Raw Pellets Research Articles

Granulated Expanded Glass Manufacturing Method Using Electromagnetic Waves

The paper presents experimental results obtained in the process of experimental manufacture in a microwave oven of lightweight granulated glass aggregates. The process was conducted to obtain the highest dimensional class (between 18-23 mm), the almost spherical shape of the aggregates being facilitated by cold processing of raw spherical pellets (between 11-15 mm) containing the powder mixture formed by glass waste, borax. calcium carbonate, aqueous sodium silicate solution and water addition and then rotation of the high electromagnetic wave susceptible ceramic crucible containing raw pellets during the heat treatment at temperatures between 822-835 ºC. In terms of quality, the expanded glass aggregate granules are almost similar to those manufactured in conventional rotary kilns heated by burning fuel, having the following characteristics: bulk density of 0.17 g/cm3, compressive strength of 2.2 MPa, thermal conductivity of 0.047 W/m·K, water absorption of 1 vol. % and pore size between 0.3-0.6 mm. The experimental product has not yet been tested as a raw material in the manufacture of some light weight concretes, but the use of similar granulated glass aggregates manufactured in the world confirms the ability of this aggregate type to produce light weight and energy efficient concretes for building construction.

The Effects of Additives on the Pelletization of Raw and Torrefied Food Waste

This study evaluates the effect of various binders on the pelletization of raw and torrefied food waste (FW) towards its physical properties, including density, moisture reabsorption, and tensile strength of the formed pellets. Three binders; starch, lignin, and vegetable oil, were used to make the raw and torrefied FW pellets. It was found that the addition of lignin helps to improve the density of both, raw and torrefied FW pellets by 40% for raw FW pellets and up to 27% improvement for the torrefied FW pellets. In addition, increasing the concentration of lignin may also reduce moisture reabsorption from 48% to 40% of raw FW pellets, and the sorption was further reduced for the torrefied FW pellets. The addition of lignin improves the tensile strength, mainly the torrefied FW pellets. Results show that lignin inclusion demonstrates significant enhancement to the physical properties of FW pellets.

Effect of in-situ torrefaction and densification on the properties of pellets from rice husk and rice straw

The research on preparing high-quality pellets by combining torrefaction and densification of biomass has received widespread attention. This paper investigated the influence of torrefaction temperature on biomass and evaluated the quality of three kinds of pellets (raw pellets, ex-situ torrefied densified pellets and in-situ torrefied densified pellets). When the torrefaction temperature was raised to 300 °C, the energy yield of rice straw (RS) and rice husk (RH) quickly decreased to 71.08% and 77.62%, and the cellulose was decomposed significantly. The results proved that 250 °C was an optimum temperature for RS and RH torrefaction. The densities of RS and RH in-situ torrefied densified pellets were 1236.84 kg/m3 and 1277.50 kg/m3 under 150 MPa, respectively. The density, Meyer hardness, hydrophobicity, and mechanical specific energy consumption of the pellet increased with the increase of molding pressure. The in-situ pellets had higher Meyer hardness, hydrophobicity, and lower mechanical specific energy consumption under the same molding pressure than raw pellets and ex-situ torrefied densified pellets. In addition, the bonding mechanism was studied by using scanning electron microscopy and ultraviolet auto-fluorescence. In-situ torrefaction and densification facilitated the formation of self-locking and the migration of lignin between particles. Compared with RH pellets, RS pellets had higher quality due to the higher hemicellulose content, which was necessary for forming stable hydrogen bonds.

