Process control slurry samplers from Multotec Process Equipment installed at the Gamsberg zinc project near Aggeneys in the Northern Cape, South Africa, will allow reliable real-time process results to be generated by the metallurgical plant. Gamsberg 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/min.
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.
The picture shows a primary slurry sampler complete with a 450 steel angle, 304 stainless cutter to allow free flow of sample increments, minimising sample extraction error.
