Insoluble Residue Research Articles

Preparation of Calcium-based Phosphate Adsorbent and Mineral-rich Humic acid Fertilizer from Biomass ash and Bamboo by Hydrothermal-pyrolysis: Performance and Mechanism

Biomass ash (BA) contains alkaline cations such as K, Ca, and Mg. Due to its high pH, direct application to the soil may result in soil salinization. Composting of BA with organic matter is an effective strategy, but the composting cycle is long and there is a large amount of insoluble residue in the product. Therefore, this research proposed for the first time using the hydrothermal method to rapidly convert BA and bamboo powder (BP) into water - soluble fertilizer (WSF) within 2 hours. The insoluble hydrothermal residue was further converted into calcium - rich biochar phosphorus adsorption material by a simple pyrolysis process. WSF was neutral and contained humic acid and elements like K, Ca, Mg, and Si. A 14 - day wheat hydroponic experiment showed that the addition of 0.0125% WSF increased the fresh weight of wheat by 18.77% compared with deionized water. The calcium - based biochar adsorbent produced by pyrolysis had an ideal adsorption capacity of up to 113.6mg P g-1 for phosphate in water, higher than many existing reports. The adsorption mechanisms mainly included surface precipitation, ion exchange, and electrostatic attraction. Moreover, the calcium - rich biochar sample slowly released phosphorus into water after adsorbing phosphate. When the pH was 3 or 4, the removal rate of Pb2+, Cd2+, and Cu2+ at 15 - 20 mg L-1 was as high as 99%. This indicated its potential as a slow - release fertilizer and heavy metal remediation agent. This research provided a new way of thinking for the treatment and disposal of BA.

New Discovery of Natural Zeolite-Rich Tuff on the Northern Margin of the Los Frailes Caldera: A Study to Determine Its Performance as a Supplementary Cementitious Material.

The release of Neogene volcanism in the southeastern part of the Iberian Peninsula produced a series of volcanic structures in the form of stratovolcanoes and calderas; however, other materials also accumulated such as large amounts of pyroclastic materials such as cinerites, ashes, and lapilli, which were later altered to form deposits of zeolites and bentonites. This work has focused on an area located on the northern flank of the San José-Los Escullos zeolite deposit, the only one of its kind with industrial capacity in Spain. The main objective of this research is to characterize the zeolite (SZ) of this new area from the mineral, chemical, and technical points of view and establish its possible use as a natural pozzolan. In the first stage, a study of the mineralogical and chemical composition of the selected samples was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and thermogravimetric analysis (TGA); in the second stage, chemical-qualitative and pozzolanicity technical tests were carried out at 8 and 15 days. In addition, a chemical analysis was performed using XRF on the specimens of mortars made with a standardized mixture of Portland cement (PC: 75%) and natural zeolite (SZ: 25%) at the ages of 7, 28, and 90 days. The results of the mineralogical analyses indicated that the samples are made up mainly of mordenite and subordinately by smectite, plagioclase, quartz, halloysite, illite, and muscovite. Qualitative chemical assays indicated a high percentage of reactive silica and reactive CaO and also negligible contents of insoluble residues. The results of the pozzolanicity test indicate that all the samples analyzed behave like natural pozzolans of good quality, increasing their pozzolanic reactivity from 8 to 15 days of testing. Chemical analyses of PC/SZ composite mortar specimens showed how a significant part of SiO2 and Al2O3 are released by zeolite while it absorbs a large part of the SO3 contained in the cement. The results presented in this research could be of great practical and scientific importance as they indicate the continuation of zeolitic mineralization beyond the limits of the San José-Los Escullos deposit, which would result in an increase in geological reserves and the extension of the useful life of the deposit, which is of vital importance to the local mining industry.

