Lithium has found widespread application areas; from glass and ceramics to pharmaceutics. Moreover, last decade has witnessed a significant increase in the demand for lithium batteries. The Studies made in Turkey showed that about 2000 ppm lithium occur in boron clays. Extraction of lithium from clays was the subject of many researchers, but all concluded that it was not economical when compared to extraction from minerals and brines. A major source of the cost is the raw materials used in such an extraction process. This study aims to achieve cost reduction by extracting lithium from boron clays using natural (limestone-clay) materials and waste of boric acid production as a source of gypsum. Statistical modelling of the extraction process has enabled 18% increase in the extraction yield even under these circumstances. This study demonstrates that it is possible to design more economical processes through use of appropriate statistical modelling while using low quality materials. (C) 2005 Elsevier Ltd. All rights reserved.