Many foundries make the casting process their primary focus, and do not consider total manufacturing cost and environmental implications; so the inevitable used sand would be dumped somewhere, possibly on an adjacent or nearby site, or hauled away to an approved landfill site.
But, today, a successful foundry business requires a wider focus, and in particular close management of operating costs and profit margins. These foundry operations are constantly looking for ways to reduce their overall operating costs.
For foundries that currently ship their spent sand to approved landfill sites, the costs of disposal and the subsequent purchase of new sand can easily justify investing in an in-house sand-reclamation system, especially if the sand is re-usable. Today’s heightening and enforcing of the Waste Management Act, as well as the environmental pressures and challenges are forcing management to come up with solutions.
Grant Ramsden, Operations Director, Weir Minerals Africa and Middle East and Gavin Dyer, Regional Managing Director of Weir Minerals Africa at the inauguration of the new G-U-T secondary sand reclamation plant installed at Weir Heavy Bay Foundry in Port Elizabeth, Eastern Cape
It is said that in most cases if a foundry generates two tons per hour of disposal sand, then sand reclamation should be investigated. For foundries generating five tons per hour of disposal sand, sand reclamation should be considered as a viable cost-saving project. And, for foundries generating 10 tons per hour or more of disposal sand, the savings can be significant and the payback quick.
Weir Minerals Africa
Weir Minerals Africa is a market leader in manufacturing slurry handling equipment with specialisation in the delivery and support of a wide range of slurry equipment solutions. This includes pumps, hydrocyclones, valves, dewatering equipment, wear-resistant linings, rubber products, screening machines, centrifuges, crushers, feeders, washers and material handling equipment for hard rock mining, sand and aggregate and industrial markets.
This broad portfolio of highly engineered products finds application in critical customer processes. The metal performance of Weir Minerals Africa’s products is equally important and so too are the castings that make up the products. Prior to 2006 Weir Minerals Africa procured their castings from local foundries, and imported them from Weir Minerals foundries located elsewhere in the world.
This supply chain of castings was augmented when Weir Minerals Africa commissioned its own greenfields foundry at its South African operations in Isando, Gauteng, in 2006. Although this foundry filled an important area when Weir Minerals decided to invest in the manufacturing capacity of the African organisation, the local operation was still hampered by size of castings produced at the Isando foundry.
The new G-U-T secondary sand reclamation plant consists of three 70 ton silos that store the facing sand, reclaimed sand and new sand
The filter plant and cyclone which are part of the installation
Maximum size of castings was pegged at two and half tons per casting, and today Weir Minerals Africa offer products that can weigh up to 42 tons once fully assembled. Individual castings can weigh up to 18 tons.
The company had already seen that the benefits of the investment in the Isando foundry had had an immediate impact. Customers had the assurance that quality issues are resolved at source, that there was a reduction in lead times and a dramatically improved response time to customer demand.
In line with its policy of controlling the quality and service for its supply chain, Weir Minerals Africa looked at investing in facilities that would be capable of producing the large parts that it had been unable to cast in the past.
As a result, Weir Minerals Africa signed an agreement with John Exley to acquire the plant, equipment and buildings of Xmeco Foundry, a specialist large casting foundry based in Markman Industrial Township, Port Elizabeth, South Africa, from the Xmeco Group.
The Weir way
Xmeco Foundry had been manufacturing large, heavy castings in SG, high chrome and various alloyed steels since it moved to its current location in 1978 although its origins date back to 1951. Run as a family owned business until its acquisition by Weir Minerals Africa it supplied general engineering castings, including pump components to Weir. The foundry had also been one of the few foundries in South Africa to undertake the supply of large bells and these can be heard ringing throughout South Africa.
The investment Weir Heavy Bay Foundry serves to improve the reclamation and reusability of the sand employed in the moulding process, thus reducing the impact on the environment whilst improving the quality of the product at substantially reduced production costs
The plant also includes cooler-classifiers, a rotary scrubber and a magnetic separator
The foundry had been supported on the machining side by an associated company, Xmeco Heavy Engineering, which is located on the same site. This arrangement is still in place thus ensuring that all castings leaving Weir Heavy Bay Foundry are machined to customer requirements.
The Weir Heavy Bay Foundry occupies a 5.2 hectare site that is situated less than eight kilometres away from the Port of Ngqura, the heart of the Coega Industrial Development Zone. The site is big enough to allow the company to develop the facilities to cater for future planned growth and market demand.
Since acquiring the Heavy Bay Foundry, Weir Minerals Africa have concentrated on transforming the facility to align with the Weir way. The Weir Group has a system of engineering excellence that includes global best practice sharing, Design Centres of Origin and Group specific Environmental Health and Safety Management systems that adhere to both local and international codes of best practice.
