Apex Welding and Safety Screens are made from a specially formulated P.V.C. material and provide optimum safety in workshop environments where harsh ultra violet light and dangerous u.v. radiation occurs during welding and grinding processes.
This locally manufactured safety screen incorporates a heavy duty ultra violet light absorber, which safely contains all u.v. radiation in the curtained off area enhancing safety in the environment and providing a high level of protection for workers in close proximity to welding and grinding activities.
Standard tinted P.V.C. material while offering a visible barrier does not provide adequate protection. Extensive tests conducted by the SABS proved that Apex Welding and Safety Screens are superior to conventional tinted material.
Tested for ultra-violet transmittance, the conventional material gave readings of 0,0005%, 0,008% and 5.0% as opposed to Apex readings of 0,005%, 0,001 and 0,005%. When tested for total visible light transmittance, the tests were conclusive – the conventional material allowed 78%, while the Apex material allowed only 15,5% light transmittance – a dramatic difference.
Apex Welding and Safety Screens are impervious to burning, and this is of particular importance should the material come into contact with welding splatter.
Access to cordoned off areas is easy as the patented Balledge design on the individual PVC strips facilitates easy access for both personnel and equipment. The strips parts on contact and return to their original configuration ensuring an efficient close.
Available in several configurations to suit individual requirements, the most popular version is the freestanding frame that facilitates both easy handling and portability. The screens’ angled feet allow optimum utilisation of the floor space and the screens can be butted together at a 90-degree angle.
In addition to Apex Welding and Safety Screens, the company markets a range of high-speed roll up and fold up doors, which represent a leap forward in warehouse closure systems.
The significant benefits offered by Fibreglass Floor Grating has seen this composite material product increase in popularity, especially in applications where it is necessary to guard against environmental factors or corrosive chemicals.
Lance Quinlan, marketing manager at Andrew Mentis, says that the composite structural materials used in the construction of the grating allow the product to be installed in extremely harsh applications where corrosion is a factor.
“The product offers excellent corrosion resistance coupled with increased strength, long life and enhanced safety benefits, and over time has proven itself in demanding applications including industrial facilities and wastewater treatment plants,” Quinlan says.
“While the cost of material is always an important criterion, it does not always reflect the total cost of a project,” he says. “It is essential for design engineers to consider the related cost of installation as well as the maintenance of floor grating over time.”
Fibreglass Floor Grating is simple to install and requires no welding or end banding. It is also lightweight making it easier to install large sections. This translates into lower installations costs.
The structural integrity of the product is enhanced as the corners on the inside of the square opening are moulded to a small radius. During construction the bars are tapered towards the bottom and this prevents build-up of debris and makes cleaning simple.
By optimising the glass fibre content not only is it corrosion resistant but the load bearing capacity is optimised. Quinlan says that the one piece moulded construction results in enhanced strength in both directions and eliminates loosening of the product with repeat use.
Fibreglass is non-conductive and is not affected by temperature fluctuations. It also provides electrical insulation making it suitable for all applications.
The product will not rust and does not need painting or coating. It is also not affected by the sun and does not become brittle and break. Quinlan says it is virtually maintenance free which can be a major long term cost saving.
Fibreglass Floor Grating is complementary to the well-known Mentis range of steel floor grating products.
The recent Knysna wildfires and building fires in Johannesburg, as well as mine fires underground, are a reminder of the value of specialised construction materials in passive fire protection, especially in reducing explosive spalling.
Such a solution is the specially designed Adfil IGNIS® monofilament polypropylene fibres, distributed locally by CHRYSO Southern Africa, leading supplier of concrete and cement admixtures and ancillary products. Developed by Adfil Construction Fibres, a division of the UK-based Low & Bonar Group, the IGNIS fibres have been used in concrete mixes to enhance the fire rating of concrete structures and have been successfully applied in tunnels, sprayed linings, precast segments and pumped concrete behind slip-formed shuttering.
In a move that will bring this innovated technology closer to home, Adfil recently appointed CHRYSO Southern Africa as its partner to grow its fibre business into Africa. There will also be collaboration between Adfil and specialist South African company Oxyfibre, which has developed patented surface technologies and nano-technologies for polypropylene fibres; it has also treated and supplied fibres to CHRYSO Southern Africa for almost two decades.