Integrated study on obtaining oxide pellets from brown iron ore

Introduction. Currently, the main raw materials for the production of cast iron and steel at metallurgical plants are iron concentrates obtained from magnetite (ferrous) quartzites, titanium-magnetite, and skarn ores. The existing technologies for processing these types of ores, which mainly include separation processes based on magnetic properties, size, separating of equally falling grains, and surface wettability allow us to produce both ordinary iron concentrates and high quality ones. The use of such schemes in the processing of brown iron ore does not allow obtaining high rates of mineral concentration. One of the methods for processing this type of ore is a roasting-magnetic scheme, which allows converting weakly magnetic (non-magnetic) forms of iron into strongly magnetic ones. Research objective is to develop the mode of magnetizing roasting of brown iron ore, technology of concentrating of the burn-out product in order to obtain iron concentrate and oxide pellets. Methods of research. The duration of heat treatment of the charge consisting of iron ore from the Abail deposit and coal from the Ekibastuz deposit and the required mass fraction of solid carbon contained in the coal are determined. Technological studies of the roasted product were carried out in order to obtain a concentrate with a mass fraction of iron at least 67%. According to the developed technology, a batch of iron concentrate was developed in order to obtain and study raw and oxide pellets. Results. The modes of magnetizing roasting of brown iron ore from the Abail deposit and cooling of the roasted material have been developed. A scheme for mineral processing of the roasted material has been developed in order to obtain a concentrate with at least 67% of iron mass fraction. The process of obtaining strong raw and roasted pellets from iron concentrate is studied. Conclusions. The developed mode of magnetizing roasting of the charge consisting of coal and ore from the Abail deposit makes it possible to obtain a roasted product with a degree of magnetization of 93%. The using of desliming of the roasted product makes it possible to remove magnetic floccules from the processing that reduce the concentrate quality, and to obtain a concentrate with a mass fraction of iron of at least 67% in the last stage of magnetic separation. From the iron concentrate, it is possible to obtain oxidized pellets with a strength of at least 200 kg/pellet at temperature of pellets firing of 1325 °C.

Improvement of Biomass Gasification/Combustion Characteristics by Microwave Pretreatment of Biomass Pellets

AbstractA wider use of the regional bioenergy resources for the development of environmentally friendly energy production providing microwave pretreatment of lignocellulosic biomass pellets (wood, straw, and peat) of different origin at a frequency of 2.45 GHz is promoted. A hypothesis is proposed and tested that microwave pretreatment of biomass pellets and blending of such pretreated pellets with raw pellets can be applied to enhance the thermochemical conversion of lignocellulosic biomass blends from different origin. The test results confirm that increased reactivity and heating value of pretreated biomass pellets enhances heat energy production and limits the formation of green house gases (GHG) emissions, thus advancing a more efficient usage of agricultural and forestry waste for energy production.

Effect of degassing treatment durations on physico-chemical and electrical properties of 500 kV extra HVDC XLPE cable insulation

• This paper analyzes the effect of different degassing duration on the content of cross-linking by-products, morphological structure and insulation properties of 500 kV EHVDC XLPE insulation. • The measured content of the crosslinking by-products is consistent with the theoretical values calculated by Fick's second law. • The electrical performance of the XLPE material exhibited a trend of first increasing and then decreasing with the increase in the degassing treatment duration. • 36 h of degassing treatment is found to be an optimal duration to obtain the enhanced overall properties. An optimal degassing treatment duration for the preparation of commercial 500 kV extra high voltage direct current (EHVDC) cross-linked polyethylene (XLPE) insulation can improve its overall properties, reduce the manufacturing cost and time, which is urgently needed for high voltage cables suppliers. This paper analyzes the effect of different degassing duration on the content of cross-linking by-products, morphological structure and insulation properties of 500 kV EHVDC XLPE insulation. The raw pellets of commercial 500 kV EHVDC XLPE cable material are used to prepare the test samples by the hot-pressing method. Five samples with the different degassing durations of 0 h, 12 h, 36 h, 90 h, and 200 h were at 70°C. Physico-chemical and electrical methods are used to characterize the overall properties of the material under the different degassing durations. The results show that the measured content of the crosslinking by-products is consistent with the theoretical values calculated by Fick's second law. The oxidation induction time of the samples is reduced and tensile properties are improved with the increase of the degassing time. Furthermore, degassing treatment increased the lamellae thickness in the early stages and reduced the difference in the internal aggregation structure of the material. It was found that the degassing treatment significantly suppressed the space charge accumulation inside the material. Moreover, the degassing treatment of 36 h can increase the dielectric breakdown strength and reduce the current density of the samples.

