# Alkaline Extraction of Organomineral Potassium Humate from Coal Mining Waste
## 3 Results and Discussion  
### Characteristics of Coal Mining Waste  
Brown coal is a solid fossil fuel of humus nature and a low degree of carbonification. In the series of fossil coals, brown coal occupies the lowest stage, a transitional link between peat and hard coal [19]. Brown coal deposits in the city of Lenger in the Turkestan region were exploited from the time of tsarist Russia until the 1960s. At that time, mining and open-pit methods were used for the extraction of brown coal. As a result, there are currently seventumps accumulated in the form of landfills on the territory of the city. Samples for experimental studies were taken from landfill No. 1 (Figure 1). As can be seen from the map, fourlandfills are located on the territory of the city, and the remaining threeare in nearby areas. The total volume of all landfills is approximately 34 thousand tons. Wind erosion significantly affects the ecological situation in the city and nearby villages, although the impact of these types of waste on air quality in the city has not been studied. However, there are publications about the complaints of local residents about coal dust, which rises during winds and hurricanes [20,21]. The impact of coal dust on the human body is very toxic, causing chronic lung diseases [22]. In this regard, the study of physico-chemical properties and the search for methods of coal mining waste disposal is relevant. Chemical, elemental-weight and microstructural analysis of samples taken from this dump werecarried out. The surfaces of the studied samples were examined in the spectrum at 40-fold magnification. The results of the study are presented in Tables 1 and 2 and Figure 2.  
According to the above data, the main part of coal mining waste is carbon, as well as substances such as sulfur, aluminum and silicon oxides. Potassium and calcium compounds are also present in small amounts.While in the microstructure of the obtained sample, minerals of sulfur, iron and calcium compounds are represented by whole clusters, minerals in the form of a small hexagonal crystal prove the presence of calcium aluminates. The silicon-containing compounds in the test sample are described by fine-type chain compounds [23]. The results of X-ray diffraction analysis of coal mining waste are shown in Figure 3. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Element** & **Weight, \%** & **Oxides** & **In Terms of Oxides, \%** \\ \hline C & 43.00 & - & - \\ O & 39.43 & - & - \\ Al & 3.79 & Al\({}_{2}\)O\({}_{3}\) & 7.16 \\ Si & 6.42 & SiO\({}_{2}\) & 13.73 \\ S & 1.03 & SO\({}_{3}\) & 2.57 \\ K & 0.40 & K\({}_{2}\)O & 0.48 \\ Ca & 0.43 & CaO & 0.60 \\ Fe & 5.49 & Fe\({}_{2}\)O\({}_{3}\) & 7.85 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Element-weight composition of coal mining waste. Figure 3: X-ray diffraction analysis of coal mining waste. Figure 2: Microstructure and energy dispersion analysis of coal mining waste. According to the data shown in the figure, the structure of coal mining waste wascharacterized by minerals such as quartz, kaolinite and muscovite. It was found that a significant part of the structure wasoccupied by quartz-type minerals (90.4%). Moreover, compounds in the form of kaolinite and muscovite hadfractions of 7.1% and 2.4%, respectively. X-ray diffraction analysis showedonly the inorganic part of the original sample. To describe the organic part the method of IR spectral analysis was used, carried out on a modern IR-Fourier device Shimadzu IR Prestige-21. The results of the study are presented in Table 3 and Figure 4.  
According to the IR spectrogram, the composition of coal mining waste contained compounds C-H, O-H, occurring at wavelengths 3700-2630 cm\({}^{-1}\), whereas the wavelengths 1900-1500 cm\({}^{-1}\) werecharacteristic of compounds with a double bond C=C. Diffraction peaks between 1230 and 850 cm\({}^{-1}\) indicated the presence of organosilicon compounds such as Si-O-C, Si-O-Si.