Modeling and Optimisation of Spiral Concentrator for Beneficiation of Iron Ore Slimes from Kirandul, India

Abstract

Experiments were carried out using a spiral concentrator test rig containing feed conditioner, centrifugal pump and a spiral concentrator with feed to spiral and recirculation. Time samples of concentrate and tails were collected, weighed, dried analysed. Regression equations were developed for Concentrate yield, grade and percent recovery of iron values using Box Behnken Model and Minitab 19 software. The optimised yield, grade and percent recovery are 69.98, 64.98 and 79.20 against the target values of 70.00, 65.00 and 80.00 respectively at 16.00% solids, 2.20 m3/h feed rate and 14.40 cm splitter position. Surface (wire mesh) plots were drawn using Minitab 19 to explain the relation between independent variables and response variables. Maximum yield predicted was 80.24% by weight at a feed consistency of 20.00% solids, feed rate of 1 m3/h and at a splitter position of 16.00 cm whereas the minimum yield predicted was 17.19% by weight at a feed consistency of 30.00% solids, feed rate of 3 m3/h and splitter position of 12.00 cm. Maximum grade predicted was 68.73%Fe at a feed consistency of 30% solids, feed rate of 1.00 m3/h and splitter position of 12.00 cm, whereas the minimum grade predicted was 61.03%Fe at a feed consistency of 10% solids, feed rate of 1 m3/h and splitter position of 16.00 cm. The maximum percent of iron values recovery predicted was 86.19 at a feed consistency of 20.00% solids, feed rate of 1.0 m3/h and splitter position of 16.00 cm whereas the minimum recovery predicted was 18.82% at a feed consistency of 30% solids, feed rate of 3 m3/h and splitter position of 12.00 cm. Surface plots were used to explain the variation in response variables concentrate yield, grade and recovery of iron values.