Consequently, when it comes to moving massive amounts of bulk material from Point A to Point B, C or beyond, mine operators— through necessity—are knowledgeable and demanding. However, it wouldn’t be unreasonable to argue that a large part of the mining industry’s reputation as expert material movers is due to its ability to choose from a vast array of products, services and techniques to accommodate almost any materials-handling (MH) site requirement.

A quick look at recent developments around this sector indicates that MH business is, if not brisk, at least encouraging, and the technology is moving ahead at a rate that closely parallels the expanding demands of major-league material movers such as miners and port operators.

Waiting for the BRICs to Arrive
The slumping global economy has slowed the rate of development of major mining projects, but business for MH equipment suppliers serving the industry generally has not suffered quite as drastically as other equipment sectors, although competition is fierce for the few large projects working their way through the pipeline. Major MH equipment vendors have been able to count on relatively steady income from their replacement- parts, rebuild/reman and other downstream service businesses while waiting for larger opportunities to materialize; but they remain, in most part, bullish on prospects for future MH business, particularly from potential mineral development and other heavy industrial activity in the BRIC nations.

For example, when commenting on receipt of a recent $47.6-million (€35-million) contract award for a coal-handling system from an Indian power utility, FLSmidth Group CEO Jørgen Huno Rasmussen said MH systems and products is the fastest growing segment of his company’s portfolio. In 2009, 37% of FLSmidth Minerals’ high-value orders booked were for MHrelated equipment and services, and 71% of group revenue was generated from business in emerging economies.

Recognizing the advantages of presenting “one face” to customers looking for integrated solutions to their MH requirements, the FLSmidth Minerals group company recently restructured its organization in this sector; its various MH-related businesses have been integrated into a single division encompassing a range of technologies for the mining and cement industries. The division now includes FLSmidth Koch/MVT (Germany) for port facilities, stockpiling and coking technology; FLSmidth RAHCO (Washington, USA) for mobile materials handling solutions; and FLSmidth Conveyor Engineering (Idaho, USA) for conveyor technology.

FLSmidth Minerals has scored some notable recent victories in the contract wars. In addition to the previously mentioned award from the Indian utility, in November 2009 it announced receipt of a contract from Chinese-owned Minera Chinalco Peru for equipment for its Toromocho copper mine in the Morococha mining district about 140 km east of Lima. Contract value, according to the company, is more than $30 million (€21.85 million), and calls for detailed engineering and design, as well as manufacture and delivery of equipment that includes two overland conveyors, seven in-plant conveyors and two belt feeders. The overland conveyor, described as one of the most complex systems of its type in the world, will be 5.2 km long and have 9 MW of installed power. The conveyor will have complex vertical and horizontal curves and can demand or regenerate power depending on loading conditions.

FLSmidth RAHCO, which provides service and equipment packages for heap leach stacking and reclaiming, overburden removal and stacking, tailings conveying and stacking and overland transport applications, is currently working on an innovative mobile conveyor-based overburden handling system now undergoing final commissioning at a large Australian mine. According to the company, two of these systems will eventually be installed at the site; they are similar in design and operation to overburden stripping/handling systems RAHCO has installed at surface operations elsewhere around the world, but include a number of new technologies. (E&MJ will report on this technology in the April issue.)

Sandvik, another major player in MH technology, hasn’t been sitting still, either. With 50% of its business now coming from the Southern hemisphere, it recently opened a new facility near Belo Horizonte, Brazil, which will primarily manufacture components for conveyor systems. It has introduced several new products in the MH sector, and followed up on delivery of a R300-million ($39.4-million) order for iron-ore stockyard equipment at Assmang’s iron ore operations in South Africa—including stackers, bucketwheel reclaimers and conveyors—by garnering another R120- million ($15.8-million) contract for another stacker and reclaimer to be installed as part of a mine expansion project there.

In November 2009, Sandvik signed an agreement with energy company RWE Power AG in the Netherlands for a turnkey materials-handling system. The SEK 650- million contract includes a complete materials- handling system for the Eemshaven power plant, comprising two grab-type ship unloaders, two stackers and three portal reclaimers, plus a 38-unit conveyor system capable of handling coal or biomass fuel.

Sandvik’s latest compact bucketwheel excavator weights 1,650 tons and is designed to move 12 million
bank cubic meters (15.7 million bank cubic yards) annually at a Hungarian lignite mine.

The 1,650-t compact BWE has a 28-m (92-ft) boom supporting a 12-m (40-ft) diameter wheel. The entire unit, including beltwagon, is designed to move 6,700 lm3/h (8,760 lyd3/h), for an annual capacity of 12 million bank m3 (15.7 million byd3).

