Search

The effects of erbium addition on the rheological properties and microstructure of a semisolid A356 alloy were studied. The semisolid slurries were prepared through the serpentine channel technique before they were thixoformed using parallel-plate compression with cylindrical discs. The grain and globule size decreases as the Er content increases, resulting in an improved and uniform distribution of spherical primary α-Al phase within the semisolid slurry. The addition of the Er modifies the grain morphology and size of the α-Al grains, resulting in a better and more uniform distribution of spherical primary α-Al phase within the semisolid slurry. As a result, rheocast quality index increases with the addition of Er, which is suitable for the thixoforming process. The A356 alloy without Er has the highest viscosity herein. The viscosity decreases, and the flow characteristics of the semisolid feedstock are expected to improve when Er is added as a result of the refinement of primary α-Al and modification of eutectic silicon. Furthermore, the refined semisolid A356 alloys with Er show a slightly larger fraction of high-angle grain boundaries compared to that for the unrefined alloy.

To repair the damaged SiC coated C/C composites, a double-layer system including a Sm-doped borosilicate glass external layer and a Si SiC inner layer was prepared by a slurry-based laser cladding technique. Isothermal oxidation experiment and indirect/direct thermal-radiation measurements were performed. The results showed that the absorbance of borosilicate glass to the laser at 900–1200 nm was improved significantly by Sm-doping. Consequently, the repaired coating with a more compact structure and better oxidation resistance was obtained. After oxidation at 1773 K for 10 h, the mass loss of the damaged sample could be reduced by 74.98% with repairing. By increasing laser-absorption and reducing viscosity, the thermal-radiation property of the repaired coating was enhanced to decrease the surface temperature greatly. A repair system with excellent thermal protection performance was achieved.

Spent MoSi2 heating elements were used to fabricate MoSi2, ZrB2/MoSi2 and MoSi2-ZrB2/MoSi2 oxidation resistant coatings via a two-step process of slurry painting and spark plasma sintering. Cracks appeared in simple MoSi2 and ZrB2/MoSi2 coatings, whilst MoSi2-ZrB2/MoSi2 coating was crack-free as CTE mismatch was reduced. Mo5Si3 and MoB diffusion layers formed under MoSi2-ZrB2 transition layer in MoSi2-ZrB2/MoSi2 coating, revealing good metallurgical combination between the substrate and coating. On one side the silica layers covering MoSi2 and ZrB2/MoSi2 coatings displayed diffused cracks after oxidation at 1773 K for 100 h, on the other side it was dense and continuous for MoSi2-ZrB2/MoSi2 coating, showing low oxidation rate constant at 1773 K. Furthermore, MoSi2-ZrB2 transition layer in MoSi2-ZrB2/MoSi2 coating possessed good short-term oxidation protective properties at 1873 and 1973 K since the formation of ZrSiO4 improved the stability of Si-O-Zr composite oxide scale and diminished the oxygen permeability, therefore demonstrating good high-temperature oxidation resistance.

In the present work, nanostructured hydroxyapatite (HA)-containing coating was prepared on a Ti surface by ultrasonic mechanical coating and armoring (UMCA). A Ti plate was pre-coated with HA slurry, followed by UMCA, which was achieved by high-frequency ZrO2 ball bombardment. The UMCA process comprised several cycles of pre-coating and ball bombardment, providing high amounts of HA and good coating adhesion. The coating mainly consisted of nano-HA particles (less than 10 nm) and a small amount of Ti. Furthermore, the deformation structures of the Ti surface region were characterized in a nanocrystalline layer with a grain size of 50–200 nm. Additionally, the coating exhibited improved bioactivity and corrosion resistance in Hanks’ balanced salt solution than the Ti surface. Furthermore, the in vitro cytotoxicity test assessed that the HA-containing coating was non-cytotoxic.

