Optimising Regrinding Chemistry for Pyrrhotite Flotation
Bibliographic record
Abstract
Changes in the surface properties of minerals with grinding and regrinding play a key role in mineral flotation performance, being recognised in industry through the development of the IsaMill and Stirred Mill Detritor. This paper describes some initial results in a larger study which attempts to quantify changes in the flotation properties of sulphide minerals with regrinding using different mills. Pyrrhotite has been chosen in the current study due its importance in the recovery of Platinum Group Minerals and in its separation from pentlandite in Sudbury basin nickel ores. This current paper focuses on the results obtained using a Magotteaux Mill only. Factors which affected pyrrhotite flotation were particle size, grinding media contamination, and exposure of new mineral surface. Pyrrhotite recovery decreased with size reduction from 90%, achieved before regrinding, to 77%, 64%, 30% and 7% after regrinding with stainless steel medium to d{80} values of 60, 40, 20 and 10 m, respectively. Contact angle measurements were applied to quantify surface hydrophobicity as a function of particle size and the B.E.T. method was used to obtain the surface area. Increased collector addition only partially restored pyrrhotite recovery. The surface of the pyrrhotite mineral was changed by regrinding in a way that hindered collector adsorption onto the new mineral surface. A further dramatic depression of pyrrhotite recovery when using mild steel regrinding medium demonstrated that there was an additional contribution to pyrrhotite depression from media contamination in this case.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".