1 OUTOTEC CUSTOMER eNEWSLETTER Editor: Laura White, [email protected]SOUTH EAST ASIA PACIFIC CONTENTS • Case study - Yara paste plant, page 1 • Mill maintenance - 3 simple ways, page 3 • Holiday closure and business news, page 6 • Concentrate burner - maintenance, page 8 • Handy download tools, page 10 3/2017 The paste tailings plant delivered by Outotec as an EPC project to Yara’s phosphate mine, increases tailings solids content, improves tailings beaching properties and extends the capacity and lifetime of the existing tailings storage facility. Yara International ASA is a Norwegian fertilizer company. Its largest business area is the production of nitrogen fertilizer. Yara Siilinjärvi site in the Eastern Province of Finland consists of a phosphate mine, two sulphuric acid plants, one phosphoric acid plant, one nitric acid plant and one NPK-fertilizer plant. The mine together with the phosphoric acid plant supplies the phosphorus raw material to the NPK fertilizer plants and feed phosphate plant in Finland. Annually the mine produces about one million tonnes of apatite concentrate, and about ten million tons of tailings. Background to the project In 2015, Yara´s tailings area was filling up and was close to its end of life capacity. Teija Kankaanpää, Head of Siilinjärvi Mine had three options: build a new tailings storage facility, raise the dams, or invest in new technology that would allow the use of the old tailings storage facility for years to come. Not wanting to go the route of creating a new tailings pond and expanding the footprint of the facility, Teija decided to turn to a trusted partner. Thickening of the Yara Siilinjärvi tailings was first studied in the 1980s. At the time, the technology to process EUROPE’S LARGEST PASTE PLANT EXTENDS LIFESPAN OF YARA’S TAILINGS STORAGE FACILITY tailings and achieve a two-degree or more beach angle at the tailings discharge was not yet available. The challenge was the unique properties of the tailings material. The material is coarse, but also contains a high proportion of mica and a fine fraction, which is difficult to aggregate with the coarse particles using flocculation. The material settles and consolidates rapidly to form a highly structured material at a high density and yield stress. This creates problems in mixing tanks, thickeners, pumps and pipelines, and causes blockages if the material segregates and consolidates. In 2010, Outotec worked with Yara for a thickened tailings project at the Siilinjärvi site. The work included initial test work and sizing for two 35-meter high compression thickeners. Based on the test work, Yara commissioned Outotec to build a demonstration plant with a 14-meter thickener. The plant was in operation in 2013-2014. During its operation the design criteria for the full-scale thickener plant and discharge system was established. In 2015, Yara awarded Outotec with the €40 million contract for the full-scale paste thickening plant as an Engineering, Procurement and Construction (EPC) project. “There are few companies in the world that can supply this kind of technology that we were looking for, and who had also track record in supplying this kind of plants,” said Teija. “We chose Outotec because they have good technology, and they were willing to offer us an EPC contract.”
The paste tailings plant delivered by Outotec as an EPC project to Yara’s phosphate mine, increases tailings solids content, improves tailings beaching properties and extends the capacity and lifetime of the existing tailings storage facility.
Yara International ASA is a Norwegian fertilizer company. Its largest business area is the production of nitrogen fertilizer. Yara Siilinjärvi site in the Eastern Province of Finland consists of a phosphate mine, two sulphuric acid plants, one phosphoric acid plant, one nitric acid plant and one NPK-fertilizer plant. The mine together with the phosphoric acid plant supplies the phosphorus raw material to the NPK fertilizer plants and feed phosphate plant in Finland. Annually the mine produces about one million tonnes of apatite concentrate, and about ten million tons of tailings.
Background to the projectIn 2015, Yara´s tailings area was filling up and was close to its end of life capacity. Teija Kankaanpää, Head of Siilinjärvi Mine had three options: build a new tailings storage facility, raise the dams, or invest in new technology that would allow the use of the old tailings storage facility for years to come. Not wanting to go the route of creating a new tailings pond and expanding the footprint of the facility, Teija decided to turn to a trusted partner.
