Water Network Optimization Of Sb Recovery From Lead Anode Slime

Lead anode slime, which is rich in Sb and other noble metals, is produced in lead electrolytic process. It costs large quantities of freshwater to recover metals from lead anode slime and produces much wastewater, and forms a water network. It is necessary to design a technological process of Sb recovery in the lead anode with no pollution to environment and high economic benefit, it also avoids form new waste and pollution.The main contents of this paper are as follows:(1) Water network optimization is applied to Sb recovery from lead anode slime based on superstructure, waste liquid and waste slag produced during the refining with the technology of hydrometallurgical treatment is also taken into account. An NLP model with consideration of both the wastewater minimization and Sb recovery is developed. Besides the traditional mass balance, chemical reactions are also considered. The model parameters are determined based on experimental data of real process. The optimal result has been obtained with an improvement of 87.4% reusable water, and solved by General Algebraic Modeling System (GAMS). Reasonable process with solvent recycle, provids effective suggestion for building industrial device process of Sb recovery from lead anode slime. Discussions on the flowsheet with optimal structure are presented.(2) Flexibility analysis for the affect on water network superstructure of uncertainty parameters in the NLP model is proposed. In this paper, three uncertainty parameters: charge of freshwater, residual of As and HCl are analysised, respectively. It is shown that charge of freshwater affects reuse between some processes greatly, and increases with the minimum of objective function linearly, corresponds to project design practice. Residual of As affects reuse between each process and total freashwater remarkably, and also increases quickly with the minimun of objective function linearly. The feasible optimizational superstructure can be achieved when residual of As is between 0.01% and 10%. However, residual of HCl affects reuse between each process and total freashwater and the minimun of objective function littlely, the main reason is that the influence between residual of HCl and water network superstructure, the minimun of objective function is not showed in this paper, because of strict requirements of entrance solution during hydrolyzing of SbCl3 and relaxation limits of environmental emission.