Use of mine planning software for the evaluation of resources and reserves of a sedimentary nickel deposit

Η χρήση λογισμικού μεταλλευτικού σχεδιασμού για την αξιολόγηση κοιτασμάτων και την εκτίμηση ορυκτών πόρων και αποθεμάτων είναι διαδεδομένη και θεωρείται προϋπόθεση για την αναφορά αποθεμάτων με βάση διεθνή πρότυπα και κώδικες αναφοράς. Οι βασικές αρχές λειτουργίας και εφαρμογής αυτών των κωδικών είναι η διαφάνεια του αναφερόμενου υλικού, η σχετικότητα των αναφερόμενων πληροφοριών (ουσιαστικότητα) και η επάρκεια των ατόμων που εμπλέκονται στην παραγωγή των αναφορών. Η εφαρμογή ειδικού λογισμικού μεταλλευτικού σχεδιασμού που περιγράφεται στην εργασία αυτή λαμβάνει χώρα στα λειτουργικά μεταλλεία ιζηματογενών κοιτασμάτων νικελίου στην Κεντρική Εύβοια. Περιλαμβάνει όλα τα στάδια της επεξεργασίας ερευνητικών δεδομένων συμπεριλαμβανομένης της εισαγωγής, ανάλυσης, επεξεργασίας και μοντελοποίησης των δεδομένων, της γεωστατιστικής εκτίμησης των ποσοτήτων και ποιοτήτων των ορυκτών πόρων και αποθεμάτων, και το σχεδιασμό, βελτιστοποίηση και προγραμματισμό των μεταλλευτικών δραστηριοτήτων.The use of mine planning software in the evaluation of deposits and estimation of mineral resources and reserves has become widespread and is considered a prerequisite for the reporting of reserves according to international reporting standards and codes. The main principles of operation and application of these codes are transparency of reported material, the relevance of reported information (materiality) and the competence of people involved in producing the reports. The application of specialised mine planning software described in this paper currently takes place at operational mines of sedimentary nickel deposits in Central Evia, Greece. It involves all stages of processing of exploration data including entry, analysis, processing and modelling of data, geostatistical estimation of quantities and qualities of mineral resources and mineral reserves, and the design, optimisation and scheduling of mining operations

Mineralogical investigation and preliminary beneficiation tests for upgrading the Hudenisht nickeliferous lateritic ore

The nickeliferous iron ore of Hudenisht is located in the Pogradec area, Albania. It is developed in layers above altered ophiolite and is covered by limestone of the Upper Cretaceous. The ore was characterized through XRD, ore microscopy and SEM analysis and found that the main mineral phases are hematite, goethite and chromite, with chlorite (clinochlore, nimite), lizardite, calcite and spinel as minor phases. The main Ni-bearing phase is nimite, which appears mainly in the groundmass of the ore. The chemical analysis through XRF showed that it is a lowgrade nickel ore (about 0.8% NiO) with Fe2O3 (74%) as the most abundant constituent. The ore was upgraded through physical beneficiation processes, namely gravimetric and magnetic separations. The received samples were homogenized, crushed to -8 mm and the product was sieved following the wet sieving procedure to obtain four size fractions, i.e. −8+4 mm, −4+1 mm, −1+0.250 mm and −0.250+0.063 mm. Each fraction was subjected to upgrading and the chemical analysis through XRF showed that the best results among the two processes were obtained through the gravimetric separation. It is observed that the float products are richer in nickel mainly in finer size fractions