Analysis of the Possibility of Using New Types of Protective Coatings and Abrasion-Resistant Linings under the Operating Conditions of the Spiral Classifier at KGHM Polska Miedź S.A. Ore Concentration Plant

Abstract

A study was carried out to select the appropriate coatings for corrosion protection of the spiral classifier working at KGHM Polska Miedź S.A. Ore Concentration Plant. The abrasion resistance of selected protective coatings and wear-resistant linings was investigated using a DT-523 rotary abrasion tester with Taber CS-10 rubber abrasive discs. The average weight loss of the coatings after a cycle of 2000 revolutions was determined. Tests of protective coatings using the electrochemical impedance spectroscopy (EIS) technique were carried out to determine the suitability of coatings in the highly saline environment of the aqueous suspension of ground copper ore. During the measurements, changes in resistance, polarising current and capacitance were determined as a function of time for the tested coatings. The linings selected on the basis of laboratory tests were also tested under industrial conditions. Their degrees of wear were characterised. The results obtained indicated the highest abrasion resistance of materials from the polyolefin group (polyethylenes), where the average weight loss did not exceed 5 g/dm2. In the case of protective coatings, the highest durability was demonstrated by coatings with additives of ceramic aggregates, phenol-epoxy, and an elastomeric coating based on polyurea, whose average weight loss during the test cycle did not exceed 19 g/dm2. EIS measurements showed that the tested coatings were resistant to the aggressive environment of the feedstock. Tests under cathodic polarisation conditions of the samples at a potential below the protection potential showed that they were resistant to a highly saline environment and were also resistant to its alkalinisation resulting from the application of cathodic protection, which will be used to protect the classifier together with protective coatings. Tests carried out under industrial conditions using wear-resistant linings made of plastics have made it possible to analyse the mechanism and degree of wear of the various materials during the operation of the classifier. Measurements of lining wear were made in relation to baseline volumes. Polyurethane, a polymer lining based on MDI and PTMG, and those made of ultra-high-molecular-weight polyethylene with anti-stick additives showed the lowest wear rates.

Cathodic Protection System of the Spiral Classifier at the KGHM Polska Miedź S.A. Ore Concentration Plant—Case Study of Commissioning and Control of Operating Parameters

“…In the case of coating layers, the highest durability is exhibited by phen epoxy-and urea-based elastomer materials, as well as materials containing hard cera additives [10]. The lowest weight losses among a number of tested linings (in the origi study presented in [11]) were exhibited by ultra-high molecular polyurethanes and po The operating environment of the classifier is very demanding, due to the presence of highly saline process water and crushed rock [8], 95% of the grains of which are smaller than 1 mm. The 2021 data originating from the chloride and sulphate monitoring system created for the purposes of KGHM Polska Miedź S.A. indicate the presence of chloride ions (Cl − ) at a level of 36.05 g/dm 3 , while the concentration of sulphate ions reaching the Polkowice area is 1.81 g/dm 3 .…”

“…In the case of coating layers, the highest durability is exhibited by phenolic epoxy-and urea-based elastomer materials, as well as materials containing hard ceramic additives [10]. The lowest weight losses among a number of tested linings (in the original study presented in [11]) were exhibited by ultra-high molecular polyurethanes and polymer materials, including polyamides containing added molybdenum disulphide [12]. The application of a barrier coating and lining protection significantly limits the degradation process of a device, namely, the spiral classifier.…”

Multiclass Level-Set Segmentation of Rust and Coating Damages in Images of Metal Structures

“…The availability of metal, oxide, composite and non-metallic coatings allows for rationally combining the base and coating materials’ properties. The most frequently used coatings are paint coatings [ 1 , 2 , 3 , 4 , 5 ], polymers [ 6 , 7 , 8 ], and biopolymer films [ 9 , 10 ]. All these types of widespread coatings are used in various fields of technology and medicine.…”