Ўзбекистон республикаси фанлар академияси навоий бўлими ташкил этилганининг 5 йиллигига бағишланган “фан, таълим ва ишлаб чиқаришнинг

МЕЖДУНАРОДНАЯ НАУЧНО-ПРАКТИЧЕСКАЯ КОНФЕРЕНЦИЯ 
«ИНТЕГРАЦИЯ НАУКИ, ОБРАЗОВАНИЯ И ПРОИЗВОДСТВА – ЗАЛОГ ПРОГРЕССА И 
ПРОЦВЕТАНИЯ», ТОМ I, ГОРОД НАВОИ, РЕСПУБЛИКА УЗБЕКИСТАН, 2022 
- 104 -
Hydrogen peroxide were used for leaching pyrite in sulphuric acid 
condition. The investigation held in various parameters: temperature, stirring 
speed, particle size and concentrations of H
2
O
2
and H
2
SO
4
[4]. The results of 
investigations indicate that, increasing the stirring speed and the sulphuric 
concentration decreases the pyrite dissolution. Furthermore, the leaching rate is 
directly proportional to the hydrogen peroxide consumption. 
O
2
and Fe
3+
have also been found as the two most essential oxidizers for 
pyrite oxidation [5]. These oxidants, including varying pH, Eh, stirring speeds, 
grain size and temperatures setup to study pyrite leaching [5]. Investigations 
establishes that the addition of oxidants, Fe
3+
and O
2
, considerably inclines the 
rate of pyrite dissolution. In order to maintain high redox potential, further adding 
catalysts in the presence of these oxidants, leads to maximum oxidation rate of 
pyrite mineral. 
The kinetics of leaching pyrite within potassium dichromate solution was 
investigated [6]. The parameters studied were: stirring rate, temperature and 
particle size have been examined. The reaction
O
H
Cr
SO
Fe
H
O
Cr
FeS
2
3
2
4
3
2
7
2
2
19
10
4
2
38
5
2
+
+
+
=
+
+
+
−
+
+
−
From the results of these investigations revealed that the rate of leaching is 
limited by the chemical reaction on the surface particles. Besides this, the toxicity 
of potassium dichromate can cause serious problems to the environment, which 
making it hazardous method in mineral processing. 
Catalytic application of manganese could be another option to increase 
oxidation rate of pyrite. Because manganese has the feature, which increases the 
redox potential of the solution. The previous studies show, that the effectiveness 
of the bioleaching process of arsenopyritic gold ore improved by adding 
pyrolusite [7]. As a result, the bio-oxidation process was decreased obviously and 
leaching rate of gold from low grade sulphide ores reached 95,8% by cyanide 
leaching.
Based on a review of the literature, lot of investigations have been carried 
out on the oxidation of sulphide minerals using chemical, electrochemical and 
bioleaching techniques. There has been a fair amount of investigations into the 
ferric dissolution of pyrite, and there is no enough redox potentials occurring 
during this investigations, whereas the oxidation rate would be lower than redox 
potentials in bioleaching. Electrochemical principles can be applied to increase 
leaching rate, by adding several catalysts in the presence of O
2
and Fe
3+
. 
Therefore, it is important to use catalytic application to leaching process of 
pyrite. 
References 
1. S.R. la Brooy, H.G. Linge, G.S. Walker, Review of gold extraction from ores, Miner. 
Eng., 7 (1994), pp. 1213-1241 

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