Modern Quarrying Q3 2019

QUARTER 3 – 2019

BUCKING THE TREND

CONTENTS In the face of a tough aggregates market and a very competitive market landscape within its vicinity, Afrimat’s Kliprug Quarry continues to buck the trend with a steady growth trajectory that has seen it achieve record volumes in May this year

QUARTER 3 – 2019

ON THE COVER

AT THE QUARRY FACE

WET PROCESSING

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PUTTING YOUR DIESEL REBATE HOUSE IN ORDER PAGE 30

THE QUEST FOR SCREENING EFFICIENCY PAGE 34

AROUND THE INDUSTRY 04 New face for Aspasa enviro audits 04 NewMining Charter Audit for Aspasa members 05 AfriSam’s relentless focus on carbon emission reduction WEIGHING SYSTEMS 46 VEI systems from Dynamic Weigh Systems 47 Improve your bottom line with onboard weighing systems

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INCREASED OPERATIONAL EFFICIENCYWITH SCANIA’S NTG At a time when the local

DRIVING NEW LEVELS OF EFFICIENCY A major plant upgrade and investments in new technologies are driving new levels of efficiency at SPH Kundalila’s Cape Town-based Bridgetown Dolomite Mine.

NICO’S VIEW 48 Keeping the morale high

quarrying industry is seeking sustainable and cost-effective operation, Scania South Africa’s newly-launched New Truck Generation (NTG) range drives high standards of efficiency.

CIRCULATION Karen Smith PUBLISHER Karen Grant

EDITOR Munesu Shoko quarrying@crown.co.za ADVERTISING Bennie Venter benniev@crown.co.za DESIGN Ano Shumba

DEPUTY PUBLISHER Wilhelm du Plessis

PRINTED BY: Tandym Print

PUBLISHED QUARTERLY BY: Crown Publications P O Box 140 Bedfordview, 2008 Tel: +27 11 622 4770 Fax: +27 11 615 6108 www.crown.co.za

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TOTAL CIRCULATION 2 465

The views expressed in this publication are not necessarily those of the editor or the publisher.

TAKING THE LOAD OFF WEIGHT PROBLEMS

A short time ago, I visited a sand-producing operation which had recently installed a load weighing system on its wheel loader used to stockpile and load customer trucks on site. Under- and over-loading customer trucks – which resulted in huge losses of high-value material and unwanted downtime – was a major problem on site which necessitated the adoption of the technology. Following the installation of the system, the quarry has removed guesswork out of its production planning and loadout processes, and the manager of the operation believes every quarry needs to install this technology on its loading tools to maximise productivity and optimise loadout processes. My view is that not only do quarries need on-board scale technology for their loading tools, but for their

on-board weighing technology from a growing pool of suppliers to optimise operations. The weighing solutions vary from on-board conveyor belt scales to wheel loader scales, and each system is designed for different applications in quarries. The scales save a tremendous amount of time and effort because of their ability to directly weigh materials from any vehicle or equipment. This eliminates redundant efforts invested in the payload process andminimises downtimes. Most of the scales on the market are compatible for use with conveyor belts and quarrying equipment so they can easily be integrated with a number of vehicles like excavators and haul trucks. They facilitate real- time tracking of loads while vehicles are in transit as a result of the time invested in weighing payloads is significantly minimised. Benefits of scale installation abound and include time and money savings, reduced fuel spend, elimination of operational disruptions, productivity improvement and increased safety, among others. While you can still get your job done without these technologies, the productivity is sure to suffer significantly. Your conventional practices can increase your operational expenses over time and your workforce may end up spending most of the time doing tasks that are less significant. To get around this whole scenario, I recommend that quarry owners install on-board scales that can turn all the tedious weighing tasks into a total breeze.

haulers too. Any operation that carries and transports payloads needs efficient and accurate weighing solutions because the precise determination of the weight that is being carried is a crucial parameter for the industry. This is why an increasing number of local quarries are employing on-board scales for improved efficiency, throughput and reduced overhead costs. There are several instances in quarries when weighing from a specific site becomes entirely inefficient and inconvenient. This is when on-board scales come into play. The digital display fitted in the cabin of the vehicle offers easy assessment of weight metrics which minimises supervisory overhead and human errors. Many local quarry owners are starting to capitalise on advanced

COMMENT

Munesu Shoko – Editor quarrying@crown.co.za

@MunesuShoko

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MODERN QUARRYING QUARTER 3 - 2019

INDUSTRY NEWS

New face for Aspasa enviro audits

“The fate of our environment is mainly in the hands of our corporate leaders and the consultants advising them.” These are the words of Lizette van der Walt, new inde- pendent environmental auditor for Aspasa. The energetic environmental lawyer took over from long-serving auditor, Alan Cluett, in January this year. She says her predecessor did sterling work in raising and maintain- ing awareness of the need for good environmental management. After several months on the job, she only has praise for Aspasa members, whom she says have displayed an above-average commitment and interest in environmental affairs. This makes her job as the association’s auditor easier as she continues to assist members to meet environmental legal exposure risks and to manage environmental impacts in accordance with the best practices as underlined by the association. Van der Walt sees her appointment as a personal challenge and wants to use the opportunity to promote better environmental management. “Too often companies have the best intentions of upholding sound environmental managements, but due to incor- rect prioritisation of environmental issues or misplaced advice from consultants they make fundamental mistakes. I would, therefore, like to use my time at Aspasa to share my experience with the members to ensure that their efforts yield the intended results while enabling them to build relationships of trust with regulators.” l

Lizette van der Walt, new independent environmental auditor for Aspasa.

