Spiral separator is widely used in mineral processing operation for concentrating different minerals and coal. The popularity of spiral separator is due to its simplicity, low operating cost and ease of operation. Spiral separator is generally operated in the size range of 2 mm to 45 pm to obtain high separation performance. However, its application to treat particles of size below 45 pm is not explored. In the present investigation, three factors three level Box-Behnken design of experiments coupled with response surface methodology (RSM) was employed to understand the performance behavior of fine mineral spiral separator for separation of pre-concentrated iron ore slime. Pre concentration of iron ore slime was done using hydrocyclone. Concentrate obtained from hydrocyclone operation was used in the present study. The objective of this research is to develop the models for predicting the alumina content (%Al2O3) and yield of concentrate fraction of fine mineral spiral separator by varying operating parameters like feed pulp density, feed rate and splitter position. Optimization of operating parameters was done for achieving minimum alumina content (%Al2O3) and maximum yield of concentrate fraction. It was observed that, minimum alumina content of 1.63% was achieved at feed pulp density of 20% solid by weight, feed rate of 43 m(3)/h and splitter position of 3 cm. Similarly, maximum yield of 54.54% can be achieved at feed pulp density of 20% by weight, feed rate of 2.90 m(3)/h and splitter position of 4.91 cm. Predicted values of alumina content (%Al2O3) and yield of concentrate fraction were in agreement with the experimental values. The influence of operating variables of the fine mineral spiral separator on alumina content and yield of concentrate fraction was presented and discussed in 2D surface plots. (C) 2015 Elsevier B.V. All rights reserved.