Enhanced Oil Palm Waste Properties through Torrefaction and Pelletization

Torrefaction is a thermal pre-treatment process to treat biomass at temperature range of 200-300°C under an inert atmosphere. It was known that torrefaction process strongly depended on the decomposition of the lignocellulosic constituents in oil palm waste namely hemicellulose, cellulose and lignin. The objective of this research is to study the effect of torrefaction on the characteristics of pellet formed from palm mesocarp fiber (PMF), oil palm frond (OPF) and palm kernel shell (PKS) as a solid fuel. The samples were torrefied at 270°C for 30 minutes. The torrefied samples were then densified into pellets through hot press machine at different temperatures (110 °C, 130 °C, 150 °C) and different pressure (10 MPa, 12 MPa, 14 MPa) for 20 minutes to find the optimum pelletization condition. The pellets were analyzed through mass yield, high heating value, fourier-transform infrared spectroscopy (FTIR) analysis, moisture absorption and compression test. Compression test is to study the strength of pellet by identifying the force required to break the pellet. The result shows that the mass yield of PKS was higher than PMF and OPF. The high heating value of torrefied oil palm waste improved as compared to the raw oil palm waste. Through FTIR, the changes of chemical bonds in oil palm waste after torrefaction have been identified. From the analysis of the pellet, the optimum conditions for pelletization were obtained, which are 130 °C and 12 MPa. The moisture absorption rate of torrefied pellet was lesser than raw pellets. Lastly, the torrefaction and pelletization process produced better quality pellets in term of high heating value, durability and more hydrophobic compared to raw pellets which can used as biofuel to replace the coal.

Characterization and quality analysis of wood pellets: effect of pelletization and torrefaction process variables on quality of pellets

A lab-scale single-channel press was employed for producing pellets and the effect of pressure, die temperature, moisture content (MC), particle size, and binding agent on pellet quality was investigated. Meanwhile, torrefaction subsequent to pelletization was performed and the quality of pellets was evaluated under different torrefaction conditions. From the analysis of variance (at p < 0.05), temperature (70–200 °C), pressure (70–160 MPa), and MC (5.5–28%) were found most significant factors for density, strength, and compression energy of pellets. Particle density and strength of raw wood pellets were significantly affected by temperature and pressure. The highest particle density and strength (1.307 g/cm3, 11.8 N/mm2) for particles of 0.25–0.5 mm and (1.300 g/cm3 and 10.7 N/mm2) for particles of 0.5–1.41 mm were found at a temperature of 200 °C (pressure ≥ 100 MPa and MC 5.5%), indicating that pelletization at a temperature of 200 °C was beneficial. The relaxed density of pellets remained the same as of particle initial density after storage time of 2 weeks. The expansion ratio of the pellet was found lower. Use of synthetic resin as a binder in the proportion of 1:9 was found optimum, the particle density increased from 1.19 to 1.24 g/cm3 (0.25–0.5 mm) and from 1.17 to 1.22 g/cm3 (0.5–1.41 mm) and energy consumption reduced by 9.39% (0.25–0.5 mm) and 8.7% (0.5–1.41 mm). Pellets made at a temperature of 200 °C were found water-resistive as compared to those made at other temperatures. The highest lower heating value, i.e., 26.76 MJ/kg of torrefied pellets (TOPs) was achieved at 300 °C and 120 min. Torrefaction process parameters adversely affected the particle density, volumetric energy density, strength, and durability of TOPs. The highest true density (1.85 g/cm3) and porosity (65 v %) for TOPs were achieved at 300 °C and 120 min, much higher than those of raw pellets. Moisture uptake of TOPs at 300 °C was 2.0–2.8 wt.%, showing strong water-resistant ability. From the results of FTIR, O–H bond was destroyed after torrefaction.

