The year of peak construction activity at Oyu Tolgoi mine in the Gobi desert of Mongolia (IM April and May issues this year) is nearing its end, with the project approximately three-quarters complete. A great deal has been accomplished this year, and over the last ten years since the first discoveries were made by Ivanhoe at Oyu Tolgoi. 2012 will see the start of first copper-gold-silver production at Oyu Tolgoi. The mine is to be a combined open pit and underground operation. It lies in Khanbogd sum within the south Gobi Desert, approximately 235 km east of the Ömnögovi Province capital Dalanzadgad.

The project is the largest financial undertaking in Mongolia’s history and is expected upon completion to account for more than 30% of the country’s gross domestic product. Copper production is expected to reach 450,000 t/y.

Here are a few highlights from 2011’s last week of construction (pictures can be found on the Ivanhoe website:
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Headframe construction and shaft sinking continued at Shaft #2, which will be the first production shaft from the Hugo Dummett underground mine

• Ongoing pre-stripping of the Southern Oyu open-pit mine
• Completion of the roof framing for the coarse-ore storage building and ongoing installation of roof panels and exterior siding
• Installation of ore-processing components in the concentrator complex.

Outotec has developed a two-stage partial roasting process to remove impurities - such as arsenic, antimony and carbon - from copper and gold concentrates as a pre-treatment to actual extraction processes. It has also established a new continuous pilot plant at the company’s research center in Frankfurt, Germany to test customers’ concentrates with the new process. During the tests it is possible to collect reliable and necessary data for industrial process scale-up. Depending on concentrate composition and plant capacity, the process can either be run in a stationary fluidised bed or in a circulating fluidised bed.

“This new process complements our portfolio of sustainable technologies for the minerals and metals industry. With Outotec roasting technology the harmful elements can be removed in environmentally sustainable way. We are currently building the world’s largest arsenic-removing roasting furnace at Codelco’s Mina Ministro Hales mine in Chile, where the new partial roasting process will be used. More than 90% of the arsenic contained in the concentrate can be removed to produce clean copper calcine”, says Outotec CEO Pertti Korhonen.

The partial roasting process for copper concentrates is a single-stage roasting process. The impurities are volatilised and the process produces calcine, which is rich in copper sulphide but has a low impurity content. The calcine is mixed and can be further processed in copper smelters. The partial roasting process is also combined with post-combustion of process gas to convert all volatile compounds into oxides.

The roasting process for refractory gold concentrates contaminated with arsenic and carbon is a two-stage process. Arsenic is removed in the first roasting stage while carbon and remaining sulphur are removed in the second stage. All sulfur, iron and carbon are fully oxidised in the process and calcine suitable for actual gold leaching is produced.

Britain’s coal producers have tabled a five-point plan that they say “will give the nation’s electricity users cheaper, reliable and sustainable power supplies whilst safeguarding jobs, stimulating investment and reducing energy imports.” The Confederation of UK Coal Producers (CoalPro) says current Government White Paper plans for decarbonised electricity “catastrophically fail the affordability test, fail the low carbon test and comprehensively fail to meet the security of supply test.”

In a New Year message to energy industry policy makers, David Brewer, Director General of the Wakefield-based organisation which represents mining and supply companies in England, Scotland and Wales says: “The current White Paper policy measures fail to meet the Government’s own criteria in every respect. Our future electricity supply will not be affordable because customers will have to fund windfall gains for existing gas and nuclear generators and pay high prices for electricity and imported gas. It will not be low-carbon because it will lead to long-term lock-in of high carbon emissions from unabated gas. It will not be secure because it will be excessively dependent on imported gas, especially at peak periods, and lead to a reduction in indigenous coal production.”

Coal currently provides 30% of the UK’s electricity, a proportion which rises to 50% or more at peak periods in winter. Coal output in the UK is increasing and is an industry worth over £1 billion a year to the UK economy. Market uncertainties resulting from Government policy measures risk the ongoing investment needed to maintain this growth with consequent premature closure of mining capacity.

Says Brewer: “Coal has for many years been a cornerstone of Britain’s electricity supply and can remain so, more cleanly and reliably, if changes are made to evolving energy policy. Britain can reduce its dependence on both imported coal and gas by putting in place policy measures which will encourage long-term investment in new capacity which will provide the nation with reliable, sustainable and cheaper supplies than relying on expensive imported gas.

“We support the Government’s commitment for secure, low-carbon and affordable electricity, and we are not opposed to the development of other forms of energy. That is why we are recommending policy changes which will ensure an ongoing role for coal and reduce the nation’s exposure to supply and price risks.”

Measures being proposed by the coal industry include:

Rapid implementation of the carbon-capture demonstration program
A review of Carbon Price Support, a tax on the carbon content of fuels used for electricity generation. It will unreasonably incentivise gas and in the first three years alone, will cost consumers £3.2 billion. It will adversely affect the competitiveness of UK industry and is a tax on jobs
Time-limited relief from carbon price support on the unabated proportion of plants investing in carbon capture
A clearly stated requirement for the progressive retrofit of carbon-capture plant at gas-fired power stations to an early defined timescale
A clear signal that capacity payments, intended to ensure sufficient generating capacity is available to meet demand during the transition to low-carbon electricity generation, will be available to existing coal-fired plant through the mid 2020s.
Brewer adds: “Unless the government acts quickly, electricity consumers will be locked in to getting their power supplies from high carbon gas-fired stations, intermittent wind and inflexible nuclear power. With a more level playing field, we can continue the progress in reducing emissions without it costing the earth for power users.”