According to Izak Louw, operations manager at Oxyfibre, fire can cause explosive spalling in concrete structures when ‘free water’ in the concrete pores – water that has not been consumed during the hydration reaction and remains unused in the concrete – becomes steam when exposed to fire and causes explosions that break up the concrete.
“Falling concrete then presents a serious safety risk, and the integrity of the concrete structure is also compromised,” says Louw.
To enhance the fire rating of concrete structures and reduce the risk of spalling, Adfil’s polypropylene fibres are added to the concrete mix for the purpose of increasing permeability during heating, thus reducing pore pressures.
“In the case of fire, the fibres will start to melt when the heat of the concrete is approximately 160°C,” he says. “When the temperature reaches 360°C, the fibres will disintegrate to provide millions of capillaries in the concrete for the moisture to escape. The result of using these fibres in concrete is that there is no build-up of pressure and hence no explosive spalling.”
According to Louw, there is substantial scope in South Africa and in Africa more broadly for the use of specialised fibres in concrete as passive fire protection, as it can prevent the catastrophic failure of concrete structures – from mine tunnels to high-rise buildings.
“Furthermore, polypropylene fibres offer a three-dimensional system, which helps to prevent shrinkage cracks from occurring,” he says. “The fibres increase the tensile strain capacity of the mix at the plastic stage, while crack control reinforcement would merely hold the cracks together once the concrete has failed.”
Proven at such test facilities as TNO in Holland and the BRE in England, Adfil IGNIS® has been used in many road tunnels, primarily to avoid the potential collapse of these structures in the event of serious fires.
Leuze distance sensors have a solid reputation for maximum accuracy over both small and large distances. These sensors are used everywhere geometric parameters such as height or width need to be determined and are characterised by high resolving capacity at high measurement rates.
The Leuze ODSL 30 is capable of measuring distances on black objects up to 30 metres away and on bright objects that are as far as 65 metres away. The sensor resolution of 1 mm facilitates highly accurate measurements with an accuracy ratio of +/-2 mm over the complete measurement range.
By automatic adjustment of the exposure time to the intensity of light, independence from the reflectivity properties of an object can be achieved further ensuring the accuracy of the measurement values. The unit also has a referencing function which prevents fluctuations in measurement value.
The unit is equipped with an integrated display which shows the measurement values and this allows the sensor to be easily adapted to the measurement application at hand.
The Leuze ODSL 30 has an integral key pad with an LCD display and the unit interfaces with analogue outputs, serial RS 232/485 interfaces and teachable switching outputs.
It is available from Countapulse Controls, leading southern African sensing solutions company. With more than 35 years of experience on the continent the company offers a wide range of sensing solution for all industries and is able to assist customer in appropriate selection of the best fit for an application.
With coal miners moving into more difficult geological conditions, a detailed characterisation of the ore body is increasingly vital when specifying feeder breakers or mineral sizers, according to PC Kruger, capital sales manager at FLSmith Buffalo.
“Most of the ‘easy’ coal seams in the Witbank coalfields have been mined,” says Kruger, “and what remains tends to include a high level of hard rock intrusion as well as tramp material such as steel, wood and concrete.”
In particular, a strip mining of old underground bord-and-pillar mine often encounters a substantial portion of rock, which has a much higher ultimate compressive strength (UCS) than the coal. While the UCS of coal ranges from about 40 MPa to about 60 MPa tests in the Witbank region, over a number of decades, have found that some rock intrusions easily measure up to 210 MPa in strength.
He says that feeder breakers are well suited for most underground mining conditions where the coal is relatively soft and homogenous.
“However, they are not designed to deal with high strength material,” he says. “Where there are regular hard rock intrusions, you will generally opt for mineral sizers.”
Another critical consideration in specifying equipment for coal processing is the principle of reduction ratios in each stage of sizing. Kruger says the ‘the rules of the game’ require that, in the primary sizing stage, the ratio between the input size of coal and the output size should be about 4:1 or 5:1.
“In other words, a large chunk of material with dimensions of 1 200 mm in two or three dimension can realistically only be reduced to about 300 mm in size in the primary phase,” he says.
Similarly, in the secondary sizing stage, the ratio should be 3:1, which can reduce this 300 mm coal down to 100 mm. In the tertiary sizing stage, a ratio of 2:1 is the norm, breaking the material down further to the minus 50 mm size that the end-user usually requires.