Torrefaction of oil palm empty fruit bunch pellets: product yield, distribution and fuel characterisation for enhanced energy recovery

In this study, the non-oxidative torrefaction of oil palm empty fruit bunch (OPEFB) pellets was investigated from 250 to 300 °C for 30 min in a horizontal fixed bed tubular reactor. The effects of the selected conditions on the yields, distributions and fuel characteristics of the torrefaction products were examined. The mass or solid yield (MY) decreased from 68.1 to 36.2%, whereas the liquid yield (LY) and gas yield (GY) increased from 19.4–40.1% and 12.5–23.7%, respectively, due to drying, devolatilization and depolymerisation during torrefaction. Physicochemical and calorific analyses showed that the torrefied OPEFB pellets have high carbon but low oxygen contents, which accounts for the high heating values (HHV = 22.83–25.81 MJ/kg). The torrefied OPEFB pellets also exhibit lower moisture (2–4%) and volatile matter (34.38–65.31 wt.%) but high ash (4–20 wt.%) and fixed carbon (28.69–41.62 wt.%) compared to the raw pellets. The OPEFB pellet fuel properties, namely pH that ranged from 6.65 to 7.74, hydrophobicity from 100 to 23.04% and grindability from 53.66 to 108, were markedly enhanced after torrefaction at 300 °C. The LY consisted of organics (67.64–62.62%) and water (32.36–37.38%) fractions characterised by high acidity (pH = 2.89–3.22) and dark hues formed by holocellulose and lignin thermal degradation at higher torrefaction temperatures. Based on the findings, the torrefied OPEFB pellets is a highly grindable, hydrophobic, thermally stable and promising solid biofuel for firing, co-firing or substituting coal in power plants provided the existing challenges that affect global biomass supply chains are addressed in detail.

Study of bentonite clay influence on indicators of pellet quality

Laboratory tests have been conducted to determine the suitability of bentonite clays of different mineralogical composition and exchange ion complex for the production of pellets. To assess the metallurgical characteristics of the obtained pellets, the moisture content of the pellets, the compressive strength of the raw and dry pellets, the number of drops without breaking the raw pellets and the temperature of the «shock» have been determined. Tests of the clays of Layers IV and Layer II composite mixtures and Layer II and Layer III composite mixtures were carried out, which showed that the quality of the raw pellets with Cherkassky bentonite is slightly worse than the pellets with Sarygyuhsky bentonite, but the absolute values of all the indicators satisfy the requirements imposed by the industry. Comparative tests of pelletizing different humidity charges, with the addition of 0,5% alkaline bentonite and the clays of Layers IV and Layer II composite mixtures of the Cherkassky deposit have been carried out. It has been shown that with increasing humidity in pellets with both types of binder additives, the dynamic strength, porosity and temperature of the «shock» of the pellets increases, the difference in the absolute values of indicators with different binders being minimum. It has been shown that the impact strength and compressive strength of raw pellets with a slightly increased specific consumption of bentonite of Cherkassky alkaline earth bentonite are not inferior to the same properties of pellets with alkaline Sarygyuhsky bentonite used as a binder. It has been shown that the clays of the Layer IV which are a natural mixture of alkaline earth bentonite of Layer II and palygorskite (Layer III), are preferable, to ensure good quality of the raw pellets, of the Cherkassky deposit clays

Solid-State Compounding for Recycling of Sawdust Waste into Green Packaging Composites

The present study explores solid-state cryomilling for the compounding of green composites. Herein, wood plastic composites (WPCs) composed of sawdust (SD) and poly(ε-caprolactone) (PCL) with various compositions were prepared. Two compounding techniques, namely, extrusion and cryomilling, were utilized to prepare WPC raw material pellets and powders, respectively, for comparison purposes. Flat pressing was further utilized to prepare WPC films for testing. Morphological, structural, thermal, mechanical, and surface wettability properties were investigated. Results indicate the advantages of cryomilling in producing WPCs. Scanning electron microscopy (SEM) along with optical micrographs revealed well ground SD particles and uniform distribution in the PCL matrix. Tensile strength and elongation at break of the composites declined with increasing SD content, however, the modulus of elasticity significantly increased. Water contact angles averaged less than 90°, implying partial wetting. Visual observations and thermo-gravimetric analysis (TGA) indicated thermal stability of composites during processing. In conclusion, PCL/SD WPC is a potential candidate to replace conventional plastics for packaging applications. This would also provide a much better utilization of the currently undervalued wood waste resources.