Systematic multistep extraction process for the total valorization of fiber fractions from fruit seeds

This study explores a systematic multistep extraction process to valorize various fruit seeds (mango, cherry, lemon, pumpkin, avocado, litchi, peach, and apricot) by fractionating and isolating different fiber components. A first mild treatment, i.e., a protease-assisted extraction, was employed to disaggregate the plant cell structure and isolate soluble fibers. Subsequently, the insoluble residue underwent extraction by hot acidic water to solubilize and separate the pectin fraction. The remaining solid material was finally subjected to hydrothermal treatment to recover recalcitrant hemicellulose. Cherry, lemon, and pumpkin seeds emerged as the most advantageous by-products overall, showing great extractable quantities of low molecular weight pectin, pectin oligosaccharides, arabinogalactans, xylan, and xylo-oligosaccharides (extraction yields up to 63% and 68% in the first and third step, respectively). Peach and apricot seeds yielded fiber extracts that were similar to each other but distinct for each fraction, suggesting potential applications in different food formulations, albeit with lower yields. The purity of the extracts increased with each stage, reaching 42.6% for soluble fibers, 67.3% for pectin, and 76.1% for hemicellulose. Mango, avocado, and litchi seeds were less suitable for this method but could be utilized for starch recovery. This cascade process effectively maximizes the utilization of fruit by-products, offering a scalable solution for the sustainable extraction of valuable fibers.

Tracking environmental changes in an Early Cretaceous epicontinental sea: Sedimentology and geochemistry of the Romualdo Formation (Araripe Basin, NE Brazil)

The Early Cretaceous geological record contains evidence of major and abrupt global environmental changes. Understanding the past water-column redox fluctuations and paleoenvironmental evolution of Early Cretaceous environments is, therefore, pivotal for a better comprehension of this period as a whole. In this sense, to investigate the processes that modulated the deposition and preservation of the Romualdo Epicontinental Sea sediments (Aptian–Albian record of the Araripe Basin, Brazil), we present a multi-proxy study using samples from a new borehole drilled in the central area of the Araripe Basin. To unravel the origin, evolution, and demise of this shallow sea, a sedimentological and geochemical characterization was applied. We combine facies association, trace-fossil and petrographic analyses, bulk chemical data (pXRF), TOC and IR quantification (total organic carbon and insoluble residue, respectively), and SEM-EDS images. We identified twelve lithofacies that were grouped into four facies associations. The onset of the deposition of the Romualdo Formation is characterized by the transition from a fluvio-deltaic environment (FA-1) to an epicontinental sea (FA-2) that prevailed and further shifted into a deltaic environment (FA-3). The uppermost facies association (deltaic-fluvial; FA-4) reveals a continentalization process and the demise of the shallow sea. The variations of geochemical proxies were examined to assess terrigenous supply, salinity, redox conditions of bottom water, and primary bioproduction. Based on these proxies, we determined five chemostratigraphic units (U-A to U-E) that revealed a dynamic interplay between organic matter accumulation, paleoenvironmental shifts, and redox conditions. Our results demonstrate that the influx of nutrients from continental sources fostered pulses of biological productivity that, coupled with the low-oxygen environment, resulted in the preservation of organic-rich rocks (high TOC horizons). Notably, the enrichment of redox-sensitive trace elements (RSTEs) suggests that these organic-rich rocks were deposited under euxinic/oxygen-depleted environmental conditions, demonstrating that substantial variations in oxygen levels occurred. Overall, geochemical fluctuations indicate that climatic conditions and siliciclastic input primarily drove the lithofacies variation and organic matter accumulation. Lastly, the results provide constraints on the driving mechanisms that allowed the preservation of organic-rich mudstones of the Romualdo Formation, which is particularly relevant for other studies investigating similar processes in past epicontinental seas.

Paleoenvironmental factors controlling organic-rich formations deposition in the Babouri-Figuil Basin (Northern Cameroon)

