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Granular fertilizers (especially those based on ammonium nitrate (AN)) tend to agglomerate during storage. The aims of this research were to develop effective anti-caking coatings for ammonium nitrate fertilizers while improving the quality of fertilizers and to optimize the composition of effective anti-caking coatings. The influence of the composition of the prepared organic coatings on the effectiveness of preventing the caking of fertilizers was studied by response surface methodology (RSM) using Box–Behnken design (BBD). Additionally, the effect of the developed anti-caking agents on the quality of fertilizers was determined by measuring the crushing strength of the granules. The prepared coatings included fatty amine, stearic acid, surfactant, and paraffin wax. Gas chromatography–mass spectrometry (GC–MS) was used to analyze these coatings. The morphology of the fertilizers were examined by scanning electron microscopy (SEM). Composition studies, based on statistical assessment, showed the coating components had a varying influence on preventing the caking of fertilizers after granulation and after 30 days of storage. The results demonstrated that increasing the content of fatty amines and reducing surfactant in the composition of coating had positive effects on caking prevention. In this study, more effective and economically viable anti-caking coatings were developed. In addition, the present work could serve as a basis to further improve anti-caking coatings.

Sticking of particles has a tremendous impact on powder-processing industries, especially for hygroscopic amorphous powders. A wide variety of experimental methods has been developed to measure at what combinations of temperature and moisture content material becomes sticky. This review describes, for each method, how so-called stickiness curves are determined. As particle velocity also plays a key role, we classify the methods into static and dynamic stickiness tests. Static stickiness tests have limited particle motion during the conditioning step prior to the measurement. Thus, the obtained information is particularly useful in predicting the long-term behavior of powder during storage or in packaging. Dynamic stickiness tests involve significant particle motion during conditioning and measurement. Stickiness curves strongly depend on particle velocity, and the obtained information is highly relevant to the design and operation of powder production and processing equipment. Virtually all methods determine the onset of stickiness using powder as a starting point. Given the many industrial processes like spray drying that start from a liquid that may become sticky upon drying, future effort should focus on developing test methods that determine the onset of stickiness using a liquid droplet as a starting point.

To address the problem that granular compound fertilizer 1s prone to agglomeration during mechanized direct seeding of oilseed rape in the middle and lower reaches of the Yangtze River, which causes clogging of the fertilizer discharger and leads to a reduction in the uniformity and stability of fertilizer discharge, research on the crushing mechanism of caking compound fertilizer was performed. Considering that it is difficult to measure the bonding force between caking fertilizer particles directly, a simulation model of caking composite fertilizer was established with the bonding model in EDEM discrete element software. To decrease error between the simulation and physical test results, the normal contact stiffness, tangential contact stiffness, critical normal stress, critical tangential stress, bonding radius, and other parameters of the bonding model of caking composite fertilizer were calibrated. The three-dimensional structure of the caking composite fertilizer was obtained via three-dimensional scanning, the critical crushing displacement and critical crushing force of the caking composite fertilizer were measured via compression testing with a mass spectrometer, and the optimal parameter combination of the bonding model was determined via EDEM discrete element simulation of the Plackett-Burman test, steepest ascent test, and Box-Behnken test. The results of the simulated compression tests under the optimal parameter combination show that the relative errors of the critical crushing displacement and critical crushing force with respect to the physical test results were 0.296% and 0.343%, respectively. Using the crushing rate of caking compound fertilizer as an evaluation index, the feasibility of the calibrated parameters was verified for a four-head spiral two-row fertilizer discharger installed in a direct seeding machine for oilseed rape. The results show that the relative errors of the caking fertilizer crushing rates from the simulation relative to those of the bench and field tests were 5.81% and 5.06%, respectively, indicating that the calibration parameters of the discrete element model were accurate and could be used for parameter analysis of caking fertilizer with a discrete element model. These results can provide a reference for the structural optimization of fertilizer discharger crushing of caking fertilizer of direct seeding machine for oilseed rape.

Due to the large production of sorghum, the generation of associated agricultural residues, which contain high contents of silica, is inevitable. Also, these agricultural residues are not utilizing properly and it creates environmental pollution. Thus, we are utilizing the sorghum residues as a silica precursor to fabricating biogenic silica nanostructures using sequential processes. The physicochemical features of the synthesized BSNs, i.e., amorphous nature, surface functional groups, thermal stability, structure, and morphology, were analyzed using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, scanning electron microscopy, and transmission electron microscopy. The cytotoxic properties of the S. bicolor -derived BSNs were assessed using human colon carcinoma cells as an in vitro model and cell-based assays, including an 3–4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide (MTT) assay, and acridine orange/ethidium bromide staining (AO/EB). The silica content of S. bicolor leaves was around 9.34%. We observed peaks at 1089 cm −1 and 801 cm −1 in the FTIR spectra of BSNs that corresponded to asymmetric, symmetric, and bending vibrations of O–Si–O. The BSNs had spherical morphology with diameters of 30–90 nm and an amorphous nature. The cytotoxic analysis suggested that BSNs do not induce cell death in colon carcinoma cells. Overall, the results suggested that BSNs exhibit good compatibility in colon cells, and may be applicable as an anti-caking agent in the food sector.