New Mining Charter Audit for Aspasa members

important for all South African mines to work strictly within the confines of the charter. “While the charter’s main function is to secure one’s licence to operate, it now has a stronger focus on socio-economic development. Then, increasingly local communities are becoming aware of their rights and holding mining compa- nies to account. Overall, the new char- ter’s message is clear; if a mine strays from implementing and maintaining its duty to society, it runs the risk of having its operations suspended or its licence withdrawn,” says Kunene. l Resources (DMR) officials. “While some of the demands are not provided for in legislation and others are simply impractical, they are having an impact on the running of mining operations. A Blasting Audit that’s in line with all new requirements of the MHSA is a positive step toward in clar- ifying the legal parameters of mining operations, and particularly when it comes to the use of explosives,” says Pienaar. To develop the audit, Aspasa has tasked an explosives solutions com- pany that manages explosives related legal challenges, blasting engineering

Aspasa introduces Blasting Audit Following the publication of the Mining Charter’s Implementation Guidelines and Amendments in December 2018, Aspasa has extended its service to members with a new Mining Charter Audit. After a seven-month engagement pro- cess with stakeholders, South Africa’s new Mining Charter was developed to boost sustainable growth, enforce pro- curement of local goods and to further support broad-based, meaningful Black Economic Empowerment of the local mining and minerals industry. Independent mining law consultant Sibongile Kunene cautions that it’s To assist members with compliance to the mining charter, technical and quality requirements, Aspasa is further extending its strategic service to members with the introduction of a new Blasting Audit. According to director Nico Pienaar, Aspasa has decided to offer Blasting Audits to members due to the numer- ous legal challenges faced by the sector since the Mine Health and Safety Act’s (MHSA) new explosives regulations came into effect on 14 December 2018. There have been var- ious demands made by affected com- munities and Department of Mineral

Independent mining law consultant, Sibongile Kunene will provide auditing assistance to Aspasa members.

Explosives experts William Mlanje (left) and Corrie Rautenbach will be conducting blasting audits on behalf of Aspasa.

improvement initiatives and indepen- dent investigations to undertake audits of members’ sites. l

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MODERN QUARRYING QUARTER 3 - 2019

ACI shows marginal improvement year-on-year Afrimat, the JSE-listed open pit mining company providing industrial minerals,

especially via a revival of the RDP hous- ing scheme and restoring the functional- ity at dozens of bankrupt municipalities. The latter will assist local governments in accessing conditional grants earmarked for infrastructure.” l

Limestone mining at Dudfield began in 1949, with the first kiln established in 1965. Today, the plant produces over a million tonnes of clinker on its Kiln 3 plant to meet mar- ket demands. The plant has a cement production capacity of over 1,3-mil- lion tonnes. The plant also has the flexibility to supply bulk cement by both road and rail, as well as its own bagged cement. There are 65 years of proven limestone reserves on AfriSam Dudfield’s 3 608 ha mining licence. AfriSam invests constantly in energy saving strategies at its cement plants. Since 1990, it has achieved a cumulative reduction of 31% of cement-specific thermal consump- tion, measured in megajoules per tonne of cement. Meyer highlights the potential of the new carbon tax – in force from 1 June 2019 – to incentivise ener- gy-saving innovation. “The depressed state of the economy has dampened many of industry’s good ideas, and if carbon tax revenues could cover recorded for the economy as a whole since the first quarter of last year. “The recessionary environment in the South African construction sector is con- firmed by a declining trend in the ACI’s four-quarter average value that lasted for seven successive quarters, although there was a marginal upward movement this quarter.” Botha also points out that the ACI is now 9,1% higher than eight years ago (the base period for the index), com- pared to an increase of 12,2% in the GDP over this period – signalling a below-par performance for a sector that plays a key role in the development of infrastructure, housing and new production capacity in the economy. “This reflects a dire need for govern- ment to incentivise a higher level of business activity throughout the whole of the construction sector supply-chain,

bulk commodities and construction materials, has released the findings of its Afrimat Construction Index (ACI) for the first quarter of 2019. The ACI is a composite index of the level of activity within the building and construc- tion sectors, compiled by renowned economist Dr Roelof Botha on behalf of Afrimat. This quarter’s ACI broadly followed the same disappointing trend evident in overall economic activity during the first quarter of the year, during which South Africa’s gross domestic product (GDP) declined by more than 3% (compared to the fourth quarter of 2018). According to Botha, it is nevertheless encouraging to note that the first quarter ACI level increased on a year-on-year basis, which is better than the zero real growth

Andries van Heerden, CEO of Afrimat.

