Tag Archives: tailings thickening

Outotec looks for consistent and efficient dewatering with new paste thickener

Outotec has introduced the 2nd Generation Paste Thickener to, it says, maximise underflow density regardless of challenging mineralogy and tailings feed-rate variation.

The thickener enables consistent and efficient dewatering performance – even with changing process conditions, according to the company.

“Through consistent performance and high underflow density, the 2nd Generation Outotec Paste Thickener maximises beaching angle in the tailings storage facility to provide safer operations and maximised lifespan,” Outotec said.

The new paste thickener provides ease of operation and reliability for applications requiring a high degree of dewatering, such as minerals tailings, mine backfill, and pre-leach and counter current decantation circuits, according to the company. “The technology is customised to address each operation’s unique drivers, which can include environmental concerns, water recovery, regulatory requirements, tailings management, or limitations on available land space,” the company said.

Outotec has a history of developing paste thickeners, as well as the design and delivery of large-scale paste thickening projects. “This has given us a deep understanding of the key aspects of high-density thickeners, including effective flocculation, dewatering, raking, prevention of rotating mud beds, process control, and the discharge of thickened solids,” it said.

“One such case was the deployment of Outotec paste thickener technology – including a full-scale paste tailings plant and Outotec ACT Thickener Optimizer system – at Yara’s Siilinjärvi apatite mine in Finland (pictured),” Simon Courtenay, Product Manager for the Outotec 2nd Generation Paste Thickener, said. “The plant generates around 10 Mt of tailings a year and, thanks to the Outotec ACT Thickener Optimizer, the paste thickeners can consistently run with a high and stable underflow solids content of 66-68%, regardless of challenging mineralogy and tailings feed-rate variation. This results in average beach slope angles of 3.5° (6.1%) in the tailings disposal area, helping to extend its lifespan. The system has also enabled a 10-20% reduction in flocculant costs.”

The new 2nd Generation Paste Thickener builds on this proven performance with a range of innovative new features, according to the company. For example, vertical load monitoring with the Smart Rake Lift system means the Outotec Paste Thickener is one of the only systems in the world that can detect early formation of rotating beds, enabling counteractions to be taken early, Outotec said.

The system also monitors and actively adjusts the individual hydraulic cylinders to maintain alignment of the rake mechanism. Incorporating vertical load sensing with plant process data in the Outotec ACT Thickener Optimizer control system means the solids inventory within the tank can be maintained to ensure a consistent underflow density, stable process, and improved overall thickener performance, according to the company.

In addition to mechanical improvements, process control has been further developed to stabilise and optimise the performance of the paste thickener, Outotec said.

The company said: “Outotec’s ACT Thickener Optimizer utilises a multivariable controller to manage process changes and the associated delays in the response time of the thickener that can be challenging for traditional control systems. It can also be configured to manage the effects of variable feed types to ensure optimum performance despite changing inputs to the process. Short installation and configuration time of the system is coupled with on-going services to ensure a practical yet flexible long term control solution.

“Our application-specific design of the thickener begins with the use of methods such as discrete element modelling to understand solid particle movement within the thickener, computational fluid dynamics for feed system design and finite element analysis for structural steel design. Our paste thickening solutions are also designed with ease of maintenance in mind, with a skid-mounted hydraulic power unit for centralised connection of hydraulic hosing from the rake lift cylinders and drive unit.”

Other key design features include:

  • Low profile rakes with tie-cable load sharing that minimise rake drive torque requirements;
  • Rake blades supported by thixoposts to move the rake arm away from the highest density thickened solids;
  • High sidewall and steep tank floor slope for more efficient dewatering of flocculated solids and compaction of the bed, as well as better transport of the solids inward toward the tank discharge point;
  • High installed drive torque to move the rake blades through beds of thickened solids with high yield stress and viscosity, and;
  • Feed systems with break tanks when required for different thickener feed situations, including our patented Vane Feedwell, and break tanks inside the thickener perimeter to save on site layout space.

“Beyond technology and equipment, Outotec provides complete solutions for thickening needs,” the company said. “Proven design features and process guarantees, combined with lifecycle service support, help ensure operational reliability. We can also support customers with ongoing operation and maintenance services after plant commissioning.”

IntelliSense.io creates AI algorithm to predict thickener performance

A UK-based startup says it has devised a machine learning-algorithm that can help mining companies predict how thickeners will operate an hour into the future.

IntelliSense.io, which has been helped along the way by Digital Catapult (an agency for the early adoption of advanced digital technologies) and the UK’s Department for International Trade, said it wanted to help the mining industry become more efficient and sustainable by harnessing the power of artificial intelligence.