“Trying to operate outside the boundaries of these reduction ratios invariably leads to increased wear and running costs,” he says. “Putting over-sized material – say, larger than 150 mm material – into a tertiary sizer designed for 100 mm material, prevents the positive ‘bite’ that breaks the product down. Instead, the size and geometry of the pieces means that they do not pass cleanly through the rotors, and cause undue wear on the rotor teeth and other components.”
He emphasises that trying to reduce capital expenditure by having fewer sizing stages – and therefore less equipment – is usually false economy. With the capital cost of this equipment making up only 8% to 10% of its total cost of ownership over its lifespan, the operating cost normally outweighs any upfront saving by orders of magnitude.
In its efforts to promote South Africa’s skills growth and continuous product improvement, the Multotec Group recently donated one of its SC20/7VC small diameter seven-turn spirals to the University of Pretoria (Tukkies). The spiral will support research and development as well as effective and experiential learning among students.
According to Wynand Roux, lecturer in the Department of Material Science and Metallurgical Engineering, proper research needs the involvement of industry players like Multotec. Significantly, the organisation has a long standing relationship with Tukkies that has included providing both funding and equipment donations.
“Ongoing interaction with equipment suppliers affords our students the opportunity to undertake projects aimed at providing innovative solutions and new technology for the mining and metallurgical sectors,” says Roux. “Having access to equipment like Multotec’s spiral certainly assists in bridging the gap between theory and practice, and allows students to better understand what this sort of equipment can achieve.”
Post graduate student Bernard Fundikwa, who is doing his Master’s degree in the department, says the equipment is used by both undergraduates – for practical work – as well as by post graduate students who are conducting research.
Rikus Immink, managing director of Multotec Process Equipment and himself a Tukkies graduate, says the donated spiral has a shallower angle and is equipped with a mouth organ product box and three sliding splitters.
“This particular spiral offers the ability to process a variety of minerals, coarse or fine and ranging from low density to high density ores, which could include mineral sands, heavy minerals and rare earth minerals,” says Immink. “The through angle is designed such that it falls between the high-grade spiral and fines spiral, and can be used for pre-concentration or for cleaning purposes.”
Attending the handover ceremony with Multotec group CEO Thomas Holtz, Immink reiterates that the company is proud to be associated with the University of Pretoria, and looks forward to future research projects that will be conducted using the spiral.
Users of equipment driven by diesel engines can look forward to many more years of economical operation if they understand that these modern engines are designed for two, three or more ‘new lives’ between overhauls; but proper maintenance goes hand-in-hand with quality remanufacturing to make this possible.
“Beyond their first overhaul at about 15,000 hours, most diesel engines are designed to be overhauled several times,” says Andrew Yorke, operations director of specialist diesel engine component remanufacturer Metric Automotive Engineering. “However, many users will try to cut corners on the maintenance side, especially under the current tough economic conditions – quickly putting pay to this valuable benefit.”
The end result of poor maintenance practices is that machine ownership ends up costing more, and the potential value of a longer working life for the unit is lost.
“Sadly, the situation leads to a sort of self-fulfilling prophecy, where the purchasers of used equipment are even less likely to maintain it properly – arguing that it is not worth the expense,” says Yorke. “They buy used plant because they can’t afford new, but then further undermine its value by wanting to spend less on servicing too.”
The fact is, he says, that many engines do not get the right level of service workmanship or the best quality parts at the latter stages of their lives – so their possible longevity is cut short.
“By viewing the equipment and its engine as a pure cost, the asset value and reliability is not fully realised, and the second and third lives of those engines are severely compromised as a result,” he says.
Several original equipment manufacturers (OEMs) contract Metric Automotive Engineering to remanufacture customers’ engines that are still under a maintenance plan – as a positive way of protecting their warranties.
“From an engineering point of view, we can see the difference between those engines that have been correctly and timeously maintained, and those that have not,” says Yorke. “The condition that these units are in varies dramatically.”
He adds that the component repair costs of a well-maintained engine are also significantly lower, so any savings that an end-user thought they were going to make – by reducing maintenance or by stretching service intervals – is completely nullified by the cost they pay to repair the engine components during the mid-life overhaul.
“Equipment users should also consider the ‘complete picture’ rather than just viewing an engine overhaul in isolation,” he says. “The condition of each component has a knock-on effect on the others, so they need to consider the transmission, the cooling system, the air filtration and other elements.”
If these components are not in good condition, they will in turn compromise the engine; indeed, an overhauled engine could even introduce power levels to the other components that they are no longer in a position to deal with sustainably.
