Tag Archives: Peter Schubert

Magnetite Mines plots Razorback DFS path that includes ore sorting

Magnetite Mines is preparing to commence a definitive feasibility study at its Razorback iron ore project in South Australia after receiving positive results back from a pre-feasibility study (PFS).

The PFS supports declaration of a maiden ore reserve of 473 Mt based on 12.8 Mt/y plant throughput and 2 Mt/y of high-grade concentrate, but it has opened the door for two other options.

Process plant optimisation, for instance, could see a nominal 15.5 Mt/y feed using three grinding stages, three stage magnetic separation and flotation to generate a premium-grade magnetite concentrate with 67.5-68.5% Fe content. And a “Head Grade Improvement Case”, based on higher mining rates with a head grade upgrade from selective mining or ore sorting, could see around 2.7 Mt/y of high-grade concentrate produced.

Razorback would involve initial capital investment of $429-$506 million for a post-tax internal rate of return of 14-33%. This is based on the range of throughput and concentrate production options, in addition to 62% Fe iron ore prices of either $110/t or $150/t.

Magnetite Mines said preparation for a prompt commencement of a definitive feasibility study is well advanced with further drilling, test work, metallurgical investigation and engineering workplans in progress.

Magnetite Mines Limited CEO, Peter Schubert, said: “The PFS is a significant milestone for the company, and defines our optimised go forward scope, which has been developed following rigorous and methodical testing of various options. The resulting scope meets our objectives of practical scale, capital efficiency, attractive returns, high quality product and an expected low emissions footprint.

“This small-scale start-up allows for a practical development of a long life, high quality business with a targeted date for first ore on ship at the end of 2024.”

The mining strategy involves a simple, small-scale mining operation, using mining contractors at start-up to simplify development and leverage the advantages of low strip ratio and short, flat hauls due to orebody geometry and outcropping nature, it said.

“The potential for selective mining is a key criterion and a simple truck and shovel operation was selected as a flexible, reliable and selective method of resource extraction,” the company said. “Bulk methods such as electric rope shovels, in-pit crushing and conveying and continuous miners were investigated but not selected.”

The selected fleet used a single 350 t excavator as primary unit with wheel loader back-up loading medium class (150-190 t) rear dump trucks. The 350 t excavator class was chosen as the maximum size of excavator that can achieve the 1 m of selectivity required to take advantage of the orebody characteristics. Ancillary gear has been sized to a size class appropriate for the excavator productivity and road geometry.

“During the definitive feasibility study, as further geological drilling and geo-metallurgical testing is undertaken, the fleet mix will be reassessed match capacity requirements once selective mining strategies are finalised,” the company said.

During the PFS, investigations and modelling showed there is significant potential in accelerating mining activities and realising higher plant feed grades, from some combination of accelerated and selective mining, stockpiles strategy and/or ore sorting, the company said.

Magnetite Mines has been investigating the potential application of a NextOre magnetic resonance analyser (MRA) with ore sorting technology to the Razorback resource. The use of the MRA allows for a high throughput, high accuracy bulk sorting application that is typically added to the front-end of a processing flow sheet to divert waste ores away before processing, it said. “This has the effect of improving mining grades by pre-concentrating the ore that will be subject to processing, whilst rejecting significant tonnages of low-grade material to tailings via a diversion method such as a chute flop gate or dead box diverter,” the company added.

In October, the company announced it had entered into an agreement with NextOre to supply a mobile bulk ore sorting plant using a magnetite resonance sensor for a trial of the NextOre technology. While the bulk trial was originally scheduled for later in 2021, NextOre and the company have agreed to reschedule this trial until later in the development schedule to allow for the results of planned infill drilling and metallurgical test work that are part of the planned definitive feasibility study to be incorporated in the bulk trial design, the company said.