Thickening of the Yara Siilinjärvi tailings was first studied in the 1980s. At the time, the technology to process
EUROPE’S LARGEST PASTE PLANT EXTENDS LIFESPAN OF YARA’S TAILINGS STORAGE FACILITY
tailings and achieve a two-degree or more beach angle at the tailings discharge was not yet available. The challenge was the unique properties of the tailings material. The material is coarse, but also contains a high proportion of mica and a fine fraction, which is difficult to aggregate with the coarse particles using flocculation. The material settles and consolidates rapidly to form a highly structured material at a high density and yield stress. This creates problems in mixing tanks, thickeners, pumps and pipelines, and causes blockages if the material segregates and consolidates.
In 2010, Outotec worked with Yara for a thickened tailings project at the Siilinjärvi site. The work included initial test work and sizing for two 35-meter high compression thickeners. Based on the test work, Yara commissioned Outotec to build a demonstration plant with a 14-meter thickener. The plant was in operation in 2013-2014. During its operation the design criteria for the full-scale thickener plant and discharge system was established. In 2015, Yara awarded Outotec with the €40 million contract for the full-scale paste thickening plant as an Engineering, Procurement and Construction (EPC) project. “There are few companies in the world that can supply this kind of technology that we were looking for, and who had also track record in supplying this kind of plants,” said Teija. “We chose Outotec because they have good technology, and they were willing to offer us an EPC contract.”
In 2017, the paste plant with two 30-meter paste thickeners went through water testing in freezing minus 25 degrees Celsius (-13 degrees Fahrenheit) weather. The performance test passed within one month of the start-up, and the plant has been in operation since February 2017.
Project scopeThe scope of the EPC project included basic and detailed engineering, project management, procurement, construction and civil works for the foundation and buildings, installation of piping and equipment, site management, training, commissioning, start-up and the performance test. Outotec´s proprietary equipment included two 30-meter paste thickeners, OKTOP slurry tank and flocculant-dosing unit. The third party equipment and services included positive displacement pumps, building and piping materials, auxiliary mechanical equipment, construction and installation work.
Outotec paste thickeners• Diameter 30 m and height 26 m• Feed 45-48% w/w solids; slurry flow 1720 m3/h• Underflow 68-70% w/w solids; slurry flow 940 m3/h• Overflow to water ponds; flow 810 m3/h
Thickener developments have been important part of the successful operationWhile paste thickening is not new, it still comes with challenges and risks, especially with material behaviour as seen with the Siilinjärvi tailings. Through the piloting work and with new developments in Outotec Paste Thickener mechanism design and control systems, solutions to these challenges have been realised. The combined results deliver reliable and predictable performance for paste thickener applications.
Co-operative approach delivers resultsThe new, high-density tailings disposal system is able to increase the overall percentage of solids in the slurry, which has a significant impact on how it can be stored. In fact, projections suggest a potential beach angle of four degrees, meaning the material is so thick that it forms piles.
Higher-density tailings also minimizes chances of leaks and seepage from the storage area, improving safety. Meanwhile, reclaimed water is returned to the process, reducing overall costs and waste.
The project brought with it plenty of challenges that Outotec and Yara had to overcome. As Teija puts it: “We have had some tough times during this project, which is happening in all projects. Nothing new in that one, but we were able to solve even the difficult problems in co-operative way. I have to give credit also to Outotec’s good safety performance and safety attitude during the project.”
She continues: “The meaning of this project is that Siilinjärvi mine can continue operation until the end of its lifetime, which is today 2035. For the Siilinjärvi town it means that there are around 800 jobs still existing here for the years to come.”
One of Outotec’s two 30m paste thickeners on site. Projections suggest a potential beach angle of four degrees, meaning the material is so thick that it forms piles.
MILL MAINTENANCE - 3 SIMPLE WAYS TO KEEP YOUR MILL AT ITS BESTWith the grinding mill critical to a plant’s throughput, it pays to ensure mills receive the necessary care and main-tenance. Too often mill maintenance is reactive, occur-ring due to a breakdown. The result is higher repair costs as resources are rushed to site, as well as site mainte-nance staff under unnecessary stress, battling to get the mill operational again.
