Characterization and dissolution of scale formed during continuous pressure acid leaching of laterites
Bibliographic record
Abstract
The focus of this work was the study of scale produced as a by-product from the Falconbridge laterite pressure acid leaching campaigns conducted during the period 2000 to 2002. The objective was twofold: (i) scale characterization, (ii) scale dissolution. The results obtained from the scale characterization studies revealed that alunite formed in fresh water and saline water had the general chemical formula of (H3O)Al3(SO4)2(OH) 6 (hydronium alunite) and NaAl2Fe(SO4)2(OH) 6 (sodium alunite), respectively. In saline water campaigns, Fe substitutes Al within the alunite structure---compared to that of pure hydronium alunite---at an average Al:Fe molar ratio of 2:1. Alunite comprises 67 wt% of the scale mass with hematite, making up the balance. The scale dissolution tests examined the effectiveness of chemicals dissolving scale as a measure of descaling. Two scales were tested, I3 and I6. Maximum dissolution was attained with HCl, instead of H2SO 4 at the most vigorous conditions of 200°C and 0.5m. Also, the dissolution kinetics of I3 were twice as fast as those of I6 due to the five-fold porosity of the former scale. The scale growth rates were found to be highest at the compartment of acid addition. Those obtained from the saline water campaigns were 200% greater than fresh water campaigns.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| 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 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".