A review of the determination of organic compounds in Bayer process liquors

Abstract

Bayer process liquors present a difficult and complex matrix to the analytical chemist, and the history of the application of modern analytical techniques to this problem is a case study in innovation. All Bayer process liquors contain organic compounds, in amounts varying from traces to several grams per litre. The total organic carbon content of Bayer liquors may be less than 5 g/L up to as much as 40 g/L. The presence of these organic impurities is of concern to Bayer technologists because they can have significant impacts on the economics of the process and the quality of the product. This review examines the history and current state-of-the-art of the analysis of organics in Bayer process liquors, and provides guidance on the applicable techniques matched to a comprehensive list of the compounds most likely to be present.

Lithium adsorption performance of a three-dimensional porous H2TiO3-type lithium ion-sieve in strong alkaline Bayer liquor

“…The Bayer process for producing rened smelter grade alumina has been applied for more than 100 years in industry. [1][2][3][4][5][6] In the Bayer leaching process, the Bayer liquor containing a high concentration caustic sodium solution (ca. 200 g L À1 ) is circularly used for alumina leaching.…”

Equilibrium studies of oxalate and aluminum containing solutions

“…The precipitation of oxalate from Bayer process liquors is a confounding process that can limit the aluminum production rate and therefore also much studied. 7,8,9 However, again finding data directly relevant to SRS tank waste chemistry proves challenging. Significant effort has been expended to model the solubility of aluminum solutions of the Bayer process in the hopes of increasing efficiency.…”

Rapid start-up of a bioelectrochemical system under alkaline and saline conditions for efficient oxalate removal

“…After the product aluminium hydroxide (gibbsite, Al(OH) 3 ) is separated from the process liquor, the remaining caustic solution (spent liquor) is recycled to the digestion reactors to minimise caustic consumption (Hind et al, 1999;Meyers, 2004). With the continuous recycling of the spent liquor during the Bayer process, organic substances extracted from the bauxite also accumulate in the process liquor (Hind et al, 1999;Power et al, 2011b). These organics consist of various compounds ranging from very complex high molecular weight humic substances to simple organic acids (Power et al, 2012).…”