Aspire Mining Ltd is focused on developing metallurgical coal assets in Mongolia, principally its wholly owned Ovoot Coking Coal Project (OCCP).
The company has advised that Sedgman Pty Ltd has completed Stage 2 of the front-end engineering and design (FEED) study for the coal handling and preparation plant (CHPP) infrastructure to be constructed at the OCCP and issued its final report outlining the design and cost estimate (FEED study).
In response to feedback gathered during community consultation, the elimination of potential dust emissions was an express objective of the design and engineering. Result of this is evident in the planned coal handling, stockpiling and truck loading infrastructure. The concept presented in this FEED study represents a significantly more sophisticated processing and materials handling solution than that contemplated in the March 2019 pre-feasibility study. Leading technologies are also incorporated to minimise power and water consumption.
This is an important step in the development of the OCCP, as establishment of a CHPP at the Ovoot site is an important factor to enable consistent delivery of high-quality metallurgical coal to market. Currently, only one other Mongolian coking coal producer beneficiates its coal on site to a globally recognised product specification (Mongolian Mining Corp.).
Key outcomes from Stage 2 of the FEED study include:
- Preparation of concept design with nameplate capacity of 350 tph feed, based on a simple, robust process flowsheet comprising proven technologies.
- Incorporation of reliable equipment capable of operating more than 7200 hr/y and 20 years life with appropriate training and maintenance regimes in place.
- Meeting design objectives to maximise water and power efficiency, containment of potential dust emissions, and avoidance of requirement for tailings storage facility.
- Optimisation of layout conducive to future phased expansion, including product handling system capable of supporting doubling of initial throughput.
- Engineering conducted in sufficient detail to underpin ±15% capital and operating cost estimates.
- Forecast construction schedule of 15 months on the ground.
- Total capital cost for construction of the described CHPP infrastructure herein this announcement is estimated at US$77 million, including assumed EPC contract margin but excluding project and owner contingency allowances.
- Increase in estimated capital cost is primarily attributable to modified scope of facilities incorporated within design, intended to support achieving and maintaining a social license to operate, application of more stringent design standards and a back-drop of stretched supply chains and higher capital cost environment leading to conservative and short duration price estimates.
FEED study overview
Aspire is pleased to advise that Sedgman has completed Stage 2 of the FEED study on the CHPP infrastructure intended for construction at the OCCP. The final report has been issued outlining its proposed design, and the estimated capital cost, construction schedule and operating costs.
Stage 1 of the FEED study was previously completed in July 2021, comprising an initial concept study, considering, and evaluating potentially applicable process technologies and infrastructure layouts to achieve the design objectives.
After completion of Stage 1, an additional Stage 1b programme was completed in November 2021, to optimise and validate costs for the chosen combination of equipment and infrastructure layout, which allowed for further refinement before embarking on the more detailed Stage 2 work.
Stage 2 has drawn from conclusions reached in Stages 1 and 1b and refined and optimised the plant layout and design drawings to support estimation of capital and operating costs to an accuracy of ±15%. These deliverables provide sufficient detail to enable future tenderers to provide binding bids.
The resulting CHPP design can wash 2.1 million tpy of ROM coal feed at a base-line forecast of 6000 operating hr/y. Sedgman note that good maintenance and operating practices could see the plant operate at more than 7200 hr/y treating 2.5 million tpy of raw coal with a minimum 20-year lifespan.
It is relevant to note that Sedgman has previously delivered three 5 million tpy coal processing modules to Mongolian Mining Corp. at the Ukhaa Khudag coal deposit in the South Gobi region of Mongolia. Mongolian Mining Corp. remains the only other metallurgical coal miner in Mongolia capable of exporting a washed coking coal product that consistently meets international product specifications.
Materials handling overview
The design brief focused strongly upon reducing dependence on mobile equipment and preventing and/or containing potential dust generation as result of coal handling. The result of this is a mechanised and contained process from delivery of ROM coal by mine trucks through to deposition of product coal into road haulage trucks for transportation to Erdenet or reject material into mine trucks for co-disposal in mine overburden dumps.
ROM coal is to be delivered into a drive-over ROM coal receival hopper, designed within a drive-through building. The mine trucks intended for use are of smaller cross-sectional profile in comparison to standard off-highway trucks and eject their payload rather than tip it. Additional to being cost effective in comparison to off-highway trucks of similar capacity, this functionality reduces dust generated when discharging payload and allows for containment.
The CPP has been located to allow future duplication without major changes to either the product coal or reject material conveyor systems. These would only need to be extended slightly, and for motors and gearing to be upgraded in support the higher belt speeds necessary to handle the increased tonnage.
Product coal is conveyed from the CPP into a large product coal storage (PCS) building, with maximum stockpile capacity of more than 55 000 t. This building is of a clear span design, approximately 92 m long and 60 m wide, mounted upon a 5 m high concrete retaining wall. Importantly, this building will enable a significant amount of product inventory to be maintained at site, sheltered from inclement weather, and thus preventing dust emissions from being generated
Coal will be reclaimed inside the PCS building through vibrating feeders to conveyor inside tunnel beneath the stockpile, which will deliver it to a truck loadout bin for semi-automated loading of road haulage trucks for delivery to Erdenet. If required, road haulage trucks will also be able to be directly loaded by front end loader within the PCS building.
Estimated operating cost
The unit operating cash cost for the CHPP infrastructure is estimated to be US$2.39 per ROM t, when at 2.5 million tpy throughput rate. This includes for operations, maintenance and supervisory labour, maintenance parts and materials, process consumables, general and administrative expenses and sustaining capital provisions. This does not include for the CHPP mobile plant, delivery of raw coal, and collection of product coal and reject material (which are to be completed as part of mining and transportation activities).
Aspire provided input regarding locally sourced labour and consumables and Sedgman provided input regarding parts, materials, and capital provisions. Costs for electricity and heating are not included, pending further investigation and analysis of plausible sources, though the respective average peak and seasonal loads have been determined for this purpose.
The company is continuing to liaise with the Ministry of Nature, Environment and Tourism in relation to the review and approval of the company’s detailed environmental impact assessment to underpin completion of the OCCP definitive feasibility study.
Read the article online at: https://www.worldcoal.com/coal/24052022/aspire-mining-completes-chpp-infrastructure-feed-study/
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