The corroded microstructures of the Cr2O3–Al2O3–ZrO2 refractory brick in an industrial opposed multi-burner (OMB) coal water slurry gasifier were investigated. It was found that the chromite spinel isolation layer rich in iron and magnesium was formed on the surface of the corroded brick body. By comparing and analyzing the corrosion of different zones in the gasifier, the results indicated that the molten slag entered the brick through the gaps and generated the spinel layer along the edge of the gaps, causing the dense structures of the refractory surface destroyed. In addition, in the high chrome brick corrosion experiment conducted by HTSM, 3 μm sized spinel were observed covering on the surface. The FactSage calculation results showed that the amount of spinel produced would drop significantly as the slag penetrated.

A quartz microreactor containing 28 microchannels of 500 µm width and 105 mm length has been used to photoproduce hydrogen from liquid water-ethanol using an Au/TiO2 photocatalyst and UV light. The photomicroreactor has been tested in two flow configurations: (i) as a catalytic wall photoreactor by coating the microchannels with the photocatalyst, and (ii) as a slurry photoreactor by dispersing the photocatalyst in the liquid mixture of water-ethanol. The catalytic wall photoreactor configuration shows superior performance, with hydrogen yields more than three times higher than those obtained with the best slurry configuration under the same operation conditions.

SS 404 is one essential material because of its anticorrosion and high heat resistance property. Also, the hardness of SS 404 is less than other available steel. Therefore, to resolve the problem of micro-hardness (improve micro-hardness) of SS 404, coating of WC (80%) with Ti O2 (20%) has been applied. A slurry mixture is prepared to analyze the erosion wear resistance against fly ash, which is examined in a slurry pot tester. The slurry of different particle sizes such as 106–150 µm, 150–212 µm, 212–300 µm, and 300-350µmhas been considered during the experiment. The rotation speed of the pot has been set at 600, 850, 1100, and 1350 rpm with a total time period of 90 min. High-Velocity Oxygen Fuel (HVOF) coating is sprayed on the SS 404 as protection material against erosion. From the experiment, it is observed that coated WC with TiO2 performed well against erosion compared to uncoated SS 404.

The article considers the method for controlling the ferromagnetic component content in slurry flow by ultrasonic and magnetic measurements. One of the basic factors determining the efficiency of magnetic separators at iron ore concentration plants is the quality of distribution of the ground ore into the product containing the ferromagnetic component and the waste rock. Due to the fact that in most cases, magnetic separators extract minerals with strongly magnetic properties, it is essential to find the magnetic component content in the input ore and products of its distribution in order to improve control over the technological process. Currently, low accuracy and reliability make existing means of operative control over the ferromagnetic component content in the slurry flow inefficient. Density of slurry is one of the primary disturbing factors affecting the accuracy of measurements, and this fact determines the necessity of measuring this parameter while controlling the ferromagnetic component content. Combined methods of measurements are a promising trend in designing sensors of useful component content in the slurry flow. The article describes the method for controlling the ferromagnetic component content in slurry flow by ultrasonic and magnetic measurements.

The deterioration of fluid machines due to slurry and cavitation erosion significantly impairs their serviceability. In the present work, we investigated the influence of deep cryogenic treatment (DCT) on the slurry and cavitation erosion resistance of WC-10Co-4Cr coatings developed using the detonation spraying technique. For comparison, hydroturbine steels and other conventional (Alumina and Stellite 6) coatings were also investigated. All thermal spray coatings showed typical lamellar structure along with the presence of pores and splat boundaries. Among all the coatings, the WC-10Co-4Cr showed the highest slurry (up to 15 times) and cavitation (2 times) erosion resistance owing to high hardness and fracture toughness. Post DCT, the WC-10Co-4Cr coating showed further improvement due to reduced porosity and improved hardness without decrement in fracture toughness. As a result, the DCT coating showed 1.5 to 4.2 times improved slurry erosion resistance than the as-sprayed counterpart, along with 1.6 times higher cavitation erosion resistance. The improved tribological performance of the coating after DCT is associated with enhanced hardness due to the presence of nano precipitates and densification as analyzed using electrochemical techniques. The topological analysis of the eroded surfaces indicated micro-cutting, micro-cracking, and delamination as the primary mechanism controlling the erosion behavior of the coatings.