With the increasing coal mining depth, dynamic disasters are occurring more frequently in coal mines. The loading rate has a close relation to the mechanical properties, behaviors and failure mechanisms of both coal and rock. In order to examine the influence of loading rates on tensile properties, deformation characteristics, failure mode, and micro-failure mechanism of non-caking coal, acoustic emission (AE) tests were conducted under Brazilian splitting conditions with five different displacement rates. The experiment results indicate that the tensile strength of non-caking coal increases logarithmically with the increase in displacement rate, and the duration of the primary fracture compaction stage shortens with the displacement rates. The AE spatio-temporal evolution for coal with varying displacement rates shows similar trends, and the AE event reaches to a maximum at 0.8 σ c (peak stress). The high amplitude AE events appear at different phases at varying displacement rates, and the concentration area of AE events coincides with the fracture surface. The spatial fractal dimensions of the AE events range from 1.1 to 1.9 under varying displacement rates and show a downward trend with the increase of stress. The fractal dimension of the fracture surface range from 2.14 to 2.25 and increases with the displacement rate. The micro-failure mechanism of non-caking coal discs under varying displacement rates is a mixture of tension-shear cracks (mainly tensile cracks), followed by shear cracks. The external load causes tensile and shear cracks at high displacement rates, while mainly tensile cracks at low displacement rates.

In this work, the objects of the study were CWC coals (coking weakly caking coals). The samples were characterized by technical analysis, which showed that the coals are close in ash content (Ad = 3.4-8.4%) and the yield of volatiles (Vdaf = 18.4-21.4%). Petrographic analysis determined the vitrinite reflection index (Ro, r), which showed that the studied coals, according to the genetic classification, belong to the 11-13 class, corresponding to the CWC grade coals. Based on the vitrinite reflectance index, reflectograms were compiled, which are an effective means of assessing the quality of coal.

Co-carbonization of weakly caking coal and zinc-containing dust to prepare highly reactive ferro-coke and collaboratively recover zinc powder is one of the feasible ways for steel enterprises to recycle zinc-containing dust. The pyrolysis mass loss behavior of adding blast furnace dust with different zinc contents to different ferro-coke materials was systematically studied by thermogravimetry and differential thermogravimetry analysis, and the kinetic mechanism of pyrolysis-reduction reaction of hybrid briquette was explored. The results of thermogravimetric curve analysis show that the addition of zinc oxide to the sample has no significant effect on the mass loss rate of the sample below 580 °C, and the pyrolysis mass loss of zinc oxide mainly occurs between 800 and 1000 °C. Kinetic analysis results show that the pyrolysis of zinc-containing samples is controlled by chemical reactions below 580 °C. The reaction at 580–700 °C is controlled by the nucleation and growth model, and that above 700 °C is mainly controlled by diffusion. The results of X-ray diffraction analysis show that the pyrolysis process can effectively remove zinc oxide from ferro-coke.

Unwanted changes in powder flow behavior can unexpectedly occur when a product is exposed to certain conditions of temperature and humidity. This can happen during production, but also during transport or storage. The work reported here demonstrates the novel approach of using an amended powder rheology set-up for measuring and predicting such changes in powder flow behavior. The developed methodology makes it possible to vary in-situ the temperature and the relative humidity of the air to which the product is exposed, thereby mimicking realistic conditions of production or related unit operations. An air flow capable of fluidizing the powder particles is controlled at a specific constant temperature and its relative humidity can be altered while measuring the torque in the fluidized powder bed in real time. The fluidization is necessary for generating a homogeneous introduction of temperature and relative humidity. Results obtained using citric acid and commercial coffee whitener products have proven this methodology to provide both similar and in certain instances dissimilar results compared to the more established methodology such as measuring the vapour adsorption isotherms. These observations are explained. In this way, it can be predicted under which combinations of temperature and humidity a product does or does not become sticky. The main advantages of our approach are that the flow properties are directly assessed, the interpretation of the obtained data is more straightforward and that the measurement times are shortened substantially.

Agglomeration is an undesirable phenomenon that often occurs in spray-dried microcapsules powder. The objective of this work is to determine the best solution for spray-dried hydroxypropyl-β-cyclodextrin (HP-β-CD) microcapsules from four anticaking agents, namely calcium stearate (CaSt), magnesium stearate (MgSt), silicon dioxide (SiO2), and mannitol (MAN), and to explore their anticaking mechanisms. Our results showed that MAN was found to be the superior anticaking agent among those tested. When the MAN ratio is 12%, the microcapsules with a special Xanthium-type shape had higher powder flowability and lower hygroscopicity and exhibited good anticaking properties. Mechanism research revealed that CaSt, MgSt, and SiO2 reduce hygroscopicity and caking by increasing the glass transition temperature of the microcapsules, while MAN prevents the hydroxyl group of HP-β-CD from combining with water molecules in the air by a crystal outer-layer on the microcapsule surface.

Shenmu (SM) subbituminous coal without caking property was treated by low-temperature rapid pyrolysis (LTRP) to modify its caking and coking properties. The treated samples were characterized by Fourier transform infrared spectrometry, vitrinite reflectance, and X-ray diffraction to determine the modification mechanism. Moreover, caking index ( G ) and coking indices (mechanical strength, coke reactivity, and coke strength after reaction) were employed to evaluate caking and coking properties, respectively. The results showed that SM coal was gradually upgraded with increasing processing temperature. Furthermore, the G values for the treated samples were significantly higher than that for SM coal, and G reached the maximum value at 450 °C, implying the modification of caking property and the existence of an optimum temperature (450 °C). Additionally, laboratory coking determinations showed that LTRP increased the mechanical strength of coke and coke strength after reaction and decreased coke reactivity when the treated coals were used in the coal blends instead of raw SM coal. Overall, LTRP treatment is effective to improve the caking and coking properties of SM coal. A mechanism was proposed for the modification. Suitable upgrading degree with suitable molecular masses and some releasable hydrogen-rich donor species present within the coal, which dominate the development of caking property, is important.