Carbon dioxide torrefaction of oil palm empty fruit bunches pellets: characterisation and optimisation by response surface methodology

The carbon dioxide (CO2) torrefaction of oil palm empty fruit bunch (OPEFB) pellets was investigated at various temperatures from 250 to 300 °C and residence times from 15 to 60 minutes. The objective was to investigate the effects of CO2 torrefaction on the yield and characteristics of the torrefied products. The optimal conditions for maximum mass yield (MY) of CO2 torrefaction were also examined by response surface methodology (RSM) using full factorial design. Results revealed that temperature and time significantly influenced the mass (MY), liquid (LY) and gas (GY) yields. The MY and energy yield (EY) decreased with increasing severity of torrefaction, whereas the LY, GY, energy density (DE) and higher heating value (HHV) increased during the process. Characterisation revealed substantial improvements in the microstructure, pH, hydrophobicity and grindability of the torrefied pellets compared with the raw pellets. The thermal ignition and degradation characteristics of the OPEFB pellets were also significantly transformed after torrefaction. The liquid torrefaction products contained an acidic, turbid and pungent mixture of water and organic compounds. RSM optimisation revealed the optimal conditions: temperature of 275 °C and residence time of 35 minutes with the predicted MY of 50.54%, mass loss of ML = 49.46% and HHV = 24.47 MJ/kg. The findings revealed that CO2 torrefaction is a practical approach to clean energy recovery.

Effect of FLUMAG M flux on strength properties of iron ore pellets

Currently, the most common fluxing additive to pellets is d mite CaCO 3 ·MgCO 3 , in which the content of magnesium oxide can be from 17 to 22 %. But if it is necessary to increase magnesium oxide in pellets, it is necessary to increase the dosage of dolomite, and thus the iron content decreases, which entails a decrease in yield ratio at subsequent processing. One of the fluxes containing magnesium is brucite. Compared with dolomite, magnesium oxide content in pure brucite is more than 3 times higher. The basis of FLUMAG M flux is brucite. The content of magnesium oxide in it is not less than 55 %. The paper presents series of laboratory studies on the effect of FLUMAG M flux dosage on pelletizing ability of the charge and such properties of iron ore pellets as compressive, impact and abrasion strength. We have made the tests on raw and fired pellets with FLUMAG M flux. The comparative analysis of strength properties of the pellets obtained with the use of FLUMAG M and limestone was performed. Content of the binder – bentonite and magnetite concentrate for all experiments remained unchanged. The results of these experiments indicate that FLUMAG M does not interfere with charge pelletizing ability. The strength of raw pellets for discharge and compression with FLUMAG M flux has small deviations from the pellets with the addition of limestone. Roasted pellets with the addition of FLUMAG M flux have higher strength than ones with limestone. The higher difference in strength properties is observed at the flux content of 2 %.

Reduction behaviour of Odisha Sands Complex, India ilmenite-coke composite pellets

Presently, ilmenite concentrates from Odisha Sands Complex at Chhatrapur, India are utilized to produce TiO2 slag by direct smelting in an electric arc furnace. However, the process involves the consumption of excess electrical energy and difficulty in handling the arc furnace due to frothing effects. A more efficient process of pre-reducing the ilmenite before smelting has been proposed in the present communication. In particular, studies have been undertaken on the reduction process of ilmenite-coke composite pellets. The difference in the reduction behaviour of raw ilmenite and ilmenite-coke composite pellets has been established and compared with that of the pre-oxidized raw pellets. The effects of various processing parameters like temperature, residence time, and reductant percentage on the metallization of composite pellets in a static bed have been investigated. Metallization of about 90% has been achieved at 1250 °C for a reduction period of 360 min with a 4°% coke composition. Furthermore, the reduced pellets have been characterized through chemical analysis, optical microscopy, field emission scanning electron microscopy and X-ray diffraction analysis. The reduction behaviour of composite pellets has also been found better than that of pre-oxidized pellets indicating the former to be more efficient.

