95% Recovery of Ore And 52% Improvement in Head Grade From Bulk Ore Sorting Trial
- 95.1% recovery of contained Nd2O3+Pr6O11 on 1.8 tonne sorted bulk sample.
- 52% increase in head grade from 0.71% to 1.08% Nd2O3+Pr6O11.
- 37.1% of the sample mass rejected from ore sorting testwork.
- Standard commercial ore sorting technology, X-Ray transmission (XRT), has proven to be extremely effective at removing dilution on samples used in the testing program.
- Technical and engineering programs will continue to investigate the operating scenarios where benefits can be realised for the project.
Hastings Technology Metals Limited (ASX: HAS) (“Hastings” or “the Company”) is pleased to announce successful completion of bulk sample testing through an ore sorting circuit. These outstanding results confirm earlier results from smaller drill core derived samples, which were tested with two different ore sorter vendors.
Previous small-scale test work has shown that off-the-shelf x-ray transmission (XRT) ore sorting technology could be applied to separate out a barren waste stream from the ore. This presents an opportunity to remove waste dilution material from the mining process before the material is fed into the processing plant, potentially resulting in energy and reagent savings in the beneficiation circuit.
The crushed bulk ore sample of 1.8 tonnes was screened into two size fractions -10.5mm and +10.5mm. The sortable fraction (+10.5mm) after being diluted with waste material at either 35% or 60% proportions was screened on a Tomra commercial sorter using XRT technology at 32 tonnes per hour feed rate.
In the base case sorted ore sample, crushed and screened to +10.5mm and diluted with 35% waste material, a total of 37.1% of the sample mass was rejected at a grade of 0.09% Nd2O3+Pr6O11, representing a loss of Nd2O3+Pr6O11 of just 4.9% or an overall recovery of 95.1% Nd2O3+Pr6O11 in the Ore. A corresponding 52% increase or upgrade in the ore head grade was achieved from 0.71% to 1.08% Nd2O3+Pr6O11.
In the sorted sample diluted with 60% waste material, the ore sorting test work program achieved an upgrade factor of 2.16 taking the feed grade from 0.43% Nd2O3+Pr6O11 to 0.93% Nd2O3+Pr6O11, whilst recovering 90.6% of the Nd2O3+Pr6O11.
The sorting tests of the sortable fraction showed that the standard commercial Tomra technology was able to successfully sort the Yangibana ore using XRT technology.
Andrew Reid, Hastings Chief Operating Officer, said “the Yangibana orebody continues to amaze us. Not only with its world-class ratios of Nd2O3+Pr6O11, but now these results have confirmed that ore sorting presents a real and future prospect to gain higher operational efficiencies from the Yangibana Processing Plant”
Figure 1: TOMRA ore sorter used for the bulk ore sorting sample
Detailed quantitative mineralogy is pending on the ore sorting waste stream. However, the results indicate that the REO rejected in the ore sorter waste stream is not composed heavily with liberated monazite, but rather with low-grade REO intergrowths which would not be recovered in the flotation process. The benefit for the Yangibana project is in removing this barren gangue early in the process flowsheet, with potential benefits gained in streamlining the efficiency of the beneficiation plant.
The full opportunity for including ore sorting technology into the Yangibana process flowsheet is still being assessed. Based on these testwork results, technical and engineering programs will continue to investigate the benefits that can be realised across the project.
Figure 2: Yangibana ore being feeding to the ore sorter at 32 tonnes per hour
Competent Person Statements
The scientific and technical information in this announcement and that relates to process metallurgy is based on information reviewed by Ms Narelle Marriott (Principal Engineer – Beneficiation) and Mr Zhaobing (Robin) Zhang (Process Engineering Manager) of Hastings Technology Metals Limited. Both Ms Marriott and Mr Zhang are members of the AusIMM. Each has sufficient experience relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined by the JORC Code 2012. Ms Marriott and Mr Zhang consent to the inclusion in this announcement of the matters based on their information in the form and context in which it appears.
TERMINOLOGY USED IN THIS REPORT
Total Rare Earths Oxides, TREO, is the sum of the oxides of the light rare earth elements lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), and samarium (Sm) and the heavy rare earth elements europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho, erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y).
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