Journal of Chemical Technology and Metallurgy, 53, 3, 2018 564 STUDY OF SODA EFFECT ON THE SINTERING PROCESS OF LOW TITANIUM SLAG Galymzhan Maldybayev 1 , Madali Naimanbaev 2 , Irina Shadrunova 3 , Nyna Lokhova 2 , Rustam Sharipov 4 ABSTRACT The article presents study results of the sintering process of soda with low-titanium-containing slag, where the slag is produced during processing of titanium magnetite concentrate. The purpose of sintering is to change the mineralogical composition of Ti-containing phases and to obtain a product suitable for chemical separation of ti- tanium dioxide from impurities. The X-ray phase analysis revealed that the obtained titanium slag belonged to the spinel-anosovite type. The factors influencing the sintering process were studied: the slag to soda mass ratio, the process duration, the temperature and the size of slag particles. The thermal analysis of the slag and soda sinter- ing process revealed that the optimum process temperature is 900°C. This temperature ensured the formation of sodium titanates and a sinter of sufficient porosity. The results demonstrate that the effective decomposition process requires a pretreatment of titanium slag by fine grinding. It was found that grinding of titanium slag particles to 40 µm contributes to more complete decomposition of the anosovite with a formation of sodium titanates. It was found that during the sintering of titanium slag with soda at a mass ratio of slag:soda = 1:1.05, decomposition of the ano- sovite occurs, and practically all titanium is bound to sodium titanates. The optimum conditions of the process are determined as follows: the mass ratio of slag to soda is 1:1.05, the sintering temperature is 900°C, the duration is 60 minutes and the particle size of the slag is 40 μm. Titanium-containing slag phases are converted into Na 2 TiO 3 and Na 8 Ti 5 O 14 during the sintering. The presence of a significant amount of silicon dioxide and the sodium-magnesium silicate phase was observed in the sinter. Electron microprobe analysis showed that impurity elements are adsorbed on the particles of the formed Na 2 TiO 3 . Keywords: titanium magnetite concentrate, titanium slag, soda, sintering, sodium titanates, anosovite, silicates. Received 17 Octobet 2017 Accepted 10 January 2018 Journal of Chemical Technology and Metallurgy, 53, 3, 2018, 564-571 1 Kazakh National Research Technical University After K.I. Satpayev (KazNITU) Satpayev Str. 22a, Almaty city, 050013, Republic of Kazakhstan E-mail: galimjan_87@mail.ru 2 JSC Institute of Metallurgy and Enrichment, Shevchenko str./Valikhanov str., 29/133 Almaty city 050010, Republic of Kazakhstan. 3 Institute of Comprehensive Exploitation of Mineral Resources Russian Academy of Sciences, Kryukovsky impasse Moscow, 4111020, Russian Federation 4 JSC Kazakh - British Technical University, Tole bi str. 59 Almaty city, 050000, Republic of Kazakhstan INTRODUCTION Titanium dioxide is widely used as a pigment in paints, paper and cosmetic products, as well as in high-tech devices such as solar cells, semiconductors, biomedical equipment and air-cleaners [1]. There are two main industrial technologies for the production of titanium dioxide pigment - sulfuric acid and chlorine, in which the main raw material is high-titanium-containing slag and/or rutile, obtained from ilmenite concentrate. In the sulfuric acid process, the Ti-containing product is treated with concentrated sulfuric acid to produce a sulfate solution that undergoes hydrolysis and precipi- tation of titanium dioxide, and the iron passes into the solution as sulfates. By chlorine technology, rutile is first exposed to chlorine gas, titanium passes into the form of chloride and further it is converted to a pigment with the removal of chlorine at high temperature in a mixture