To improve the grinding precision and efficiency of diamond abrasives in slurries, a new type of porous diamonds was prepared by the thermochemical corrosion method. Fe, Fe2O3 and Fe/Fe2O3 were separately used as corrosive agent to explore formation mechanism of porous diamond. The results showed that Fe began to graphitize diamond at 800 °C, whereas Fe2O3 began to oxidize diamond at 700 °C. Neither was able to individually corrode the diamonds into a porous structure. Impressively, it was when a mixture of Fe and Fe2O3 powders was used as the corrosive agent that the diamonds were able to take on a porous structure. Compared to ordinary diamonds, the porous diamonds produced in our study had outstanding advantages of high specific surface area and larger pore volume, which resulted in the porous diamonds having remarkable self-sharpening properties. Grinding contrast experiments were conducted on sapphire substrates using ordinary diamonds slurry and porous diamonds slurry. Notably, when porous diamonds were used as a grinding agent in the slurry, the sapphire substrate removal rate remarkably increased by 26%, and the surface roughness (Ra) of the sapphire substrate significantly decreased by 31%. In this paper, a simple and robust method was proposed to fabricate diamonds with a novel structure, which may help to reduce the surface grinding damage inflicted on hard and brittle materials and improve the quality of processed surfaces and grinding efficiency.

Methods of coating Al2O3 on nickel micro-foam were compared and screened, aiming to overcome the capillary force and prepare the micro-foam monolithic catalyst coatings. The surface of micro-foam substrate was pretreated by a chemical etching method to improve the adhesion of the coatings on the substrate. The results showed that the slurry circulation at 162 ml·min-1 was evaluated as the optimal method. The pore size on the substrate surface can be controlled by changing the pretreatment conditions. An empirical correlation was also proposed, showing an excellent practicality for predicting the pore size. The adhesion of the coatings with substrate pretreatment was significantly better than that without substrate pretreatment. The minimum value of weight loss after ultrasonic vibration was 3.9%. This mainly attributes to the squeezing of Al2O3 particles in the pores of substrate surface. The coatings on nickel micro-foam are hopefully used in micropacked beds for catalytic reactions.

Aims at improving the utilization rate of red mud and preparing a low-cost grouting material for underground engineering, the ultrafine red mud was adopted to prepare a slag-red mud based grout, and its fresh and hardened state properties were investigated comparing with the coarse red mud. The results showed that the incorporation of red mud could prolong the setting time and decrease the viscosity and thixotropy of slag-based geopolymeric grout, and ultrafine red mud has a better decrement effect. Ultrafine red mud has an enhancement effect on the slurry stability. The mechanical strength decreased with the adoption of red mud, while the ultrafine red mud has a higher mechanical strength than coarse red mud. The microstructure analysis showed that red mud plays a filling role in the geopolymerization process, and mechanical activation could increase the reactivity of red mud, furthermore, the iron component in ultrafine red mud could take part in the geopolymerization process. The results shed light on the utilization of red mud and the application of geopolymer in grouting engineering.

Ceramic ball (CB) and cast iron ball (CIB) media were used in the grinding of chalcopyrite and pyrite (1:1) to investigate the influence of grinding media on flotation separation. The selectivity indexe values were 2.65 (CB) and 1.58 (CIB) under the optimal conditions. In the CB system, the concentrations of Cu2+, SO42−, dissolved oxygen, and pH in the slurry were slightly higher. The root-mean-square roughness (Rq) values of the CB and CIB systems ground products were 9.02 nm and 74.80 nm, respectively. Moreover, a large amount of FeOOH was formed on the surface of the CIB ground products owing to the electrochemical interaction between the minerals and the media. Density functional theory (DFT) calculations indicated that FeOOH was adsorbed preferentially on the surfaces of chalcopyrite and pyrite, thus severely hindering the adsorption of butyl xanthate. Therefore, the CB medium is beneficial for enhancing the flotation performance of chalcopyrite and pyrite.