AFRISAM’S RELENTLESS FOCUS ON CARBON EMISSION REDUCTION

industry incentives, the resulting innovations would have a range of positive spin-offs. Apart from easing demand on Eskom’s grid, this would also contribute toward the coun- try’s Paris Agreement obligations,” Meyer says. AfriSam’s commitment is clear to see – it is the first cement manufac- turer to equip all its kilns with bag filters. This brought emissions to below even the European standard of 30 mg/m³. l

It is not business as usual for AfriSam – the company has been working hard towards reducing its impact on the environment for many years. Since 1990, the leading sup- plier of construction materials has reduced its C02 emissions by 35%. But this, according to Hannes Meyer, cementitious executive at AfriSam, is not where it ends. Meyer says AfriSam continues to cut the carbon footprint of its cement. Efforts focus on using less energy in the production of clinker, while mak- ing more use of extenders like fly-ash and slag. “We are probably South Africa’s leading company in our understand- ing and application of extenders in cement,” he says. He emphasises that this field holds great scope for creating more environmentally friendly cements, but required con- siderable technical expertise. With its many years of experience, AfriSam is applying that expertise in its ongoing cement innovation.

AfriSam has reduced its CO 2 by 35% since 1990.

emissions

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QUARTER 3 - 2019 MODERN QUARRYING

TRAILBLAZING SANDWASHING

For maximum sustainability and profitability, it’s time to make the switch to the world’s first all- in-one materials wet processing and water recycling system. The next generation Combo™ with advanced cyclone technology processes both natural sand and crushed rock reserves to produce high quality materials for your customers. This energy-efficient solution provides five processes on a single compact chassis, including water recycling, to produce in spec sands that are ready for market straight off the belts. Making the switch to sand washing was a no-brainer for South African construction materials producer, Ground Breakers. Previously, the company used a bucket wheel on its Lindley quarry to transform decomposed granite into construction sand and aggregates. This system worked well, but in order to recover more value from their operations, Ground Breakers needed to decrease the loss of quality fines to settling ponds and produce a final product with less moisture. “The market required a clean washed concrete sand, and our bucket wheel was not delivering a quality product. We also lost a lot of fines to the settling ponds, wasting material that we could not sell without dredging the ponds and re-processing it through the bucket wheel.” JC Janse van Vuuren and Johan Meintjes – Owners, Ground Breakers.

With limited water sources and space, CDE created a modular sand washing solution to help Ground Breakers take its operations to the next level. The trailblazing Combo™ combines precise cut point accuracy and superior dewatering efficiencies to produce two high- quality sands simultaneously, including 0-6mm river sand and an extra 0-1.5mm plaster sand. With the system working as a full-circuit unit, it can efficiently retain fines and recycle up to 90% of the used water for immediate reuse in the process. This also significantly reduces the need for silt dams, allowing Ground Breakers to preserve valuable mining areas. “Switching from a bucket wheel system to the Combo™ has been conducive to considerable cost savings, as generally we sell per tonne. The additional -2mm product has many uses, from plastering exterior walls to making paving bricks. It has increased our profitability considerably.” JC Janse van Vuuren and Johan Meintjes - Owners, Ground Breakers. Adopting the Combo™ technology will decrease the loss of valuable fines to settling ponds, boost profitability and dramatically reduce maintenance and downtime. It’s easy to speed up your return on investment with the trailblazing Combo™ from CDE.

cdeglobal.com

A NewWorld of Resource

SWITCHING TO THE COMBO™ HAS TOTALLY CHANGED THE WAY WE WORK.”

“Our quarry site in Lanseria faced a lot of challenges; we had limited water sources and limited space to put up a proper wash plant. Our CDE Combo™ is compact and highly efficient. It produces two properly washed products and our customers are very happy that the moisture content is so low. This means a considerable cost saving to them, as generally we sell per tonne ” JC Janse van Vuuren and Johan Meintjes - Owners, Ground Breakers. Contact CDE today, to find out about our tailored finance offers and how the Combo™ can transform your operations.

Visit cdeglobal.com/comboSSA Patented: GB 2552042, WO 2018/108605

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A front-end loader loads one of the customer trucks.

ON THE COVER

L ocated in Contermanskloof, Durbanville in the Western Cape province of South Africa, Kliprug Quarry has been fully productive for five years. Owned by Afrimat, a leading open- pit mining company supplying industrial minerals and construction materials to the market, Kliprug serves the greater Cape Town and Atlantic seaboard area. Despite the tough nature of the construction industry in South Africa, compounded by the lack of meaningful government projects, Kliprug continues on a sustainable growth path. Since its inception, the operation has seen remarkable, continued sales growth. This is despite available figures indicating that government’s infrastructure budget has been shrinking during the past five years. The downward trend in the construction sector has worsened, particularly in the past two years. Industry figures show that government’s infrastructure budget has deteriorated from R947,2-billion during the 2017/18 budget, to R834,1-billion in 2018/19, representing a massive 12% nominal decrease. Against this negative background, Kliprug’s sales of aggregates have steadily increased to reach record volumes in May this year. The quarry has also expanded its market reach, allowing it to service all sectors of the market. Of note is the fact that the young quarry is situated in a very competitive market area with four other well-established quarries within a 5 km radius. According to Bevin Cornelius, key account manager for Aggregates Western Cape, Kliprug is the only quarry of the five that doesn’t have either an asphalt plant or readymix/precast concrete operation on site. What makes it tick? A combination of factors have ensured the quarry’s success in a very short space of time. Quarry manager Dave Hierons explains that the people factor is key among reasons why the operation In the face of a tough aggregates market and a highly competitive market landscape within its vicinity, Afrimat’s Kliprug Quarry continues to buck the trend with a steady growth trajectory that has seen it achieve record volumes in May this year, writes Munesu Shoko . BUCKING THE TREND

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MODERN QUARRYING QUARTER 3 - 2019

A Bell B18E is deployed to stockpile processed material on site.

