The whole world aims to reduce coal consumption, but despite such a policy, there are countries where its consumption continues to grow (China, India). If coal consumption grows, the volume of ash and slag waste (materials) that must be utilized and processed to obtain final products grows. The main elements included in the by-product of coal combustion are SiO2, Al2O3, and Fe2O3. The paper provides a review of the use and processing of ash and slag materials for recycling as well as potential directions for their disposal: as well as potential directions for their disposal: cement production, geopolymer, in zeolite synthesis, microsphere separation, in agriculture, in land reclamation, in phytoremediation as reagents for water purification, in road construction for backfilling abandoned mines. The authors employed physicochemical analysis methods to confirm that the primary components of the material are SiO2 (65.9%) and Al2O3 (22.5%). It has been established that a high proportion of silicon and aluminum can be an effective raw material for construction and geopolymer materials, as well as in the production of ceramic products. Availability of Fe2O3 (5.54%) suggests possibilities for its use in catalytic processes and pigment production. The alkaline reaction of the aqueous extract of the ash (pH = 9.25) correlates well with its chemical composition and confirms the presence of active alkaline components in the material. This alkaline nature of the ash favors geopolymerization processes and increases the material's reactivity when interacting with acidic activators. Additionally, the minor presence of TiO2 (1.11%) may improve the mechanical properties of ash-based materials.

В статье представлены результаты комплексного исследования микроминерального состава плацент жительниц Акмолинской области, региона, характеризующегося повышенной радиоэкологической напряжённостью, связанной с интенсивной добычей урана и золота, а также с наличием природных радоновых аномалий. Основной целью исследования стало выявление особенностей накопления и распределения минеральных фаз в плацентарной ткани, что позволило оценить влияние эколого-геохимических факторов на систему «мать–плацента–плод». Методическая база включала использование сканирующей электронной микроскопии (СЭМ, Hitachi S-3400N) и энергодисперсионной спектроскопии (Bruker XFlash 5010), что обеспечило высокую точность при определении морфологии и химического состава минеральных включений. В ходе анализа образцов плацент женщин, проживающих в Акмолинской области, было установлено наличие солей калия и хлора, сопровождающихся примесями натрия и алюминия. Кроме того, были зафиксированы фосфорсодержащие фазы двух типов: P–Na и P–Ca, которые играют ключевую роль в процессах кальцификации плацентарной ткани и могут быть связаны с формированием патологических кальцинатов. Особый интерес вызвало обнаружение редкой ассоциации I–Cu-частиц, ранее не описанной в плацентарных структурах. Этот факт напрямую отражает специфическое геохимическое состояние исследуемого региона и подтверждает возможность накопления в плаценте маркерных элементов, связанных с техногенным и природным загрязнением. Таким образом, полученные данные свидетельствуют о том, что плацента может рассматриваться не только как орган, обеспечивающий жизнедеятельность плода, но и как биоиндикатор состояния окружающей среды. Наличие специфических минеральных фаз отражает реальную эколого-геохимическую ситуацию и её потенциальное воздействие на репродуктивное здоровье женщин. Результаты подчёркивают необходимость дальнейших междисциплинарных исследований и разработки профилактических мероприятий, направленных на снижение риска осложнений беременности и охрану здоровья новорождённых.

One of the main methods of natural water and wastewater treatment is coagulation. Water purification from suspended solids is very difficult due to their small particle size and flocculation stability. In many cases, enhancement of these processes can be achieved by enlargement of the particles in flocculence under the action of flocculants, especially mixtures (mixing) of them. Both pure chemical salts and mineral raw materials are used as initial raw materials for flocculants. The technique of obtaining coagulant from mineral raw materials (alunite, nepheline, slag, ash and clay, bauxite) and unconditioned natural ores that are considered technical waste is much cheaper than obtaining reagents from pure chemical salts. A technology is presented that simultaneously solves the problem of obtaining low-cost, cost-effective alumina iron coagulant and reducing bauxite mining waste. This information is confirmed by the study of the physicochemical and thermodynamic conditions of the process, the validation of mathematical models, and estimated data on the efficiency of industrial wastewater treatment when a given coagulant is applied. This scientific paper presents original research on the development of coagulants-flocculants based on sulfate-chloride alumina coagulants and substandard bauxite. The novelty of the work lies in the selection of substandard materials for the extraction of effective coagulant products.

Reviewing integrated hydrometallurgical and bio-based strategies enables sustainable, selective, and economically viable rare earth recovery from primary and secondary resources.

This study presents a mineralogical and geochemical investigation of rare earth elements (REE) in leached core samples from a uranium deposit in Kazakhstan. A total of 31 samples were collected from ore-bearing, sub-ore, and barren intervals of boreholes. The analytical workflow included gravity concentration (panning), heavy liquid separation, magnetic separation, and a combination of mineralogical, immersion, microchemical, luminescence, and electron microprobe analyses. The core material is predominantly composed of clay-rich sediments with quartz interlayers and sulfide mineralization (pyrite, marcasite), along with uranium-bearing phases. The heavy fraction contains minerals capable of hosting REE, including monazite, titanite (sphene), and garnet. Monazite, identified in all samples as sparse and isolated grains, represents the principal REE-bearing phase, although its abundance is generally low (<0.01 g). Additional associated minerals include Nb–Ta phases, scheelite, and accessory minerals such as zircon, rutile, apatite, and anatase. The results indicate the presence of REE mineralization within the leached core material and suggest its potential relevance for further geochemical assessment.

This study investigates the potential for using XShP-02 chromium spinel sludge (rich fraction) from the Aktobe Ferroalloy Plant as a sorbent for the removal of phenol from the effluent of oil refineries. The sludge was subjected to alkaline modification with 1 M NaOH at 70°C, followed by calcination at 450 °C. The physicochemical properties were characterised using XRF, SEM, IR spectroscopy and TGA/DSC. The Langmuir and Redlich–Peterson models provide the best description of the adsorption equilibrium (R² = 1.000). The maximum adsorption capacity is 36.00 mg/g; an optimal dose of 0.30 g/100 ml ensures the removal of 96 % of phenol. ΔG° = - 5.97 kJ/mol confirms the spontaneous physical nature of the adsorption and the possibility of sorbent regeneration.