Solidification/stabilization (S/S) has been widely used for effective treatment of dredged sediment (DS) for many years, with the objective of improving the mechanical properties of DS through the addition of inorganic cementitious materials. Most previous studies have reported the short-term performance of S/S. However, long-term effectiveness is critical, as contaminants remain underground and are subjected to a variety of environmental stresses that can degrade S/S materials. In this regard, this experimental work investigated the long-term efficacy of solidification/stabilization of dredged contaminated sediments (DCS) treated with a new integrated method, namely PHDVPSS, which uses a prefabricated horizontal drain (PHD) assisted by vacuum pressure (VP) as well as solidification/stabilization. The DCS were treated with Portland cement (PC) as binder in the PHDVPSS method (abbreviated as VP-PC) at different zinc (Zn) concentration levels and compared with the traditional cement-based solidification/stabilization method (abbreviated as SS-PC). A series of experimental tests such as unconfined compressive strength (UCS), toxicity characteristics leaching procedure (TCLP), X-ray diffraction (XRD) and scanning electron microscopy in conjunction with energy-dispersive spectroscopy (SEM–EDS) were performed to assess the long-term strength, leaching and microstructural characteristics of high-water-content DCS, respectively. The UCS test results indicated that the strength of VP-PC mixes increased significantly with curing time compared to the limited strength development of SS-PC mixes. After 180-day curing, VP-PC mixes exhibited 3.5–5.5 times higher UCS values than the SS-PC mixes. Furthermore, when compared to the SS-PC mixes, the VP-PC mixes had 14.7–36.4% lower leached Zn concentrations at different Zn levels. This is attributed to an increase in the least reactive F4 (residual) fraction and a decrease in the most mobile F1 (acid-soluble) fraction as confirmed by the BCR method. Microstructural tests including XRD and SEM–EDS revealed that calcium silicate hydrate–like compounds were identified as the main hydration products of both the VP-PC and SS-PC mixes. However, portlandite, a major hydration product of PC, was not detected in either case, which is attributed to the retardant effect of Zn on cement hydration. Overall, the experimental results showed that the PHDVPSS method, when compared to the conventional solidification/stabilization method, is a viable choice for treating high-water-content DCS at different Zn concentration levels with low cement content.

Monel K-500 is a nickel-based alloy broadly used in several industries such as power generation, aerospace, marine and chemical processing for manufacturing several critical components. During hydraulic applications, the alloy is subjected to different degradation phenomena such as cavitation erosion, slurry erosion and corrosion. The current study assesses the potential of using two HVOF-sprayed nickel-based cermet coatings: WC-10Ni-5Cr and WC-18Hastelloy C to control the slurry erosion of Monel K-500. The coatings were subjected to slurry erosion tests for 90 min at normal (90°) and oblique (30°) impingement angles. It was observed that these coatings significantly reduced the erosive wear in Monel alloy. WC-10Ni-5Cr coating, having relatively better microhardness and fracture toughness has shown minimum erosion losses. At normal impact, WC-10Ni-5Cr coating and WC-18Hastelloy C coating reduced the erosion rate of Monel by 2.3 and 1.6 times, respectively. At oblique impact, WC-10Ni-5Cr coating and WC-18Hastelloy C coating reduced the erosion rate of Monel by 4.75 and 2.4 times, respectively. In-depth study of the erosion mechanism for the investigated materials was conducted using scanning electron microscopy. Ploughing and micro-cutting were the primary erosion mechanisms in Monel alloy, whereas coating spallation and crater formation were the primary erosion mechanisms in the coatings.

The fate of antibiotic resistance genes (ARGs) in full-scale anaerobic digestion (AD) of food waste (FW) and in the soil applied with biogas slurry has not been fully understood. In this study, 12 targeted ARGs and intI1 in FW, intermediate product, and biogas slurry from three full-scale AD were analyzed. The results showed that subcritical water pretreatment was an effective method for ARG attenuation, by which the absolute abundance of total targeted ARGs was removed by 99.69%. The predominant ARGs (ermB, tetM, and tetW) in FW were removed more than 99% after subcritical water pretreatment. The result of field experiments with biogas slurry as fertilizer showed that the absolute abundance of several ARGs (sul2, tetM, blaOXA-1, blaTEM) and intI1 accumulated significantly compared to the control group (CK) during three consecutive growth stages of the rice. The detected abundance of ARGs in paddy field soil increased from 190.50 (CK) to 8.87 × 104 copies/g (wet weight) (soil) during tillering stage, and increased from 4102.65 (CK) to 4.38 × 104 copies/g (wet weight) (soil) during heading time. Biogas slurry improved the soil nutrients (TN, AN, TP, and AP); meanwhile, the concentrations of total salt and Cl− increased. Network analysis indicated that 28 genera were the possible hosts of ARGs; variation partitioning analysis (VPA) indicated that microbial communities (contribution 59.30%) were the main factors that affected the fate of ARGs and intI1.

