Engineering Journal of Satbayev University

Overview of the main pathways for biochar utilization in iron and steelmaking

2026-09-01T11:06:55+00:00

This paper summarizes the main applications and property requirements of biochar in iron and steel production as a renewable alternative to fossil carbon materials. It discusses its application in cokemaking, iron ore sintering, blast furnace (BF) injection, basic oxygen furnace (BOF), and electric arc furnace (EAF). For each process, the functions of biochar and the requirements for its main properties, reactivity, porosity, density, and mechanical strength are systematized. It is shown that in cokemaking, the biochar share is typically limited to about 10 wt% because it deteriorates coke strength and reactivity. In iron ore sintering, 40-60 wt% of coke breeze can be replaced by biochar, and in BF injection, the substitution level depends on combustion conditions and the need to maintain a stable temperature in the tuyere zone. Biochar has the greatest potential in BOF and EAF, where it can be used as a supplementary energy source, carburizer, and slag foaming agent. The main limitations of industrial biochar application include instability of properties, low density and strength, heterogeneous ash composition, and a tendency to self-heat. It is concluded that specific biochar requirements need to be developed for each metallurgical process.

Distribution of Cu, Pb, Zn and As between the products of the reduction melting of slag from the Vanyukov furnace in the conditions of the Balkhash copper smelter

2025-08-11T06:32:58+00:00

The results on the distribution of Cu, Pb, Zn and As between the products of the reduction melting of slag from the Vanyukov Furnace (VF) in the conditions of the Balkhash Copper Smelter (BCS) are presented. Optimal technological parameters of the process of two-stage reducing depletion of slags by natural gas in the presence of coal at a temperature of 1300°C. have been established. It is shown that under conditions of two-stage reductive depletion of VF slags, the residual metal content in the reduced slag is: copper – 0.35%; lead – 0.08%; zinc – 0.18%; traces of arsenic. High recovery of metals into target products has been achieved: copper in matte – up to 98%; gold, silver in matte – 96%; arsenic in dust at the first stage of slag treatment with natural gas – up to 99% and lead, zinc in dust at the second stage – up to 98%. The results obtained were used in the development of an innovative technological platform for a comprehensive waste-free technology for processing current and accumulated BCS slags to produce marketable products.

Germanium production from Kazakhstan coals: resource potential, technological solutions and prospects

2026-08-07T05:07:04+00:00

Germanium (Ge) is a rare trace element belonging to the group of materials that are critical for the development of high-tech industries, including semiconductor manufacturing, optoelectronics, space technologies, infrared optics, and defense systems. This review examines global models of germanium production, including traditional extraction from zinc concentrates and the development of the coal-based route in China; it analyzes the geochemistry of germanium accumulation in promising coal basins of Kazakhstan and assesses the prospects for establishing high-purity germanium production in Kazakhstan based on coal feedstock and technogenic products of its processing in the power and metallurgical industries. The prerequisites are shown for forming a new model of germanium production in Kazakhstan, based on a combination of two sources - zinc metallurgy and germanium-bearing coals – as well as the considerable potential of brown-coal (lignite) basins, including the Turgai and Zhilanshik basins. A technological model is proposed for obtaining germanium concentrates from coal feedstock, producing germanium dioxide (GeO₂), and producing high-purity metallic germanium. This approach is proposed as a basis for developing an export-oriented critical materials industry.

Comprehensive monitoring of the meliorative state of irrigated lands as the basis for sustainable water utilization in the Turkistan Region

2026-03-13T21:29:30+00:00

In the conditions of a growing water scarcity, comprehensive state monitoring of irrigated lands is of particular importance. The study is based on data from the Ministry of Agriculture of the Republic of Kazakhstan and the South Kazakhstan Hydrogeological and Meliorative Expedition. The aim of the work is to assess the current state of the land in the Turkistan Region, analyze the dynamics of groundwater levels and mineralization, and identify the causes of soil degradation. The monitoring covers an area of over 550 thousand ha and includes the systematization of data from laboratory studies and hydrogeological observations. The results of the work substantiate recommendations for the restoration of drainage systems and the optimization of water use. The conclusions formed contribute to the sustainable development of the agrarian sector and the enhancement of the region’s food security in the conditions of climate change.

Rationale for the development of large-scale underground water storage systems in Central Kazakhstan using managed aquifer recharge

2026-06-03T06:45:42+00:00

This paper presents a rationale for typical artificial groundwater recharge schemes, considering the physical, geographical, and hydrogeological conditions of large underground reservoirs in Central Kazakhstan. The aim of the paper is to analyze modern aquifer recharge methods and assess their effectiveness and applicability depending on reservoir characteristics, the availability of water sources, and the region’s water demand. The paper examines various technological schemes for artificial groundwater recharge and measures to regulate filtration processes, assessing their technical and economic feasibility. The obtained results allow for the development of recommendations for the optimal use of the region’s water resources, ensuring a sustainable water supply, and mitigating the negative impact on natural ecosystems. Furthermore, the paper emphasizes the importance of an integrated approach to water use planning that considers both geological and socioeconomic factors.

Paleothermicity and hydrocarbons generation modelization in the eastern part of the Precaspian Basin and Pre-Uralian Basin (Kazakhstan)

2026-05-08T07:22:12+00:00

The Precaspian basin is the main oil province in Kazakhstan, where there are such giant fields as Tengiz, Karachaganak, Astrakhan and Kashagan. In previous works have been identified source rocks associated mainly with the sub-salt complex. However, the issue of such parameters as the depth of the oil window remains unresolved, because the geothermal gradient is low and the studied source rocks have a low maturity. By the study of the organic matter in these sediments and simulation of genesis of hydrocarbons by Petromod 1D software (IES Gmbh; now Slb), we wanted to determine the depth range of oil window for essential source rocks. This area is composed of three parts from Devonian to late Carboniferous: the Precaspian Basin subdivided into a basin (claystones, mudstones and calciturbidites) and a platform (limestone and storm sandstones), and the Pre-Uralian Basin (turbidite sandstones). For the studied sector the values of the Ro are low and varies from 0.4 to 0.7 and Tmax lies between 420 and 445°C. The simulation of the heat flow was calibrated by Vitrinite reflectance with different kinetics according to the type of organic matter – Vandenbroucke et al. (1999)’s model was chosen for the type III (Brent) and for the type II (KCF). The low value of the heat gradient can be compensated by the geological duration during which source rock undergoes the transformation. In the sector studied the phase of generation of oil can correspond to the level of evaluation, corresponding to value 0.5% of Ro and even 0.4% for the algal type or mixed OM II/III. For the studied formations, the major part of hydrocarbons was generated from the maximal phase of burial. We can distinguish four zones in which the depths of the beginning and end of the oil window are different: the western zone (basin) from 4-4.5 km to 7-9 km, the zone of slope and border from 3-3.7 km to 4.5-5 km, the zone of Preuralian basin from 2.8-3.3 to 4.5-5 km, and the eastern zone under the thrust of Ural (Izembet) from 2-2.8 to 3.5-4 km.