Yorke emphasises that for owners of poorly maintained engines, the extra costs incurred during the remanufacturing process might still be the least of their worries.
“There are plenty of worst case scenarios for an unmaintained engine,” he says. “For instance, lack of maintenance could lead to premature failure, where the equipment has to be withdrawn unexpectedly from service with all the related costs due to project disruption.”
Even worse than that, the customer could experience a catastrophic engine failure, where there are components damaged to the point that they cannot be salvaged or remanufactured.
Among the benefits of quality remanufacturing is the dynamometer testing that follows a complete engine overhaul. While poorly remanufactured engines usually fail within the first 500 hours of life, they are unlikely to endure even an hour on Metric Automotive Engineering’s specialised workshop ‘dyno’ – giving the customer peace of mind that the unit is fit to return to service.
With current cost pressures on mines in South Africa and elsewhere, the role of procurement officers in saving unnecessary expenditure has become vitally important.
Procurement officers are being increasingly relied upon to save money for the mine, according to SPH Kundalila group commercial and operations manager Graeme Campbell. He suggests a few practical ways in which these individuals can do this while achieving optimal results from their purchases.
Firstly, says Campbell, procurement officers must know when and how to negotiate. This begins with learning more about every aspect of mine procurement that they are required to control. While not being expected to be experts in every field, they can learn a lot by sitting down with contractors and service providers to gain insights into the work that is to be done.
“Suppliers can actually be important assets that many procurement officers fail to tap into,” he says. “Contractors like SPH Kundalila, for instance, have decades of experience and have acquired expert knowledge of the field they function in, from industry costs and new products right through to insights into important role players in the sector and the pioneering technology available.”
Armed with this kind of industry knowledge, procurement officers can negotiate more beneficial and cost saving contracts with better levels of service provision.
The second way to ensure good value for mine expenditure is to define an accurate scope of work, says Campbell.
“A tender bid can be a daunting and time consuming process, and more time can be lost when trying to compare contractors’ quotations when the scope is too vague,” he says. “The answer is to start off a tender process by stating exactly – and in detail – what the scope of the work will be. Getting contractors to quote according to these specifications will makes comparisons easier, and expose any hidden costs.”
Issuing a clear and detailed tender will also serve as a ‘dry run’ to gauge a contractor’s quality of service, he argues. Experienced companies, such as SPH Kundalila, have trained personnel and support teams who understand the tender’s requirements, and can quickly clarify any point of a quote or contract.
Thirdly, urges Campbell, draw from the expertise inside your own company. He says the bidding process is really an opportunity for all the mine’s departments to find the best possible contractors for their purposes.
“Bringing the input together from colleagues and department heads during a bidding process requires strong, trusting relationships between them,” he says. “Procurement officers should invest time in building these relationships with other departments, as colleagues may know of affordable service providers in the market that procurement officers are unaware of.”
A unified approach motivates all departments – and even contractors – to work together for the greater good of the mine.
At the leading edge of electric motor technology and related sectors, the Zest WEG Group is also innovating its empowerment initiatives by facilitating ownership of its shares by two black owned Non Profit Organisations (NPOs) that directly benefits communities in need.
A subsidiary of the world’s leading motor and controls manufacturer WEG, the South Africa-based Zest WEG Group has taken this step to create a broader based and more sustainable ownership foundation for its compliance with the new BBBEE codes of goods practice.
Hot off the press is the announcement that the two NPOs, together with the company’s employees Trust, now hold 51.6 % of Zest WEG Electric, the South African arm of the Zest WEG Group. One of the NPOs is in the education sector and the other in the micro-enterprise support sector. Significantly, the shareholding comprises 31.68% black female beneficiaries.
Zest WEG Group CEO Louis Meiring says that not only will most of the beneficiaries of the NPOs be black women, but the arrangement will sustain the good work of these NPOs into the future.
“Significantly, the achievement of our Level 2 BBBEE status is certainly one of the best, if not the only such one, in our market sector, and we believe this initiative breaks new ground for empowerment in South Africa. It provides a model for sustainable collaboration between business and civil society while forging a more effective implementation of the original intentions of the country’s BBBEE philosophy,” he says.
Meiring says the business has always been proactive about transformation and builds the BBBEE compliance goals into its business culture.
