Fundamental study of the monazite-calcite flotation separation

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

6 Scopus citations


The flotation of monazite is depressed when using hydroxamic acid as a collector in the presence of calcium ions which may exist due to the dissolution of minerals such as calcite. Minor dosages of sodium hexametaphosphate (SHMP) were found to effectively depress calcite, whereas the flotation of monazite was not impaired in single mineral flotation tests. However, in a mixed mineral flotation system, monazite flotation was depressed significantly. The mechanism of hydroxamate adsorption on monazite and calcite, the depression mechanism of calcite on monazite, as well as the depression mechanism of SHMP on calcite and monazite were studied using micro-flotation, electro-kinetic, and adsorption tests. Findings indicate that the adsorption of hydroxamate on monazite was due to chemisorption while adsorption on calcite was a result of physical interaction. SHMP significantly increased the negative charges of calcite surfaces which depressed the adsorption of the hydroxamate anions on the calcite surfaces due to an elevated electrostatic repulsion force. When calcium-rich minerals such as calcite are mixed with monazite, the calcium ions dissolved from the mineral surfaces specifically adsorb onto the phosphate oxygen sites on the monazite mineral surfaces thereby causing depressing effects. The addition of SHMP to suppress collector adsorption on the calcite surfaces interacts with the calcium species that were specifically adsorbed onto the monazite surface, which prevents hydroxamic acid adsorption onto the rare earth oxygen sites due steric hindrance and results in the flotation depression of monazite.

Original languageEnglish
Title of host publicationIMPC 2016 - 28th International Mineral Processing Congress
ISBN (Electronic)9781926872292
StatePublished - 2016
Event28th International Mineral Processing Congress, IMPC 2016 - Quebec City, Canada
Duration: Sep 11 2016Sep 15 2016

Publication series

NameIMPC 2016 - 28th International Mineral Processing Congress


Conference28th International Mineral Processing Congress, IMPC 2016
CityQuebec City

Bibliographical note

Publisher Copyright:
© 2016 TAPPI Press. All rights reserved.


  • Adsorption
  • Calcite
  • Calcium
  • Depression
  • Flotation
  • Hydroxamic acid
  • Monazite
  • Sodium hexametaphosphate

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geotechnical Engineering and Engineering Geology
  • Mechanical Engineering
  • Earth-Surface Processes


Dive into the research topics of 'Fundamental study of the monazite-calcite flotation separation'. Together they form a unique fingerprint.

Cite this