Notice bibliographique
Résumé
The hypothesis of this study is that the optimal plant size for a mining venture is dependent upon both uncontrollable and controllable variables. Examples of variables which are uncontrollable to the firm are characteristics of the orebody, capital and product markets, projected price levels, and tax structure. Controllable variables in determining plant size are rate of recovery, level of recovery, capital costs, and operating costs. The primary purpose of this study is to delineate the effects of these variables, both singly and jointly, upon plant size and to present a model which will interrelate the variables with that scale of plant which will maximize the value of the firm. A secondary purpose of the study is to compare the impact of both Canadian and United States tax laws upon the profitability of a given operation, and upon the optimal grade-capacity combination to be employed for a given orebody. The difference of the impact of Canadian and United States tax laws with respect to the conservation of resources is also considered. After each of the controllable and uncontrollable variables is defined and analysed, a detailed analysis is made of various methods of mine valuation, with the objective being to identify the valuation method which most closely relates to the value of the firm. Then a model is constructed which will give the mine-life annual cash flows for a given orebody under various concentrator-capacity--cut-off-grade combinations. These cash flows are then converted to internal rates of return and benefit-to-cost ratios, which are contoured for various cut-off grades and concentrator capacities under various metal prices. The model assumes an orebody with a tonnage of 40e ⁽²ˉ ⁵x⁾ million tons, where x is the cut-off grade, in percent copper. Contour plots of benefit-to-cost ratio and internal rate of return were constructed for cut-off grades ranging from 0% to 1% copper, and for concentrator capacities ranging from 5000 tons-per-day to 50,000 tons-per-day, at net smelter returns of 40¢ per lb. to per 46¢ per lb. of contained copper. The tax system under which the highest profits are attained is Canadian tax laws with pre-1968 British Columbia taxes. The operation is least profitable under United States tax laws. However, optimal plant size is least sensitive to changes in metal price under United States tax laws, and most sensitive to price changes under Canadian tax laws with pre-1968 British Columbia taxes. Similarly, optimal cut-off grade is most insensitive to changes in metal price under Canadian tax laws with pre-1968 British Columbia taxes, and most sensitive to product price changes under United States tax laws. Therefore, it can be shown that under United States tax laws, the response of an operation to changing product prices would be to change the optimal cut-off grade, while in Canada, particularly under pre-1968 British Columbia taxes, the response would be to change the optimal operating capacity. Therefore, American tax laws provide the greatest flexibility for responding to changes in product price. The tax system which produces the greatest degree of conservation of resources, as is reflected by completeness of ultimate extraction, is the American case. The lowest extraction level would result under Canadian taxes, with pre-1968 British Columbia/taxes.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,003 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,005 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».