Geometrica and Carlos Caballero SRL have created a rugged solution high in the Bolivian Altiplano. Located at over 4,000 m above sea level, San Cristobal is the largest mine in Bolivia. The open-pit silver, lead and zinc mine moves 150,000 t/d of rock, and processes 40,000 t/d of ore. The dome protects workers, the environment and neighbouring communities from the release of dust from its stockpile, and protects the material awaiting transport to the ore processing facility.In early 2010, Bolivian contractor Carlos Caballero SRL responded to a bid request for a stockpile containment solution. Caballero teamed with global storage company Geometrica to propose a customised containment solution for the mine. Following review of the proposal and visits to other Geometrica bulk storage domes in South America by San Cristobal engineers, the project was awarded to the Caballero-Geometrica team. Caballero served as the main contractor and installer of the dome, while Geometrica, as a subcontractor, engineered, manufactured and supplied the dome. Key factors in the decision to employ a Geometrica dome solution for the site included the team’s extensive experience, the capability to build around an operating stockpile, and the capability to follow an irregular shape for the supports.

The finished stockpile containment structure is a Geometrica dome 140 m in diameter and 59 m in height anchored by concrete foundation — the largest dome of its kind in South America, the companies report. The foundation, which accommodates a 9 m change in elevation over 140 m, is fitted to the terrain. The dome is designed to withstand wind speeds of up to 150 km/h and an ice load of 110 kg/m2.

San Cristobal’s Geometrica dome is made up of more than 88,000 galvanized steel tubes organised and inserted into aluminum hubs to form the structure. Local crews recruited by Caballero built the dome as deliveries by Geometrica arrived on site. Shipments consisted of containerised crates of parts, each holding 2 t of structure, and organised by construction phase. The Geometrica system requires no welding, as the prefabricated tubes slide easily into the aluminum hubs and hold fast. The precise yet simple assembly process allowed the mine to continue to operate in the midst of dome construction and made it easier to assemble the building in an environment subject to high winds.

A ventilation lantern is located at the top of the dome and the side of the dome can support dust removal equipment. The interior includes a system for lowering the material-conveyor pulley for maintenance, and a catwalk circling the dome interior. Three 13 m x 10 m doors allow simultaneous access by up to two off-road vehicles to the interior of the dome. The finished building is clad in galvanised and painted metal sheets and translucent skylights provide natural light. Material is transported from the dome to the ore processing plant via an existing underground tunnel.
•Covered area 15,493 m2
•Surface area 25,340 m2
•Base diameter 143 m
•Height from base to apex of dome 59 m
•Weight of structural dome elements 523,400 kg
•Structural material - galvanised steel and aluminium
•Number of tubes - 88,329 pieces
•Number of connectors - 25,295 pieces
•Cladding - galvanised steel, painted steel and translucent panels.

Geometrica says that “in addition to creating the largest bulk storage dome in South America at San Cristobal, [it] has designed more than 15 bulk storage domes for mining projects located in the Andes, where construction challenges include rugged terrain, remote jobsites and high snow loads. Examples of recent projects include the Barrick Zaldivar mine, the Mantos Blancos copper mine, both located in neighbouring Chile, as well as Minera Aguas Tenidas in Spain. Hundreds of Geometrica structures have been built for clients and end users around the world including BHP Billiton, Anglo-American, Barrick, Codelco, First Quantum, Fluor, Sumitomo, and other mining companies in locations ranging from the Sahara desert to the jungles of Borneo.

In addition to the solutions for irregular shapes, Geometrica offers containment solutions for automated, ring-shaped stockpiles and for spans of up to 300 m. A precise design process, the ability to package and ship a complete structure by construction phase, and mechanical structural joints that do not require welding result in a durable structure that is easily built in a wide range of environments.

Monadelphous Group has received a notice of award for a contract with BHP Billiton Iron Ore for construction works at its Port Hedland Inner Harbour Project at Finucane Island and Nelson Point, Western Australia. The contract, valued at approximately A $290 million, comprises structural, mechanical and piping work associated with materials handling and processing facilities at the port operations. Work is scheduled for completion by the first quarter of calendar year 2013.

Atlas Copco Portable Energy opens Used Equipment refurbishing centre in Poland

Atlas Copco is giving new life to pre-owned Atlas Copco portable compressors and generators. The Portable Energy Division has opened its first refurbishing center in Warsaw, Poland. It will coordinate Atlas Copco Portable Energy’s European refurbishment activities and equipment offer. In parallel with this, Atlas Copco Portable Energy is currently mapping out the worldwide roll-out of its Used Equipment program.

Atlas Copco Portable Energy will sell its branded used equipment through the existing sales channels. Before they are offered for sale, the pre-owned Atlas Copco units can be fully refurbished in the Warsaw facility. The centre will have a substantial refurbishing capacity for compressors or generators. Smaller local servicing and refurbishing activities will be carried out in customer centers throughout Europe.

“The introduction of the Used Equipment program was driven by the Atlas Copco motto of sustainable productivity,” said Sam Waes, Used Equipment Business Development Manager. Waes emphasised the importance of refurbishment in maintaining equipment quality and integrity. “Refurbishment is a crucial element in our Used Equipment program to safeguard quality and customer expectations for Atlas Copco Used Equipment.”

Poland was chosen as the location for the refurbishing center because of its central location in East Europe being an important region for pre-owned equipment in Europe. Atlas Copco already has a customer centre in Warsaw, which allows for synergies in terms of logistics and support.