Effect of Flumag M Flux on Strength Properties of Iron Ore Pellets

Currently, the most common fluxing additive to pellets is dolomite CaCO3 · MgCO3, in which the magnesium oxide content can form from 17 to 22%. If the magnesium oxide in pellets increases, then it is necessary to increase the dolomite dosage. Thus, the iron content decreases, which entails a decrease in yield ratio at subsequent processing. One of the fluxes containing magnesium is brucite. Compared with dolomite, magnesium oxide content in pure brucite is more than 3 times higher. The basis of Flumag M flux is brucite. The magnesium oxide content in it is not less than 55%. The paper presents a series of laboratory studies on the Flumag M flux dosage effects on the pelletizing ability of the charge and such properties of iron ore pellets as compressive, impact and abrasion strength. We have made the tests on raw and fired pellets with Flumag M flux. The comparative analysis of strength properties of the pellets obtained with the use of Flumag M and limestone was performed. The binder content, bentonite and magnetite concentrate, for all experiments remained unchanged. The experiment results indicate that Flumag M does not interfere with charge pelletizing ability. The strength of raw pellets for discharge and compression with Flumag M flux has small deviations from the pellets with the addition of limestone. Roasted pellets with the addition of Flumag M flux have higher strength than ones with limestone. The higher difference in strength properties is observed at the flux content of 2%.

Efficient disentanglement of polycarbonate melts under complex shear field

Disentanglement is potentially a feasible method to improve the processability of polymers without any additives. But there still lacks the methods to efficiently prepare “in-pellet” disentangled polymers. To realize the large-scale production of disentangled pellets, we firstly designed a novel Polymer Melt Disentanglement Machine (PMDM), which can uniquely impose complex shear field (superposition of rotational shear and oscillatory shear) on polymer melt to induce disentanglement. Then, the disentangled polycarbonate pellets were prepared by PMDM under rotational shear, oscillatory shear and complex shear respectively. Finally, we compared the disentanglement effect of those three shear modes and the results show that the sample disentangled by complex shear field has a lower zero-shear viscosity and a higher melt flow rate compared with the samples disentangled by other two shear modes. Besides, the processing temperature and pressure of the disentangled pellets can be reduced by 20 °C and 25% respectively compared with the raw pellets. Complex shear field can efficiently disentangle polymer melt, which indicates its application prospect to improve the processability of the engineering plastics with high melt viscosity, such as polycarbonate et al., by a large-scale production of “in-pellet” disentangled materials via PMDM prior to processing.

Experimental analysis of combustion performance of biodiesel absorbed pellets in a domestic boiler

Wood pellets gain increasing importance as an alternative and renewable fuel. In this study, biodiesel absorbed pellets were used, which is a new method for usage of pellet fuels. In this way, the naturally existing pores in pellets are filled with biodiesel, which improves the combustion properties compared to untreated (raw) pellets. Raw and biodiesel absorbed pellets were burned in a domestic experimental boiler to analyse comparatively the combustion characteristics such as thermal power, efficiency and flue gas emissions. Additionally, the absorption capacity of pellet fuels was investigated. Flue gas temperature and emissions (CO2, O2, CO, SO2 and NOx) were measured in the chimney. Combustion efficiencies were calculated and compared with each other. Experiments were performed without any modifications to the boiler, which was set for raw pellet combustion. By the usage of biodiesel absorbed pellets, the thermal power input increased from 15.2 kW to 20.9 kW (nearly 37.5% more), whereas the thermal efficiency increased from 91.7% to 93%. The average flue gas temperature was about 89.6 °C and nearly 13 °C higher than raw pellet fuel. By biodiesel absorbed pellet, significantly more CO and slightly less NOx emission concentrations in flue gases were obtained.

