Located just outside the capital city of Accra, the solution for the granite quarry has been designed and installed by QMS experts to produce a variety of material sizes for use on infrastructure projects throughout the country.
Central England-based Quarry Manufacturing & Supplies (QMS) has, since its formation in the 1980s, grown to be one of the UK's leading manufacturers, suppliers and providers of aftermarket support of crushing, screening and stockpiling equipment. With a hard-won reputation for providing the equipment, parts and services the industry needs, QMS has recently finalised the construction of a bespoke granite plant just outside the Ghanaian capital of Accra. QMS was tasked with designing, installing and supporting the new plant, the latest of the company's installations in Africa.
"The plant for the Ghanian granite quarry has been designed and built to produce a variety of aggregate sizes at a production rate of 250tph. Our equipment has to not only be able to meet the quarry owner's production targets but also consistently produce the sizes required to make the quarry a profitable ongoing concern," explains QMS managing director Jonathan Beck. "Furthermore, although we will be supporting the quarry throughout its operational lifetime, the plant has to be hard-wearing and easily maintained by quarry staff."
The plant has been designed and installed to produce six product sizes: 0-5, 6-8, 9-12, 13-16, 17-22 and 23-28mm from an initial feed size of 650mm. The feed material initially goes to the primary jaw crusher station. This consists of a QMS 1,200mm x 750mm jaw crusher - JB-1275 - with hydraulic clamping and adjustment. In addition, the station consists of a GF 1043 grizzly feeder, a feed hopper and a support structure. A primary surge tunnel with a vibrating feeder feeds the material to the secondary crushing station, which consists of a B3-XC secondary cone crusher with a corresponding support structure, including walkways.
Following secondary crushing, the material is fed to the first screening station, where an SVI-C02M 1.83m x 6m double deck inclined screen produces the first three products. Any oversize is fed to the tertiary feed hopper, including a vibratory feeder, before being fed to the tertiary crushing stage. A QMS B4 cone crusher undertakes this.
The choice of cone crusher was perhaps the most crucial part of the process. The rugged yet precise and productive QMS B-Series cone crushers feature a unique hydraulic system which provides automatic overload protection by allowing the head assembly to drop, permitting the passage of tramp iron and other non-crushable material. The system then automatically returns the head assembly to its original position. The unique design of the hydraulic system means the crusher operates at a definite setting with less setting drift and greater stability throughout the circuit. The crusher setting is instantaneously maintained even after passing a piece of uncrushable material.
"A blend of high motor power, large eccentric throw and increased speed give the B-Series greater capacity than other crushers of comparable size, whilst the truly modern design creates excellent product shape and can be configured to maximise production of premium single sized aggregates," explains Beck.
Following the tertiary stage of crushing, the material is fed along the QMS-supplied and installed conveyors to the second screening stage. This consists of an SVI-C03M 1.83m x 6m triple deck screen to produce the final material sizes. As well as providing all support structures, including walkways, QMS designed and installed all the conveyors and provided an electrical package which included all electrical panels, cabling, containers, and QMS's own in-house full plant automation and sequencing system.
Given the importance of the granite quarry to Ghana in supplying the material for the countries urgently needed infrastructure developments, equipment choice was essential. Explaining why the Ghanians chose QMS, Beck says: "We believe we offer a range of crushers and screens that match anyone else in the market with regards to the cost-to-performance ratio. As we are able to support our equipment with our own engineers in Africa and have the industry knowledge to adapt any plant to suit the quarry, mine or aggregate plant's unique requirements, we believe that our products and service provide the ideal solution whatever the size of operation."
With the Ghanaian quarry approaching full operational efficiency and the country needing the aggregates that the QMS equipment will help produce, the installation is only the first of many such plants QMS is set to deliver in Ghana and Africa. "Quarry Manufacturing & Supplies Ltd. has a reputation for equipment and plant design excellence. Our crushers, screens, feeders, conveyors, process control systems and other associated equipment are now used throughout the world in some of the most demanding of applications," explains Beck.
Beck adds that the actual installation of a quarry plant is just a primary step as QMS prides itself on supporting its equipment wherever it is found in the world. "We don't just make and install the equipment; we also support and upgrade all our plants, as well as provide aftermarket care on equipment made by other manufacturers. It is our belief that when a QMS plant becomes operational, that's only the start of the story.
"We provide the expertise, know-how and drive to keep customers' operations working at full efficiency as well as carrying a full parts inventory for maximised uptime, even in countries many miles from the UK, such as Ghana.
"All at QMS take pride in making sure that our customers are able to be as efficient and productive as possible as long as there is a requirement to do so," concludes Beck.