At an elevation of 4,200 meters, expectations are high

In July 2015, Compañía Minera Antapaccay S.A.—a Peruvian mining operation—awarded FLSmidth a contract to supply and install a new flotation line. The objective was to increase their plant production from 77,000 to 85,000 tpd of sulfide ore. Completed in July 2016, the added flotation capacity will enable Antapaccay to produce an additional 7% of copper content per year.

FLSmidth already holds a strong and long-standing relationship with the site personnel at Antapaccay, since we were a key supplier to this important customer during the construction of the original project in 2011. At that time, FLSmidth provided most of the plant equipment including a gyratory crusher, SAG and ball mills, grinding cyclones and flotation cells. 

This latest project was developed under an EPC concept for providing a flotation equipment island, made up of five Dorr-Oliver® 300 m3 flotation cells, and included plant engineering (basic and detailed), procurement, construction, commissioning startup, training and operational support services.

Organizing the flotation project
Since most of the information used to prepare the proposal was only preliminary, it was decided to approach the contract in two modes: lump sum, for the flotation cells and related equipment supply; and cost plus, for the peripheral equipment and structures, as well as for the electrical, instrumentation and automation scope.

The project would also be managed on a fast track, working simultaneously on engineering, procurement and construction, to achieve the ambitious start-up date.

Due to the conditions explained above and as per contract, our customer was able to add, whenever they considered necessary, additional equipment supply and field work to FLSmidth's scope, in order to meet project requirements.

Taking this into consideration, FLSmidth was in a position to be able to extend the project delivery date every time a change request was received from the customer. Nevertheless, understanding the urgency for bringing an additional copper production line into operation quickly, and the impact on expectations that the changes had on both sides, a very close collaboration was needed between all parties. This meant not only coordinating with our customer, but also between all involved FLSmidth entities—local and global management, and product engineering teams. Working so closely ensured efficient release of information, quicker approvals and a more productive workflow.

THE FIVE FLSMIDTH 300 CUBIC METER CELLS ARE INSTALLED WITH NEXTSTEP™ ROTOR/STATORS FOR OPTIMAL EFFICIENCY

THE FIVE FLSMIDTH 300 CUBIC METER CELLS ARE INSTALLED WITH NEXTSTEP™ ROTOR/STATORS FOR OPTIMAL EFFICIENCY

Remaining flexible to handle any situation
Internally, the project was not exempt of unexpected situations. During the engineering stage, the detail portion was developed by our engineers located in Chennai, India. But in early December 2015, torrential rains—the worst in a century—hit the city, forcing the Chennai office to close for a week. With this, the information required to move forward with many of the procurement and erection activities was impacted. Fortunately, many well-thought-out decisions and responsive actions by our global management team mitigated the potential damage and allowed activities to be recovered in a shorter period.

The Antapaccay copper plant sits at an elevation of 4,200 meters and is located 250 miles southwest of Cusco, Peru. The complex geographic situation often exposed the project to severe weather conditions, which could place the work progress in jeopardy, as well as delay scheduled milestones. With the rainy season taking place between November 2015 and March 2016, civil works had singular importance, because they would have to be executed within schedule in order to avoid a major impact on outdoor activities. This entailed no drawings-release delays, as well as a more effective and progressive materials procurement process.

Included in Antapaccay’s health, safety and environmental (HSE) policies are—understandably—very demanding safety requirements. Adherence to these standards became even more important when considering the location, season and extreme weather mentioned previously. Outstanding HSE supervision and coordination with our customer and contractors allowed the project to accumulate 250,000 man hours with no major injuries or accidents during the whole project.

Delivering in full, and on time
Since many of the deliverables were estimated and not accurately defined during the bidding process, it was found in some cases that differences existed in the budget calculations due to updated customer requirements. 

A clear example is the electrical house. The real supply practically doubled the initial budget. Here’s where close and effective coordination with the customer enabled an acceleration of the specifications and scope definition. By compressing the time, the team prioritized items with the longest delivery lead time, and accomplished receiving everything onsite for the system integration within deadlines, thus reducing unnecessary costs. 

Once mechanical and electrical were completed, the timeline for the next two stages—pre-commissioning and commissioning—was critical to guarantee a smooth and proper plant start-up and the related ramp-up stage; as well as to mitigate damage risks in the installed mechanisms and peripheral equipment during operation. Because everything was well planned, no additional shutdowns were required for the new line's tie-ins.

LOOKING OVER THE NEW 300 CUBIC METER FLOTATION ISLAND AT ANTAPACCAY

LOOKING OVER THE NEW 300 CUBIC METER FLOTATION ISLAND AT ANTAPACCAY

Successful start-up
After completing the minimum required conditions during the commissioning process to have the new flotation line working, the plant started operations on July 16, 2016—only one year since the contract was awarded and within the defined schedule.

Although a number of other locations include FLSmidth’s 300 m3 Dorr-Oliver flotation cells, Antapaccay’s newly installed 300-series cells are the very first to be operated with our nextSTEP™ rotor/stators. Including this patented technology allows our analysts to measure metallurgical and power performance at 4,200 meters above sea level, and compare those results with the 250 m3 WEMCO® cells installed in the first and second rows of the concentrator.

The flotation machines were commissioned by our Peruvian staff, and the equipment is operating to everyone’s satisfaction. FLSmidth process staff performed outstanding labor, continuing to tune and adjust the equipment parameters during the week following commissioning. During that same period, the operators at Antapaccay were able to begin the ramp-up stage, bringing flotation line operations to the nominal expected value.

Effective and coordinated teamwork within FLSmidth’s many project, service and engineering teams, as well as close collaboration with the customer, enabled the project to run at a very consistent pace and comply with high standards of safety and quality, all while keeping everyone focused on meeting the challenging completion date. 

To celebrate the success of the project, management of Antapaccay hosted a ribbon-cutting ceremony on August 9, 2016. 

The FLSmidth Peruvian team continues to perform an active role in the plant’s operation, participating in improvement projects within the plant, servicing and maintaining equipment and supplying spares from the FLSmidth Supercenter in Arequipa.  

CONTACT: Jesús Cabrera