“We previously readily achieved our Level 4 status, based on our shareholding, skills development, supplier support and community investment, and this is simply the next step in our transformation journey,” says Meiring. “Now, this ownership-related initiative takes us significantly further on our pathway as a responsible corporate citizen.”
Zest WEG Group provides a range of skills development resources to schools, universities and the broader community including teaching, equipment, financial aid and infrastructure. These aim to develop local talent and capacity, bringing young learners into the business and industry.
Juliano Vargas, Zest WEG Group’s logistics and operations director, says the organisation’s close relationships with these communities allow the identification and nurturing of talent from an early stage.
“With our double-digit growth, even through the recent downturn, our business is creating opportunities for job seekers, and we prepare them well to replenish the positions that our expansion requires,” says Vargas.
Skills are developed in-house through apprenticeships, internships and mentoring in various disciplines and are sometimes also supported with study bursaries.
“We adopt and evolve leading edge manufacturing technologies, so we need to upgrade our skill levels among all employees on an ongoing basis,” he says. “WEG in Brazil shares both their technology and their skills with us; visiting WEG factory experts conduct training for our teams regularly.”
These processes in turn promote employment equity as potential managers and leaders can be identified and developed. The company also works hard to bring small, local suppliers into the Zest WEG Group’s value chain, by developing their capacity to deliver and to become sustainable.
“Through our involvement with small business incubators, we even select and support small enterprises before they are in a position to become our suppliers,” he says. “Those that progress well may earn contracts from group companies, following which we review their performance and keep track of them to ensure that they deliver good value in their services and products.”
To allow each mining customer to choose the most effective maintenance strategy for its particular conditions, Weir Minerals is offering ‘infinite flexibility’ in its range of solutions to keep its equipment operating at the lowest cost per ton over its full life cycle.
According to Kobus Fourie, Global Services Manager for Weir Minerals, there is a refocus in the world of maintenance, as the mining industry gains a better understanding of the value of total asset management carried out by the original equipment manufacturer (OEM).
“The involvement of the OEM in ongoing plant maintenance can really make a difference to reliability while reducing maintenance costs in the long term,” says Fourie. “So, to ensure that every customer can take advantage of these benefits, Weir Minerals is extremely flexible in how we structure our support to suit any environment.”
These maintenance arrangements include a cost-per-ton model, which allows mines to budget a set premium for a pre-determined production rate. Another option is the repair-and-exchange model, where the OEM keeps key stock related to the specific customer’s requirements, so it can supply what would normally be long lead time items in just a few hours.
He highlights that the OEM supplier is in the best position to understand and support their products optimally, and this is recognised by most mining companies, who will closely link their own maintenance programmes to the aftermarket services that the OEM can provide.
“Through our service capacity, OEM’s are playing an increasingly important role in mining,” he says. “We can do this because our knowledge base – earned through extensive and ongoing investment in research and development – is well established.”
The OEM’s focus is on the capabilities and life cycle of their products, and the customer can use this focus to their advantage.
“The benefits of having an OEM maintain their own equipment far outweighs the costs, especially if you take into account the indirect cost of downtime due to the more frequent breakdowns often resulting from the use of a non-OEM part, for example,” he says.
He also emphasises the safety aspect of good maintenance strategies, reiterating the importance – for both the OEM and the customer – of a safe working environment in the plant.
“If you start to alter a product with non-OEM replacement parts, it can not only put the reliability and integrity of the equipment at risk, but also the safety of the people that work around the equipment,” he says.
Fourie acknowledges that applying a long term approach to maintenance is not always easy in the mining sector, as volatility in commodity prices creates uncertainty around the life-of-mine expectations at many operations.
“A more stable outlook allows mines to make better decisions about investing in the longevity of their critical-path plant and equipment,” he says. “Nonetheless, the key differentiator among mining competitors is a systematic approach to maintenance that can be applied irrespective of the prevailing economic climate.”
Weir Minerals pushes the envelope with maintenance options, to place the focus on total solutions. This, in his opinion, is what the mining industry needs; mines should be allowed to focus on their core business, which is to process minerals, while OEMs should support that objective by maintaining and operating their equipment to ensure lowest cost production.
“We have also joined forces with industry leading innovators Dell and Microsoft to develop cutting edge condition monitoring as part of our maintenance offering, so that we can take preventative maintenance to the next level,” says Fourie. “In time, we will be able to predict equipment failure, and apply interventions before such failure occurs; this will provide further savings to customers by avoiding lost production due to unscheduled downtime.”