Despite the disruptions brought about by COVID-19, it has been another stellar year for minerals concentration specialist GCA which continues to build on decades of success providing concentration equipment and services to some of the world’s largest mines and project firms.
GCA specialises in a range of different gravity concentrators, from lab scale alluvial projects to large- scale multiple unit installations to suit feed rates from 45 kg/hr to 1 000 tph per concentration.
Its range of products includes the proven and tested FLSmidth Knelson Concentrator. For more than 40 years, the Knelson Concentrator has been regarded as the benchmark when it comes to centrifugal concentrators.
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GCA has been representing the Knelson brand since 1997 and has been an integral part of more than 400 large-scale Knelson’s installed on the African continent.
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GCA has continued to represent the technology after the acquisition of Knelson by FLSmidth in 2012. Due to its long standing representation of the brand, the company is confidently able to advise clients on exactly which models they need to suit their ore type, technical and financial needs.
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FLSmidth Knelson Concentrators are well suited for the secure recovery of gravity recoverable gold (GRG) and other heavy metals and minerals from both alluvial and hard-rock plants.
Using centrifugal force and water injection processes, they create enhanced gravitational forces of up to 200 Gs to recover free gold, fine gold and any other precious metals or minerals with high specific gravities.
GCA is also the agent for Consep Acacia, a range of intensive cyanidation leach reactors. The Consep Acacia Reactor is a complete intense leaching plant that maximises the recovery of gold from gravity concentrates.
Often used downstream from FLSmidth Knelso Concentrators, the Acacia produces the optimum solid-liquid interaction for maximised gold leaching kinetics by using an up flow fluidised reactor as opposed to complex mechanical agitation.
It encompasses a complete process solution for the safe, reliable and maximum recovery of gold from high grade gravity concentrates. With approximately 200 units installed, GCA estimates that in excess of 15% of the world’s gold production is recovered using Consep Acacia’s around the world.
Across Africa alone there are more than 35 Consep Acacia systems installed. Recent African gold projects include Goldfields’ Tarkwa, Teranga Gold Corporations Sabodala, Thor Explorations’ Segilola, Delta Gold’s Eureka, Resolute Mining’s Syama and Golden Star Resources’ Wassa mines.
The Consep Acacia features robust and reliable reaction chemistry, high-quality solids handling techniques, compact design and simple operating philosophy. It is a highly flexible solution that allows it to be customised to fit into any flow sheet and any location.
GCA is also a leader in the supply of shaking tables. Like many of the products sold and commissioned by GCA, shaking tables are gravity-based concentrators, using only power and water to produce gold, or other heavy metals and minerals, from ore concentrates or primary feeds.
Shaking tables are generally used to produce bullion-grade concentrate on smaller mines or mines where cyanide leaching cannot be used. To deal with security issues, GCA offers an Automated Table System (ATS), which operates independently or in conjunction with automated Knelson Concentrators to provide a hands-off concentrate treatment solution.
The ATS maximises secondary recovery by continuously recycling table middlings and tails between primary machine flushes, and ejecting the spent products at the end of each cycle before receiving fresh concentrates.
The simplicity, reliability and cost effectiveness of these shaking tables are what makes them attractive to many sites. In its current form it is by no means as good as the Consep Acacia in terms of recovery, but if one takes into account the huge capital cost difference and the fact that it’s a 100% chemical free process, it sometimes makes sense giving what is considered to be “old technology “ a second look.
Furthermore, GCA is also the agent for the Filtaworx range of self-cleaning industrial filters. Regarded as one of the most important products in the company’s range, the filters are particularly helpful in African regions that have poor quality water.
The easily replaceable screens range from 50 to 800 microns, and the extensive range of filters can handle between 25 and 900 cubic meters of water per hour in a single unit. They come in a variety of sizes and can be fitted with different screen apertures to suit the application.
The filters are ideal for ensuring better quality fluidisation water for FLSmidth Knelson Concentrators as well as other mineral processors. The completely stainless steel filters can withstand the harshest corrosive environments, and minimise plant downtime in any mine.
The clean water supply can be used in many applications, from pump gland water supply right through to the water supply to the Knelson Concentrators. In fact, these filters are even used to filter the entire plant water supply.
While GCA is an agent for a trusted and proven product range, the primary driving force behind the company’s success is customer satisfaction. The company is keenly focused on offering the highest quality mineral concentration products and techniques to suit the specific needs and budget of its clientele.
With decades of experience, the GCA team always goes the extra mile for its clients. In fact, GCA staff routinely traverse Africa – and indeed the world – in order to ensure that equipment commissioning, circuit audits, machine health checks, operation and maintenance training, and spares-holding checks run perfectly.
In addition, staff are able to offer support and advise from their desks. GCA is capable of recommending and supervising mineral testwork on behalf of its clients in order to have a better understanding of ore capabilities before providing guidance on the best equipment for the job at hand.
GCA owns facilities for bench and pilot-scale testing of Knelson semi-batch and continuous technology as well as Consep Acacia intense cyanidation.
These test machines are housed at and operated by Maelgwn Mineral Services Africa in Johannesburg, with supervision and advice from GCA. In addition to this, the company has other trusted testwork partners, should clients require an external evaluation.