The Babouri-Figuil Basin is an intracratonic basin (half-graben) in northern Cameroon that is genetically connected to the Benue Trough from Nigeria, and is an area of interest in terms of petroleum prospectivity. Recent studies highlighted the presence of organic-rich formations in the basin. However, none of these works have identified factors that governed the accumulation of organic matter (OM) in the sediments. The main objective of this work is the characterization of these formations through palynofacies and organic geochemical techniques (total organic carbon - TOC, total sulfur, insoluble residue and biomarkers), in order to determine the organic facies, their depositional environments and the main drivers for organic enrichment in the basin. The current study reveals that black shale and massive claystone lithologies constitute the main organic-rich formations in the basin, with TOC reaching up to 26.08 wt%, being characterized by a dominance of bacterially-derived amorphous OM. Palynofacies and biomarker data revealed that these formations are positively associated with anoxic conditions and a partly highly saline and stratified lake water column. The deposition of organic-rich formations in the Babouri-Figuil Basin was mainly controlled by restriction conditions which developed in connection with the regional tectonic framework. The Lower Cretaceous rifting episode in the West and Central African Rift System (WCARS) basins led to the formation of accommodation space, a reduction in water levels, and the development of anoxic conditions within the basin, facilitating the deposition of organic-rich formations. Therefore, the organic enrichment of the Babouri-Figuil Basin has been predominantly controlled by its tectonic evolution, particularly during the syn-rift phase. This phase created favorable conditions for the deposition and preservation of OM, including the establishment of anoxic conditions. Additionally, the paleoclimate (arid conditions), the development of bacterial biomass, and the basin's paleogeography all played a significant role in this process. The organic-rich formations of the Babouri-Figuil Basin show characteristics of prospective petroleum source rocks (high organic content, high proportion of oil-prone kerogen, significant thickness and lateral extension). The combination of organic-rich formations with sandstone deposits above and extensive claystone/shale deposits on top can indicate the presence of an oil play in the basin. A detailed study with broader sampling is needed to investigate thoroughly the variation of organic facies and the influence of paleoenvironmental factors that control the deposition of thick source rock intervals.

ТЕХНОЛОГИЧЕСКИЕ РАЗРАБОТКИ ДЛЯ МЯСОРАСТИТЕЛЬНЫХ ПАШТЕТОВ ЗАДАННОГО СОСТАВА

The purpose of the study is to develop technological solutions for obtaining meat-and-vegetable pates of a given composition. Objectives: to develop technological approaches to the creation of protein-carbohydrate components based on soybeans, vegetables and wild-growing raw materials; to justify the technological parameters for the production of meat and vegetable pates. The general scheme of research included the development of technology for soy-carrot, soy-pepper, soy-pepper-mushroom and soy-carrot-fern granulates, as well as pates from rabbit meat and liver with the resulting granules, which were the objects of research and were assessed based on a combination of various indicators. The results of the study are presented, in accordance with which a technology has been developed for the production of protein-carbohydrate components based on soybeans, vegetables, wild-growing Far Eastern raw materials, including operations for joint disintegration and extraction, pre-soaked soybean seeds and chopped fresh carrots or sweet peppers, separation of the resulting mixture, introduction into the insoluble residue of onions, bracken, mushrooms, granulation and drying. Analysis of the chemical composition of the deve-loped protein-carbohydrate components showed that the proposed technology made it possible to increase the content of protein, fat, and dietary fiber, which exceeds similar indicators for dried vegetable concentrates existing on the market. By purposefully varying the amount of meat and protein-carbohydrate components, their optimal ratio of 70: 30 % was determined. Based on the analysis of mathematical mo-dels, the main factors influencing the quality of rabbit meat and liver pates with a protein-carbohydrate component were determined: mass fraction of the protein-carbohydrate component – 30.00–30.55 %; mass fraction of fat – 12.6–16.3 %; cutting duration is 8.6–10.7 minutes. The production technology of the designed meat-and-vegetable pates of a given composition has been experimentally confirmed.

Characterization of Functional Ingredients Extracted with Ethanol Solvents from Ponkan (Citrus reticulata) By-Products Using the Microwave Vacuum Drying Method Combined with Ultrasound-Assisted Extraction.