Core materials with high strength and excellent collapsibility are important for the manufacture of hollow composite structure castings. In this work, a novel technology to fabricate water-soluble Na2SO4-NaCl-based salt cores with high strength and low cost by material extrusion (ME) was reported. The water-soluble Na2SO4 and NaCl powders were used as the matrix materials, and the bauxite powder was used as the reinforcing material. The effects of bauxite powder content and liquid phase sintering parameters on the properties of the salt cores were studied. The results show that the salt-based slurry exhibits shear thinning property within the studied bauxite powder contents. When the content of bauxite powder was 20 wt.% and the sintering was at 630 ℃/30 min, the obtained salt cores show an optimal comprehensive performance, with the bending strength, linear shrinkage, water solubility rate, and moisture rate of 24.43 MPa, 6.3%, 207.6 (g/min·m2), and 0.29%, respectively. The complex water-soluble salt core samples prepared under optimal parameters display high-strength and well-shaped morphology.

Simultaneous multilayer coating techniques are widely known, but their industrial application remains limited to narrow market sectors. One barrier to adoption may be the mismatch between industries that are familiar with such processes but have no need, and industries that have need but are not familiar. Moreover, there are application-specific technical challenges to developing multilayer-coating processes. In this article, we describe our resolution of two specific issues in simultaneous multilayer coating of all-aqueous highly loaded slurries for new and emerging energy applications. The first issue is particle jamming (associated with shear-thickening) of the highly loaded slurries in the die internals, which we alleviated by adding small amounts of viscosity modifiers without reducing the solid loading. The second issue is a Marangoni-driven surface instability that resembles top layer de-wetting, which we solved by carefully selecting surfactants to tune the dynamic surface tensions of each slurry. Both issues were resolved early in a step-wise development, saving significant development cost which in our case was driven by expensive materials.

The thixotropic properties of electrode slurry used in the manufacturing of lithium-ion batteries affect the coating processes. Understanding the relationship between its structural parameters and microstructure evolution will be helpful for slurry preparation and coating processes. In this work, a structural kinetics constitutive model is proposed to describe the thixotropy of slurry, in which the structural parameter $$\lambda$$ is utilized to assess the evolution of the microstructure. The results show that the proposed model is in good agreement with experimental data for steady-state flow, and the degree of structure can be well described by the structural parameter $$\lambda$$ for different cathodes slurries, indicating that coarse Li(Ni,Mn,Co)O2 (NMC) powder forms an extremely brittle network structure with no significant yield stress, while fine LiFePO4 (LFP) powder presents a robust network structure. Besides, the strength of the structure is distinctly improved by adding the high-molecular polyvinylidene difluoride (PVDF) as binder and carbon black as conductive agent.

To repair the damaged SiC coated C/C composites, a double-layer coating including a SiO2-Nd2O3 external layer (∼60 μm) and a Si-SiC inner layer (∼240 μm) was prepared by a slurry-based laser cladding technique, and the laser-ablation tests under two heat fluxes (23.89/39.81 MW m−2) were performed. The spectrophotometer, X-ray diffraction, scanning electron microscopy and 3D profilometer were used for characterization. For avoiding the secondary damage of laser-ablation, the laser-reflection of the repaired area was enhanced, which was conducive to the mitigation of mass and linear ablation. Combined with Finite Element Analysis, by raising the reflectivity, the surface and back temperature of samples could be reduced greatly by 1224 K and 983 K respectively, and plenty of ablation reactions could be avoided. Therefore, the SiO2-Nd2O3 coating possessed an excellent laser-ablation resistance and protected the C/C substrates from thermal damage and oxidation effectively.

