SLUDGE-FREE PRODUCTION OF PURE ALUMINA FROM ROCKS CONTAINING IRON OXIDES AND SILICA

J.М Alieva,G.V Shadlinskaya,I.A Talibli,A.M Gasimova,A.N Mammadov,R.G Gamidov,G.M Samedzade

doi:10.32737/0005-2531-2022-1-68-72

Abstract

It has been established that the extraction of aluminum from the rocks containing large amounts of alkali-soluble silicates and iron oxides can be processed by the acid-alkali method, except for the formation of wasted sludge. The carried out thermodynamic analysis showed the possibility of carrying out the process of reduction of a mixture of aluminum and iron sulphate salts with hydrogen. The optimal conditions for the reduction of aluminum and iron sulphates with hydrogen have been found with the production of S2 and SO2 and stub in the gas phase. Pure aluminum is obtained from stubby the Bayer method

Highlights

The use of pure alumina in various industries is growing every year
The presence of the endothermic effect can most likely be attributed to the release of an excess of sulfuric acid adsorbed during the precipitation of aluminum and iron sulphate salts, which is 3% of the mass fraction of the sample
From the obtained mixture of sulphate salts, which was dehydrated at 3504000C, a sample of 0.3 g was reduced with hydrogen in an alundum boat in a flow-through quartz reactor in the form of a tube

Summary

Introduction

The use of pure alumina in various industries is growing every year. The purest alumina is obtained after the processing of aluminumcontaining raw materials according to the alkaline Bayer scheme. Considering that during desiliconization in the alkaline method, per 1 kg of SiO2, Na2O and Al2O3 lose up to 0,6 kg and 1 kg, respectively, as well as up to 1 kg of wasted red mud is formed, the high requirements for bauxite, from which alumina is obtained, are understandable [1–7]. From acidic salts, according to the alkaline Bayer scheme, pure alumina and sludge are obtained in the form of AZERBAIJAN CHEMICAL JOURNAL No 1 2022. Preliminary reduction of sulfate salts of aluminum and iron with the use of gaseous reducing agents was proposed to obtain SO2, S, H2O in the gas phase and the stub composed of Al2O3, Fe2O3 and FS in the gas phase [6]

Thermodynamic analysis

Findings

Experiments and discussion of their results

Conclusions