For this study, microwave vacuum drying (MVD) was combined with ultrasound-assisted extraction to compare the effects of different ethanol volumes on ponkan extract and to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and total ascorbic acid content (TAAC). High-performance liquid chromatography with photodiode array detection (HPLC-PDA) was used to analyze the flavanone contents and antioxidant activity of ponkan (Citrus reticulata) peels. The experimental results showed that the TPC and TFC increase with ethanol volume. Ethanol extraction (75%) showed significant advantages by increasing the TPC to 17.48 mg GAE/g (DW) and the TFC to 2.96 mg QE/g (DW) of ponkan extract and also exhibited the highest antioxidant activity. The TAAC improved along with increased water content. Water extraction showed the highest content (13.07 mg VitC/100 g, DW). The hesperidin content analyzed by HPLC-PDA was 102.95-622.57 mg/100 g (DW), which was the highest among the flavanones. Then, the ethanol insoluble residue extracts were taken from the pectin with four different solvents, evaluating TPC, TFC, and antioxidant activity. The TPC, TFC, and antioxidant capacity of pectin are significantly lower than those of the peels. Combining MVD and 75% ethanol with ultrasound-assisted extraction in the pre-treatment process can effectively eliminate polyphenols, flavonoids, and other compounds, thus enabling the extraction of high-methoxyl pectin. The total dietary fiber (TDF) content of MVD ponkan by-products was 25.83%. Ponkan by-products have the potential for the future development of functional foods and supplements.

Molecular changes and interactions of wheat flour biopolymers during bread-making: Implications to upcycle bread waste into bioplastics

This study aims to understand the molecular and supramolecular transformations of wheat endosperm biopolymers during bread-making, and their implications to fabricate self-standing films from stale white bread. A reduction in the Mw of amylopectin (51.8 × 106 vs 425.1 × 106 g/mol) and water extractable arabinoxylans WEAX (1.79 × 105 vs 7.63 × 105 g/mol), and a decrease in amylose length (245 vs 748 glucose units) was observed after bread-baking. The chain length distribution of amylopectin and the arabinose-to-xylose (A/X) ratio of WEAX remained unaffected during bread-making, suggesting that heat- or/and shear-induced chain scission is the mechanism responsible for molecular fragmentation. Bread-making also resulted in more insoluble cell wall residue, featured by water unextractable arabinoxylan of lower A/X and Mw, along with the formation of a gluten network. Flexible and transparent films with good light-blocking performance (<30 % transmittance) and DPPH-radical scavenging capacity (~8.5 %) were successfully developed from bread and flour. Bread films exhibited lower hygroscopicity, tensile strength (2.7 vs 8.5 MPa) and elastic modulus (67 vs 501 MPa) than flour films, while having a 6-fold higher elongation at break (10.0 vs 61.2 %). This study provides insights into the changes in wheat biopolymers during bread-making and sets a precedent for using stale bread as composite polymeric materials.

Two glycosyl transferase 2 genes from the gram-positive bacterium Clostridium ventriculi encode (1,3;1,4)-β-D-glucan synthases

The exopolysaccharides of the Gram-positive bacterium Romboutsia ilealis have recently been shown to include (1,3;1,4)-β-D-glucans. In the present study, we examined another Clostridia bacterium Clostridium ventriculi that has long been considered to contain abundant amounts of cellulose in its exopolysaccharides. We treated alcohol insoluble residues of C. ventriculi that include the exopolysaccharides with the enzyme lichenase that specifically hydrolyses (1,3;1,4)-β-D-glucans, and examined the oligosaccharides released. This showed the presence of (1,3;1,4)-β-D-glucans, which may have previously been mistaken for cellulose. Through genomic analysis, we identified the two family 2 glycosyltransferase genes CvGT2–1 and CvGT2–2 as possible genes encoding (1,3;1,4)-β-D-glucan synthases. Gain-of-function experiments in the yeast Saccharomyces cerevisiae demonstrated that both of these genes do indeed encode (1,3;1,4)-β-D-glucan synthases.

Effects of air frying on protein digestive properties in scallop (Patinopecten yessoensis) adductor muscles and the mechanisms involved

