Engineered for use in the most aggressive duties, Warman® Mill Circuit pumps easily manage large size particles in highly abrasive slurries. These pumps are designed for the most severe slurry applications such as ball and SAG mill cyclone feed as well as water-flush crushing in mineral processing plants. Weir Minerals Africa is showcasing its flagship mill circuit pump – the Warman® MCR®450 at Electra Mining Africa 2018. Marnus Koorts, Product Manager – slurry pumps at Weir Minerals Africa, says “customers will be able to see this massive pump with its 1.5 metre diameter. Like all pumps in the Warman® MCR® range, this 13 ton slurry handling machine is designed to increase productivity and decrease downtime, compared to older generation and other pumps in the industry”. Koorts says that the Warman® Mill Circuit pumps are based on 80 years of fundamental and applied research, backed by wear performance field trials. “Mill circuit applications are among the toughest in a minerals processing plant, and the Warman® MCR® pumps incorporate the latest in hypereutectic alloy and elastomer technology,” he says. “This significantly extends the wear life of the pump in highly abrasive and corrosive slurries, reducing operational costs.” The high resilience rubber wear liner enables the handling of coarse particles and ball scats with ease, while its lightweight design relative to other pumps in its category facilitates safer handling. It is also a lower cost than traditional heavy metal liners. Importantly, different material combinations are available to ensure that the customer gets a fit-for-application pump capable of providing reliable performance cost effectively, tailored to their site conditions. The Warman® MCR® pump has a large diameter, low speed, high efficiency impeller. Koorts explains that this can be manufactured from a range of abrasion resistant alloys allowing the most appropriate material to be selected for the customer application. This will increase wear life and reduce operating costs when compared to other pumps in its category. Reduced recirculation is achieved by the deep expelling vanes on the front of the high chrome alloy impellers. Expelling vane tip turbulence is minimised by the patented shroud feature that traps tip vortices and prevents localised scouring on the throatbush face. This, again, extends wear life and reduces maintenance. The split outer casing on the Warman® MCR® pump provides structural integrity and high operating pressure capability, ease of maintenance and safety. This feature also allows internal liners to be fully worn before replacement. Warman® throatbushes feature pre-swirl vanes which offer optimum reliability and wear life. There is a patent pending on this innovative throatbush design which was developed to improve impeller eye wear life and reduce the wear caused by recirculation at the impeller-throatbush interface. This has been accomplished by a series of guide vanes in the pump inlet which induce a rotational velocity in the slurry. An adjustable stuffing box allows for the centering of the stuffing box and lantern restrictor to the shaft sleeve. This increases packing life and decreases gland seal water consumption. Another new design feature is the single-point gland adjustment which facilitates safe packing adjustment outside of the stuffing box guard while the pump is operating. “Our Warman® Mill Circuit pumps are engineered to offer the most cost effective solution across a range of applications, and with installations on many leading mine sites across the globe it is proven to be the mill circuit pump of choice for the hard rock mining industry,” Koorts concludes.

Process control slurry samplers from Multotec Process Equipment are installed at the Gamsberg Zinc project near Aggeneys in the Northern Cape, and will allow reliable real-time process results to be generated by the metallurgical plant.

The Gamsberg Zinc project is currently being constructed by ELB Engineering Services, and Multotec Process Equipment’s process engineer Modisaotsile Nyokong says the equipment supplied includes gravity (shark fin type) and pressurised (pressure pipe) samplers. Significantly, each sampler is custom-designed to suit the flow requirements of each analyser.

The samplers will provide a continuous sample to the online particle size analyser (PSI) and X-ray fluorescence (XRF) analysers. PSI analysers require 100 litres per minute, while XRF analysers require 100 to 300 litres per minute.

According to Nyokong, the unique single-stage vezin sampler and double-stage ‘Two In One’ metallurgical accounting samplers will collect representative final composite sample sizes of less than 20 litres per shift from streams ranging from 80 NB to 700 NB inlet-correct.

Nyokong emphasises the importance of metallurgical accounting in ensuring that AMIRA standards and best practice are being applied in the plant’s sampling applications. “The metallurgical plant needs to ensure that samples collected from metallurgical accounting samplers are representative of the whole shift operation and are used for accurate metal accounting balances,” he says.

The benefit of the total sampling solution supplied by Multotec is to have both a process control sampler and a metallurgical accounting sampler in the same stream. Process control samplers are specimen takers, providing samples that are used for real time process control purposes.

The ‘Two in One’ metallurgical accounting sampler comprises two separate sample units in one, with a primary and a secondary sampler unit assembled into a compact unit allowing for a net plug and play solution. The design allows easy access, as the primary cutter can be inspected through a bolted hatch on the top and side of the housing. The secondary cutters can also be inspected with ease, through an inspection cover on the top of the secondary housing.

An advantage is that the sampler cutter of the primary unit cuts the full stream of the slurry at constant speed with sufficient volume to collect the sample, minimising sampling extraction and delimitation errors. The sampled slurry then reports to the secondary vezin sampler where the four cutters cut the full stream of the primary sample.

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