Flotation Investigations on Ni-Cu Sulphide Ores With Pyrrhotite, Talc and Pre-Oxidation Issues
Bibliographic record
Abstract
Canadian Ni-Cu sulphide ores vary in complexities from location to location posing serious processing issues. This thesis represents an experimental investigation of the fundamental characteristics and flotation of two Ni-Cu sulphide samples, namely, an oxidized ore blend and a fresh ore blend. Bench-scale flotation tests were conducted to better understand the effects of complexity associated with gangue mineralogy involving talc, chlorite and pyrrhotite (Po) in the behaviour of low-grade blends assaying 0.4-0.5% Ni & 0.5-0.7% Cu. Po content at 5.8-7.5% was much higher than the pentlandite (Pn) and chalcopyrite (Cp) combined. The reagents included a collector (PIBX) and depressants (CMC, DETA, SMBS, YTD & FTD). The colour of the oxidized ore blend was yellowish brown due to the formation of iron oxide species compared to the dark greyish colour of the fresh ore blend. The ionic conductivities of the oxidized ore blend slurry were much higher than those with the fresh-ore blend, which were, in turn, higher than the case with the tap water used. The pH value of the oxidized ore blend slurry was lower than the fresh-ore blend case due to acid-producing reactions, requiring about 2.2 more lime in batch tests. As part of characterization, extraction tests were conducted using toluene and EDTA/DETA to quantify elemental sulphur and metal ions suspected of causing inadvertent activation of Po. Through flotation investigations, CMC, YTD & FTD for depression of talc/chlorite and DETA & SMBS for Po depression were demonstrated to be effective when used in selected combinations. Flotation selectivity was assessed using plots of concentrate grade/recovery and relative recoveries of Po vs Pn and Cp. The relation between extracted sulphur and the mineralogical composition of the concentrates investigated using multivariable regression indicated strong correlations for collectorless flotation of the oxidized ore blend, indicating elemental sulphur is associated primarily with Pn and secondarily with Cp. Flotation kinetics involving the reagent systems and particle size effects were analyzed using the first-order models. Overall, the most effective reagent formulation for Po depression was SMBS/DETA combination, but YTD was also highly effective. Particle size distribution was found to be a significant factor, with finer particle sizes resulting in increased recovery of Pn and Cp but decreased recovery of Po.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".