environment is conducive for healthy and productive employees, especially in a mining setup,” says Hierons. “Our people are the most important asset in our quest for growth. Without the Kliprug staff ensuring that we had stock of aggregates available to sell, we could not have been able to achieve production targets and record volumes,” adds Hierons. Malcolm Knipe, sales manager at Kliprug, adds that an effective sales and marketing team has also had a fair share of credit in the success of the operation. The team punches beyond the time clock and brings the passion to serve the customer beyond the call of duty. This has resulted in repeat and referral sales in a very short space of time. Product range The rock mined at Kliprug Quarry belongs to the Tygerberg formation of the Malmesbury Supergroup and is a hornfels in general (greywacke). The product range is extensive and spans across concrete stone, base material and dust products, among others. The concrete stone product range includes the 53 mm, 37 mm, 28mm, 20mm, 14 mm, 10mm and 7,1 mm. Base material starts fromG7, G6, G5 to G2. The 10mm crusher dust is the major product in the dust product range. Gabion and rock fill complete the line of products produced at the quarry.

KEY TAKEAWAYS

Since its inception five years ago, Kliprug’s sales of aggregates have increased steadily

The operation achieved record volumes in May this year

Despite the fact that the young quarry is situated in a very competitive market area, it has been able to hold its own in the markeplace

Kliprug is a major supplier to the vertically integrated Afrimat Readymix business

continues on a growth path. He says striving towards a common goal is a major part of what makes a successful mining operation, in the true spirit of the Afrimat way. Many factors contribute to the success of a business – having a sound strategy, a marketable product or service and efficient processes are all important. However, it falls to the people within an organisation to actually execute strategies, plans and processes for a business to be successful in its endeavours. Management at Kliprug fully understands this concept. “A great deal of effort is directed towards engaging in activities that keep everyone in the team motivated and boosting morale in the camp. The focus is on enhancing the team’s strengths and improving on weaknesses. A safe working

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volume drivers. To meet the growing demand for these base materials, Afrimat has invested in a dedicated plant that particularly focuses on the production of these three materials. “We have experienced big demand on the G4 in particular, driven by road projects in our vicinity. To ensure stock availability, we invested in a separate process plant in March last year,” says Hierons. Production process To run a successful operation, there is a big focus on efficiency on site, all the way from drilling and blasting to load and haul and processing. From a blasting point of view, Hierons explains that blasts are kept fairly large, ensuring sufficient material on the ground per month. The quarry makes use of both conventional shocktube and new electronic blast- ing systems from BME. Hierons says electronic detonation is preferred for tricky areas. It offers accurate hole initiation for better blast fragmentation, which has a big effect on downstream functions such as load and haul and crushing. An electronic detonation also offers higher precision, improved blasting result owing to a wide range of delays, reduction of airblast/ground vibration and safe use in extraneous environments. When it comes to load and haul, the correct pairing of the loading tool and a hauler ensures efficient production. Two 35 t excavators, a Kobelco SKL 350 and a Hitachi 330L are used to load five Bell articulated haulers deployed to haul run of mine material from the pit to the processing plants over an 800 m distance. The dumpers include two Bell B30D units, one Bell B30E and a Bell B18E. Haul distances have been kept fairly short to reduce diesel burn and optimise cycle times for greater productivity. One of the key challenges on site is the fact that the mining area is still in the development stage. It takes a great effort to remove the overburden to expose the mineable blue rock. Overburden is sold as fill material, but its handling costs money and effort. “Ongoing plant modifications to produce cost-effectively offset the costs of overburden removal,” concludes Hierons. l

ON THE COVER

A Bell B30E is loaded by a Kobelco SKL 350 in the pit.

Kliprug achieved record sales in May this year.

A Bell B30D hauls run of mine material from the pit to the tipping point over an 800 m haul distance.

choice in the area. “The flexibility of our processing plant allows us to tailor make some of the products to the client’s specific needs. This is a key competitive edge for us,” says Cornelius. When it comes to some specialised products, Hierons makes special mention of the G2 to G4, which have since become some of the key

Base and sub-base material are currently the largest volume drivers, with civil contractors working in the area driving the uptake. This is followed by concrete stone products supplied to several readymix outlets. Speaking about the quarry’s competitive edge, Cornelius says the operation’s flexibility to make special products has made it the quarry of

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MODERN QUARRYING QUARTER 3 - 2019

Significant among some of the key initiatives in recent years at Blurock Quarries was the investment in new generation Sandvik crushing and screening equipment for the upgrade of the secondary and tertiary stages of the main processing plant.

WATER TANKS AT THE QUARRY FACE

BOOSTING OPERATIONAL CAPACITY

W ith technology innovations to help their businesses run efficiently and maximise growth opportunities. A case in point is Blurock Quarries, a family-owned quarry located in the heart of Estcourt, a small town in the uThukela District of KwaZulu-Natal Province, South Africa, which committed a huge investment in a major plant upgrade with new technology equipment that has significantly boosted capacity and constantly advancing, industries are looking for ways to utilise the latest

A plant upgrade and several improvement measures at Blurock Quarries – anchored by an investment in new generation Sandvik crushers and screens – have almost doubled the operation’s production capacity, as well as creating the much needed operational efficiencies and flexibility, writes Munesu Shoko .