The effects of air frying at different temperatures (140 °C, 160 °C, 180 °C, and 200 °C) on the simulated digestive properties of proteins in scallop adductor muscle (SAM) and the mechanisms involved were investigated. The results of the simulated gastrointestinal digestion showed that the 160 °C-treated SAM group had significantly higher protein digestibility than the fresh SAM group, which was reflected in higher degree of hydrolysis, more low molecular weight (<0.5 kDa) protein digestive products, and less insoluble residues, while the 140 °C-, 180 °C- and 200 °C-treated SAM groups all had opposite results. Moreover, air frying altered the solubility, secondary structure percentage and surface hydrophobicity of SAM proteins, as well as the microstructure of insoluble residues in simulated gastric juice. Correlation analysis showed that the protein digestive level of the air fried SAMs was positively correlated with the ratio of soluble proteins before digestion and the surface hydrophobicity of insoluble residues, but negatively correlated with the content of α-helix of soluble proteins dissolved in simulated gastric juice. Therefore, the highest digestibility of the 160 °C-treated SAM group can be attributed to the lowest α-helix content of soluble proteins, as well as the highest surface hydrophobicity and the largest pores size of insoluble residues. The present study provides a good basis for understanding the effects of air frying temperature on the digestive properties of aquatic muscle foods and the mechanisms involved, which contributes to establish precise air frying method for aquatic muscle foods.

Теоретические аспекты получения гранулированного и пастообразного корма на основе композиций из сои и зерна

The article discusses the preparation of post compositions based on soy coagulate and soy-grain insoluble residue and dried granulate. A scheme for the preparation of feed products based on soy-grain insoluble residue (NSZO) and coagulate is presented. The proposed device for the preparation of paste compositions shows that the length of the cylindrical chamber Lk depends on such factors as the shear stress (sliding) τ of a visco-plastic body; the coefficient of friction of the product against the walls of the chamber - f, the radius of the chamber - R and, accordingly, on the pressure created in the compression chamber - P. Analyzing the processes under consideration, the following conclusions can be drawn: - loading the hopper of the device with components must be carried out in a certain ratio; - the formation of a monolith in a compression chamber will be carried out with a certain diameter and length, under a certain pressure P. Keywords: PASTE COMPOSITION, FEED PRODUCTS BASED ON SOY-GRAIN INSOLUBLE RESIDUE (NSZO) AND COAGULATES, CALCULATIONS, THE WORKING PROCESS OF THE PASTE-LIKE MIXTURE

Dysphagia food: Impact of soy protein isolate (SPI) addition on textural, physicochemical and microstructural properties of peach complex gels

In this study, dysphagia-friendly diets were prepared based on the interaction between polysaccharides from peach, namely Meirui (MR), Yangshan (YS) and Cons758 (Cons), and soy protein isolate (SPI). MR-alcohol insoluble residues (AIR) and YS-AIR were low methoxylated polymers, while Cons-AIR was high methoxylated polymer. According to the international dysphagia diet standardization initiative, YS-SPI and MR-SPI could be qualified as level 5-minced/moist dysphagia diets. Following SPI addition, the apparent viscosity, G′ and G″ of peach pulp-SPI complexes were significantly increased. At the shear rate of 10 s−1, corresponding to oral processing, MR-SPI performed the highest apparent viscosity (35.2 Pa s), followed by YS-SPI (33.5 Pa s). Additionally, the SPI-treated strategy pronounced improved the hardness, springiness, adhesiveness and chewiness of complexes. Both YS-SPI and Cons-SPI showed the reduced particle size, alongside the uniform distribution, owing to the strong hydrogen bonding and electrostatic interaction between peach pulp substances and SPI, which was confirmed by FT-IR result. The biggest ζ-potential value (−23.55 mV) was found in YS-SPI. Meanwhile, compared with peach pulps, the highest increase ratio (87.94%) of water holding capacity was depicted in MR-SPI. LF-NMR analysis revealed immobilized water was dominant in peach pulp-SPI. The results suggested that MR was promising for the optimal choice to form gel food for people with swallowing problems.

A comparative multidimensional evaluation of parameters and alternatives for transformation of sustainable cement production in Pakistan