The Aumund Group, primarily comprising Aumund Fördertechnik and Schade Lagertechnik GmbH in Germany and B&W Mechanical Handling Ltd. in the U.K., has seen recent ongoing success for its shiploading equipment in particular, with B&W selling MH systems to South American mining clients for loading and handling of copper and gold ore and copper concentrates.

B&W recently reported that, following years of successful operation of two of its Lancaster loaders at the Russian Port of Visotskiy, the customer recently installed and commissioned two more of these units. The Lancaster loader has been a part of B&W’s portfolio since 1986. Its primary function in the Russian application is as a hopper-fed, inclined-belt, stockpile loading machine but there are many other installations around the world where it is employed for loading smaller ships and river barges.

Port Visotskiy, located in the Leningrad region in Russia, is a major coal-export terminal. Run-of-mine coal arriving at the port by rail often contains significant amounts of tramp metal picked up during the mining operation, which must be removed before shipment. By combining the mobile loader with a permanent magnet system, the port believes it has found a method to solve this problem, according to B&W.

The systems run around the clock at a rate of 600 mt/h. To ensure the machines can operate reliably at winter temperatures dropping as low as –30°C, B&W fitted special oil heaters to the hydraulic power pack. Two sets of interchangeable hopper liners are supplied; steel for the summer and plastic to facilitate the loading of frozen coal in the winter. Material flow also is assisted by the inclusion of two external hopper-mounted vibrator motors. The 25-m-long boom has variable inclination from 10° to 30°.

Two new Lancaster loaders from Aumund Group’s B&W Mechanical Handling Ltd. in the U.K. were recently
commissioned to join two similar loaders in service at the Port Visotskiy coal terminal in Russia.

Taking Cover
Although the term “materials handling” typically invokes visions of bulk material flowing up, through or down various moving components, sometimes the requirement is for a more static—but no less important— solution. For example, following collapse of an ore-stockpile cover structure, Barrick's Zaldivar mine in northern Chile needed a large replacement dome—fast. Zaldivar is an open-pit, heap-leach copper mine located at an elevation of 3,300 m, approximately 1,400 km north of Santiago and 175 km southeast of the port city of Antofagasta.

The mine had to act quickly; local regulations don’t permit uncovered stockpiles of this type because of the risk of dust pollution and worker endangerment from fines in the material. Additionally, copper values would be lost in the dust carried on strong local winds.

The major issues in designing a new structure included the extreme altitude and the fact that much of the construction would take place during winter, posing special challenges. Dust from the stockpile itself presented another environmental hazard to workers. And, the new cover had to be built while the ore pile remained in operation, making it impossible to use temporary internal supports during the building process. The design would have to eliminate any issues arising from ore spillage off the conveyor onto the roof of the facility (the problem that had damaged the original structure), and the structure would also have to able to withstand the snow loads that occur in the high Andes (estimated pressures in the range of 3 kPa).

The mine contracted with SKMMinmetal, a global mining engineering company with a strong presence in Chile. SKM had previous successful experiences with metal domes and drew up specifications for a dome large enough to encompass the incoming conveyor and its discharge point to avoid any possibility of conveyed material damaging the cover. The structure itself was provided by Geometrica, an international firm that has designed, manufactured and installed domes and space frame structures since 1992. The company has developed unique technology to build long-span structures for industrial applications. Geometrica had previous experience with these types of domes in Chile, at Mantos Blancos, Escondida and Pucobre, for example.

The Geometrica system comprises structural and cladding components. The structure was assembled from prefabricated galvanized steel tubes joined together by slotted aluminum hubs. No welding was required because the connection between tubes and hubs is mechanical. Cladding consisted of corrugated galvanized sheet metal panels plus FRP panels to admit light to the interior. Other cladding components included galvanized ridge caps, rain gutters and skirt flashings.

The dome structure was erected by Zaldivar's crews under the guidance of two Geometrica technical consultants, one for structure and one for cladding. The geometry of the Geometrica dome is inherently strong even before construction is complete, which proved critical: At one point an earthquake interrupted installation of the cladding, but resulted in no damages or injuries.

The dome was built without having to interrupt mine operations, with the entire process completed in 149 days. Vital statistics include a covered area of 12,155 m2, a base diameter of 95 m and height from base to dome apex of, 40.22 m. Total weight of dome structural elements is 210 mt, with cladding adding another 80 mt. The dome required 34,000 structural tubes and 10,000 connectors.

 
TShown here is the start of construction (left) on a 95-m-base diameter ore storage dome at Barrick’s Zaldivar mine in Chile, and the completed dome (right).
Assembly of the dome, designed by Geometrica, required no welding; all connections for its 34,000 structural tubing components are mechanical..