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KEY TAKEAWAYS

Blurock Quarries has made a major investment in new generation Sandvik crushers and screens

The first Sandvik machine to be purchased was the CH440 cone crusher in 2016

The quest to improve efficiencies at the secondary crushing stage started with the purchase of a Sandvik CS430 cone crusher. This was purchased in 2016, but was only installed in 2018

2017

As part of the new layout, a Sandvik SS1633H scalping screen was bought in November 2017

Following the plant upgrade, Blurock has almost doubled its production capacity

increased operational efficiencies. Blurock Quarries mines a dolorite rock with some sandstone intrusions. After the overburden layer, which is stockpiled for rehabilitation, comes a layer of weathered rock, a mixture of shale and sandstone, which is crushed to produce sub-base material (G5 and G7). Below that formation is a mixture of dolorite and a competent sandstone, which is used to manufacture G2 and general concrete products. Below that layer lies the clean dolorite, used to make road stone (20 mm, 14 mm and 10 mm), as well as 26 mm concrete stone and crusher dust. The biggest selling products at the moment are the 20 mm concrete stone, crusher dust, G5 and road stone (20 mm, 14 mm and 10 mm). Since taking the reins as CEO of the family-owned enterprise back

The first Sandvik machine to be purchased was the CH440 cone crusher.

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WATER TANKS AT THE QUARRY FACE

The Sandvik CS430 cone crusher has been designed to allow the crusher to run either full or empty, with its own dedicated feed bin.

Plant upgrade In 2016, Blurock engaged the services of a business development consultant, Deon Bosman, who suggested a growth and development plan for the operation. Based on Bosman’s previous experience with the Sandvik product, he recommended Sandvik Mining and Rock Technology to Blurock Quarries. In 2016, Blurock started looking at areas where effi- ciencies could be created. The first Sandvik machine to be purchased was the CH440 cone crusher. Adam Taylor, Lifecyle Services Manager – Crushing and Screening at Sandvik Mining and Rock Technology Southern Africa, says the CH440 is suitable for a high-capacity secondary application or a high-reduction tertiary or pebble-crushing application, and it can be matched to changes in produc- tion through the selection of crushing chambers and an eccentric throw. The flexibility means that it’s suitable for a wide range of applications. In this instance, the CH440 was deployed as a tertiary crusher, replacing both the Metso HP300 and the Telsmith 36” fine cone. “We removed two crushers and replaced them with a single, new generation crusher,” says Hunter- Smith. “Apart from an increase in crushing throughput, this simplified our plant layout and having one crusher in the tertiary crushing stages, instead of two, reduced our maintenance effort,” says Hunter-Smith. The Telsmith 36” fine cone was an old crusher which called for regular maintenance, which in turn resulted in unwanted downtime. In addition, maintenance of the old Telsmith posed safety hazards for the maintenance crew because its older technology did not have the means to lift the top of the crusher hydraulically like the new generation Sandvik CH440. This feature has resulted in a reduction in downtime related to clearing blockages, which have been reduced from three hours on the old crusher, to about half an hour on the new crusher. With the new CH440, Hunter-Smith also opted for Sandvik’s Automatic Setting Regulation control system (ASRi), which enables real-time performance management, allowing the machine to consistently run at optimum levels. “When a Sandvik CH440 cone crusher is equipped with ASRi, it automatically adapts the crusher to variations

in 2015, after having served as the manager since 2010, Jeremy Hunter-Smith has focused his efforts on taking the business to the next level. He tells Modern Quarrying that following several recent interventions, the business has grown from strength to strength. Significant among some of the key initiatives in recent years was the investment in new generation Sandvik crushing and screening equip- ment for the upgrade of the secondary and tertiary stages of the main processing plant. This was followed by recent investments in the modernisation of enabling infrastruc- ture – new powerline, new substation, new switch room and a new control room, among others. “In recent years we have focused on upgrading our operation to be in line with the technological revolution. With the market slowdown, we have put our efforts into increasing efficiencies. A dip in the market can actually be an eye opener for a business – it has driven us to refocus our efforts on things that really matter, such as cutting wastages and driving efficiency in every way possible,” says Hunter-Smith. Old plant Prior to the plant upgrade, Blurock Quarries operated an old processing plant that lacked capacity, efficiency and flexibility. The primary crusher was a Nordberg 1109 jaw crusher. It was a very old unit, one of only four brought into the country many years ago. From there, material was sent to a Telsmith 2536 jaw crusher, used as a secondary jaw crushing unit. “We had a primary and secondary jaw crusher. The reason was that we were able to feed into either jaw, which created a bit of flexibility in the event of a challenge with either of the two,” explains Hunter-Smith. From there, material would go to the intermediate stockpile, from which it would be fed into a Metso HP300 cone crusher, which in turn fed the Ore Master vertical shaft impact (VSI) crusher. From the VSI, material would be fed into a Dabmar double-deck screen. All oversize material would report back to a Telsmith 36” fine cone, before being fed into a 5” x 12” triple-deck screen for final segregation. This would then feed the bins, from which the articulated dump trucks were loaded for stockpiling.

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The Sandvik CS430 cone crusher was purchased to create operational flexibility.

Adam Taylor of Sandvik (left) with Jeremy Hunter- Smith, CEO of Blurock Quarries.