The United Nations has declared its latest climate report a ‘code red,’ sounding the alarm and prompting a global call for scientists and policymakers to adopt comprehensive, systems-wide integrated strategies for promoting sustainable life on Earth. The need for collaborative and holistic approaches for the transformation of cement production into a socio-ecologically sustainable industrial segment had never been more imperative. This paper rigorously evaluates the parameters and alternatives for the sustainable transformation of Pakistan's cement industry. Economic, environmental, and social parameters are explored and screened using multiple methodologies. Real-world data collected from the operating cement plants in Pakistan are analyzed using Principal Component Analysis (PCA) and Grey Relational Analysis (GRA). The consolidated list of sustainability criteria and alternatives is evaluated using the Multi Actor Multi Criteria Analysis (MAMCA) framework, which incorporates the involvement of both local and international stakeholders for prioritization of the transformation goals. Data analytic results reveal that carbon emissions have a strong degree of statistical association with production ingredients such as SiO2, Insoluble Residue (IR), Al2O3, and Fe2O3. Although there are a few interesting variations in the priorities computed from the recorded perspectives of different stakeholders, the consensus on giving top priority to environmental parameters and the alternatives like ‘Waste-heat Recovery Plants’ and ‘Vertical Rolling Mills’ is novel and promising. By taking all the main sustainability domains into account, employing multidimensional techniques, and involving multiple stakeholder perspectives under the context of a developing country, the research outcomes of this study become highly attractive for researchers, investors, and policymakers all over the world.

Study of Preg-Robbing with Quicklime in Gold Cyanide Solutions Analyzed by Time-of-Flight Secondary Ion Mass Spectrometry

Preg-robbing is a phenomenon in which minerals retain gold, especially due to the presence of species like carbonaceous matter and silicates in the mineral. This study demonstrates the impact of quicklime, used to adjust the pH of a gold cyanidation solution, on the retention of gold contained in pregnant cyanidation solutions and sorption mechanisms. The retention capacity of four quicklime solutions was evaluated using proportions of 200 g of lime in 800 mL of solution and 10 g of lime in 500 mL of solution. The concentrations of the gold cyanide solutions were 10, 15, and 25 ppm. The insoluble lime residue in the acetic acid solution was separated and analyzed by XRD, FTIR, elemental carbon, and Raman spectroscopy techniques. SEM and TOF-SIMS were used to analyze the lime samples after exposure to the gold cyanide solution. The results show that retention was attributable to quicklime due to the effects of its carbon and silicate content, although chemisorption and physisorption mechanisms may also be responsible.

Synthesis and photo‐initiated radical polymerization of methacrylates derived from bio‐based ω‐hydroxycarboxylic acids

AbstractThe bio‐based methacrylates 9‐(methacryloyloxy)‐10,18‐dihydroxyoctadecanoic acid/9,18‐dihydroxy‐10‐(methacryloyloxy)octadecanoic acid isomer mixture and 22‐methacryloyloxydocosanoic acid were synthesized from 9,10‐epoxy‐18‐hydroxyoctadecanoic acid and 22‐hydroxydocosanoic acid. The white crystalline 9,10‐epoxy‐18‐hydroxyoctadecanoic acid and cream‐colored 22‐hydroxydocosanoic acid were isolated from both the bark of Betula pendula and cork of Quercus suber after extraction of the milled plant materials with methanol, treating the insoluble residues with 2‐propanole containing suspended sodium hydroxide, application of a working up procedure developed in this work for the resulting mixture, and purification of the products obtained. The new bio‐based methacrylates show higher reactivity in the photoinitiated polymerization in comparison with the commercial laurylmethacrylate as detected by photo‐differential scanning calorimetry (DSC). For comparison, traditional free radical polymerization of the new bio‐based methacrylates was carried out in dimethylsulfoxide using 2,2'‐azobis‐(2‐propionitrile) as initiator. Furthermore, the quantitative conversion of the bio‐based monomers during the photoinitiated polymerization makes these bio‐based monomers interesting for application in coatings. As expected, the photopolymer made from the 9‐(methacryloyloxy)‐10,18‐dihydroxyoctadecanoic acid/9,18‐dihydroxy‐10‐(methacryloyloxy)octadecanoic acid isomer mixture is amorphous. Interestingly, the photopolymer made from the 22‐methacryloyloxydocosanoic acid contains crystalline structures as detected by DSC investigation.

