Preparation of Tio2-Enriched Material from Ti-Bearing Slag by Acid Roasting

Willie Nheta, Edward Malenga

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

EVRAZ Highveld Steel and Vanadium has about 45 million tons of slags which assays at 31% TiO2. This slag can become a raw material for extracting titanium instead of it being a waste product and causing environmental pollution (Zhang et al, 2014). Several mineral processing and metallurgical processes have been proposed for treating Ti-bearing slags such as middle grade rutile making, titanium pigment making by H2SO4 method and Si-Al-Ti alloy by smelting (Zhong et al, 2014, Sui et al, 2013, Lasheen, 2008). Due to the solid solution of titanium and other elements in the slag and complex interfacial combinations, the application of these processes may results in poor recovery and high cost as previously shown. (Liu et al, 2007). An attempt to upgrade the titanium content from the slags was investigated. Combined pyrometallurgy and hydrometallurgy processes were applied based on the reactivity of Mg, Si, Ca and Fe with selected solvents. Acid roasting with phosphoric acid was used with the objective of modifying the structure of the sample in order to form water soluble compounds of Mg, Fe and Ca after roasting at 1000OC. The calcine was then leached in sulphuric acid in order to remove the formed Mg, Ca and Fe compounds. The residue was then leached in sodium hydroxide in order to remove the silicates. It was observed that an upgrading of TiO2 to 48.3% by weight was realized when leaching with 1% H2SO4 while the XRD results revealed the presence of titanium in the form of rutile (TiO2) ,Ilmenite [Fe (Ti O3)] and Karrooite (Mg Ti2 O5) as major phases. TiO2 grade was further increased to 61% after leaching in the residue in sodium hydroxide.

Original languageEnglish
Title of host publicationProceedings of the World Congress on Mechanical, Chemical, and Material Engineering, MCM 2015
EditorsJamal Chaouki, Yuyuan Zhao
PublisherAvestia Publishing
ISBN (Print)9781927877173
Publication statusPublished - 2015
EventWorld Congress on Mechanical, Chemical, and Material Engineering, MCM 2015 - Barcelona, Spain
Duration: 20 Jul 201521 Jul 2015

Publication series

NameProceedings of the World Congress on Mechanical, Chemical, and Material Engineering
ISSN (Electronic)2369-8136

Conference

ConferenceWorld Congress on Mechanical, Chemical, and Material Engineering, MCM 2015
Country/TerritorySpain
CityBarcelona
Period20/07/1521/07/15

Keywords

  • Leaching
  • Phosphoric acid
  • Roasting
  • Ti bearing slag

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • General Chemical Engineering

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