DETERMINATION OF CHEMICAL AND MINERALOGICAL FORMS OF RARE METALS CONTAINED IN TECHNOLOGICAL WASTE OF "ALMALYK MINING AND METALLURGICAL COMPLEX" JSC

ABSTRACT

The chemical composition of the molybdenum production waste of "Almalyk Mining and Metallurgical complex" JSC was analyzed and a scientifically based approach and complex studies were conducted to study its physicochemical properties. Methods for extracting valuable components from waste by acid treatment have been suggested.

АННОТАЦИЯ

Проанализирован химический состав отходов молибденового производства АО «Алмалыкский горно-металлургический комбинат» и проведены научно-обоснованный подход и комплексные исследования по изучению его физико-химических свойств. Предложены способы извлечения ценных компонентов из отходов кислотной обработкой.

Keywords: refractory molybdenum ores, concentrates, oxidative roasting, pyrite, chalcopyrite, arsenopyrite, coal, processing efficiency, mineral decomposition, thermal interpretation.

Ключевые слова: упорные молибденовые руды, концентраты, окислительный обжиг, пирит, халькопирит, арсенопирит, уголь, эффективность переработки, разложение минералов, термическая интерпретация.

Introduction. Important tasks are defined in the fourth paragraph of the action strategy for the further development of the Republic of Uzbekistan. In this regard, scientific research aimed at increasing the yield of valuable components and intensification of the process in the complete extraction of molybdenum from molybdenite cakes in the waste products of JSC "Almalik Mining and Metallurgical Complex" (Almalyk MMC) is of great importance [1-3].

Powder metallurgy, which is of great importance in solving the specified tasks, its methods allow not only the creation of materials with new quality and operational characteristics, but also the introduction of waste or low-yield technologies for the production of materials and products for various purposes [4 ].

One of the main reasons for the complex use of man-made mineral raw materials is the lack of reliable information about its quality. Work on passporting and compilation of solid waste of non-ferrous metallurgical enterprises of Kazakhstan showed that it is the most reliable and complete information about the quality of metallurgical waste. At present, 15 mln. more than tons of solid and liquid molybdenum slurries have been collected, which contain Mo -4.66%, copper, rhenium and other precious metals. Involvement of these materials in production allows the combine to additionally obtain molybdenum and other precious metals.

Almalyk MMC is idle due to the lack of raw materials of a large amount of equipment and technological lines. In this regard, it is aimed at attracting waste to production, which is a very urgent task.

The purpose of this work is to study the laws of location and mineralogical and material composition of metals in molybdenum industry waste using modern physico-chemical methods.

Method and materials. The objects of research are composite molybdenum-containing industrial product (PPM), molybdenum soot (MO), as well as waste cakes of the Almalyk mining and metallurgical combine. "Almalyk MMC" JSC molybdenum soot (MO) is a multi-component composite system with a complex composition in the form of molybdenum (VI) oxide, unoxidized molybdenite, molybdates of various metals.

 A complex of chemical, physical and instrumental methods was used to analyze the elemental and material composition of waste. Elemental analysis of the samples was performed on an inductively coupled plasma mass spectrometer ICP-MS (Elan-6000, Perkin Elmer, USA). The chemical composition and microstructure of the obtained samples were analyzed by SEM-EDX (Jeol, IT 100, Japan). To establish the identity of the synthesized complex compounds, diffraction patterns were taken using a LabX XRD-6100 diffractometer (Shimadzu, Japan) with CuKα radiation.

The obtained results and their discussion

The material composition of the given samples was studied using a set of modern methods such as semi-quantitative, spectral, mass-spectral and some other types of modern analysis.

The semi-product of molybdenum has a complex composition. As can be seen from the X-ray phase analysis (Fig. 1), the intermediate product mainly consists of the following molybdenum compounds - MoS₂, CaMoO₄ and MoO₃, as well as Si, Mg, Cu, Fe, P, As determined from the energy dispersive spectra.

Figure 1. X-ray phase analysis image of a molybdenum semi-product

Based on energy dispersion spectra, the composition of PPM was determined (Fig. 2).

Figure 2. Microstructure and ED spectrum of PPM

The material composition of the given samples was studied using a set of modern methods such as semi-quantitative, spectral, mass-spectral and some other types of modern analysis.

Table 1 shows the results of spectral analysis of molybdenum-containing wastes.

Table 1.

Results of spectral analysis of molybdenum content wastes

Dissolving the waste using the soda method

At Almalyk MMC, caustic soda is used for breaking down concentrates containing molybdenum, which is not aggressive and does not require anti-corrosion equipment. We conducted experiments on alkalizing molybdenum cakes with caustic soda.

The burning process was carried out in a heat-resistant flask at a temperature of 450-500 C. The burning process lasted for 1 hour, and it was determined that the amount of molybdenum in the initial "waste" was equal to 7.18%. At the same time, it was mixed and alkalized by adding soda in different proportions. Alkalization with soda was carried out at high temperature, the temperature of the solution dropped to 60-70 C, and the Q:S ratio was ensured to be 1:4.

After filtering, the amount of molybdenum in liquid and solid phases was determined. The next table shows the cake composition data in the central laboratory of "Almalyk MMC" JSC

The mineral composition of the sample according to the X-ray phase and microscopic analysis is represented by the following components in Table 2

Table 2.

Results of the analysis of the initial cake and the control cake after laboratory training on soda hydrolysis

Mo content is 7.18%. It follows from the data of Table 3 that the amount increases from 49.4% to 71.2% as a result of three times alkalizing cakes with soda solution.

Table 3.

The results of hydrolysis of cakes with soda solution with a concentration of 120 g / l

Sem-edx results of ppm

Figure 3. Microstructure and ED spectrum of PPM

As a result of preliminary studies, ways of cleaning molybdenum industrial products from inorganic and organic impurities by hydrometallurgical method were determined.

The scientific basis of the work is the scientific results obtained during a number of research works in the field of pure metals.

Conclusion. As a result of the research, it was found that the raw material of semi-industrial carbon black containing 36.5% molybdenum contains the following harmful compounds (in %). Cu - 1.79; SiO2 - 9.32; P - 0.011; Au - 0.012; MoS2 is 0.65 and Re is 0.009.PPM samples were taken in the technological structure developed on the basis of the analysis of the complex of scientific and research works carried out in the laboratory, the analysis of its chemical composition showed that the amount of molybdenum in the chemical composition of the obtained PPM was 49.66%.

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