxite that can be processed without causing problems. Similarly, ores that will disturb plant operations can be easily avoided. Methods for controlling certain impurities have also been developed and these are likely to lead to greater efficiency in processing local bauxite.

Through our efforts, more of Jamaica's bauxite will be processed in alumina and the product made will still be of the required quality. Already, we have identified bauxite deposits that were considered unsuitable for mining and have shown tat they can be processed successfully without negative effects.

Careful study of Jamaica's bauxite is critical if our industry is to remain globally competitive. Much of Jamaica's future bauxite are of marginal quality and will be challenging to process. However, our UWI team is committed to carrying out the research necessary to develop new technologies to ensure that these resources can be processed in an effective and environmentally friendly way.

The researchers wish to acknowledge the UWI and Alcoa World Alumina, Australia, for funding support.