JOURNAL OF MATERIALS SCIENCE 19 (1983) 1522-1529 Rutile from ilmenite using coconut pith as a reductant ANNIE GEORGE, V.S. KELUKUTTY, L. G. RADHIKA, P. N. MOHANDAS*,P. K. ROHATGIt Regional Research Laboratory (CSI R), Trivandrum 659 019, India Rutile, the raw material needed for chloride route has to be prepared by removing iron from ilmenite, as rutile deposits are scarce in nature. In this study, the iron oxide present in ilmenite was reduced for different times and temperatures using coconut pith which is an agrowaste available in large quantities in Kerala. Pith has low S, P and ash contents and has a moderate calorific value. The reduction process was studied using chemical analysis, SEM, X-ray and EPMA. Reduction of iron oxide in the ilmenite reaches a maximum at 3 to 4 h at 1040 ~ C containing 84% of iron in the metallic state and the rest in the ferrous state. Treatment with 20% hydrochloric acid at 80 ~ C for 1 h with stirring, leaches out most of the iron from the reduced ilmenite leaving behind only 2% iron. The SEM and X-ray data show the gradual reduction and structural changes taking place during reduction of ilmenite with coconut pith. 1. Introduction Ilmenite and ruffle are the important source minerals of titanium. Ilmenite is available abun- dantly in nature, whereas the availability of ruffle is very limited. The titanium extraction plants follow the chloride route, in which rutile is con- verted to TIC14. The Kerala beach sands contain ilmenite and ruffle of the order of 130 and 7 million tonnes respectively [ 1 ]. Iron which is present in iimenite has to be removed to obtain ruffle. Many methods, such as reduction, smelting, reduction and leaching, etc., have been tried by various workers [2-6]. It has been found that reduction of the iron oxide using coal, or CO gas followed by acid leaching, is a fairly good method for the production of syn- thetic ruffle. Jena et aI. [7] have reported a study on the utilization of Indian ilmenite to produce ruffle, whereas the ilmenite is subjected to reduc- tion using coal, followed by leaching with hydro- chloric acid which gave a product containing 92% TiO:. Coconut pith is the waste fluffy material dis- carded during the separation of coconut fibres *To whom all correspondences should be addressed, '~Present address: Director, Regional Research Laboratory (CSIR), Bhopal, India. 1522 0022-2461/84 $03.00 + .12 from the coconut husk. The annual production of pith in Kerala, India, and the world are 0.5, 0.65 and 3.6 million tonnes respectively. Practically all the pith is going to waste at present. In fact, the discarding of pith in back-waters has led to the pollution of back-waters in Kerala. This paper describes the results of our experi- ments on the preparation of synthetic rutile by the reduction of ilmenite using coconut pith as a reductant. The reduction process has been studied using chemical analysis, scanning electron micro- scopy, X-ray diffraction and electron microprobe analysis. 2. Experimental methods and materials Chemical assay of the coconut pith and pith char- coal was carried out using standard methods and the results are shown in Table I. The average com- position of Kerala ilmenite [8] is shown in Table II. Reduction experiments were carried out in static conditions using pith and ilmenite in the weight ratio 4 : 1. The reaction set-up (Fig. 1) con- sisted of a stainless steel tube of length 75 cm and outer diameter 6.25 cm. Ilmenite was put on a bed 9 1984 Chapman and Hall Ltd.