Metakaolin - Opacifier
Metakaolin Opacifier will comprise 9.6% of Kaolin products and 0.8% of all products produced by the Project at full production levels.
An alternative and more valuable use of MK than as a cement pozzolan is as an opacifier in the production of paper and as an additive to paints. The demand, however, for opacifiers is much lower than that for pozzolans, and so the market is considerably smaller.
Metakaolin plays an important role in paper manufacture and is known in the industry as calcined paper coating kaolin. It is the most highly processed grade of kaolin and so is generally the most expensive. Despite direct competition with Precipitated Calcium Carbonate (PCC) and Ground Calcium Carbonate (GCC), kaolin can be blended with calcium carbonate to provide benefits of both materials and allow the production of paper with very specific properties. When used in news print, MK can allow for a reduction in the required paper thickness by reducing strikethrough (the ability to see printing on the reverse side of the page). This in turn reduces the amount of pulp required in producing a given amount of paper.
Demand for kaolin in paper is expected to grow at a rate in excess of 1% p.a. for the next five years.
The best pigment, with respect to opacifying power, is titanium dioxide (TiO2), which is priced at around AUD3,000-4,000/t. Calcined kaolin, which is proven to exhibit opacifying properties second only to TiO2, is approximately 20% of the cost (AUD600-800/t). Samples of kaolin from Newnes Junction are currently undergoing laboratory testing for suitability as calcined kaolin paper fillers.
Metakaolin is also used in the paint industry as an opacifier, partially replacing TiO2. Kaolin products are available with the same particle size as TiO2, which makes paint formulations easier to manufacture.
As this is a high-value material, it is expected that a year will be required for to ensure optimal finished product quality is achieved, and for potential customers to take test samples to determine the suitability of this particular product for their individual requirements. Thus, no significant sales are expected for the first year of operation.
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