Synchronous grouting has a very important effect on shield tunnel, which directly affects the stability of excavation face and the safety of segment structure. Testing the setting time and early strength of mortar is conducive to timely control the surface settlement and prevent the segment from floating. The flow table test can ensure that synchronous grouting can fill the excavation gap of shield machine to the greatest extent. Oedometer test can obtain physical and mechanical indexes such as elastic modulus, Poisson's ratio, compression and drainage of slurry at different ages. The test results showed that the use of well-graded, small-sized machine-made gravel (0–5 mm) and natural sand (0–2 mm) with high-efficiency additives promoted the formation of early strength in grout and reduced the probability of plugging in the grouting pipe at the tail shield. The oedometer test results indicated that the quantity of water drained from a grout mixed for more than 2 h was stable and the grout deformation within 1 h of compression accounted for 80% of the total deformation. The Young’s modulus of the grout reached 10 MPa when the grouting pressure was > 0.2 MPa, meeting the requirements for field injection. In this study, an efficient synchronous grouting mixture proportion suitable for calcareous sand layer is proposed, and the performance of slurry in fresh state is obtained through a variety of tests, which can be widely used in shield tunnels in similar strata.

This paper presents an experimental investigation of propagation and fluid pressure of grouting in a two-dimensional fractured network replica. Two-dimensional fracture network models with a rough profile were simulated based on Barton’s standard roughness curves, and an orthogonal experiment of chemical grouting was conducted to explore the relationship between the sealing efficiency and different factors, including the joint roughness coefficient, initial water flow rate, gel time of slurry, and grout take rate. The results show that the initial water flow rate had the greatest influence on the sealing effect, followed by the joint roughness coefficient, grout take rate, and gel time of slurry. Together with the grouting quality and slurry diffusion form, the grouting sealings were divided into two types, i.e., partial plugging with edge unfilled and completely plugging with fracture fully filled. The slurry propagation sequence in the intersected fractures indicates that the slurry first diffuses downstream of the current fracture, then downstream of the cross fracture, and finally upstream of the cross fracture. The grouting pressure on the later stage of grouting was greater than that at the beginning of the grouting, resulting in a better grouting effect.

The paper aims to avoid premature failure of slide valve, flapper valve and slurry backflush system for fluid catalytic cracking unit due to slurry abrasive wear by depositing Ni-Cr-Mo-W alloy on 304 austenitic stainless steel using synergic pulsed gas metal arc welding. An average coating thickness was obtained in the range of 2.41 mm to 2.78 mm and dilution level varied from 17% to 26.74%. The microstructure revealed that hypoeutectic Ni-FCC dendrites and interdendritic region with MC, M23C6 and M6C carbides were present. The formation of carbides was directly related to dilution level of the coating, since dilution level influenced the proportional amount of carbon and carbide forming alloying elements. Slurry abrasive wear resistance initially increased with an increase in dilution level up to 23.88% of dilution, later on it started to decrease due to reduction in solid solution alloying elements and carbide fraction. Slurry abrasive wear resistance of the coated surface was found up to 3.5 times higher than that of the substrate. The mechanism of abrasive wear under the operation of microcuttings, pits formation and ploughing with a little plastic deformation was witnessed on the worn-out surfaces.

Face-centered-cubic crystallized super-fine (~ 2 nm in size) wet-ceria-abrasives are synthesized using a novel wet precipitation process that comprises a Ce4+ precursor, C3H4N2 catalyst, and NaOH titrant for a synthesized termination process at temperature of at temperature of 25 °C. This process overcomes the limitations of chemical–mechanical-planarization (CMP)-induced scratches from conventional dry ceria abrasives with irregular surfaces or wet ceria abrasives with crystalline facets in nanoscale semiconductor devices. The chemical composition of super-fine wet ceria abrasives depends on the synthesis termination pH, that is, Ce(OH)4 abrasives at a pH of 4.0–5.0 and a mixture of CeO2 and Ce(OH)4 abrasives at a pH of 5.5–6.5. The Ce(OH)4 abrasives demonstrate better abrasive stability in the SiO2-film CMP slurry than the CeO2 abrasives and produce a minimum abrasive zeta potential (~ 12 mV) and a minimum secondary abrasive size (~ 130 nm) at the synthesis termination pH of 5.0. Additionally, the abrasive stability of the SiO2-film CMP slurry that includes super-fine wet ceria abrasives is notably sensitive to the CMP slurry pH; the best abrasive stability (i.e., a minimum secondary abrasive size of ~ 130 nm) is observed at a specific pH (6.0). As a result, a maximum SiO2-film polishing rate (~ 524 nm/min) is achieved at pH 6.0, and the surface is free of stick-and-slip type scratches.