The reason we selected this particular scalping screen was because of its compact build and high throughput, which allowed us to sidestep the space constraints we had onsite,” says Hunter-Smith. The Sandvik CS430 cone crusher was purchased because Blurock wanted to create flexibility by being able to take out some of the products at the scalping screen before and after the secondary crushing stage before the product reported to the maintenance stockpile. This has been made possible by the CS430’s ability to produce a better aggregate shape earlier in the crushing process. In terms of plant design, the Sandvik CS430 cone crusher has been designed to allow the crusher to run either full or empty, with a dedicated feed bin feeding into it. “We built a big feed bin before the cone crusher, which is good crushing practice because you have the necessary continuous feed into the crusher,” says Hunter- Smith. “Once everything has been set up, we will install an automated door on the feed bin – if the crusher is full, it will stay open, but if there isn’t enough material in the bin, it will close the door and wait for the bin to fill so that the crusher will never run three-quarters or half full. It will either be full or empty – that’s the best way to run a cone crusher.” The scalping screen allowed Blurock to take out some of the product at the secondary stage. From the new Sandvik SS1633H scalping screen, they are now able to take out a handstone, G5, general concrete stone and dump rock material. “The investment into a scalping screen and the whole secondary setup was to facilitate the manufacture of all products that we want using our main plant, instead of having to rely on our mobile crushing and screening train for some of the products. The second- ary stage upgrade is definitely money well spent,” says Hunter-Smith. The results of the plant upgrade are apparent – with the old plant system, Blurock had the capacity to produce about 100 t per hour. “We were very limited because of the old equipment we had. Following the upgrade – through Sandvik product and other efficiency improvement mea- sures – we are now able to produce between 170 and 180 t per hour,” concludes Hunter-Smith. l

in feed conditions. By continuously measuring and com- pensating for crusher liner wear, the automation system allows for full utilisation of crusher liners and schedules liner replacements to coincide with planned maintenance stops. It also assists in keeping the crusher choke fed. This maximises rock-on-rock crushing, which helps to optimise the quality of the final product,” explains Taylor. Installing the Sandvik CH440 has altered the whole tertiary section setup while producing the exact quality that was achieved by having a fine cone crusher in the mix, says Hunter-Smith. “Another major benefit is that we have managed to relieve the pressure on our VSI. We are able to reduce the speed of the VSI due to the CH440’s attrition crushing. Reducing speed on the VSI also lowers the amount of 0,075 mm material in our crusher dust. Our concrete and asphalt manufacturing customers want as little 0,075 mm as possible in their crusher dust,” explains Hunter-Smith. Along with the Sandvik CH440, Blurock purchased the SV1252 vibrating grizzly feeder (VGF). This feeds the Nordberg 1109 primary crusher and was bought to improve feeding capacity at the primary crusher. “In terms of selec- tion, we looked at other manufacturers, but the Sandvik VGF fitted perfectly into our existing structure. Our previ- ous VGF created a bottleneck as we could not get enough feed into the jaw, so we were not running the jaw full. That resulted in poor liner wear and poor attrition crushing,” adds Hunter-Smith. Secondary stage upgrade In early 2017, Blurock started looking at its whole secondary crushing application. It engaged the services of Imilingo Mineral Processing, which designed the new secondary crushing layout. The quest to improve efficiencies at the secondary crushing stage started with the purchase of a Sandvik CS430 cone crusher. This was purchased in 2016, but was only installed in 2018. “It was the exact crusher we needed to upgrade our whole secondary crushing application,” says Hunter-Smith. As part of the new layout, a Sandvik SS1633H scalping screen was bought in November 2017. “We started instal- lation in December 2017 and commissioned in June 2018.

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QUARTER 3 - 2019 MODERN QUARRYING

DRILLING: • Epiroc DP1500i

LOADING: • Cat excavators and wheel loaders

HAULING: • Bell articulated haulers

EQUIPMENT ON SITE

AT THE QUARRY FACE

ON PHOTO: SPH KUNDALILA’S Cape Town-based Bridgetown Dolomite Mine

DRIVING NEW LEVELS OF EFFICIENCY A major plant upgrade and investments in new technologies are driving new levels of efficiency at SPH Kundalila’s Cape Town- based Bridgetown Dolomite Mine. Munesu Shoko was recently on site.

KEY TAKEAWAYS

A recent plant upgrade has resulted in a 20% increase in production

Real-time belt weighing scales take the guesswork out of the production process

Drone technology informs efficient decision making on site

T l he current business climate in the aggregates industry is characterised by price volatility, shrinking margins and increasing operational costs, among several other challenges that relate to legislative requirements. This is exacerbated by a steady decline in the growth of aggregates demand due to the lack of meaningful SPH Kundalila’s Bridgetown Dolomite Mine produces metallurgical dolomite, agricultural lime and construction aggregates.

The quarry introduced an innovative dust suppression system in June

Metallurgical dolomite constitutes about 70% of the total offtake per month

Construction aggregates and agricultural lime make up the remaining 30%

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CRUSHING: • Sandvik D-907 HD Jaw crusher • Sandvik H3000 EC cone crusher • Pilot Crushtec AC 07 VSI

SCREENING: • BDM Plant • Svedala MNS 30012134 triple-deck (Screen 1) • Sandvik SF 1843 triple-deck (Screen 2) • Joest screen (Washing screen) • Ag Lime plant • Pilot Crushtec Trio TD 6118 triple-deck • Mobiles • Terex Finlay 683 screens

With that in mind, efficiency is sought in every sense of the word at SPH Kundalila’s Bridgetown Dolomite Mine. The Cape Town- based quarry mainly produces metallurgical dolomite for Saldanha Steel, as well as agricultural lime and construction aggregates.

single operational process, but paying attention to the production process as a whole, all the way from blasting and drilling, load and haul, to crushing and screening. Adopting new technologies can also set new levels of operational efficiency at quarry sites.

construction projects in South Africa. To survive and mine profitably during such a low growth cycle, quarry owners need to capitalise on the opportunity to improve their productivity and focus on one factor they can control: efficiency. Operational efficiency cannot be achieved by focusing on a

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A Cat 329D excavator loads articulated haulers in the pit.

