Investigation of lime usage impacts on bauxite processability at ETI Aluminyum Plant

Hüseyin Arıkan,Sema Vural,Gökhan K Demir

doi:10.1007/s40090-019-0171-x

Hüseyin Arıkan, Sema Vural + Show 1 more

Open Access

https://doi.org/10.1007/s40090-019-0171-x

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Abstract

ETI Aluminyum A.Ş., the primary aluminium manufacturer of Turkey, is also one of the major integrated plants of the world capable of performing production from mining until end product. The alumina refinery was designed on a certain boehmitic bauxite quality basis. However, bauxite properties have changed over the years, resulting in the urgent need for process optimization to not only keep the refinery cost efficient, but also prevent serious bottlenecks in the near future. Lime can be used to overcome problems when using bauxites with specific and variable chemical and mineralogical characteristics. Although lime is extensively used when processing diasporic bauxites, the studies on boehmitic bauxites and the overall effects on the process are limited. In this paper, lime impact was investigated at all stages of the Bayer process including the effect on alumina quality, energy and raw material consumptions. The results showed significant improvements in the product quality as well as recordable savings on consumptions.

Highlights

The Bayer process is used for producing alumina (Al2O3) from bauxite ore
Lime is widely used as an additive in alumina production by the Bayer process, as it provides higher alumina recovery and lower caustic soda consumption [3, 4], controlling impurities and minimizing the inhibiting effect of sodium titanates [7,8,9], promoting settling and filtering properties of the red mud [10, 11]
We investigated the effect of lime usage on the Arvana and Kakliktas bauxites

Summary

Introduction

The Bayer process is used for producing alumina (Al2O3) from bauxite ore. The process was developed and patented by Karl Josef Bayer in 1887 [1], which led to a dramatic reduction in the cost of aluminium metal. Keywords Bayer process · Lime usage · Caustic consumption · Digestion · Alumina quality · Boehmitic bauxite Lime is widely used as an additive in alumina production by the Bayer process, as it provides higher alumina recovery and lower caustic soda consumption [3, 4], controlling impurities and minimizing the inhibiting effect of sodium titanates [7,8,9], promoting settling and filtering properties of the red mud [10, 11]. Haematite to goethite ratio (H/G) is an indicator of settling performance of bauxite residue (red mud): higher the bauxite, the better is it for the Bayer process.

Results

Conclusion