Stanisław Małecki

A Methodology for Optimization in Multistage Industrial Processes: A Pilot Study

The paper introduces a methodology for optimization in multistage industrial processes with multiple quality criteria. Two ways of formulation of optimization problem and four different approaches to solve the problem are considered. Proposed methodologies were tested first on a virtual process described by benchmark functions and next were applied in optimization of multistage lead refining process.

Analysis of the chemical processes occurring in the system PbSO4ZnS

Abstract Research carried out on the interactions between PbSO 4 and ZnS, using mixtures with variable molar ratios of PbSO 4 :ZnS, showed that the process starts at 803 K. It was found that a few reactions occur at the same time, including transformation of zinc sulfide into its oxide and PbS formation; the secondary lead sulfate containing the sulfur from ZnS also appears. The PbS is derived primarily from PbSO 4 , and some of it contains the sulfur from ZnS.

Analysis of the reaction between PbSO4 and ZnS

The reaction between ZnS and PbSO4 has been studied at different mole ratios. It has been found that the reaction is multistage. The products of the first stage of the reaction consist mainly of ZnO, PbS and PbSO4 in different amounts, depending on the mole ratio of the substrates. The following stages consist in the interaction of PbS formed in the first stage with PbSO4. It has been found that the reaction rate depends on the temperature and on the PbSO4∶ZnS mole ratio (up to 3∶1).ZusammenfassungDie Reaktion von ZnS mit PbSO4 wurde bei verschiedenen Molverhältnissen untersucht. Man fand, daß die Reaktion in mehreren Schritten abläuft. Die Produkte des ersten Schrittes sind hauptsächlich ZnO, PbS und PbSO4, deren Mengen vom Molverhältnis der Reaktanten abhängen. Die folgenden Reaktionsschritte bestehen aus den Zusammenwirkungen von dem primär gebildeten PbS mit PbSO4. Dabei hängt die Reaktionsgeschwindigkeit von der Temperatur und vom Molverhältnis PbSO4∶ZnS (bis zu 3∶1) ab.РезюмеИзучена реакция межд у сульфидом цинка и сульфатом свинца при их различном молярном соотношени и. Найдено, что данная р еакция является многоступе нчатой. Главными продуктами разложен ия на первой стадии ре акции являются оксид цинка, сульфид свинца и сульфат свинца, колич ество которых зависи т от молярного соотношен ия исходных компонен т. На последующих стади ях происходит взаимо действие сульфида свинца с сул ьфатом свинца. Установлено, что скор ость отдельных стади й реакций зависит от температу ры и молярного соотношения сульфат а свинца и сульфида ци нка (верхный предел 3∶1).

Reduction of lead and zinc sulphates by hydrogen

In this paper, the results of the thermogravimetric tests reduction of lead and zinc sulphates by hydrogen are presented. Tests performed under isothermal conditions allowed to determine the effect of temperature on the formed products of the reaction. The temperatures at which the maximum content of sulphides present in the products of reduction were determined. For the reduction of lead sulphate, value of the activation energy of the process and the participation of partial reactions in the process were determined.