Microplastics in fishes and their living environments surrounding a plastic production area

Microplastic-associated risks in freshwater ecosystems have triggered significant concerns in recent years. However, the contribution of plastic production processing to microplastic pollution is largely unknown. The present study investigated microplastic pollution in biotic and abiotic compartments in three sites which are in surrounding area of a plastic industrial colony and a site from a reservoir for drinking water as reference. The abundances of microplastics were 0.4–20.5 items/L in surface water, 44.4–124.7 items/kg (ww) in sediment and 1.9–6.1 items/individual in guts of Hemiculter leucisculus from the industrial area. In contrast, the abundances were much lower levels of 0.1 ± 0.1 items/L in surface water, 0.5 ± 0.2 items/kg (ww) in sediment and 0.2 ± 0.01 items/individual in H. leucisculus in the reference site, respectively. A large quantity of raw pellets were found on the grounds surrounding the plastic factories. The dominant shapes of microplastics found in sediment were fragments (67%), followed by pellets (18%). Unexpectedly, neither fragments nor pellets (> 1 mm) were found in any fish. The organ index of liver in Hemiculter leucisculus, including four types of histopathological changes, was up to 5.5–9.9 in the plastic production area and only 1.6 in the reference site. Our results strongly suggest that microplastic pollution was in high level, and the histopathological damage in fish tissues strongly confirmed the microplastic pollution and ecological response of the plastic production area. Our results also indicate that the feeding types of local fish species might be the reasons leading to the absence of raw pellets or fragments in fish, despite high abundances of microplastics existed in their living environments. Capsule abstractThe plastic production area is a special point source of microplastic in the environments.

Study of bentonite clays influence on quality indicators of pellets

Quality of iron ore pellets depends on many factors, including the type and properties of binding materials, in particular, bentonite clays. Laboratory studies of bentonite clays, differing by mineralogical composition and exchange ion complex. To assess the metallurgical characteristics of the pellets obtained with various kinds of binders, the moisture of the pellets, the compressive strength of the wet and dry pellets, the number of the wet pellets discards without destroying, and the “shock” temperature were determined. The carried out tests have shown that the impact strength and compression resistance of wet pellets at a slightly increased specific consumption of bentonite of cherkasy alkaline-earth bentonite does not concede to the correspondent properties of pellets with application of alkaline saryugyshsky bentonite as the binder. It was shown that clays of the IV layer, which are a natural mixture of alkaline-earth bentonite of the II layer and palygorskite III layer of the Cherkassky deposit, are favorable, to ensure good quality of the raw pellets. Tests of composite mixtures of clays IV with II and II with III layers showed that the quality of raw pellets with cherkassky bentonite is slightly worse comparing with sarygyuhsky one, however, the absolute values of their indicators satisfy the industry requirements. Tests of pelletizing of charges with different wetness, with the addition of 0.5% alkaline bentonite and a mixture of clays of the IV and II layers of the cherkassky deposit were carried out. It was shown, that with wetness increasing, pellets with both types of binder additives show the increase of the dynamic strength, porosity and temperature of the “shock” with a minimum difference in the absolute values of indicators with different binders. For confirmation of the possibility of using alkaline-earth bentonite of the Cherkassky deposit (II–III–IV layers) in the production of pellets, it is necessary to accomplish comparative industrial tests at a pelletizing plant (for example, at SevGOK), which uses a concentrate and industrial water of increased hardness.

Novel Porous Forsterite Ceramics Biocompatibility and Bioactivity Evaluation

This study is aimed to evaluate the biocompatibility and bioactivity of some new porous forsterite ceramics (FCs) produced from high-purity nano forsterite powder, synthesized by an original sol-gel method, which was subjected to pressing into pellets, by using a poly vinyl alcohol solution as a binding component. Then, the raw pellets were sintered at 1200 �C, 1300 �C, 1400 �C and 1450 �C. The obtained four forsterite ceramics, FC-1200, FC-1300, FC-1400 and FC-1450, were fully characterized by density, porosity and shrinkage measurements. The forsterite ceramics exhibited excellent biocompatibility determined by an in vitro cell viability assay, such as MTT test. Furthermore, the in vitro bioactivity test was performed by immersing the forsterite ceramics into simulated body fluid (SBF) and examining the hydroxyapatite (HAP) formation on forsterite ceramics, as evidenced by XRD, FTIR, SEM with EDX. Moreover, the relationship between porous structure and bioactivity of forsterite ceramics in SBF as well as the performance of FC in a cell culture was evaluated. The findings strongly recommend these forsterite ceramics for biomedical applications, as potential bone substitutes.