Organic fertilizer can yield higher production compared to regular fertilizer if properly applied. Thus, it can be a solution to improve nutrient content of soil. The biggest source of bio slurry in plantation is from Palm Oil Mill Effluent (POME) and cow dung biogas. This research aimed to analyze the residue’s potential from the result of biogas processing and bio slurry from POME as slow-release fertilizer pellet. Bio slurry was processed into pellet through densification process using pellet mill. The research was arranged in a Randomized Block Design method with five slurry compositions as treatments, including 70:30, 60:40, 50:50, 40:60, and 30:70 (ratio of biogas slurry and POME slurry), each consisted of three replications. According to the data obtained, fertilizer pellets had characteristics of 25 – 29 mm of length, 5.23 – 5.85 mm of diameter, 0.44 – 0.53 g/cm3 of density, 54.78% - 81.96% of durability, and 7.81% - 8.57% of moisture content. Based on density and durability aspects, 30:70 composition was the higher. Macronutrient content of the five compositions were 1.88% - 2.72%, in which on day 22, N, P, and K release was 0.36 – 1.01%, 73.51 – 97.48%, and 3.19 – 7.85%, respectively. Meanwhile, on day 17, the nutrition solution conductivity of all compositions had already reached 0.80 – 1 mS/cm.

The effects of bio-based strengthening agents and mineral filling procedure on the 3D elongation of chemi-thermomechanical pulp (CTMP) handsheets with and without mineral (PCC) filling have been investigated. The 3D elongation was measured using a press-forming machine equipped with a special converting tool. The strength of the handsheets was altered using either cationic starch or microfibrillated cellulose. Precipitated calcium carbonate (PCC) was added to the furnish either as a slurry or by precipitation of nano-sized PCC onto and into the CTMP fibre. The 3D elongation of unfilled sheets was increased by the dry-strengthening agents, but no evidence on the theorised positive effect of mineral fill on 3D elongation was seen in either filling method. The performance of the strengthening agent depended on whether the PCC was as slurry or as a precipitated PCC-CTMP. The starch was more effective with PCC-CTMP than when the PCC was added directly as a slurry to the furnish, whereas the opposite was observed with microfibrillated cellulose. The 3D elongation correlated positively with the tensile strength, bursting strength, tensile stiffness, elastic modulus and bending stiffness, even when the sheet composition was varied, but neither the strengthening agent nor the method of PCC addition affected the 3D elongation beyond what was expectable based on the tensile strength of the sheets. Finally, mechanisms affecting the properties that correlated with the 3D elongation are discussed.

This work analyzes the synergy of corrosion and sand erosion during erosion–corrosion of A890 7A-duplex steel and the effect of manganese on it. The variations in material removal mechanisms at different velocities between 4 and 13 m/s were studied in 1% sand slurry with continuous corrosion monitoring for synergy analysis. Material removal at lower velocities was mainly contributed by corrosion-enhanced erosion. Contribution of corrosion-assisted mechanisms to material removal reduced as velocity increased, and as the slurry velocity approached 10 m/s, pure erosion became dominant. Electron microscopy of eroded surfaces revealed lip formations at lower velocities, and pits with severe plastic deformations as erosion became prominent. Study on the effect of manganese revealed that, at 13 m/s slurry velocity, the alloy with 5% manganese showed nearly 30% reduction in material removal rate compared to 1% manganese alloy. Whereas at low slurry velocity (4 m/s) where corrosion-assisted mechanisms dominate, no significant reduction was observed. Augmentation in the hardness of the alloy was caused by solid solution strengthening of manganese and nitrogen partitioning, which lead to the reduction in material loss due to pure erosion. Since, at lower velocities, corrosion-assisted mechanisms dominated, manganese did not show any significant influence on material removal rate.

