Many Democratic Republic of the Congo (DRC) hydrometallurgical plants are confronted with the presence of silicaSilica which is one of the deleterious elementsElements co-extracted into the pregnant leach solution (PLSPregnant Leach Solution (PLS)) from leachingLeaching to solvent extractionSolvent extraction (SX) where it can cause operational issues. Levels of this impurityImpurity can vary from one plant to another, and for the same operationOperation they might fluctuate over time depending on the tenor in the plant feed material and leachingLeaching conditions. Higher concentrations of silicaSilica in PLSPregnant Leach Solution (PLS), usually above 500 ppm, are known to increase crud formationFormation, cause slow phase disengagement timesPhase disengagement time and instabilities of the desired mixer’s organic continuity, and thus reduced plant operating capacity due to increased entrainmentEntrainment and crud run. Various coagulantCoagulant chemistries have been introduced to the DRC hydrometallurgical industry in the past 10 years, some of them were considered for laboratory trials while few among them were selected for plant applications. Different silicaSilica elimination levels were achieved depending on the nature of the product, the dosage and addition point. Varied impacts were noticed on downstream processes: Solid liquid separation (SLS) and SX. This paper discusses the observations made during comparative laboratory testing works in different hydrometallurgical plants, and the implications of using two different products, i.e. cationic polyaminePolyamine and neutral polyetherPolyether coagulantsCoagulant.