Search Results (5)

The processing of fine and technogenic chromite-bearing raw materials accumulated in tailings and sludge storage facilities is a key challenge for sustainable metallurgical development. This paper presents the results of laboratory and pilot-scale studies on the application of vibro-briquetting technology for flotation concentrates and waste materials from JSC “TNC Kazchrome” (ERG). For the first time in Kazakhstan, a pilot-scale validation of vibro-briquetting of flotation chromite concentrates was carried out, resulting in pilot confirmation of the vibro-briquetting technology. The optimal technological parameters of the process were established, and the effectiveness of various types of binders was evaluated. Pilot-scale trials demonstrated that the use of organic and mineral binders ensures the production of durable briquettes with a low yield of fines (around 2%). Comparison with conventional agglomeration technologies (pelletizing, sintering, roller-press briquetting, extrusion briquettes) highlighted the advantages of vibro-briquettes in terms of energy efficiency, environmental performance, and suitability for fine raw materials. It was shown that composite binders (lignosulfonate + cement) provide enhanced strength and water resistance in briquettes, as well as optimal conditions for strength development during thermal–moisture treatment. The findings confirm the high potential of vibro-briquetting technology in Kazakhstan as an energy-efficient and environmentally friendly solution for the integrated utilization of local chromite resources. The proposed vibro-briquetting technology makes it possible to process previously unused gravity and flotation tailings of chromite ores from the Kempirsai Massif, thereby improving the comprehensive utilization of mineral resources and reducing environmental impact. This development is of great importance for Kazakhstan’s industry, as it represents the first pilot-scale testing of cold vibro-briquetting technology for flotation concentrates. Full article

This article presents the results of a pilot study on the treatment of sludge from a water treatment plant in the city of Almaty, Republic of Kazakhstan, to ensure further disposal. The main objective of the study was to compare the efficiency of sludge drying by natural and artificial methods. The qualitative characteristics of the leachate from the dewatering unit, the chemical composition of the dried sludge and the granulometric analysis of the dried sludge were also studied. The greatest reduction in moisture content was recorded for drying in natural conditions (2.1%), but this process required the longest drying time. The leachate obtained from sludge dewatering was characterized by significant contamination (e.g., turbidity—55.65 on average, color—67.7, total Fe—5.15 mg/L, total N—79.6 mg/L, COD—311 mg/L, BOD—336.15 mg/L), which indicates the need for its pretreatment before further management in the technological system of the treatment station. The content of chemical substances contained in the dry residue of the sludge was also determined, of which aluminum was 0.94–13.8 mg/kg, silicon was 50.24–146.3 mg/kg, potassium was 1.72–5.51. mg/kg, calcium was 71.8–79.1 mg/kg, iron was 2.0–7.54 mg/kg and nickel was 0.9–4.4 mg/kg. A particle size analysis of the dried sludge showed that the majority fractions were fine and very fine sand, with a total of 20.2%, and silt and clay, with a total of 78.3%. Such properties justify the rationality of considering the reuse of dried sludge as a raw material for making, for example, construction materials or soil remediation material. Full article

This study investigates the presence of microplastics in tap drinking water and evaluates the efficacy of various sorbents for their removal in the context of Kazakhstan’s water treatment system. Water samples taken in the cities of Kokshetau and Krasny Yar (Akmola region) were analyzed. Microplastics were detected in all samples, with concentrations ranging from 2.0 × 10⁻² to 6.0 × 10⁻² particles/dm³, predominantly in fiber form (74.1%). Outdated technologies and non-compliance with treatment regimens contribute to poor water quality, including high turbidity (87% of samples), color deviations (40% of samples), and acidity issues (20% of samples). To address these challenges, the study examined the sorption efficiency of different sorbents, with results indicating high retention rates (82.7–97.8%) for microplastic particles. Notably, aliphatic structures like PE and PP exhibited higher retention than PET. Among the sorbents tested, the synthesized carbon sorption material (CSM) demonstrated the highest efficiency in both microplastic retention and improvement in water quality parameters, making it a promising option for water treatment facilities and household filters. Full article

Prolonged development of ore deposits, ore beneficiation and metallurgical smelting of concentrates result in the accumulation of wastes, forming large-scale dumps and sludge ponds negatively affecting the environment and human health. The creation and introduction of industrial waste treatment technologies will make it possible to dispose of them with the production of valuable commercial products and improve the environmental situation. In a research article on chemical beneficiation with the subsequent gravitational beneficiation of chrome-containing slurry tailings of Donskoy Ore-Mining and Beneficiation Plant (DOMBP), which processes chrome ore of the Kempirsay deposit in the Republic of Kazakhstan, Aktobe region, having considerable stocks of such waste is presented. The chromium-containing slurry tailings were heat-treated at 1100 °C, sintered with ammonium sulfate, water and sulfuric acid in a defined ratio at 300 °C, and then the resulting sinter was leached with water at 90 °C. The cake was washed to separate the liquid part from the solid part. The solid precipitate is the chromium-containing cake, which is upgraded by gravity concentration to a grade concentrate for ferroalloy production. When the solution is evaporated, magnesium sulfate with ammonium sulfate forms the Tutton’s salt ammoshenite. High-throughput chromium oxide extraction of 93.9% was achieved as a result of the research, and three products were obtained: (1) standard chromium concentrate with 49.48% Cr₂O₃ content, (2) ammoshenite used as a nitrogen–magnesium fertilizer and (3) forsterite, which is concentrated in gravity concentration tailings and can be used in the production of refractory minerals. Full article

Zeolite materials are among the relatively cheap and readily available materials for wastewater treatment. However, the performance of zeolite-based systems can be highly affected by the material properties. In this study, the treatment system based on natural zeolite materials from Chankanai mines in Kazakhstan was compared with a synthetic zeolite treatment system for the purification of groundwater. Water quality indices were also developed from a set of selected water quality parameters to further assess the state of water quality of raw groundwater and the effluents treated with natural and synthetic zeolite. The lowest removal efficiency of natural zeolite (30%) was observed with zinc, while the lowest removal efficiency (36%) of synthetic zeolite was observed with arsenic. With turbidity and beryllium, we observed the maximum removal efficiency (100%) of natural zeolite, whereas with turbidity, we observed the highest removal efficiency (100%) of synthetic zeolite. When the groundwater samples were put through the natural zeolite treatment system, removal efficiency of 50% and above was obtained with 27 (79.4%) out of the 34 water quality parameters examined. On the other hand, when the groundwater samples were put through the synthetic zeolite treatment system, more than 50% removal efficiency was attained with 30 (88.2%) out of the 34 water quality parameters studied. The aggregated water quality index of raw groundwater was 3278.24, falling in the “water unsuitable for drinking” category. The effluent treated with natural zeolite generated 144.82 as a water quality index, falling in the “poor water” quality category. Synthetic zeolite generated 94.79 as a water quality index, falling in the “good water” quality category. Across the board, it was shown that the synthetic zeolite treatment system outperformed the natural zeolite treatment system according to a number of water quality parameters. The findings of this study offer substantial knowledge that can be used to develop more efficient groundwater treatment technologies. Full article