In an ideal world, mill maintenance would only ever take place over planned shutdowns. Whilst this ideal may never be achieved, with good planning, you can identify potential problems early, saving thousands of dollars and wasted hours in the process. Here are three simple ways to keep your mill operating at its best.
Step 1 - keep your mill cleanThis may sound obvious – but a fundamental part of mill care is cleaning the mill – and this step is often neglected. If a mill is kept clean, then ‘leaks and creaks’ (such as grease leaking from bearing seals) will be identified earlier, cost less to repair, and fixed before major equipment failure.
A faulty bearing seal, when identified early, can be quick and inexpensive when compared to a complete bearing overhaul from a significant bearing failure. Weeping from shell flanges, hard to identify unless the mill is clean, is a critical indicator in diagnosing loss of fastener tension or failure issues. In addition, damage to equipment,
protective coatings and cracking of grout will be more visible. Early repair can prevent more extensive damage.
P.S “clean” is not just a hose down!However straightforward cleaning a mill may sound, it is not as simple as hosing equipment down periodically. Hosing down a hot casting may cause it to crack, or shrink it onto its contained bearing, reducing the bearing clearance and spinning the bearing on the shaft. A thoughtlessly directed high-pressure-spray could lead to water ingress behind a bearing seal, causing premature bearing failure.
It is important, therefore, to ensure that staff are trained and competent for the cleaning task. This is where it definitely pays to consult with your mill supplier, who should be able to talk you through important steps and offer useful hints and tips. So, in summary,
1. Clean the mill regularly2. Do not clean hot components (especially castings)3. Do not clean seals with water sprays or jets4. Ensure staff are trained5. Get advice from the mill supplier
Step 2 - inspect your mill regularlyAfter ensuring that the mill is kept clean, the next logical step is to inspect it regularly, ensuring early detection of any leaks or damage.
Most mill control panels show sensor readings from mill critical parts, and this can be reliably used to inspect these parts during operation.
Some areas, such as gear tooth temperatures and gearbox bearing vibrations, may need specialist instruments to take readings, whilst other parts will simply need visual inspections (e.g. leaks from seals). Some inspections will not be possible during operation, so scheduling minor shutdowns to inspect areas like the ring gears, bearings and shaft alignments might be necessary.
Step 3 - keep regular records on your millMost mill control panels will show transducer readouts from various inspection points, and even give alarms at ‘high’ and ‘low’ warning set points before the mill is tripped on ‘high-high’ or ‘low-low’ alarm settings. This is a useful function to protect the mill, but the ‘high’ and ‘low’ alarms are reactive, rather than proactive, and sometimes can only warn of the inevitable. The monitoring process is therefore paramount to identify trends of any developing problems. Good monitoring will include: being methodical with inspections, keeping good records of inspections and tracking records and values over time.
Perhaps the best way to demonstrate this is with an example... Suppose the oil temperature for the mill bearings was slowly and steadily increasing, but had not yet tripped a high alarm. Following further investigation in the oil tank heaters and oil cooling system, the only irregularity was with the cooling water on the discharge of the heat exchanger which was steadily lowering in temperature. This would indicate that the source of the oil temperature increase is probably due to the heat exchanger, and this could be flagged for close monitoring until a detailed inspection at the next shutdown.
How to plan for your maintenance shutdownWhen planning maintenance shutdowns, first identify outstanding maintenance and inspection tasks. These will include regular tasks (shaft alignments, journal inspections, fastener tensioning, slip ring chamber cleaning, inch brake adjustments, etc) with various ad hoc tasks flagged from inspections and monitoring.
These tasks should then be grouped on their importance (low, medium, critical) to the continued mill operation and used to prioritise objectives, balancing this with the usual budgetary and time constraints. All too often a mill
A spare pinion - ready for stripping and rebuilding
Before - seals with excessive contamination After - seals cleaned
shutdown is extended through one task taking more time and resources than expected, but if properly understood, non-critical tasks can be postponed until a later shutdown, or critical tasks assigned more resources.