“Traditional operations technology cannot handle dynamic conditions, so IntelliSense.io is focused on using advanced digital technologies to create a platform that can predict varying conditions and is, therefore, far more responsive to change,” it said.

This led the company to develop an application to control thickeners in mining operations, which, IntelliSense.io says, would provide three key benefits:

  • Less water would be needed to complete the thickening process;
  • More water could be recycled, resulting in less wastewater;
  • Reduced power would be consumed as less water would be pumped into the thickener.

To create an algorithm, IntelliSense.io needed to analyse three years’ worth of data from six thickeners, each measuring roughly 800 different metrics collected every minute.

“This represents a volume of data that would only be possible with a significant amount of computer power and specialist expertise,” the company said. This led to IntelliSense.io applying to join Machine Intelligence Garage, Digital Catapult’s AI programme that helps businesses access the computation power and expertise they need to develop and build machine learning and artificial intelligence solutions.

Thanks to this assistance, IntelliSense.io has devised an AI tool that ingests these 800 different metrics every minute and can, according to the company, “predict how thickeners will operate an hour in the future”.

“This invaluable knowledge will make mining more efficient and sustainable, and provides optimum operating condition recommendations to maximise output,” the company said.

The thickener algorithm has since been applied in an optimisation stability project at a gold-copper mine in Chile where the miner in question had seen low underflow percentage solids and water recovery, and high flocculant consumption.

The implementation of the IntelliSense.io Thickener Circuit Optimisation application at the mine, which integrated data from SCADA and other control systems with advanced statistical data modelling and machine learning algorithms and first principle models, came up with a solution.

This has seen, among other benefits, decreased variability in the thickener circuit operation, enhanced water recovery at the thickener circuit and reduced equipment downtime due to stricter torque constraints.

The payback period has been less than 12 months with projected direct savings calculated at $400,000 in the first year alone, according to IntelliSense.io.

The company has also signed a memorandum of cooperation with JSC AK Altynalmas, a gold producer in Kazakhstan. This involves the development of an AI system for predictive analysis and optimisation of the grinding process, according to IntelliSense.io.

This agreement is part of a wider pact around the implementation of industry 4.0, IntelliSense.io says.

Iluka Resources bolts on second SciDev OptiFlox trial in Australia

ASX-listed SciDev Ltd is to add a chemical products trial to the commercial OptiFlox® System test it is due to carry out in the December quarter at one of Iluka Resources’ Australia mineral sands operations.

The two-week trial of the chemical products will run concurrently with the OptiFlox System testing, the latter of which was announced earlier this month and aims to optimise water recovery, consumable usage and improve tailings deposition in the tailings thickener section of the operation over a matter of months.

“Pending success of both the chemical trial and the associated OptiFlox system trial, SciDev will seek to progress discussions with Iluka in respect of an ongoing chemical sales contract,” the company said.

OptiFlox comprises an extensive range of chemicals and the company’s patent-pending technology. Its range of polymers is specifically tailored for the treatment of process water and wastewater in mining and minerals, “recovering valuable mineral resources more efficiently, while minimising losses in productivity and revenue caused by inadequate wastewater clarification in tailings thickeners”, SciDev says.

In addition to this mineral sands trial win, SciDev has been given six months to trial its technology at Peabody Energy’s North Goonyella coking coal mine in Queensland, Australia, and the company was recently contracted by the coal miner to supply its coagulant product to one of its US operations.

SciDev to install OptiFlox system in Australia mineral sands operation

SciDev has added mineral sands to its growing list of OptiFlox® industry users after an Australia operation signed up for a multi-month commercial trial.

The system will be installed at the tailings thickener at the operation in the December quarter, according to SciDev.

This is the second multi-month trial the company has received in the past few months. In July, Peabody Energy signed up for a six-month test to improve water efficiency, productivity and operating costs at the tailings thickener section of the North Goonyella coking coal mine in Queensland, Australia.

SciDev said the award of the mineral sands trial followed extensive on-site technical evaluations by the company’s personnel.

The trial aims to optimise water recovery, consumable usage, reduce operational engagement and provide operational insights from the generation and analysis of process data, SciDev said, adding that a successful trial “may result in a long-term contract”.

The OptiFlox range of polymers is specifically tailored for the treatment of process water and wastewater in mining and minerals. It aims to recover valuable mineral resources more efficiently, while minimising losses in productivity and revenue caused by inadequate wastewater clarification in tailings thickeners.

This is the fifth OptiFlox installation in Australia across four industries: thermal coal extraction, dairy manufacturing, coking coal extraction and mineral sands production.