Mining companies today are facing unprecedented pressure to perform more efficiently in all aspects of their operations. High on the list of management concerns and shareholder expectations, for example, are improved capital efficiency and asset utilization. With the average grade of ore taken from active deposits around the world falling each year, compounded by the need to replenish reserves from often-remote locations or difficult-to-process ore types, the pressure will only increase as miners search for technologies and techniques that will allow them to maintain control over project costs, complexity and competitive performance. This focus isn’t limited to mine development; it extends into the mineral processing sector as well.
Tenova Bateman Technologies is expanding its modular plant capabilities to process a wider array of commodities. Shown here is one of the company’s new iron ore modular plants at about the 50% completion stage.
Tenova Mining & Minerals is an integrated solutions provider to the global mining, bulk materials handling, and minerals beneficiation and processing sectors, offering technological solutions and process and commodity expertise across the mining industry value chain. Tenova Bateman Technologies (part of Tenova Mining & Minerals) offers project-specific process technologies that include solvent extraction for hydrometallurgical and bio-processing, electrowinning, ion exchange, in-house R&D facilities, expertise in mineral beneficiation and complementary processes from acid to water treatment plants. Having pioneered the concept in the 1960s, its modular plants also offer competitive mineral processing packages while reducing risk in difficult project locations.
Recently, E&MJ Managing Editor Russ Carter spoke to Albert du Preez, managing director of Tenova Bateman Technologies, about its advanced technologies for mineral processing.
What kinds of technologies and services can Tenova Bateman Technologies offer clients that directly relate to, or result in, less complex, more efficient and more dependable mineral processing plants?
Tenova Bateman Technologies, with its sister companies Tenova Takraf and Tenova Delkor, provides technologies to assist in selecting the optimum, “fit for purpose” flowsheet. As an example, MetRIX (Metal Recovery through Ion-eXchange) RIP (resin-in-pulp) technology, solvent extraction (SX) technology, and related solid-liquid separation circuits can be optimized for a specific customer’s needs.
Another technology that is often used is dense media separation (DMS) in, for example, copper circuits where the ore is upgraded upfront, resulting in reduced operating cost and a smaller processing plant.
A suite of proprietary technology is also applied to enhance the efficiency, offer ease of maintenance and operation, reduce the plant footprint, and optimize costs in SX circuits. This includes the Bateman Settler, which provides high process efficiency with low organic loss, short construction time, and low capital cost (approximately a 20% reduction in capital cost for the SX plant).
The Bateman Pulsed Column can be applied to many industrial SX processes, particularly those with a fast rate of mass transfer. This high efficiency contactor enhances SX during extraction, stripping and scrubbing or washing processes. Its advantages include being a multi-stage continuous process, and being able to handle liquids with suspended solids or which form third phases. This safe and environmentally friendly SX contactor has a head space that can be inerted, which virtually eliminates solvent loss and fire risk.
The Turbulent Technologies Mixing System, a new mixing technology, is also part of the suite. Tenova Bateman Technologies is the exclusive licensee to the mining industry for the technology, developed by Turbulent Technologies, which offers considerable benefits in both retrofit applications, as well as in new plant installations. For the first time, by applying this technology, there is no need to compromise performance between the mixer and the settler in both current and new plants.
Retrofitting of existing plants with Turbulent Mixing reduces operational expenditure and may increase production, showing a very high return on investment for the technology despite the price premium. Because replacement of the mixing tanks is not necessary (only internals require replacement), installation of Turbulent Technologies mixers is easily performed during routine shutdowns. Tenova Bateman Technologies is carrying out the first commercial installations of these mixers, which are being retrofitted at various plants around the world. Existing auxiliary mixers are being replaced in situ, in order to increase mass transfer and solve problems of high entrainment.
New plants incorporating Turbulent Mixing benefit from lower capex, with higher flux/throughput and/or smaller settlers, as well as smaller media filters for organic removal.
As the physical characteristics of the organic and aqueous phases in each SX plant are unique, each customer’s unique parameters are processed, using special turbulent flow software to custom design a uniform mixing regime at a precise level of turbulent mixing energy.
Plants can therefore mix more intensively to optimize mass transfer, without fear of negative consequences downstream. At the same time, they are actually reducing entrainment, improving mass transfer and therefore increasing recoveries. Extensive on-site testing has shown that Turbulent Mixing delivers a greater than 50% reduction in entrainment, and provides very stable and consistent performance, even when process parameters are changed. For a plant producing 40,000 t/y of Cu, an increase in 0.5% of extraction efficiency means increased annual production of 200 t of Cu.
Mine operators are becoming increasingly attentive to the water-consumption requirements, as well as water-recovery and treatment capabilities, of new or expanded processing plants. Can Bateman Technologies offer assistance in this technology area? How about help with energy savings?
We can indeed offer our own as well as applied technology in this area. Solutions include concepts ranging from simple practices such as keeping waste water streams segregated, to selective removal of undesirable contaminants through ion exchange.
Optimizing the removal of contaminants/valuable metals at the correct place in the process can lead to reduced sizes of effluent treatment plants and consequently reduced energy consumptions and disposal costs. Incorporation of MetRIX RIP in a flowsheet will generally result in a lower overall water inventory; that is, higher solution tenors on the plant and, although the overall water requirement for the plant might not be significantly lower, the water treatment requirements should be lower.
An under-utilized technology is the further treatment of domestic effluent, rendering it fit for re-use as process water, reducing fresh water intake requirements. Most of the solutions rely on a combination of several processes to achieve the desired result. This requires capital spending and the good solutions are those that succeed in targeting the high-impact areas to gain the most significant results at the lowest investment cost.
With respect to energy savings, the most significant impact for new plants can be achieved during the initial plant design. The best opportunity is during flowsheet development, followed by good hydraulic design and lastly, selection of efficient process equipment.
To achieve savings once a plant is operational is usually a challenge, requiring capital investment, which may be out of proportion to the savings that can be achieved. It is possible, however, and in a case where water recovery is retrofitted to an existing plant, power savings can also be indirectly achieved. This is usually as a result of reduced pumping costs. Once again, solutions are unique with the potential effect determined by the process design, physical configuration and location of the plant.
Modular plants are usually regarded as a useful option in special situations involving recovery of familiar products such as gold, coal and diamonds. Are there any recent developments for new, “novel” modular-plant technology involving processing of other metals and minerals?
We have successfully broadened our modular plant technology offering from our traditional focus on DMS for diamond processing to provide modular solutions, incorporating complete flowsheets, for processing a range of commodities. We utilize different processing technologies, such as SX, ion exchange, electrowinning (EW) or gravity concentration, to design a robust plant that optimizes the balance, not only between capex and opex, but also process efficiency.
For example, using ultra-high DMS technology for beneficiating iron ore, one can increase the densities at which separation can be achieved (above 4.2 g/cm3). This will potentially enable significantly higher yields to be achieved at the same product grades, when compared with jigging technology, due to the high separation efficiencies that are possible.
Tenova Bateman Technologies also completed designs for a modular gold and copper ore-to-metal solutions, including unit operations such as DMS, flotation, SX and EW, and is currently developing a modular MetRIX RIP plant that can be applied to gold and base metals, and uranium processing.