Once the maintenance tasks, man-hours and resources are planned, then you need to identify and secure specialist tools and equipment, personnel and additional manpower, and spare parts for repairs. The plan should also consider unnecessary conflicts. For example, some tasks require the mill to be inched periodically. Unless completely unavoidable, it is not good planning to schedule high voltage motor inspections at the same time (unless the coupling has been disconnected) as the motor shafts will rotate during inching. Your mill supplier can be key in such a planning process as they are aware of issues such as interrelated tasks, which deliver best results when completed in sequence, and the required resources for each.
Successful maintenance shutdownsApart from operational errors, an unscheduled mill stop represents a failure of the last planned maintenance shutdown. A successful mill shutdown should not just be measured by the usual ‘on time, on budget’, but also by how long the mill operated continuously after the previous shutdown. This is where mill maintenance requires an intimate knowledge of the workings of your mill, through a planned care, inspection and monitoring programme.
The mill is one of the more complex pieces of process equipment and, as such, it will always pay to involve industry expertise in the inspecting, planning and execution of mill maintenance. Outotec’s mill service team, for example, offers services including shutdown assistance, pre-shutdown inspections, training and information on current best practices.
HOLIDAY CLOSURE INFORMATIONIn preparation for this year’s holiday period, Outotec’s Australian offices will be closed from Friday December 22, 2017 and re-open Tuesday January 2, 2018.
We at Outotec would like to encourage you to review critical maintenance and spare parts holdings to ensure your required parts are delivered on site in time to support your requirements.
During our holiday closure period, please use the following numbers to reach our Services teams.
Contact field and site services team +61 8 9211 2449/+61 427 877 [email protected]
GOLD PROCESSING TECHNOLOGY TO FRUTA DEL NORTE IN ECUADOROutotec has been awarded an order for the delivery of minerals processing technology packages by Lundin Gold for their greenfield project Fruta Del Norte in Ecuador.
Ecuador, until recently only known by its oil resources, is quickly gaining ground as a mining investment destination in Latin America thanks to significant gold and copper resources. Fruta del Norte, property of Lundin Gold, is one of the world’s largest, highest grade undeveloped gold deposits, with reserves estimated at about 4.8 million ounces of gold and 6.3 million ounces of silver. Fruta Del Norte is expected to produce approximately 325,000 ounces of gold a year over a 15-year mine life.
Outotec’s scope includes process engineering and the delivery of grinding mills, flotation, thickening and filtration tech-nology packages. The deliveries will take place before the end of 2018.
More information is available here....
ZINC ELECTROWINNING TECHNOLOGY TO ZGH BOLESLAW IN POLANDOutotec has been awarded a contract by ZGH Boleslaw for the delivery of electrowinning technology to a zinc plant modernization in Bukowno, Poland.
ZGH Boleslaw is going to build a new zinc electrowinning plant to replace the existing one. Outotec’s scope includes engineering and delivery of the main equipment, such as two stripping machines, anode washing and flattening machine and two electrode handling cranes, process control and advanced monitoring system, as well as 96 electrolytic cells. The stripping machines will be Outotec’s first delivery of a new robotic machine. The new cellhouse will have an annual production capacity of 100,000 tonnes zinc and later even 120,000 tonnes. Over half of the zinc will be produced from recycled materials. Outotec’s deliveries will take place in the second half of 2018.
More information is available here....
MINERALS PROCESSING EQUIPMENT TO AUSTRALIAOutotec has been awarded orders for the delivery of process equipment for a greenfield copper concentrator in Australia.
Outotec’s scope of delivery includes semi-autogenous (SAG) and ball mills, HIGmill® high intensity grinding mill, flotation cells, sampler and automation technology, plus thickeners for concentrate and tailings treatment. The deliveries will take place during 2018.
More information is available here....
