Simulation-Assisted Evaluation of Salt Purification for Industrial Textile Applications

Abstract

The textile industry requires high-purity salt as a critical raw material for dyeing. However, in many developing countries, including Honduras, locally produced marine salt does not consistently meet industrial purity specifications, resulting in dependency on imports and higher production costs. This study presents the design and simulation of a marine salt purification process aimed at textile-grade applications, using Aspen Plus as the primary modeling tool. The proposed process integrates brine pretreatment, chemical coagulation, filtration, heat exchange, vacuum crystallization, centrifugation, and convective drying. An electrolyte-based thermodynamic model was implemented to accurately represent salt dissociation, impurity precipitation and phase behavior. Equilibrium constants, solubility data, and reaction sets were defined to simulate impurity removal, particularly magnesium and calcium salts. Laboratory-scale data were used to validate feed composition and preliminary operating conditions. Process performance was evaluated through mass and energy balances, product composition analysis, and sensitivity studies on key operating variables such as reagent dosage, water addition, vapor flow rates, and drying conditions. The simulation results indicate that the process achieves a final sodium chloride purity of approximately 98.3% by mass, suitable for industrial textile use, with an overall process yield of 93.3%. Sensitivity analysis identified optimal operating regions that maximize purity while minimizing reagent and energy consumption.