Quality is a central philosophy at Weir Minerals and its quality strategy has brought about a fundamental shift from quality control to quality assurance. While quality control calls for an inspection at the end of a process, quality assurance focuses on redesigning the elements of a process in order to ensure that the quality of the product is 100% when it reaches the customer.
During the last three years, management at Weir Heavy Bay Foundry have been implementing the safety, process and cosmetic changes that make up the Weir way, while at the same time investing in new processes and equipment in the manufacturing area. This included purchasing new equipment, upgrading and refurbishing existing equipment and generally organising the various areas to streamline the operations.
The new G-U-T secondary sand reclamation plant is a pneumatic conveyor system type that is operating at 14 tons per hour
Weir Heavy Bay Foundry uses the lost foam process to manufacture some of its castings
Some of the changes in the foundry included the purchase of a 20 ton an hour continuous mixer that has been installed by Lauds Foundry Equipment and four new 20-ton driven moulding tables have been installed in the large casting bay to significantly improve the production rate. A new 160kW Ingersoll Rand compressor has replaced four old piston-type compressors and a large Demag overhead crane installed.
The company has also purchased two Romer 7-axis arms from Retecon Machine Tools that have been integrated with an RS1 laser scanner. This now allows Weir Heavy Bay Foundry to deliver 3D scanning solutions for a variety of applications and use them for feature inspection to CAD, free-form surface inspection to CAD.
The 5 000m² pattern shop and storage facility now has a racking system, a Haas GR-712 gantry-style router to mill patterns and a new coreshop. Magmasoft casting simulation software, as well as Siemens NX design software and a CAD/CAM package compliment these areas of the foundry.
The metals sampling and testing laboratory has been rebuilt and upgraded with the latest technologies and equipment such as a Spectro spectromer and a Struers Tegramin material preparation system for grinding and polishing of specimens.
Inauguration of new secondary sand reclamation plant at Weir Heavy Bay Foundry
Although giant leaps have been made in quality and processes since acquiring the foundry, management of Weir Minerals Africa have embarked on another investment phase. The first of these to be implemented is the installation of a G-U-T (Giesserei Umwelt Technik) secondary sand reclamation plant.
“We have invested significantly in upgrading our facilities and operational procedures in our Port Elizabeth facility, all in line with our long-term growth and cost reduction strategy. We are now in a position to leverage growth opportunities thus supporting local economic development and job creation, while at the same time having a positive impact on the environment,” said Gavin Dyer, Regional Managing Director of Weir Minerals Africa at the inauguration of the new secondary sand reclamation plant.
“Core to the company’s manufacturing strategy is the application of lean and environmental principles which serve to reduce all process waste.”
A casting in the fettling bay, which has also seen a major upgrade
Machined castings ready for delivery
“This investment serves to improve the reclamation and reusability of the sand employed in the moulding process, thus reducing the impact on the environment whilst improving the quality of the product at substantially reduced production costs. As part of the casting process, chromite sand is added to furan sand for moulding purposes. The subsequent build-up of chromite sand in the furan sand not only leads to quality issues but also limits the reclamation and reuse of the sand. The new plant processes have been introduced to improve the reuse of the sand, including scrubbing the resin from the sand by attrition, as well as magnetic separation of the chromite sand from the furan sand.”
The new G-U-T secondary sand reclamation plant is a pneumatic conveyor system type that is operating at 14 tons per hour. The plant consists of three 70 ton silos that store the facing sand, reclaimed sand and new sand, cooler-classifiers, rotary scrubber and magnetic separator.
Local economic upliftment
“In support of the company’s philosophy of contributing to the economic upliftment of the communities in which it operates, fabrication work for the new sand plant was outsourced to local companies in the Port Elizabeth area.”
“Weir Heavy Bay Foundry not only contributes to the company’s requirements from a Weir Africa perspective, but also offers large, heavy casting services to third parties, notably the automotive industry.”
“Currently we have enough capacity and capabilities to fulfill most of Weir Minerals Africa’s requirements within the target range of the two foundries, as well as to continue servicing external clients, no matter what their request. In Port Elizabeth we currently have capacity to produce up to 650 tons of castings per month, but intend ramping this up to over 1000 tons per month in the next three to five years. This would mean implementing a three shift system and thus adding to our existing 100 staff complement.”
“In our short period as owners of Weir Heavy Bay Foundry we have implemented many different staff training courses, either managed internally or attended externally. Additionally we have trained 10 apprentices as moulders and are about to have a further intake of 10.”
“With our recent OHSAS 18001, ISO 14001 and ISO 9001 accreditation and the installation of the new secondary sand reclamation plant, coupled with all the previous improvements and investment to upgrade the facilities to world-class standards, we are proud to say that this facility in Port Elizabeth now stands out amongst the Weir Group.
For further details contact Weir Heavy Bay Foundry on TEL: 041 461 1407 or visit www.minerals.weir