AT THE QUARRY FACE

downtime,” says Pretorius. The BDM plant currently produces between 1 000 and 1 500 tonnes of material per day. The Ag Lime plant produces about 450 tonnes a day of agricultural lime, excluding construction-related aggregates, which are typically produced per order. In terms of overall production, metallurgical dolomite constitutes about 70% of the total offtake per month. Construction aggregates and agricultural lime make up the remaining 30%. Belt weighing scales As part of its technology revolution, SPH Kundalila has installed real-time belt weighing scales, which give exact tonnages of material passing selected belts in real time. These have been installed on the metallur- gical dolomite product belt, the Ag Lime belt and on the out loading belt. A key feature of the belt weighing scales is that they are now GPRS- enabled, which allows them to send information to a server. Management can see, in real time, the exact tonnages passing through each belt, anytime and from anywhere. With this software, one can also download pdf documents and do Excel exports of the production figures. “The technology takes guesswork out of the production equation, which makes it easier in terms of production planning. This is

system is that you get slippage on the belts, especially during cold mornings when the belts are wet,” explains Pretorius. Another key intervention was to change the plant setup. Pretorius explains that previously the plant was an old linear system which ran in a straight line with a ‘scorpion’ belt setup. A scorpion setup comprises two belts running against each other all the time. “We had a lot of complications with the setup, which resulted in breakdowns and downtime,” says Pretorius. To get rid of the linear setup, the Sandvik H3000 EC cone crusher was rearranged from its usual middle position in the plant, and was moved up the line. “We put in three new belts and a hopper feeder and moved the cone out of the line it was previously located. The hopper was installed to regulate the feed rate of the cone to keep it at choke feed level. Previously, it was fed directly by the screen and you couldn’t choke it. With the hopper feeder, we can regulate the feed to keep it at a constant level,” explains Pretorius. Pretorius notes that a combination of these changes has resulted in about 20% increase in production. “We are now able to produce more, mainly because of the hopper feeder, which has created a bit more capacity. Production has also increased because we have very little

Several interventions, including a recent plant upgrade and the adoption of three major technologies – a drone system, an innovative dust suppression system and real-time belt weighing scales – have ushered in new levels of efficiency. Plant upgrade Bridgetown Dolomite Quarry runs two processing plants – the main BDM plant which produces metallurgical dolomite and the Ag Lime plant, which produces -2 mm agricultural lime and several selected aggregate sizes for the construction sector. In 2016, a decision was made to upgrade the main BDM plant. A key feature of the plant upgrade was the replacement of the old Svedala screen with the new Sandvik SF 1843 screen. “With the old screen it took us a couple of hours to replace screen media. With the new Sandvik SF 1843, it takes us less than an hour to do the same job. This is proof enough that new technology has its advantages,” says Louis Pretorius, site manager at Bridgetown Dolomite Mine. As part of the upgrade, the Sandvik H3000 EC cone crusher was also completely refurbished. “We also replaced our V-belt and pulley- driven gearboxes on the plant. We now operate a gearbox and a motor directly without the need for pulleys. A major shortcoming of the V-belt

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“The software gives us concrete evidence to back up our decision making. We have grown in terms of technology use. The main benefit is that it makes decision making and planning a lot quicker and efficient,” adds Pretorius. The data from the drone technology can now be uploaded onto a server. The surveyor uploads the data after his fly over and within 30 minutes to an hour, Pretorius has access on the Cloud to a whole 3D model of the mine, which he can utilise as he sees fit. The drone technology deployed at Bridgetown Dolomite Mine is manufactured by South African- based Aquila Drones, with design and development done by parent company, WCD Engineering Consultants. Aquila Drones was founded in 2014 with the focus to develop specialised unmanned aerial vehicle solutions. Founder of Aquila Drones, Johan Janse van Rensburg, explains that typically two models are being used for survey purposes. The AQMRS is

Massamatic, an independent manufacturer of industrial weighing equipment based in the Western

Four Bell B25 articulated haulers haul material from the pit to the processing plants.