To assess the impact of improved head grades in the PFS, meanwhile, results from an ore sorting case have been developed, using an increased mining rate and the block model used for reserves, then applying the previously released ore sorting results to generate improved plant head grades and mass recoveries.

“These results are consistent with the analysis earlier in the year on the discrete mineralised bands of the deposit and the gridded seam model,” it said. “Due to these encouraging results, the go-forward case for Razorback will be based on the higher head grades available from selective mining and ore sorting, which will be investigated further with comprehensive infill drilling of the Razorback orebody planned and designed to inform a selective mining schedule to definitive feasibility study standards.”

For the PFS, in addition to the test work completed as part of the 2013 PFS and additional high resolution DTR (Davis Tube Recovery) test work, a comprehensive mineralogical test program was completed to better understand the mineralogical composition of the Razorback and Iron Peak deposits, complementing the existing data from the previous test work program. This was informed by the results of the 2013 PFS study, which was completed for a two-module processing plant for a total of 6.2 Mt/y, and an optimised business case for a third module bringing it to 9.3 Mt/y.

Designed by the company’s process engineering consultants, the test work was used to improve the flowsheet. The flowsheet in the 2019 scoping study had three stages of grinding, three stages of magnetic separation and a final cleaning stage with a hydro separator producing final magnetite concentrate at a grind size of a P80 of 25 μm. This is a widely used, low risk flowsheet, but has significant power requirements and generates a very fine magnetite concentrate with potential filtration and product use issues, the company said.

The company has now generated a preferred flowsheet and plant layout for the PFS, which has significant advantages in efficiency and separation over the conventional configuration used in the scoping study estimates, it said. The inclusion of fine grinding and flotation allows efficient production of high-quality concentrate. The final scale of the preferred go-forward option is plant feed of approximately 15.5 Mt/y with ability to process up to 20% DTR with a capacity of up to 3.1 Mt/y concentrate.

Magnetite Mines up for NextOre magnetic resonance ore sorting pilot at Razorback

Having shown potential in lab-based test work to increase head grades at the Razorback project, NextOre’s magnetic resonance (MR) ore sorting technology is to now get an outing in South Australia at the high-grade iron ore development.

Razorback owner, Magnetite Mines, says it has entered into an agreement with NextOre to supply a mobile bulk ore sorting plant using a magnetic resonance (MR) sensor for a trial of the technology at the project.

The company said: “This advances our exclusive partnership with NextOre and is an important step in our journey to unlocking the potential of the Razorback project. The company is excited by the potential of the NextOre technology to enhance processing of by ‘pre-concentrating’ run of mine ore feed to increase plant head grade.”

The NextOre agreement includes a non-refundable deposit of A$100,000 ($71,418) and contemplates further, staged payments of A$700,000, Magnetite Mines says. The scope covers supply of a full-scale mobile ore sorting plant to site at Razorback for sorting magnetite ore using MR technology during the trial period for the purpose of mine feasibility analysis. The agreement includes milestone dates, with the equipment despatch from the CSIRO Lucas Heights facility, in New South Wales, expected in 2021.

Formed in 2017 by CSIRO, Advisian Digital and RFC Ambrian, NextOre supplies MR ore sorting solutions to global mining companies that applies mineral sensing technology developed by the CSIRO.

Unlike traditional ore sorting technologies that are based on X-ray or infra-red transmission, NextOre’s on-belt MR analyser ore sorting solution allows for the grade of high throughput ore to be measured at industry-leading accuracies and speeds, NextOre says. Due to the high speed of the technology, the integrative system is able to perform the analysis, computation and physical diversion of waste ores down to one second intervals allowing for fast diversion or high-resolution sorting.

As previously reported, the company entered into an exclusivity agreement with NextOre granting Magnetite Mines exclusive use of its MR ore sorting technology for any magnetite processing applications Australia-wide and all iron ore applications in the Braemar (including New South Wales) for a period of four years.