MINERALS PROCESSING EQUIPMENT TO CHILEOutotec has been awarded orders for the delivery of process equipment for a copper concentrator expansion in Chile.
Outotec’s scope of delivery includes two HIGmill® high intensity grinding mills and thickeners for concentrate as well as for tailings treatment. In addition, Outotec will provide engineering, spare parts and installation supervision services for the delivered equipment. The deliveries will take place by the end of 2018.
CONCENTRATE BURNER - REDUCE MANUAL MAINTENANCE WITH FLASHGUARDThe alignment of the concentrate or matte burner is known to have a great effect on the overall efficiency of the Flash Smelting or Flash Converting process. If the process air distribution is not optimal, the furnace campaign times can also be noticeably shorter. A misaligned burner can result in increased weak acid production as well, as was learned at the Atlantic Copper Huelva smelter after the 2011 shutdown (refer to Figure 19 in 13th Flash Conference Article “A Review of recent improvements to control weak acid production at the Huelva smelter) . Before the introduction of the Outotec® FlashGuard a few years ago, measuring the alignment required quite a bit of manual work using the chain & ball tool, results of which might vary based on the user as well.
Our first generation FlashGuard enabled the online measurement of the burner’s alignment with the help of digital cameras and sophisticated machine vision algorithms. Now the second generation of the Outotec FlashGuard has been further developed based on customer feedback and experiences. In this latest design the cameras are easier to retrofit to the air chamber without modifications to the air chamber’s roof as the camera boxes can be installed on the existing air chamber inspection windows.
Additionally adjusting the cameras during commissioning and maintenance is now easier and the cameras are updated to higher resolution models, which can withstand higher operating temperatures.
The estimates of the current buildup conditions on the visible surfaces are also provided by the system. The results are calculated as easy to understand percentage KPI’s as “alignment efficiency” and “buildup prevention efficiency”. These results are available through OPC for the client for further use and analysis.
Still the single feature we’re most enthusiastic about is the new optional automatic concentrate or matte burner alignment system (patent pending), which removes the need for traditional “measure, adjust, re-measure, re-adjust” - workflow and hence significantly reduces the manual work and downtime required for the task and aligns the results by removing the human aspects. The alignment and buildup measurements from the FlashGuard system are automatically utilized in the alignment control of the burner so that the burner is always properly aligned to the center of the guiding cone so that the process air flow to the reaction shaft is as even as possible. The arrangement with three servo motors adjusting the alignment of the burner based on the FlashGuard measurements is illustrated in the pictures.
Like the FlashGuard system’s cameras, the new burner alignment option is straightforward to retrofit into an existing Outotec concentrate or matte burner: only the flexible bellow together with the servo motors is required. The existing flexible bellow is simply replaced with the servo equipped flexible bellow - this way the system can be preinstalled on the spare CJD in the workshop and taken into use during a CJD changeover.
Close-up of the FlashGuard camera box installed on an existing inspection window. In this example servomotors are used to adjust the concentrate burner’s alignment. Adjacent manual screws as a backup adjustment and as mechanical limiters
The efficiency of your process equipment is a critical factor in maximizing your operational profitability. See how our tailored modernization packages bring measurable value across three key areas of flotation (product recovery, plant availability and operational costs).
To download flotation modernization guidebook click here
HANDY TOOLS AVAILABLE TO DOWNLOAD!
SMELTING CATALOG
Learn how Outotec technologies and services can help you in non-ferrous processes.
To download smelting catalog click here
FLOTATION VALUE CALCULATOR
Evaluating your flotation circuit modernization is now a lot easier thanks to our value calculators! We have two handy calculators, the FloatForce calculator (to review potential benefits from upgrading your float mechanisms) and the TankCell calculator (replacing your flotation cells).
Simply input your parameters (ie process specs, utilization, prices and costs etc) to discover potential economic and environmental benefits!
Here we discuss simple, effective modernization options for thickeners. Over a thickener’s life (often in excess of 20 years) much can change from its original design. Find out your options here..
