MechChem Africa October 2018

⎪ Minerals processing, metallurgy and materials ⎪

Process control slurry samplers for real-time results Accurate mineral’s sampling is important to ensure thatAMIRA standards of metallurgical accounting and best practice are being applied in a plant’s sampling applications and are representative of the whole shift operation. 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.

Dise Nyokong.

P rocesscontrolslurrysamplersfromMultotecProcess Equipment have been installed at theGamsbergZinc project near Aggeneys in theNorthernCape andwill allow reliable real-time process results to be gener- ated by the metallurgical plant. TheGamsbergZincprojectiscurrentlybeingconstructedby ELB Engineering Services, andMultotec Process Equipment’s process engineer Modisaotsile Nyokong says the equipment supplied includes gravity (sharkfin type) andpressurised (pres- sure pipe) samplerswith each sampler being custom-designed to suit the flow requirements of each analyser. The samplers will provide a continuous sample to the on- line particle size analyser (PSI) and X-ray fluorescence (XRF) analysers. PSI analysers require100 ℓ /min,whileXRFanalysers require 100 to 300 ℓ /min. According to Nyokong, the unique single-stage vezin sam- pler and double-stage ‘Two In One’ metallurgical accounting samplers will collect representative final composite sample sizes of less than 20  ℓ per shift from streams ranging from 80 to 700 nominal bore inlets. Nyokong emphasises the importance of ensuring that AMIRA standards for metallurgical accounting and best prac- tice 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.

‘Two In One’ sampler consisting of breathers (two on either side) to allow for primary cutter inspection and prevention of back pressure.

The benefit of the total sampling solution supplied by Multotec is to have both a process control sampler and a metallurgical accounting samplerinthesamestream.Processcontrolsam- plersarespecimentakers,providingsamplesthat are used for real time process control purposes. The ‘two-in-one’ metallurgical accounting sampler comprises two separate sampler units in one, with a primary and a secondary sampler unit assembled into one compact unit allowing for a net plug-and-play solution. The design al- lows 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 inspec- tion cover on the top of the secondary housing. Anadvantage is that the sampler cutter of the primary unit cuts the full stream of the slurry at constant speedwith 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 streamof theprimary sample. q

A primary slurry sampler complete with a 45° steel angle and a Grade 304 stainless cutter to allow free- flow of sample increments and minimised sample extraction error.

36 ¦ MechChem Africa • October 2018