Education of the republic of uzbekistan tashkent state technical university named after islam karimov

Keywords
: desiliconization, ammonium fluoride, slags, nanopowders, amorphous silicon 
dioxide, particle size, ammonium hexofluorosilicate. 
 
INTRODUCTION. 
At present, JSC "Almalyk MMC" has accumulated at least 15 million tons 
of dump slags from copper-smelting production, containing a lot of such valuable components as 
non-ferrous, noble and also rare metals, the extraction (or additional extraction) of which, from a 
technological point of view, is a rather difficult task. The chemical composition of these man-
made wastes has a peculiarity in that they consist of 30 to 40% silicon dioxide SiO
2
. Therefore, 
removal of SiO
2
from slags, i.e. desiliconizing them, allowing you to obtain a concentrate of the 
above valuable components. In addition, the implementation of an effective technology for the 
integrated processing of dump slags from copper-smelting production will also expand the raw 
material base of the republic's mining industry and improve the environmental situation.
 
The addition of SiO
2
nanopowders makes it possible to improve and impart new 
properties to various materials. In particular, the addition of amorphous SiO
2
nanoparticles 
increases durability, changes the viscosity and fluidity of paints, varnishes, adhesives and 
sealants [1-4], and in the food industry, the addition of SiO
2
nanopowders to food products 
prevents their clumping and sintering during heat treatment [5, 6]. It is known the use of SiO
2

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№3/2021 year. 
Technical science and innovation 
26 
nanopowders in the pharmaceutical industry [7, 8], in the production of glass, abrasives, 
ceramics, as well as in the production of concrete as the main component [9, 10], which 
increases its strength and other performance characteristics, and, finally, in electronics in the 
production of microcircuits and fiber -optical cables [11, 12]. It should be noted that one of the 
important areas of application of amorphous SiO
2
is the production of industrial rubber goods 
and plastics [13]. The addition of SiO
2
as a reinforcing filler in a mixture for rubber production 
significantly increases the strength of products and, in comparison with carbon black, 
significantly reduces, for example, such a parameter as tire rolling resistance, which, in turn, 
leads to a decrease in vehicle fuel consumption [14]. 
The purpose of this work is to develop an effective technology for desiliconization of 
dump slags of copper smelting production in order to extract valuable components from them 
and control the synthesis of highly dispersed powders of amorphous silicon dioxide. 
The development of efficient technologies for processing copper slags of the Almalyk MMC 
have been discussed many times [15, 16], but the problem of their desiliconization has not been 
considered in them. 
Table 1 (a) shows the results of chemical analysis of waste slag according to the passport 
data of JSC "Almalyk MMC" and according to the data of the Central Laboratory of the State 
Committee for Geology of the Republic of Uzbekistan (b).