Thermal Spray Coatings for Ball Valves Used in Nickel/Cobalt Pressure Acid Leaching
Bibliographic record
Abstract
Abstract Pressure acid leaching (PAL) of lateritic nickel ores requires the use of extremely severe processing conditions (250 °C, > 4000 kPa, 98 % H2SO4). In addition to the severe corrosive nature of the acid solution, up to 30% of abrasive solids are present in the slurry. PyroGenesis Inc. has applied its expertise in materials science and thermal spray technologies into developing and commercially applying coatings for the protection of ball valve components used in PAL autoclaves. Vacuum plasma spray (VPS) and atmospheric plasma spray (APS) processes are used to apply coatings of metals and ceramics for corrosion and wear resistance, respectively. A comparative study on the microstructure and mechanical properties of different coatings, applied with the two processes, will be presented. Although APS coatings provide enhanced abrasive resistance, VPS coatings have shown the potential for superior properties. The extreme temperatures and pressures associated with the actual PAL conditions are too severe to simulate in laboratory conditions, hence, corrosion testing was not possible. Microstructural analysis, microhardness, adhesion, and abrasion testing were determined for each coating/processing combination.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 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".