Minerals processing plant design
Our experienced multi-disciplinary teams deliver detailed mineral processing plant design for precious metals such as gold and silver; base metals including copper, lead and zinc; industrial minerals; bulk materials such as metallurgical and thermal coal and iron ore.
We also offer a proven ability to transfer technology applications and processing techniques across commodities.
- Processing plant design - including expertise in comminution (crushing as well as grinding/milling), fine classification, dense medium separation, spirals, reflux classifiers and flotation, leaching, metal recovery, concentrate dewatering, storage handling and transport
- Tailings handling design including long distance pumping, tailings settling and mechanical dewatering including filtration and coarse, fine and ultrafine centrifuging
- Materials handling design - inlcuding long-distance conveying, run-of-mine receival systems, rail or truck load out (TLO) systems, and a wide range of stockpile stacking and reclaim configurations
- Technical reviews and audits. (e.g. structural integrity audits, effciency audits, debottlenecking reviews, optimisation assessments, new technology assessments).
Performance commitments are just one way we stand by the quality of our engineering capability.
Sedgman has a long history of plant design and processing innovation that has contributed to our standing as an international industry leader. A snapshot of some more recent innovations include:
- A crushing and screening system that minimised fines with reduced transfer tower heights, a space efficient overall site footprint and simple to relocate
- First applications of reflux classifiers instead of spirals in manganese, mineral sands and coal processing circuits that increased overall recovery
- Dewatering technology that delivered extremely reliable and robust results with low product moisture
- An optimised site layout that achieved a smaller footprint, reduced conveyor lengths and transfer stations, and reduced earthworks while still incorporating appropriate maintenance access to achieve more than 8,000 operating hours per year
- A reduced milling circuit footprint that significantly lowered materials quantities, simplified construction and decreased capex, while improving maintence efficiency
- An above-ground thickener design that simplified layout and footprint, and reduced earthworks and pumping requirements
- Consolidation of flotation with grinding circuits that lowered materials quantities, improved equipment access, decreased pumping, and reduced operations interaction and tie-ins
- Modular designs for off-site or on ground preassembly that consisttently enhance construction timeframes and safety
- First application of filter press' and a dry stack tailings system in a red mud (bauxite procesing) application.
From incremental improvements to large-scale innovations, our team embraces the opportunity to challenge thinking and optimise designs to maximise processing efficiency, while delivering simpler and safer outcomes in constructability and operability. Sedgman’s mineral processing plant design delivers maximum economic return.
Bulk materials handling
Sedgman has been providing industry leading bulk materials handling solutions to the Australian and international mining industry for more than 40 years across a range of both greenfield and existing brownfield projects for commodities including copper, gold, manganese, iron ore, coal and mineral sands. Our large in-house team of dedicated mechanical and materials handling specialists comprising of both engineers and drafters provide reliable, efficient and innovative solutions to the global mining industry.
Our team is supported by other in-house dedicated engineering discipline teams covering process, structural, civil, electrical, controls, operations and maintenance reliability to provide complete design solutions. We have extensive experience with a proven track record of capabilities including overall site layout and plant positioning, conceptual flowsheet design, feasibility studies, trade off/ value engineering studies, detailed design, procurement management, construction and commissioning support, operations and maintenance support, and brownfield optimisations.
Our project and engineering company, Sedgman Onyx, provides industry leading analysis and visualisation of bulk material flow to improve and optimise equipment design and to troubleshoot materials handling problems. Our clients include the major iron ore producers in Western Australia, BHP, Rio Tinto and Fortescue Metals Group (FMG). Essential to our service is the advanced capabilities of rocky discrete element modelling (DEM) software and the speed of its graphics processing unit (GPU) powered solver. We developed calibrated material flow behaviour through the simulation of industry standard lab-based tests. The behaviour of these material models is then carefully validated with full scale chute simulations which are directly compared to site observations of flow and wear patterns.
We also provide general site audits including reliability, capacity increase, troubleshooting, integration and upgrade to incorporate new plant, standards compliance for surface bulk materials handling systems.
Our materials handling services specialise in the following:
- Materials handling flowsheet development
- Equipment selection and integration
- Design of conveyors including small belt feeders to overland conveyors
- Surge bins and stockpiles
- Transfer chutes
- Crushing and sizing systems
- Storage facilities including stacking/reclaiming systems and truck, train, ship loadout facilities
- Associated facility infrastructure including sampling, weighing, ore quality analysis systems, dust suppression and fire protection systems.
Where practical, we leverage an extensive in-house database of existing projects and building blocks from the past 40 years to provide known outcomes as well as providing bespoke custom one-off design solutions specific for the application.
We utilise both inhouse and proprietary design software packages for all aspects of design including conveyor and chute design, flowsheet circuit simulation, material flow simulation - discrete element modelling (DEM), and project capital cost estimating.
Our experienced multi-disciplinary teams deliver detailed comminution design, assessments and debottlenecking in numerous commodity types, including precious metals, such as gold and silver; base metals including copper, lead and zinc; and industrial minerals.