Magnetite Mines Chairman, Peter Schubert, said: “NextOre’s magnetic resonance sorting technology, developed over many years in conjunction with the CSIRO, has a rapid response time allowing unprecedented selection accuracy and speed. The result is potential for a substantial increase in the head grade of plant feed, resulting in lower unit operating costs and a significant improvement in capital efficiency.

“This technology also offers potential environmental benefits, with enhanced water efficiency and reduced tailings volumes.”

He added: “We are particularly interested in the potential of the NextOre technology to increase the grade of ore fed to the concentrator. The bulk trial of this exciting technology will contribute to the study work now underway.”

Chris Beal, CEO of NextOre said: “We are enthusiastic supporters of Magnetite Mines’ vision of unlocking the vast resources in South Australia’s Braemar region. Their disciplined approach, which leverages emerging technologies with well-established mining methodologies, is a testament to the team’s knowledge and experience in the field.

“In our collaborative planning, the Magnetite Mines methodology of carefully integrating mine and mill activities speaks strongly to the ability to generate the maximum value from bulk ore sorting solution. I am thrilled that NextOre can contribute to this transformative project and I look forward to jointly developing Australia’s reputation as a global leader in green resource extraction.”

NextOre’s ore sorting tech shows potential at Magnetite Mines’ Razorback project

Magnetite Mines Ltd says a study looking at applying NextOre’s on-belt magnetic resonance ore sorting solution at its Razorback Iron project, in South Australia, has shown the potential for a significant increase in plant throughput at the asset.

The ASX-listed company said results to date indicated that Razorback ores are especially well suited to bulk ore sorting with substantial improvements to ore mass recovery demonstrated in the study, completed by NextOre (a partnership between CSIRO and industry players Advisian and RFC Ambrian).

NextOre’s solution uses an on-conveyor magnetic resonance sensor to continually sense the grade of the material on the belt. This information is used to control a diverter gate that separates material above the selected cutoff grade (accepted material) from material below that grade (rejected material).

Magnetite Mines and NextOre, in October, signed an agreement that allows the development company exclusivity over any magnetite processing applications, Australia-wide, and all iron ore applications in the Braemar (including New South Wales) for a period of four years.

NextOre’s Razorback report demonstrates that the heterogeneity of the Razorback and Iron Peak resources allows for the potential for significant upgrading from ore sorting, Magnetite Mines said.

“For example, at a 50% rejection level (corresponding to a cutoff grade of approximately 16% Fe at Iron Peak and 14% Fe at Razorback), the grade of the accepted material would be increased by a factor of about 1.4,” the company said.

Were this to be implemented as part of a development of the project, by increasing mining rates, and pre-concentrating the plant feed, the throughput of a given plant capacity could be increased by some 40%, the company said. This would create significant savings in capital and operating costs per tonne of concentrate product, it added.

In order to assess the potential for bulk ore sorting at Razorback, NextOre used data drawn from the overall geological model for the Razorback and Iron Peak resources (the two resources that make up the Razorback project). The Razorback project currently has an inferred and indicated resource of 2,732 Mt at a grade of 18.2% Fe, but Magnetite Mines intends to produce a 68.8% Fe concentrate from the project.

NextOre then applied a fractal model, applying a mixing model to assess the predicted grade variation or heterogeneity of ‘pods’ of ore as they would present to an on-conveyor bulk ore sorting implementation, Magnetite Mines explained. Various sorting cutoff grades were selected to demonstrate a range of grade improvement scenarios, the company noted.

Magnetite Mines said: “Following the recently completed scoping study for a low capital cost, staged development of the Razorback project resources, this study highlights the applicability of NextOre’s magnetic resonance bulk ore sorting technology to the processing of the Razorback ores.

“When applied to a large, heterogeneous, low strip ratio deposit, such as Razorback, bulk ore sorting represents a pre-concentration technology ahead of the concentrator that can enhance throughput, improve economic efficiency and reduce tailings and water use.”

