experimental design to evaluate a reagent system for a nickel ore flotation n.
Skip this Video
Download Presentation
Experimental Design to evaluate a reagent system for a nickel ore flotation

Loading in 2 Seconds...

play fullscreen
1 / 18

Experimental Design to evaluate a reagent system for a nickel ore flotation - PowerPoint PPT Presentation

  • Uploaded on

Experimental Design to evaluate a reagent system for a nickel ore flotation. Authors. Jean Louzada; Ronald Hacha ; Marisa Monte and Mônica Cassola (a) CETEM – Centre for Mineral Technology, Rio de Janeiro, Brazil (b) Clariant S.A, São Paulo, Brazil. MOTIVATION.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Experimental Design to evaluate a reagent system for a nickel ore flotation' - kyran

Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
  • Jean Louzada; Ronald Hacha; Marisa Monte and Mônica Cassola
  • (a) CETEM – Centre for Mineral Technology, Rio de Janeiro, Brazil
  • (b) Clariant S.A, São Paulo, Brazil
  • The optimization of flotation conditions is a complex task because many process variables can affect flotation responses.
  • It is not uncommon for multiple interactions to occur between independent variables;
  • The identification of these interactions play an important role in advancing our understanding of the chemistry of such system in plant operations.
  • To employ a factorial design to investigate the effect of chemical variables on the flotation performance of dithiophosphates for a nickel ore;
  • To optimize these variables for maximum nickel recovery and grade.
      • Ethyl secbutil sodium dithiophosphates (Hostaflot E501) and sodium dialkyldithiophosphate (Hostaflot M92) were supplied by Clariant;
      • Polypropylene glycol methyl ether (CH3(OC3H6)n-OH and other consisting of a mixture of aliphatic alcohols, ethers and esters. The two frothers were supplied by Clariant .
      • The activator and the depressant used were copper sulfate and carboxymethyl cellulose, respectively
  • A nickel ore sample from Minas Gerais, Brasil, was completely characterized for mineralogical and chemical compositions:
    • Mineralogical composition, associations and liberation were measured in a FEI Quanta 400 SEM with the Mineral Liberation Analyzer (MLA) software.
    • Chemical analysis were carried out in a PanAnalytical Epsilon 3 X-ray Fluorescence machine.
  • Factorial Design;
    • Only factors which influenced in the recovery of nickel by flotation will be presented here.
    • The factorial design was implemented with two levels and six factors resulting in thirty two experiments.
    • The Statistics software was used for the regression analysis, statistical and optimization calculations.

Table 1. Factorsandlevelsapplied in 26-1 fractionalfactorial design. Flotanol(low: 20; high: 40); Montanol (low: 20; high: 80).

  • FlotationTests
  • The samples were ground in a rod mill, to which were added the dispersant and the activator at pH 6.0.
  • Immediately after grinding, the material was deslimed and, subsequently, the sample was transferred to a cell with two liters.
  • The pulp was kept under stirring at 1400 rpm and the pH was adjusted to 9.5 with a solution of NaOH 10% (p/v).
  • pH adjustment was immediately followed by depressant addition, carboxymethyl cellulose, and conditioning for 4 minutes.
  • Afterwards, the collector was added and conditioned for 30 seconds.
  • Finally, the frother was added to the system and conditioned for 1 minute.
  • The pH was kept at about 9.5 during the conditioning with all reagents. The flotation time was 4 min.
  • Curve Fitting and Statistical Analysis
    • The important response variable chosen in this study was nickel recovery
    • The statistical significance of effects and interactions between processes and the response variable was determined using the F-test.
    • Probability (P) values larger than 0.05 were indicative of a measured effect being statistically significant at a confidence level  95%
results and discussion

Mineralogical characterization

  • These studies showed that the major minerals are talc, hornblende, ilmenite, pyrite and pyrrhotite.
  • The results revealed that talc is not the predominant magnesium carrier mineral
  • Hornblende is present and predominates over talc in all ranges of particle size.

Figure 3 - Synthesis of the results obtained for theoretical recovery and grades of pentlandite in the concentrate at different size ranges.

analysis of variance

These variables and their interactions presented higher probabilities:

  • B: Concentration of collector ;
  • D: Concentration of frother
  • BD: interactions between them
  • In other cases, the null hypothesis is rejected because the estimated values of p-levels (Test P) are smaller than 0.05, i.e., the effects have a probability smaller than 5% so they represent only of noise.
  • The results of these studies showed that the main factors that influence more significantly the nickel recovery are the collectors and frothers concentrations.
  • The differences between the collectors are the alkyl chains do not influence the recovery.