Cape. It supplies its products and services to industry and

agriculture nationwide. Because the products are locally designed and manufactured, they are tailor-made to suit each customer’s operating conditions. Drone technology A few years ago, SPH Kundalila pio- neered the use of drone technology for aerial surveying and stockpile management in the South African quarrying sector. The use of drone technology has since been expanded to include elevation management in the pit. Pretorius and the management team now use drone technology to determine elevations and slope angles in the pit. This is a fantastic tool in terms of pit planning. “We can calculate the amount of tonnages we have already moved out of the pit, and more importantly, the amount of material we can still take out of the pit,” says Pretorius.

a powerful tool to measure the actual production from crushers and screens, as well as monitoring loadout of trucks,” says Pretorius. The technology is supplied by

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of the application of the already surveyed data, Van Rensburg says given the typical small areas to be surveyed for quarry operations, Aquila typically captures the complete site on every survey. Subscribing to a regular aerial survey service with Aquila Drones, however, creates the potential for any quarry or mine operation to expand the deliverables to include much more than only volumetric results of stockpiles and quarry measurements, which is what SPH Kundalila has done at Bridgetown Dolomite Mine. “Monthly surveys of an operation provide us with data that, through further processing, can become valuable management tools. The client could identify an area of interest where they would like to review what has changed over a specific time and how. An automated analysis is then performed by comparing two historic data sets which gets overlaid and provides a visual index of the change. This could be used to monitor changes and highlight material moved over a defined period. Accurate measurements and calculations can then be performed depending on client requirements. These could include any area on site or inside the quarry pit,” explains Van Rensburg. Dust suppression Another innovative technology that has come out of Bridgetown Dolomite Mine and Van Rensburg’s relationship is a revolutionary and completely new system for dust suppression, the Atomiser. It is a nozzle spraying system that has water and high-pressure air from a compressor. With its high pressure, it atomises water particles to make a fine mist which captures dust. Bridgetown Dolomite Mine is one of the very first quarry test sites to use the solution in a fixed crushing environment in South Africa. “We will install the nozzles on strategic transfer points on crushers or wherever dust is generated on the plant. We will be able to regulate the amount of water and air the system discharges,” says Pretorius. At the time of writing, the solution was due

Five Cat 950 wheel loaders are used to stockpile and load customer trucks on site.

AT THE QUARRY FACE

Typical resolution targeted during data acquisition with drones is sub 3 cm ground sampling distance. This is deemed adequate for volumetric measurements for stockpiles.

understand that the process used by Aquila Drones still involves a registered surveyor which forms part of the team in setting up ground control markers. The complete survey 3D model is thus absolute geo referenced accurately to within 2 cm,” he says. The typical resolution targeted during data acquisition is sub 3 cm ground sampling distance. This roughly equates to three dimensional point cloud model accurate to within less than 5 cm. This is deemed adequate for volumetric measurements for stockpiles. Accuracies can however be increased to 2 cm depending on client requirements. “Any surveyor would confirm that the accuracy achieved through a precision aerial survey processed with the industry leading software PIX4D will virtually always yield more accurate volumetric results. This is inherent to the fact that a typical point cloud model would consist of thousands of measurement points on the surface of the stockpile versus only a few typically taken via precision GPS systems,” explains Van Rensburg. Speaking about the expansion

a multirotor solution used for smaller survey areas in the region of 50 ha. The main advantage is the ability to take off and land virtually anywhere. Operation is also simple. The AQRVS is the fixed wing platform typically used to survey larger areas up to 500 ha depending on ground resolution required. Van Rensburg explains that in some cases the perception exists that the land surveyor volumetric calculations are more accurate. “I think it is important for clients to Louis Pretorius, site manager at Bridgetown Dolomite Mine.

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construction material, mainly G products. They are mostly used to supplement production for project- specific contracts. As part of its compliance to the Proximity Detection System (PDS) legislation, Bridgetown Dolomite Mine is currently one of the test sites for Schauenburg’s surface PDS. It is currently running these systems on its dumpers, front- end loaders and LDVs, as well as pedestrian units. “Not every machine on site is installed at the moment because we are still a test site,” says Pretorius. “Out of this exercise, we will determine our level of risk, which will determine our level of compliance to the PDS legislation.” Safety and environmental management are key focus areas at Bridgetown Dolomite Mine. This is demonstrated by high scores in the 2018 Aspasa ISHE and Environmental audits. “We achieved 94,8% in our ISHE audit in 2018 and scored 97,88% in our Environmental audit, which is Showplace,” concludes Pretorius. l

quarry has industrial pumps in place to mitigate the risk. The quarry is a typical drilling and blasting operation. Drilling and blasting, outsourced to contractor Blasting and Excavating (B&E), is done once a month and blasts are kept fairly large at 60 000 tonnes of material on the ground. Four Bell articulated haulers (2 x B25D and 2 x B25E) are loaded by a Cat 340D excavator in the pit. A Cat 329D is used as a backup excavator, and is in most cases deployed with a hammer to break oversize material. From the pit, material is hauled to the main BDM plant where it is crushed into spec. Load and haul distances are fairly short and are currently around 1,2 km from the pit to the tipping point. Cycle times are, on average, about 8,5 minutes, depending on the point of loading. A total of five Cat 950 wheel loaders are used to stockpile and load customer trucks. They are also used to feed two Finlay 683 mobile screens operating on site. The two screens are used to produce road

to be installed in June. “We have already bought the compressor, air line systems and all the necessary components.” Further developments Apart from an array of technolog- ical developments, Bridgetown Dolomite Mine has recently com- pleted a life of mine development plan. “We had mining engineers on site in 2018 to determine the life of mine and quality of resource going forward. The material looks good and at this stage we are very pleased with what lies ahead. The critical part now is pit planning. Going deeper is always tricky because you need to plan your ramp designs accordingly,” says Pretorius. The life of mine development plan revealed that the quarry’s estimated life of mine is up to 2039. Issues of importance at this point are pit planning and water management. The quarry is located close to the Berg River. The pit is at this stage below river level, which poses a big risk of flooding. The