Sedgman has a long history in mineral processing and comminution design and has experts in house who can design, optimise and assess comminution circuits for base and precious metals. Sedgman has a focus on sustainable and efficient comminution circuit design and optimisation. In-house experts design and optimise:
- Crushing circuits
- Primary grinding mills - semi-autogenous grinding (SAG) mills, autogenous mills (AG) mills, ball mills
- Pebble crushing
- High pressure grinding rolls (HPGR)
- Regrind mills
- Vertical stirred mills, high intensity grinding (HIG) mills, ISA mills
Leveraging our expertise in integrated simulation, we assess and design comminution circuits to include a range of new technologies and optimisation techniques:
- Ore sorting and ore-preconcentration
- Mine to mill assessment and operation
- Novel comminution devices
- Small scale and modular processing plants.
Hydrometallurgy processes for recovery of base and precious metals such as heap leaching typically have a lower capital intensity, offer enhanced environmental benefits over producing a concentrate and are suited to economic extraction from lower grade ores. Leaching involves dissolving the acid soluble portion of target mineral out of the ore to extract the value.
The approach can be applied to run-of-mine (ROM) stockpiles (dump leach) or crushed and agglomerated ore stacked in multi-lift heaps. The physical description of a heap is a pad with impermeable liner on which the ore is stacked and then irrigated with acid solution, most commonly for copper, cobalt or uranium, a sulphuric acid medium is used.
At Sedgman we have considerable experience in the design of gold and copper processing plant equipment to prepare ore for optimal stacking and heap performance and for efficient, low-cost purification of the solution and recovery. Plants designed by in-house hydromet experts range from 3,000tpa demonstration plants to 60,000tpa copper cathode commercial production. Studies have been update taken for capacities >300tpa.
For gold bearing minerals, dilute alkaline cyanide solution might be used. The scale of a typical heap leach operations is large, <10Mta placed on the pad in successive layers or lifts than can reach >100m high in total, so the design of a heap has important geotechnical requirements. Occasionally for footprint minimisation, cycle time or hydraulic characteristic reasons, instead of a permanent heap, a dynamic pad (ore placed on/off) is designed. Spent ore or ripios can be treated and stored, still on a lined, engineered structure as run-off, termed acid rock (ARD) or mine drainage (AMD) is a concern with leaching.
Success in heap leaching requires percolation of solution through the stacked material thus ideal permeability and hydrodynamic properties of the ore, gangue minerals and/or clay content is critical. The "leach cycle" which may include rinse, drain down and neutralisation steps, takes from one or two months for simple oxide ores to two years for nickel laterite or primary copper sulphide ores. Sometimes copper containing sulphide ores require a bacterial, or bio-leach component. Generally, the leach response is enhanced at higher temperatures and with aeration. In specific cases the mineralogy of mineral bearing concentrates can be tank leached to produce an upgrade and purification of the target mineral in aqueous form from a slurry, and incorporate the aspects of increased temperature and sparging of air or oxygen to aid ultimate recovery and shorten the cycle time. In select cases the dissolving of target mineral into solution can take place in-situ by pumping weak acid or other lixiviants into the group though injection wells and collecting the enriched solution for processing, without mining the ore. In most cases, for base or industrial metals the downstream processes involve a solution purification step such as solvent extraction or ion exchange, followed by metal recovery or precipitation to an intermediate chemical state to produce a saleable product.
Benefits of leaching process route:
Environmental, Social and Governance
- Sustainable use of resources, through reduced energy use (not reliant on comminution), lower water consumption (compared to milling) and minimal greenhouse gas emissions
- Reduced carbon emissions footprint and costs from not shipping concentrate (containing ~10% water)
- Improved land, waste and supply chain management aids social license to operate and offers revenue from waste
- Leverage benefits of producing and marketing pure metal (London Metal Exchange grade (LME) grade cathode) direct to a customer and no smelter / refinery tolling charges, product rejection or penalties value generation.
- Capital intensity ~65% compared to mill /flotation route plus full quartile reduction in operating expense
- Ability to balance acid consumption and neutralisation requirements of different co-located processes.
Resource Optimisation / Asset Utilisation
- Integrate with existing capital and up-stream facilities having available capacity or reaching end-of-life
- Use of already disturbed / permitted sites
We combine the latest technologies with tested methodologies to support on-site operations. From continuous improvement initiatives to complex plant upgrades, we ensure maximum electrical availability of equipment:
- Electrical support
- Electrical audits
- Failure investigations and defect studies
- Problem investigations and solution implementation
Specialising in electrical and controls systems for mineral processing plants allows our teams to develop optimised solutions based on repeat project feedback and learning.
Civil and bulk earth works engineering
Sedgman is a leading provider of mineral processing and associated infrastructure solutions to the global resources industry. Delivering major infrastructure has been a key component of many of our projects undertaken for clients over the past 40 years.
Sedgman’s civil engineering group has a proven track record in the design and delivery of civil infrastructure projects, mine development, stormwater runoff and bulk earthworks - in brown and green field sites, commonly known as non-process infrastructure or NPI.
Our experienced civil engineering design team assists clients throughout each phase of works from the planning phase, with conceptual civil engineering design and management plans, through to the construction phase including site supervision and contract administration.
We pride ourselves on delivering superior outcomes in shorter timeframes thereby providing valuable cost and time savings.