Extraction, recovery, and characterization of lignin from industrial corn stover lignin cake

Lignin utilization in value-added co-products is an important component of enabling cellulosic biorefinery economics. However, aqueous dilute acid pretreatments yield lignins with limited applications due to significant modification during pretreatment, low solubility in many solvents, and high content of impurities (ash, insoluble polysaccharides). This work addresses these challenges and investigates the extraction and recovery of lignins from lignin-rich insoluble residue following dilute acid pretreatment and enzymatic hydrolysis of corn stover using three extraction approaches: ethanol organosolv, NaOH, and an ionic liquid. The recovered lignins exhibited recovery yields ranging from 30% for the ionic liquid, 44% for the most severe acid ethanol organosolv condition tested, and up to 86% for the most severe NaOH extraction condition. Finally, the fractional solubilities of different recovered lignins were assessed in a range of solvents and these solubilities were used to estimate distributions of Hildebrand and Hansen solubility parameters using a novel approach.

Obtaining of silicon dioxide from abrasive wastes

In the production of abrasive materials from metallurgical slags, fine waste with a size of less than 40 microns is produced, which contains valuable components. Unlike slag, this waste does not need to be pulverized for processing, which greatly simplifies the process. However, without silica extraction, it is impractical to carry out waste treatment. The authors of the work considered the possibility of obtaining silicon dioxide from abrasive wastes of Rezh, Orsk and Kyshtym, containing up to 20,7 % of silicon, up to 31,7 % of iron and up to 0,7 % of the sum of nickel and copper. Sulfuric acid treatment of waste produced a solution containing magnesium and iron (II) sulfates and silicic acid. It was found that during processing of Orsk wastes the degree of components extraction is significantly lower in comparison with Rezh and Kyshtym wastes 24,5, 67,8 and 59,3, respectively. The obtained solution is used to produce silica powders by dehydrating it. The dried mixture is subjected to aqueous washing of metal sulfates. As a result, samples with high specific surface area in the range of 387,6 to 841,5 m2/g were obtained. The average pore size is 2,3–3 nm, which allows us to attribute these silicas to mesoporous silica. SiO2 content in the samples reaches up to 98 %. Samples of silicon dioxide from abrasive materials were compared with that obtained from metallurgical slag of Pechenganickel Combine and have similar parameters. The obtained insoluble leaching residue contains concentrate of non-ferrous metals and according to X-ray data it consists of calcium sulfate, so after separation of non-ferrous metals it can be used in construction industry.

Study of the influence on potassium chloride enrichment technology in potassium ore

Due to the fact that the rich reserves of potash minerals are decreasing in the world, scientific research is being carried out on the development of effective technologies for beneficiation of minerals containing a small amount of potassium. In this regard, to study the mineralogical composition of low-grade potassium ores of the Tyubetagan mine, to conduct theoretical analysis of the galurgic method of beneficiation and to carry out research in laboratory conditions, to study the influence of various technological parameters on product output and to find optimal conditions, to develop a technological scheme of beneficiation of low-grade sylvinite ores by the galurgic method special attention is paid to the output. In this study, the mineralogical composition of potash ores of Tubegatan mine was studied and methods of beneficiation were proposed according to the relationship between the content of KCl, NaCl, insoluble residue and particle size of potash ores.

Study of filtration processes in obtaining a chlorate-containing defoliant from dolomite

This article considers the separation of an insoluble residue from a suspension of calcium and magnesium chlorides obtained as a result of the decomposition of a dolomite mineral with hydrochloric acid of various concentrations was studied by methods of filtration, settling and the use of centrifugal force. For each method, the optimal deposition rate is set depending on the time. The filterability of pulp with sediments of calcium and magnesium chlorates, chloride and sodium chlorate, formed in the process of obtaining calcium-magnesium chlorate defoliant was studied in it.

Нерастворимый остаток нижнепермских сильвинитовых пород западного и северо-западного обрамления Прикаспийской впадины

The paper presents the results of a study of the insoluble residue of sylvinites and sylvin-halite rocks of the Lower Permian halogen formation, common within the Perelyubsky areas (Western and Eastern), promising for industrial development (Saratov Region) and the Gremyachinsky potash deposit (Volgograd Region). A technique for studying the insoluble residue of sylvinites is presented. The types of insoluble residue are distinguished according to the form of occurrence in sylvinites and its mineral composition is characterized. The conditions for the formation of sylvine-bearing rocks are refined, taking into account the data obtained on the composition of the insoluble residue.