Magnetite Mines Chairman, Peter Schubert, said: “While our scoping study results for a low capital, staged development have been highly encouraging, we are now confident that the use of leading edge ore sorting technology can further enhance results, providing the company with a sustainable competitive advantage.”

Magnetite Mines and NextOre sign ore sorting exclusivity pact

Magnetite Mines Ltd says it has entered into an exclusivity agreement with ore sorting technology company NextOre to use its leading-edge magnetic resonance ore sorting technology for pre-concentration of magnetite and iron ore projects.

The terms of the agreement include exclusive use for any magnetite processing applications Australia-wide and all iron ore applications in the Braemar (including New South Wales) for a period of four years.

Formed in 2017 by RFC Ambrian, Advisian Digital and the CSIRO, NextOre aims to commercialise magnetic resonance ore sorting technology, an on-belt mineral sensing technology developed by the CSIRO. The technology uses a magnetic resonance analyser (MRA), a form of radio frequency spectroscopy, for the quantitative measurement of target ore minerals.

The use of the MRA allows for a high throughput, high accuracy bulk sorting application that is typically added to the front-end of a processing flow sheet to divert waste ores away before processing, according to Magnetite Mines. “This has the effect of improving mining grades by pre-concentrating the ore that will be subject to processing, whilst rejecting significant tonnages of low-grade material to tailings via a diversion method such as a chute flop gate or dead box diverter.”

The theorised result of ore sorting is a reduced volume of upgraded ore that performs better in the processing plant while reducing processing costs as nil-value material that would ordinarily be subject to downstream processing is rejected early on, according to the company.

“Unlike traditional ore sorting technologies that are based on X-ray or infra-red transmission, NextOre’s on-belt MRA ore sorting solution allows for the grade of high throughput ore to be measured at industry-leading accuracies and speeds. Due to the high speed of the technology, the integrative system is able to perform the analysis, computation and physical diversion of waste ores down to 1 second intervals allowing for fast diversion or high resolution sorting.”

Magnetite Mines Chairman, Peter Schubert, said: “We see great potential for technology to unlock a step change in competitiveness of our Razorback iron project (pictured). NextOre has completed an initial mathematical assessment based on our extensive geological data and the results are encouraging.”

Schubert said the company was moving to bulk test work to prove its application in its Razorback iron project, which has generated some 3,900 Mt of iron ore resources and has over 110 km of unexplored strike. The company believes it will be able to produce a 68.8% Fe concentrate from the project.

He added: “NextOre’s magnetic resonance sorting technology, developed over many years in conjunction with the CSIRO, has a rapid response time allowing unprecedented selection accuracy and speed.

“The result is a substantial increase in the head grade of plant feed, resulting in lower unit operating costs and a significant improvement in capital efficiency. But the application of this technology also gives environmental benefits, with enhanced water efficiency and lower tailings levels.”

Razorback already has advantages of scale, proximity to established ports, proximity to rail and shallow stripping, according to Schubert, “but the NextOre technology takes the competitiveness of the resource to another level”.

The company has initiated a desktop study of NextOre’s ore sorting solution with initial results to-date being very positive, it said.

Initial analysis of the macro-scale heterogeneity of the Razorback iron project JORC 2012 mineral resources indicates that the orebodies are suited to the application of ore sorting.

“The highly selective technology is particularly well suited to magnetite measurement and can be calibrated for several mineral types,” it said. “Further test work is envisaged in the near future in aid of refining the existing flowsheet.”

Chris Beal, CEO of NextOre, said: “The Braemar Province is really an astonishingly vast mineralogical system and represents an incredible potential for value. Owing in large part to the way nature arranged its geology, the system appears particularly well suited to the application of bulk ore sorting systems.

“In terms of reductions in water and electricity consumption, tailings dam size reductions, and overall plant efficiencies, the application of bulk ore sorting has the potential to impact developments in the region in a significant way.”