Optimization of sample preparation method of total sulphur measurement in mine tailings

Original Paper

Abstract

A sample preparation method of total sulphur measurement of reactive mine tailings was optimized. The total sulphur was measured by inductively coupled plasma optical emission spectroscopy, and ultrasound technique was used for sample digestion. The optimization process was adopted by a combined approach of experimental design and response surface methodology. The digestion time, temperature and acid-oxidant combination (i.e. effect of H2O2 with a fixed amount of acid mixture) were investigated. A two-level and three-factor (23) full factorial design of experiment was applied to identify the most significant factors, and a central composite design was used to optimize the digestion procedure. KZK-1, a sericite schist, was selected as the certified reference material. The optimum methodology at 95 % confidence level (P < 0.05) was identified to be 10 min of digestion at 77 °C, with a solution of 1 ml HNO3:1 ml HCl:1.35 ml H2O2. This combination resulted in 100 % sulphur recovery. The investigated method was verified by X-ray diffraction analysis. The optimum digestion level was applied to a reactive mine tailings, which achieved satisfactory results with a percentage relative standard deviation < 3 %.

Keywords

Process optimization Response surface methodology Central composite design Total sulphur analysis ICP-OES Ultrasound-assisted digestion 

Supplementary material

13762_2013_403_MOESM1_ESM.doc (109 kb)
Supplementary material 1 (DOC 109 kb)

Copyright information

© Islamic Azad University (IAU) 2013

Authors and Affiliations

  1. 1.Department of Civil and Environmental Engineering, Faculty of EngineeringWestern UniversityLondonCanada
  2. 2.Department of Civil and Environmental EngineeringWestern UniversityLondonCanada
  3. 3.Department of Civil and Environmental EngineeringWestern UniversityLondonCanada

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