The fouling behavior of Alloy 6061 aluminum in artificial seawater in the presence of Boswellia serrata extract was investigated. Fouling is one of the major issues that occurred commonly in the marine environment. Experiments were conducted to develop a model for fouling propensity. A response surface method was used to develop a model to predict fouling behavior. The model predicts the effect of the variables on fouling in artificial seawater medium in the presence of B. serrata extract. The experimental variables chosen were temperature, flow rate and time. Performance of the regression model calculated by the response surface methodology was verified with the analysis of variance technique. The model equation that was proposed using the response surface methodology showed good agreement with the experimentally obtained data.

The effect of shearing conditions in the coating process on the uniformity of the coated layer of dense silica slurry is investigated. The pH 6.8 test slurry mainly used in this study forms a nonuniform coated layer only on the condition of large shear strain and low shear rate. The same shearing dependency was observed using not only a laboratory-scale doctor blade but also a pilot-scale comma coater. The test slurry exhibits two-step yielding, and the internal structure of the slurry is gradually destroyed after the second yielding. When the shear strain applied is within the second yielding, the test slurry is in equilibrium and a uniform coated layer is formed. As strain is increased further, the slurry changes from the viscoelastic fluid to Newtonian. When the shear strain is beyond the second yielding but the structural destruction is not completed, a nonuniform coated layer is formed. A higher coating speed or sufficiently large shear deformation, which effectively destroys the internal structure, is favorable to obtain a uniform coated layer.

Vinyl acetate is an organic chemical raw material of great industrial value. It is widely used in synthetic film, adhesive, coating and textile slurry. The production route of vinyl acetate is introduced, and the advantages and disadvantages of synthesis methods of vinyl acetate method, acetylene method, EDA cracking method, base synthesis method and Halcon method are compared. The method of carbide acetylene has high economic efficiency, low energy consumption and good environmental protection, proposing the development direction of ethylene acetate production technology.

The corrosion evolution of steel disposal container largely depends on the evolution of surrounding bentonite environment in the long-term geological disposal of high-level radioactive wastes. This study focused on the influence of the deteriorated bentonite sediments on the corrosion behavior of NiCu low alloy steel in the top supernatant and bottom slurry formed by Gaomiaozi bentonite and 0.05 M NaHCO3 + 0.1 M NaCl + 0.1 M Na2SO4 solution. In the top supernatant, the cathodic process of the steel corrosion was transformed from the reduction in oxygen to the reduction in ferric corrosion products with time as same as that in the blank solution. While in the bottom bentonite slurry, the cathodic process always maintained as the hydrogen evolution reaction due to the coverage of more bentonite sediments. Meanwhile, the corrosion rate of NiCu steel was obviously decreased. In addition, the localized corrosion tendency of the steel could also be reduced by the large amount of deteriorated bentonite sediments.

The wear behaviors of 4145H drilling tool steel in water-based slurries were investigated under the conditions of various concentrations of SiO2, Al2O3, and SiC sands using a modified ASTM B611 rub...

Lime treatment combined with vacuum preloading has been used in the treatment of dredging slurry for many years. Previous studies have indicated that particle grading, which is one of the essential...

Most of the materials used in engineered cementitious composite are fine in size to achieve ductile nature. Stone slurry powder (SSP) is an inert material obtained from stone industries as by-product which may cause hazardous impact on environment. In this research work, partial replacement of silica sand (SS) and fine sand (FS) by SSP with different contents (25% and 50% each) for making engineered cementitious composite has been explored. The performance was evaluated on the basis of strength, tensile strain, mid span deflection capacity, ultra-sonic pulse velocity and microstructure. Mechanical strength was found to be increased at 25% SSP in both replacements; whereas, strength decreased slightly at 50% replacement. Tensile strain, mid span deflection and quality of concrete were enhanced with increase in SSP content. Using SSP formed denser cementitious composite can help to save the natural resources and contribute in making green cementitious composite.